diff options
Diffstat (limited to 'src/engine/external/portaudio/pa_linux_alsa.c')
| -rw-r--r-- | src/engine/external/portaudio/pa_linux_alsa.c | 3323 |
1 files changed, 3323 insertions, 0 deletions
diff --git a/src/engine/external/portaudio/pa_linux_alsa.c b/src/engine/external/portaudio/pa_linux_alsa.c new file mode 100644 index 00000000..a1070637 --- /dev/null +++ b/src/engine/external/portaudio/pa_linux_alsa.c @@ -0,0 +1,3323 @@ +/* + * $Id: pa_linux_alsa.c 1105 2006-08-31 05:52:57Z aknudsen $ + * PortAudio Portable Real-Time Audio Library + * Latest Version at: http://www.portaudio.com + * ALSA implementation by Joshua Haberman and Arve Knudsen + * + * Copyright (c) 2002 Joshua Haberman <joshua@haberman.com> + * Copyright (c) 2005-2006 Arve Knudsen <aknuds-1@broadpark.no> + * + * Based on the Open Source API proposed by Ross Bencina + * Copyright (c) 1999-2002 Ross Bencina, Phil Burk + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files + * (the "Software"), to deal in the Software without restriction, + * including without limitation the rights to use, copy, modify, merge, + * publish, distribute, sublicense, and/or sell copies of the Software, + * and to permit persons to whom the Software is furnished to do so, + * subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR + * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF + * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION + * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ + +/* + * The text above constitutes the entire PortAudio license; however, + * the PortAudio community also makes the following non-binding requests: + * + * Any person wishing to distribute modifications to the Software is + * requested to send the modifications to the original developer so that + * they can be incorporated into the canonical version. It is also + * requested that these non-binding requests be included along with the + * license above. + */ + +/** + @file + @ingroup hostapi_src +*/ + +#define ALSA_PCM_NEW_HW_PARAMS_API +#define ALSA_PCM_NEW_SW_PARAMS_API +#include <alsa/asoundlib.h> +#undef ALSA_PCM_NEW_HW_PARAMS_API +#undef ALSA_PCM_NEW_SW_PARAMS_API + +#include <sys/poll.h> +#include <string.h> /* strlen() */ +#include <limits.h> +#include <math.h> +#include <pthread.h> +#include <signal.h> +#include <time.h> +#include <sys/mman.h> +#include <signal.h> /* For sig_atomic_t */ + +#include "portaudio.h" +#include "pa_util.h" +#include "pa_unix_util.h" +#include "pa_allocation.h" +#include "pa_hostapi.h" +#include "pa_stream.h" +#include "pa_cpuload.h" +#include "pa_process.h" + +#include "pa_linux_alsa.h" + +/* Check return value of ALSA function, and map it to PaError */ +#define ENSURE_(expr, code) \ + do { \ + if( UNLIKELY( (aErr_ = (expr)) < 0 ) ) \ + { \ + /* PaUtil_SetLastHostErrorInfo should only be used in the main thread */ \ + if( (code) == paUnanticipatedHostError && pthread_equal( pthread_self(), paUnixMainThread) ) \ + { \ + PaUtil_SetLastHostErrorInfo( paALSA, aErr_, snd_strerror( aErr_ ) ); \ + } \ + PaUtil_DebugPrint( "Expression '" #expr "' failed in '" __FILE__ "', line: " STRINGIZE( __LINE__ ) "\n" ); \ + if( (code) == paUnanticipatedHostError ) \ + PA_DEBUG(( "Host error description: %s\n", snd_strerror( aErr_ ) )); \ + result = (code); \ + goto error; \ + } \ + } while( 0 ); + +#define ASSERT_CALL_(expr, success) \ + aErr_ = (expr); \ + assert( success == aErr_ ); + +static int aErr_; /* Used with ENSURE_ */ + +typedef enum +{ + StreamDirection_In, + StreamDirection_Out +} StreamDirection; + +typedef struct +{ + PaSampleFormat hostSampleFormat; + unsigned long framesPerBuffer; + int numUserChannels, numHostChannels; + int userInterleaved, hostInterleaved; + + snd_pcm_t *pcm; + snd_pcm_uframes_t bufferSize; + snd_pcm_format_t nativeFormat; + unsigned int nfds; + int ready; /* Marked ready from poll */ + void **userBuffers; + snd_pcm_uframes_t offset; + StreamDirection streamDir; + + snd_pcm_channel_area_t *channelAreas; /* Needed for channel adaption */ +} PaAlsaStreamComponent; + +/* Implementation specific stream structure */ +typedef struct PaAlsaStream +{ + PaUtilStreamRepresentation streamRepresentation; + PaUtilCpuLoadMeasurer cpuLoadMeasurer; + PaUtilBufferProcessor bufferProcessor; + PaUnixThread thread; + + unsigned long framesPerUserBuffer, maxFramesPerHostBuffer; + + int primeBuffers; + int callbackMode; /* bool: are we running in callback mode? */ + int pcmsSynced; /* Have we successfully synced pcms */ + + /* the callback thread uses these to poll the sound device(s), waiting + * for data to be ready/available */ + struct pollfd* pfds; + int pollTimeout; + + /* Used in communication between threads */ + volatile sig_atomic_t callback_finished; /* bool: are we in the "callback finished" state? */ + volatile sig_atomic_t callbackAbort; /* Drop frames? */ + volatile sig_atomic_t isActive; /* Is stream in active state? (Between StartStream and StopStream || !paContinue) */ + PaUnixMutex stateMtx; /* Used to synchronize access to stream state */ + + int neverDropInput; + + PaTime underrun; + PaTime overrun; + + PaAlsaStreamComponent capture, playback; +} +PaAlsaStream; + +/* PaAlsaHostApiRepresentation - host api datastructure specific to this implementation */ + +typedef struct PaAlsaHostApiRepresentation +{ + PaUtilHostApiRepresentation baseHostApiRep; + PaUtilStreamInterface callbackStreamInterface; + PaUtilStreamInterface blockingStreamInterface; + + PaUtilAllocationGroup *allocations; + + PaHostApiIndex hostApiIndex; +} +PaAlsaHostApiRepresentation; + +typedef struct PaAlsaDeviceInfo +{ + PaDeviceInfo baseDeviceInfo; + char *alsaName; + int isPlug; + int minInputChannels; + int minOutputChannels; +} +PaAlsaDeviceInfo; + +/* prototypes for functions declared in this file */ + +static void Terminate( struct PaUtilHostApiRepresentation *hostApi ); +static PaError IsFormatSupported( struct PaUtilHostApiRepresentation *hostApi, + const PaStreamParameters *inputParameters, + const PaStreamParameters *outputParameters, + double sampleRate ); +static PaError OpenStream( struct PaUtilHostApiRepresentation *hostApi, + PaStream** s, + const PaStreamParameters *inputParameters, + const PaStreamParameters *outputParameters, + double sampleRate, + unsigned long framesPerBuffer, + PaStreamFlags streamFlags, + PaStreamCallback *callback, + void *userData ); +static PaError CloseStream( PaStream* stream ); +static PaError StartStream( PaStream *stream ); +static PaError StopStream( PaStream *stream ); +static PaError AbortStream( PaStream *stream ); +static PaError IsStreamStopped( PaStream *s ); +static PaError IsStreamActive( PaStream *stream ); +static PaTime GetStreamTime( PaStream *stream ); +static double GetStreamCpuLoad( PaStream* stream ); +static PaError BuildDeviceList( PaAlsaHostApiRepresentation *hostApi ); +static int SetApproximateSampleRate( snd_pcm_t *pcm, snd_pcm_hw_params_t *hwParams, double sampleRate ); +static int GetExactSampleRate( snd_pcm_hw_params_t *hwParams, double *sampleRate ); + +/* Callback prototypes */ +static void *CallbackThreadFunc( void *userData ); + +/* Blocking prototypes */ +static signed long GetStreamReadAvailable( PaStream* s ); +static signed long GetStreamWriteAvailable( PaStream* s ); +static PaError ReadStream( PaStream* stream, void *buffer, unsigned long frames ); +static PaError WriteStream( PaStream* stream, const void *buffer, unsigned long frames ); + + +static const PaAlsaDeviceInfo *GetDeviceInfo( const PaUtilHostApiRepresentation *hostApi, int device ) +{ + return (const PaAlsaDeviceInfo *)hostApi->deviceInfos[device]; +} + +static void AlsaErrorHandler(const char *file, int line, const char *function, int err, const char *fmt, ...) +{ +} + +PaError PaAlsa_Initialize( PaUtilHostApiRepresentation **hostApi, PaHostApiIndex hostApiIndex ) +{ + PaError result = paNoError; + PaAlsaHostApiRepresentation *alsaHostApi = NULL; + + PA_UNLESS( alsaHostApi = (PaAlsaHostApiRepresentation*) PaUtil_AllocateMemory( + sizeof(PaAlsaHostApiRepresentation) ), paInsufficientMemory ); + PA_UNLESS( alsaHostApi->allocations = PaUtil_CreateAllocationGroup(), paInsufficientMemory ); + alsaHostApi->hostApiIndex = hostApiIndex; + + *hostApi = (PaUtilHostApiRepresentation*)alsaHostApi; + (*hostApi)->info.structVersion = 1; + (*hostApi)->info.type = paALSA; + (*hostApi)->info.name = "ALSA"; + + (*hostApi)->Terminate = Terminate; + (*hostApi)->OpenStream = OpenStream; + (*hostApi)->IsFormatSupported = IsFormatSupported; + + ENSURE_( snd_lib_error_set_handler(AlsaErrorHandler), paUnanticipatedHostError ); + + PA_ENSURE( BuildDeviceList( alsaHostApi ) ); + + PaUtil_InitializeStreamInterface( &alsaHostApi->callbackStreamInterface, + CloseStream, StartStream, + StopStream, AbortStream, + IsStreamStopped, IsStreamActive, + GetStreamTime, GetStreamCpuLoad, + PaUtil_DummyRead, PaUtil_DummyWrite, + PaUtil_DummyGetReadAvailable, + PaUtil_DummyGetWriteAvailable ); + + PaUtil_InitializeStreamInterface( &alsaHostApi->blockingStreamInterface, + CloseStream, StartStream, + StopStream, AbortStream, + IsStreamStopped, IsStreamActive, + GetStreamTime, PaUtil_DummyGetCpuLoad, + ReadStream, WriteStream, + GetStreamReadAvailable, + GetStreamWriteAvailable ); + + PA_ENSURE( PaUnixThreading_Initialize() ); + + return result; + +error: + if( alsaHostApi ) + { + if( alsaHostApi->allocations ) + { + PaUtil_FreeAllAllocations( alsaHostApi->allocations ); + PaUtil_DestroyAllocationGroup( alsaHostApi->allocations ); + } + + PaUtil_FreeMemory( alsaHostApi ); + } + + return result; +} + +static void Terminate( struct PaUtilHostApiRepresentation *hostApi ) +{ + PaAlsaHostApiRepresentation *alsaHostApi = (PaAlsaHostApiRepresentation*)hostApi; + + assert( hostApi ); + + if( alsaHostApi->allocations ) + { + PaUtil_FreeAllAllocations( alsaHostApi->allocations ); + PaUtil_DestroyAllocationGroup( alsaHostApi->allocations ); + } + + PaUtil_FreeMemory( alsaHostApi ); + snd_config_update_free_global(); +} + +/** Determine max channels and default latencies. + * + * This function provides functionality to grope an opened (might be opened for capture or playback) pcm device for + * traits like max channels, suitable default latencies and default sample rate. Upon error, max channels is set to zero, + * and a suitable result returned. The device is closed before returning. + */ +static PaError GropeDevice( snd_pcm_t* pcm, int isPlug, StreamDirection mode, int openBlocking, + PaAlsaDeviceInfo* devInfo, int* canMmap ) +{ + PaError result = paNoError; + snd_pcm_hw_params_t *hwParams; + snd_pcm_uframes_t lowLatency = 512, highLatency = 2048; + unsigned int minChans, maxChans; + int* minChannels, * maxChannels; + double * defaultLowLatency, * defaultHighLatency, * defaultSampleRate = + &devInfo->baseDeviceInfo.defaultSampleRate; + double defaultSr = *defaultSampleRate; + + assert( pcm ); + + if( StreamDirection_In == mode ) + { + minChannels = &devInfo->minInputChannels; + maxChannels = &devInfo->baseDeviceInfo.maxInputChannels; + defaultLowLatency = &devInfo->baseDeviceInfo.defaultLowInputLatency; + defaultHighLatency = &devInfo->baseDeviceInfo.defaultHighInputLatency; + } + else + { + minChannels = &devInfo->minOutputChannels; + maxChannels = &devInfo->baseDeviceInfo.maxOutputChannels; + defaultLowLatency = &devInfo->baseDeviceInfo.defaultLowOutputLatency; + defaultHighLatency = &devInfo->baseDeviceInfo.defaultHighOutputLatency; + } + + ENSURE_( snd_pcm_nonblock( pcm, 0 ), paUnanticipatedHostError ); + + snd_pcm_hw_params_alloca( &hwParams ); + snd_pcm_hw_params_any( pcm, hwParams ); + + *canMmap = snd_pcm_hw_params_test_access( pcm, hwParams, SND_PCM_ACCESS_MMAP_INTERLEAVED ) >= 0 || + snd_pcm_hw_params_test_access( pcm, hwParams, SND_PCM_ACCESS_MMAP_NONINTERLEAVED ) >= 0; + + if( defaultSr >= 0 ) + { + /* Could be that the device opened in one mode supports samplerates that the other mode wont have, + * so try again .. */ + if( SetApproximateSampleRate( pcm, hwParams, defaultSr ) < 0 ) + { + defaultSr = -1.; + PA_DEBUG(( "%s: Original default samplerate failed, trying again ..\n", __FUNCTION__ )); + } + } + + if( defaultSr < 0. ) /* Default sample rate not set */ + { + unsigned int sampleRate = 44100; /* Will contain approximate rate returned by alsa-lib */ + if( snd_pcm_hw_params_set_rate_near( pcm, hwParams, &sampleRate, NULL ) < 0) + { + result = paUnanticipatedHostError; + goto error; + } + ENSURE_( GetExactSampleRate( hwParams, &defaultSr ), paUnanticipatedHostError ); + } + + ENSURE_( snd_pcm_hw_params_get_channels_min( hwParams, &minChans ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_get_channels_max( hwParams, &maxChans ), paUnanticipatedHostError ); + assert( maxChans <= INT_MAX ); + assert( maxChans > 0 ); /* Weird linking issue could cause wrong version of ALSA symbols to be called, + resulting in zeroed values */ + + /* XXX: Limit to sensible number (ALSA plugins accept a crazy amount of channels)? */ + if( isPlug && maxChans > 128 ) + { + maxChans = 128; + PA_DEBUG(( "%s: Limiting number of plugin channels to %u\n", __FUNCTION__, maxChans )); + } + + /* TWEAKME: + * + * Giving values for default min and max latency is not + * straightforward. Here are our objectives: + * + * * for low latency, we want to give the lowest value + * that will work reliably. This varies based on the + * sound card, kernel, CPU, etc. I think it is better + * to give sub-optimal latency than to give a number + * too low and cause dropouts. My conservative + * estimate at this point is to base it on 4096-sample + * latency at 44.1 kHz, which gives a latency of 23ms. + * * for high latency we want to give a large enough + * value that dropouts are basically impossible. This + * doesn't really require as much tweaking, since + * providing too large a number will just cause us to + * select the nearest setting that will work at stream + * config time. + */ + ENSURE_( snd_pcm_hw_params_set_buffer_size_near( pcm, hwParams, &lowLatency ), paUnanticipatedHostError ); + + /* Have to reset hwParams, to set new buffer size */ + ENSURE_( snd_pcm_hw_params_any( pcm, hwParams ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_set_buffer_size_near( pcm, hwParams, &highLatency ), paUnanticipatedHostError ); + + *minChannels = (int)minChans; + *maxChannels = (int)maxChans; + *defaultSampleRate = defaultSr; + *defaultLowLatency = (double) lowLatency / *defaultSampleRate; + *defaultHighLatency = (double) highLatency / *defaultSampleRate; + +end: + snd_pcm_close( pcm ); + return result; + +error: + goto end; +} + +/* Initialize device info with invalid values (maxInputChannels and maxOutputChannels are set to zero since these indicate + * wether input/output is available) */ +static void InitializeDeviceInfo( PaDeviceInfo *deviceInfo ) +{ + deviceInfo->structVersion = -1; + deviceInfo->name = NULL; + deviceInfo->hostApi = -1; + deviceInfo->maxInputChannels = 0; + deviceInfo->maxOutputChannels = 0; + deviceInfo->defaultLowInputLatency = -1.; + deviceInfo->defaultLowOutputLatency = -1.; + deviceInfo->defaultHighInputLatency = -1.; + deviceInfo->defaultHighOutputLatency = -1.; + deviceInfo->defaultSampleRate = -1.; +} + +/* Helper struct */ +typedef struct +{ + char *alsaName; + char *name; + int isPlug; + int hasPlayback; + int hasCapture; +} DeviceNames; + +static PaError PaAlsa_StrDup( PaAlsaHostApiRepresentation *alsaApi, + char **dst, + const char *src) +{ + PaError result = paNoError; + int len = strlen( src ) + 1; + + /* PA_DEBUG(("PaStrDup %s %d\n", src, len)); */ + + PA_UNLESS( *dst = (char *)PaUtil_GroupAllocateMemory( alsaApi->allocations, len ), + paInsufficientMemory ); + strncpy( *dst, src, len ); + +error: + return result; +} + +/* Disregard some standard plugins + */ +static int IgnorePlugin( const char *pluginId ) +{ + /* XXX: dmix and default ignored because after opening and closing, they seem to keep hogging resources. + */ + static const char *ignoredPlugins[] = {"hw", "plughw", "plug", "dsnoop", "tee", + "file", "null", "shm", "cards", "dmix", "default", NULL}; + int i = 0; + while( ignoredPlugins[i] ) + { + if( !strcmp( pluginId, ignoredPlugins[i] ) ) + { + return 1; + } + ++i; + } + + return 0; +} + +/* Build PaDeviceInfo list, ignore devices for which we cannot determine capabilities (possibly busy, sigh) */ +static PaError BuildDeviceList( PaAlsaHostApiRepresentation *alsaApi ) +{ + PaUtilHostApiRepresentation *baseApi = &alsaApi->baseHostApiRep; + PaAlsaDeviceInfo *deviceInfoArray; + int cardIdx = -1, devIdx = 0; + snd_ctl_card_info_t *cardInfo; + PaError result = paNoError; + size_t numDeviceNames = 0, maxDeviceNames = 1, i; + DeviceNames *deviceNames = NULL; + snd_config_t *topNode = NULL; + snd_pcm_info_t *pcmInfo; + int res; + int blocking = SND_PCM_NONBLOCK; + char alsaCardName[50]; + if( getenv( "PA_ALSA_INITIALIZE_BLOCK" ) && atoi( getenv( "PA_ALSA_INITIALIZE_BLOCK" ) ) ) + blocking = 0; + + /* These two will be set to the first working input and output device, respectively */ + baseApi->info.defaultInputDevice = paNoDevice; + baseApi->info.defaultOutputDevice = paNoDevice; + + /* count the devices by enumerating all the card numbers */ + + /* snd_card_next() modifies the integer passed to it to be: + * the index of the first card if the parameter is -1 + * the index of the next card if the parameter is the index of a card + * -1 if there are no more cards + * + * The function itself returns 0 if it succeeded. */ + cardIdx = -1; + snd_ctl_card_info_alloca( &cardInfo ); + snd_pcm_info_alloca( &pcmInfo ); + while( snd_card_next( &cardIdx ) == 0 && cardIdx >= 0 ) + { + char *cardName; + int devIdx = -1; + snd_ctl_t *ctl; + char buf[50]; + + snprintf( alsaCardName, sizeof (alsaCardName), "hw:%d", cardIdx ); + + /* Acquire name of card */ + if( snd_ctl_open( &ctl, alsaCardName, 0 ) < 0 ) + { + /* Unable to open card :( */ + PA_DEBUG(( "%s: Unable to open device %s\n", __FUNCTION__, alsaCardName )); + continue; + } + snd_ctl_card_info( ctl, cardInfo ); + + PA_ENSURE( PaAlsa_StrDup( alsaApi, &cardName, snd_ctl_card_info_get_name( cardInfo )) ); + + while( snd_ctl_pcm_next_device( ctl, &devIdx ) == 0 && devIdx >= 0 ) + { + char *alsaDeviceName, *deviceName; + size_t len; + int hasPlayback = 0, hasCapture = 0; + snprintf( buf, sizeof (buf), "%s:%d,%d", "hw", cardIdx, devIdx ); + + /* Obtain info about this particular device */ + snd_pcm_info_set_device( pcmInfo, devIdx ); + snd_pcm_info_set_subdevice( pcmInfo, 0 ); + snd_pcm_info_set_stream( pcmInfo, SND_PCM_STREAM_CAPTURE ); + if( snd_ctl_pcm_info( ctl, pcmInfo ) >= 0 ) + { + hasCapture = 1; + } + + snd_pcm_info_set_stream( pcmInfo, SND_PCM_STREAM_PLAYBACK ); + if( snd_ctl_pcm_info( ctl, pcmInfo ) >= 0 ) + { + hasPlayback = 1; + } + + if( !hasPlayback && !hasCapture ) + { + continue; /* Error */ + } + + /* The length of the string written by snprintf plus terminating 0 */ + len = snprintf( NULL, 0, "%s: %s (%s)", cardName, snd_pcm_info_get_name( pcmInfo ), buf ) + 1; + PA_UNLESS( deviceName = (char *)PaUtil_GroupAllocateMemory( alsaApi->allocations, len ), + paInsufficientMemory ); + snprintf( deviceName, len, "%s: %s (%s)", cardName, + snd_pcm_info_get_name( pcmInfo ), buf ); + + ++numDeviceNames; + if( !deviceNames || numDeviceNames > maxDeviceNames ) + { + maxDeviceNames *= 2; + PA_UNLESS( deviceNames = (DeviceNames *) realloc( deviceNames, maxDeviceNames * sizeof (DeviceNames) ), + paInsufficientMemory ); + } + + PA_ENSURE( PaAlsa_StrDup( alsaApi, &alsaDeviceName, buf ) ); + + deviceNames[ numDeviceNames - 1 ].alsaName = alsaDeviceName; + deviceNames[ numDeviceNames - 1 ].name = deviceName; + deviceNames[ numDeviceNames - 1 ].isPlug = 0; + deviceNames[ numDeviceNames - 1 ].hasPlayback = hasPlayback; + deviceNames[ numDeviceNames - 1 ].hasCapture = hasCapture; + } + snd_ctl_close( ctl ); + } + + /* Iterate over plugin devices */ + if( NULL == snd_config ) + { + /* snd_config_update is called implicitly by some functions, if this hasn't happened snd_config will be NULL (bleh) */ + ENSURE_( snd_config_update(), paUnanticipatedHostError ); + PA_DEBUG(( "Updating snd_config\n" )); + } + assert( snd_config ); + if( (res = snd_config_search( snd_config, "pcm", &topNode )) >= 0 ) + { + snd_config_iterator_t i, next; + + snd_config_for_each( i, next, topNode ) + { + const char *tpStr = "unknown", *idStr = NULL; + int err = 0; + + char *alsaDeviceName, *deviceName; + snd_config_t *n = snd_config_iterator_entry( i ), * tp = NULL;; + + if( (err = snd_config_search( n, "type", &tp )) < 0 ) + { + if( -ENOENT != err ) + { + ENSURE_(err, paUnanticipatedHostError); + } + } + else + { + ENSURE_( snd_config_get_string( tp, &tpStr ), paUnanticipatedHostError ); + } + ENSURE_( snd_config_get_id( n, &idStr ), paUnanticipatedHostError ); + if( IgnorePlugin( idStr ) ) + { + PA_DEBUG(( "%s: Ignoring ALSA plugin device %s of type %s\n", __FUNCTION__, idStr, tpStr )); + continue; + } + PA_DEBUG(( "%s: Found plugin %s of type %s\n", __FUNCTION__, idStr, tpStr )); + + PA_UNLESS( alsaDeviceName = (char*)PaUtil_GroupAllocateMemory( alsaApi->allocations, + strlen(idStr) + 6 ), paInsufficientMemory ); + strcpy( alsaDeviceName, idStr ); + PA_UNLESS( deviceName = (char*)PaUtil_GroupAllocateMemory( alsaApi->allocations, + strlen(idStr) + 1 ), paInsufficientMemory ); + strcpy( deviceName, idStr ); + + ++numDeviceNames; + if( !deviceNames || numDeviceNames > maxDeviceNames ) + { + maxDeviceNames *= 2; + PA_UNLESS( deviceNames = (DeviceNames *) realloc( deviceNames, maxDeviceNames * sizeof (DeviceNames) ), + paInsufficientMemory ); + } + + deviceNames[numDeviceNames - 1].alsaName = alsaDeviceName; + deviceNames[numDeviceNames - 1].name = deviceName; + deviceNames[numDeviceNames - 1].isPlug = 1; + deviceNames[numDeviceNames - 1].hasPlayback = 1; + deviceNames[numDeviceNames - 1].hasCapture = 1; + } + } + else + PA_DEBUG(( "%s: Iterating over ALSA plugins failed: %s\n", __FUNCTION__, snd_strerror( res ) )); + + /* allocate deviceInfo memory based on the number of devices */ + PA_UNLESS( baseApi->deviceInfos = (PaDeviceInfo**)PaUtil_GroupAllocateMemory( + alsaApi->allocations, sizeof(PaDeviceInfo*) * (numDeviceNames) ), paInsufficientMemory ); + + /* allocate all device info structs in a contiguous block */ + PA_UNLESS( deviceInfoArray = (PaAlsaDeviceInfo*)PaUtil_GroupAllocateMemory( + alsaApi->allocations, sizeof(PaAlsaDeviceInfo) * numDeviceNames ), paInsufficientMemory ); + + /* Loop over list of cards, filling in info, if a device is deemed unavailable (can't get name), + * it's ignored. + */ + /* while( snd_card_next( &cardIdx ) == 0 && cardIdx >= 0 ) */ + for( i = 0, devIdx = 0; i < numDeviceNames; ++i ) + { + snd_pcm_t *pcm; + PaAlsaDeviceInfo *deviceInfo = &deviceInfoArray[devIdx]; + PaDeviceInfo *baseDeviceInfo = &deviceInfo->baseDeviceInfo; + int canMmap = -1; + + /* Zero fields */ + InitializeDeviceInfo( baseDeviceInfo ); + + /* to determine device capabilities, we must open the device and query the + * hardware parameter configuration space */ + + /* Query capture */ + if( deviceNames[i].hasCapture && + snd_pcm_open( &pcm, deviceNames[i].alsaName, SND_PCM_STREAM_CAPTURE, blocking ) >= 0 ) + { + if( GropeDevice( pcm, deviceNames[i].isPlug, StreamDirection_In, blocking, deviceInfo, + &canMmap ) != paNoError ) + { + /* Error */ + PA_DEBUG(("%s: Failed groping %s for capture\n", __FUNCTION__, deviceNames[i].alsaName)); + continue; + } + } + + /* Query playback */ + if( deviceNames[i].hasPlayback && + snd_pcm_open( &pcm, deviceNames[i].alsaName, SND_PCM_STREAM_PLAYBACK, blocking ) >= 0 ) + { + if( GropeDevice( pcm, deviceNames[i].isPlug, StreamDirection_Out, blocking, deviceInfo, + &canMmap ) != paNoError ) + { + /* Error */ + PA_DEBUG(("%s: Failed groping %s for playback\n", __FUNCTION__, deviceNames[i].alsaName)); + continue; + } + } + + if( 0 == canMmap ) + { + PA_DEBUG(("%s: Device %s doesn't support mmap\n", __FUNCTION__, deviceNames[i].alsaName)); + continue; + } + + baseDeviceInfo->structVersion = 2; + baseDeviceInfo->hostApi = alsaApi->hostApiIndex; + baseDeviceInfo->name = deviceNames[i].name; + deviceInfo->alsaName = deviceNames[i].alsaName; + deviceInfo->isPlug = deviceNames[i].isPlug; + + /* A: Storing pointer to PaAlsaDeviceInfo object as pointer to PaDeviceInfo object. + * Should now be safe to add device info, unless the device supports neither capture nor playback + */ + if( baseDeviceInfo->maxInputChannels > 0 || baseDeviceInfo->maxOutputChannels > 0 ) + { + if( baseApi->info.defaultInputDevice == paNoDevice && baseDeviceInfo->maxInputChannels > 0 ) + baseApi->info.defaultInputDevice = devIdx; + if( baseApi->info.defaultOutputDevice == paNoDevice && baseDeviceInfo->maxOutputChannels > 0 ) + baseApi->info.defaultOutputDevice = devIdx; + PA_DEBUG(("%s: Adding device %s\n", __FUNCTION__, deviceNames[i].name)); + baseApi->deviceInfos[devIdx++] = (PaDeviceInfo *) deviceInfo; + } + } + free( deviceNames ); + + baseApi->info.deviceCount = devIdx; /* Number of successfully queried devices */ + +end: + return result; + +error: + /* No particular action */ + goto end; +} + +/* Check against known device capabilities */ +static PaError ValidateParameters( const PaStreamParameters *parameters, PaUtilHostApiRepresentation *hostApi, StreamDirection mode ) +{ + PaError result = paNoError; + int maxChans; + const PaAlsaDeviceInfo *deviceInfo = NULL; + assert( parameters ); + + if( parameters->device != paUseHostApiSpecificDeviceSpecification ) + { + assert( parameters->device < hostApi->info.deviceCount ); + PA_UNLESS( parameters->hostApiSpecificStreamInfo == NULL, paBadIODeviceCombination ); + deviceInfo = GetDeviceInfo( hostApi, parameters->device ); + } + else + { + const PaAlsaStreamInfo *streamInfo = parameters->hostApiSpecificStreamInfo; + + PA_UNLESS( parameters->device == paUseHostApiSpecificDeviceSpecification, paInvalidDevice ); + PA_UNLESS( streamInfo->size == sizeof (PaAlsaStreamInfo) && streamInfo->version == 1, + paIncompatibleHostApiSpecificStreamInfo ); + PA_UNLESS( streamInfo->deviceString != NULL, paInvalidDevice ); + + /* Skip further checking */ + return paNoError; + } + + assert( deviceInfo ); + assert( parameters->hostApiSpecificStreamInfo == NULL ); + maxChans = (StreamDirection_In == mode ? deviceInfo->baseDeviceInfo.maxInputChannels : + deviceInfo->baseDeviceInfo.maxOutputChannels); + PA_UNLESS( parameters->channelCount <= maxChans, paInvalidChannelCount ); + +error: + return result; +} + +/* Given an open stream, what sample formats are available? */ +static PaSampleFormat GetAvailableFormats( snd_pcm_t *pcm ) +{ + PaSampleFormat available = 0; + snd_pcm_hw_params_t *hwParams; + snd_pcm_hw_params_alloca( &hwParams ); + + snd_pcm_hw_params_any( pcm, hwParams ); + + if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_FLOAT ) >= 0) + available |= paFloat32; + + if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_S32 ) >= 0) + available |= paInt32; + + if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_S24 ) >= 0) + available |= paInt24; + + if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_S16 ) >= 0) + available |= paInt16; + + if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_U8 ) >= 0) + available |= paUInt8; + + if( snd_pcm_hw_params_test_format( pcm, hwParams, SND_PCM_FORMAT_S8 ) >= 0) + available |= paInt8; + + return available; +} + +static snd_pcm_format_t Pa2AlsaFormat( PaSampleFormat paFormat ) +{ + switch( paFormat ) + { + case paFloat32: + return SND_PCM_FORMAT_FLOAT; + + case paInt16: + return SND_PCM_FORMAT_S16; + + case paInt24: + return SND_PCM_FORMAT_S24; + + case paInt32: + return SND_PCM_FORMAT_S32; + + case paInt8: + return SND_PCM_FORMAT_S8; + + case paUInt8: + return SND_PCM_FORMAT_U8; + + default: + return SND_PCM_FORMAT_UNKNOWN; + } +} + +/** Open an ALSA pcm handle. + * + * The device to be open can be specified in a custom PaAlsaStreamInfo struct, or it will be a device number. In case of a + * device number, it maybe specified through an env variable (PA_ALSA_PLUGHW) that we should open the corresponding plugin + * device. + */ +static PaError AlsaOpen( const PaUtilHostApiRepresentation *hostApi, const PaStreamParameters *params, StreamDirection + streamDir, snd_pcm_t **pcm ) +{ + PaError result = paNoError; + int ret; + char dnameArray[50]; + const char* deviceName = dnameArray; + const PaAlsaDeviceInfo *deviceInfo = NULL; + PaAlsaStreamInfo *streamInfo = (PaAlsaStreamInfo *)params->hostApiSpecificStreamInfo; + + if( !streamInfo ) + { + int usePlug = 0; + deviceInfo = GetDeviceInfo( hostApi, params->device ); + + /* If device name starts with hw: and PA_ALSA_PLUGHW is 1, we open the plughw device instead */ + if( !strncmp( "hw:", deviceInfo->alsaName, 3 ) && getenv( "PA_ALSA_PLUGHW" ) ) + usePlug = atoi( getenv( "PA_ALSA_PLUGHW" ) ); + if( usePlug ) + snprintf( dnameArray, 50, "plug%s", deviceInfo->alsaName ); + else + deviceName = deviceInfo->alsaName; + } + else + deviceName = streamInfo->deviceString; + + PA_DEBUG(( "%s: Opening device %s\n", __FUNCTION__, deviceName )); + if( (ret = snd_pcm_open( pcm, deviceName, streamDir == StreamDirection_In ? SND_PCM_STREAM_CAPTURE : SND_PCM_STREAM_PLAYBACK, + SND_PCM_NONBLOCK )) < 0 ) + { + /* Not to be closed */ + *pcm = NULL; + ENSURE_( ret, ret == -EBUSY ? paDeviceUnavailable : paBadIODeviceCombination ); + } + ENSURE_( snd_pcm_nonblock( *pcm, 0 ), paUnanticipatedHostError ); + +end: + return result; + +error: + goto end; +} + +static PaError TestParameters( const PaUtilHostApiRepresentation *hostApi, const PaStreamParameters *parameters, + double sampleRate, StreamDirection streamDir ) +{ + PaError result = paNoError; + snd_pcm_t *pcm = NULL; + PaSampleFormat availableFormats; + /* We are able to adapt to a number of channels less than what the device supports */ + unsigned int numHostChannels; + PaSampleFormat hostFormat; + snd_pcm_hw_params_t *hwParams; + snd_pcm_hw_params_alloca( &hwParams ); + + if( !parameters->hostApiSpecificStreamInfo ) + { + const PaAlsaDeviceInfo *devInfo = GetDeviceInfo( hostApi, parameters->device ); + numHostChannels = PA_MAX( parameters->channelCount, StreamDirection_In == streamDir ? + devInfo->minInputChannels : devInfo->minOutputChannels ); + } + else + numHostChannels = parameters->channelCount; + + PA_ENSURE( AlsaOpen( hostApi, parameters, streamDir, &pcm ) ); + + snd_pcm_hw_params_any( pcm, hwParams ); + + if( SetApproximateSampleRate( pcm, hwParams, sampleRate ) < 0 ) + { + result = paInvalidSampleRate; + goto error; + } + + if( snd_pcm_hw_params_set_channels( pcm, hwParams, numHostChannels ) < 0 ) + { + result = paInvalidChannelCount; + goto error; + } + + /* See if we can find a best possible match */ + availableFormats = GetAvailableFormats( pcm ); + PA_ENSURE( hostFormat = PaUtil_SelectClosestAvailableFormat( availableFormats, parameters->sampleFormat ) ); + ENSURE_( snd_pcm_hw_params_set_format( pcm, hwParams, Pa2AlsaFormat( hostFormat ) ), paUnanticipatedHostError ); + + { + /* It happens that this call fails because the device is busy */ + int ret = 0; + if( (ret = snd_pcm_hw_params( pcm, hwParams )) < 0) + { + ENSURE_( ret, ret == -EBUSY ? paDeviceUnavailable : paUnanticipatedHostError ); + } + } + +end: + if( pcm ) + { + snd_pcm_close( pcm ); + } + return result; + +error: + goto end; +} + +static PaError IsFormatSupported( struct PaUtilHostApiRepresentation *hostApi, + const PaStreamParameters *inputParameters, + const PaStreamParameters *outputParameters, + double sampleRate ) +{ + int inputChannelCount = 0, outputChannelCount = 0; + PaSampleFormat inputSampleFormat, outputSampleFormat; + PaError result = paFormatIsSupported; + + if( inputParameters ) + { + PA_ENSURE( ValidateParameters( inputParameters, hostApi, StreamDirection_In ) ); + + inputChannelCount = inputParameters->channelCount; + inputSampleFormat = inputParameters->sampleFormat; + } + + if( outputParameters ) + { + PA_ENSURE( ValidateParameters( outputParameters, hostApi, StreamDirection_Out ) ); + + outputChannelCount = outputParameters->channelCount; + outputSampleFormat = outputParameters->sampleFormat; + } + + if( inputChannelCount ) + { + if( (result = TestParameters( hostApi, inputParameters, sampleRate, StreamDirection_In )) + != paNoError ) + goto error; + } + if ( outputChannelCount ) + { + if( (result = TestParameters( hostApi, outputParameters, sampleRate, StreamDirection_Out )) + != paNoError ) + goto error; + } + + return paFormatIsSupported; + +error: + return result; +} + +static PaError PaAlsaStreamComponent_Initialize( PaAlsaStreamComponent *self, PaAlsaHostApiRepresentation *alsaApi, + const PaStreamParameters *params, StreamDirection streamDir, int callbackMode ) +{ + PaError result = paNoError; + PaSampleFormat userSampleFormat = params->sampleFormat, hostSampleFormat; + assert( params->channelCount > 0 ); + + /* Make sure things have an initial value */ + memset( self, 0, sizeof (PaAlsaStreamComponent) ); + + if( NULL == params->hostApiSpecificStreamInfo ) + { + const PaAlsaDeviceInfo *devInfo = GetDeviceInfo( &alsaApi->baseHostApiRep, params->device ); + self->numHostChannels = PA_MAX( params->channelCount, StreamDirection_In == streamDir ? devInfo->minInputChannels + : devInfo->minOutputChannels ); + } + else + { + /* We're blissfully unaware of the minimum channelCount */ + self->numHostChannels = params->channelCount; + } + + PA_ENSURE( AlsaOpen( &alsaApi->baseHostApiRep, params, streamDir, &self->pcm ) ); + self->nfds = snd_pcm_poll_descriptors_count( self->pcm ); + hostSampleFormat = PaUtil_SelectClosestAvailableFormat( GetAvailableFormats( self->pcm ), userSampleFormat ); + + self->hostSampleFormat = hostSampleFormat; + self->nativeFormat = Pa2AlsaFormat( hostSampleFormat ); + self->hostInterleaved = self->userInterleaved = !(userSampleFormat & paNonInterleaved); + self->numUserChannels = params->channelCount; + self->streamDir = streamDir; + + if( !callbackMode && !self->userInterleaved ) + { + /* Pre-allocate non-interleaved user provided buffers */ + PA_UNLESS( self->userBuffers = PaUtil_AllocateMemory( sizeof (void *) * self->numUserChannels ), + paInsufficientMemory ); + } + +error: + return result; +} + +static void PaAlsaStreamComponent_Terminate( PaAlsaStreamComponent *self ) +{ + snd_pcm_close( self->pcm ); + if( self->userBuffers ) + PaUtil_FreeMemory( self->userBuffers ); +} + +int nearbyint_(float value) { + if( value - (int)value > .5 ) + return (int)ceil( value ); + return (int)floor( value ); +} + +/** Initiate configuration, preparing for determining a period size suitable for both capture and playback components. + * + */ +static PaError PaAlsaStreamComponent_InitialConfigure( PaAlsaStreamComponent *self, const PaStreamParameters *params, + int primeBuffers, snd_pcm_hw_params_t *hwParams, double *sampleRate ) +{ + /* Configuration consists of setting all of ALSA's parameters. + * These parameters come in two flavors: hardware parameters + * and software paramters. Hardware parameters will affect + * the way the device is initialized, software parameters + * affect the way ALSA interacts with me, the user-level client. + */ + + PaError result = paNoError; + snd_pcm_access_t accessMode, alternateAccessMode; + int dir = 0; + snd_pcm_t *pcm = self->pcm; + double sr = *sampleRate; + unsigned int minPeriods = 2; + + /* self->framesPerBuffer = framesPerHostBuffer; */ + + /* ... fill up the configuration space with all possibile + * combinations of parameters this device will accept */ + ENSURE_( snd_pcm_hw_params_any( pcm, hwParams ), paUnanticipatedHostError ); + + ENSURE_( snd_pcm_hw_params_set_periods_integer( pcm, hwParams ), paUnanticipatedHostError ); + /* I think there should be at least 2 periods (even though ALSA doesn't appear to enforce this) */ + dir = 0; + ENSURE_( snd_pcm_hw_params_set_periods_min( pcm, hwParams, &minPeriods, &dir ), paUnanticipatedHostError ); + + if( self->userInterleaved ) + { + accessMode = SND_PCM_ACCESS_MMAP_INTERLEAVED; + alternateAccessMode = SND_PCM_ACCESS_MMAP_NONINTERLEAVED; + } + else + { + accessMode = SND_PCM_ACCESS_MMAP_NONINTERLEAVED; + alternateAccessMode = SND_PCM_ACCESS_MMAP_INTERLEAVED; + } + /* If requested access mode fails, try alternate mode */ + if( snd_pcm_hw_params_set_access( pcm, hwParams, accessMode ) < 0 ) + { + int err = 0; + if( (err = snd_pcm_hw_params_set_access( pcm, hwParams, alternateAccessMode )) < 0) + { + result = paUnanticipatedHostError; + if( -EINVAL == err ) + { + PaUtil_SetLastHostErrorInfo( paALSA, err, "PA ALSA requires that a device supports mmap access" ); + } + else + { + PaUtil_SetLastHostErrorInfo( paALSA, err, snd_strerror( err ) ); + } + goto error; + } + /* Flip mode */ + self->hostInterleaved = !self->userInterleaved; + } + + ENSURE_( snd_pcm_hw_params_set_format( pcm, hwParams, self->nativeFormat ), paUnanticipatedHostError ); + + ENSURE_( SetApproximateSampleRate( pcm, hwParams, sr ), paInvalidSampleRate ); + ENSURE_( GetExactSampleRate( hwParams, &sr ), paUnanticipatedHostError ); + /* reject if there's no sample rate within 1% of the one requested */ + if( (fabs( *sampleRate - sr ) / *sampleRate) > 0.01 ) + { + PA_DEBUG(("%s: Wanted %f, closest sample rate was %d\n", __FUNCTION__, sampleRate, sr )); + PA_ENSURE( paInvalidSampleRate ); + } + + ENSURE_( snd_pcm_hw_params_set_channels( pcm, hwParams, self->numHostChannels ), paInvalidChannelCount ); + + *sampleRate = sr; + +end: + return result; + +error: + /* No particular action */ + goto end; +} + +/** Finish the configuration of the component's ALSA device. + * + * As part of this method, the component's bufferSize attribute will be set. + * @param latency: The latency for this component. + */ +static PaError PaAlsaStreamComponent_FinishConfigure( PaAlsaStreamComponent *self, snd_pcm_hw_params_t* hwParams, + const PaStreamParameters *params, int primeBuffers, double sampleRate, PaTime* latency ) +{ + PaError result = paNoError; + snd_pcm_sw_params_t* swParams; + snd_pcm_uframes_t bufSz = 0; + *latency = -1.; + + snd_pcm_sw_params_alloca( &swParams ); + + bufSz = (params->suggestedLatency * sampleRate) + self->framesPerBuffer; /* One period does not count as latency */ + ENSURE_( snd_pcm_hw_params_set_buffer_size_near( self->pcm, hwParams, &bufSz ), paUnanticipatedHostError ); + + /* Set the parameters! */ + ENSURE_( snd_pcm_hw_params( self->pcm, hwParams ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_get_buffer_size( hwParams, &self->bufferSize ), paUnanticipatedHostError ); + /* Latency in seconds, one period is not counted as latency */ + *latency = (self->bufferSize - self->framesPerBuffer) / sampleRate; + + /* Now software parameters... */ + ENSURE_( snd_pcm_sw_params_current( self->pcm, swParams ), paUnanticipatedHostError ); + + ENSURE_( snd_pcm_sw_params_set_start_threshold( self->pcm, swParams, self->framesPerBuffer ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_sw_params_set_stop_threshold( self->pcm, swParams, self->bufferSize ), paUnanticipatedHostError ); + + /* Silence buffer in the case of underrun */ + if( !primeBuffers ) /* XXX: Make sense? */ + { + snd_pcm_uframes_t boundary; + ENSURE_( snd_pcm_sw_params_get_boundary( swParams, &boundary ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_sw_params_set_silence_threshold( self->pcm, swParams, 0 ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_sw_params_set_silence_size( self->pcm, swParams, boundary ), paUnanticipatedHostError ); + } + + ENSURE_( snd_pcm_sw_params_set_avail_min( self->pcm, swParams, self->framesPerBuffer ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_sw_params_set_xfer_align( self->pcm, swParams, 1 ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_sw_params_set_tstamp_mode( self->pcm, swParams, SND_PCM_TSTAMP_MMAP ), paUnanticipatedHostError ); + + /* Set the parameters! */ + ENSURE_( snd_pcm_sw_params( self->pcm, swParams ), paUnanticipatedHostError ); + +error: + return result; +} + +static PaError PaAlsaStream_Initialize( PaAlsaStream *self, PaAlsaHostApiRepresentation *alsaApi, const PaStreamParameters *inParams, + const PaStreamParameters *outParams, double sampleRate, unsigned long framesPerUserBuffer, PaStreamCallback callback, + PaStreamFlags streamFlags, void *userData ) +{ + PaError result = paNoError; + assert( self ); + + memset( self, 0, sizeof (PaAlsaStream) ); + + if( NULL != callback ) + { + PaUtil_InitializeStreamRepresentation( &self->streamRepresentation, + &alsaApi->callbackStreamInterface, + callback, userData ); + self->callbackMode = 1; + } + else + { + PaUtil_InitializeStreamRepresentation( &self->streamRepresentation, + &alsaApi->blockingStreamInterface, + NULL, userData ); + } + + self->framesPerUserBuffer = framesPerUserBuffer; + self->neverDropInput = streamFlags & paNeverDropInput; + /* XXX: Ignore paPrimeOutputBuffersUsingStreamCallback untill buffer priming is fully supported in pa_process.c */ + /* + if( outParams & streamFlags & paPrimeOutputBuffersUsingStreamCallback ) + self->primeBuffers = 1; + */ + memset( &self->capture, 0, sizeof (PaAlsaStreamComponent) ); + memset( &self->playback, 0, sizeof (PaAlsaStreamComponent) ); + if( inParams ) + { + PA_ENSURE( PaAlsaStreamComponent_Initialize( &self->capture, alsaApi, inParams, StreamDirection_In, NULL != callback ) ); + } + if( outParams ) + { + PA_ENSURE( PaAlsaStreamComponent_Initialize( &self->playback, alsaApi, outParams, StreamDirection_Out, NULL != callback ) ); + } + + assert( self->capture.nfds || self->playback.nfds ); + + PA_UNLESS( self->pfds = (struct pollfd*)PaUtil_AllocateMemory( (self->capture.nfds + + self->playback.nfds) * sizeof (struct pollfd) ), paInsufficientMemory ); + + PaUtil_InitializeCpuLoadMeasurer( &self->cpuLoadMeasurer, sampleRate ); + ASSERT_CALL_( PaUnixMutex_Initialize( &self->stateMtx ), paNoError ); + +error: + return result; +} + +/** Free resources associated with stream, and eventually stream itself. + * + * Frees allocated memory, and terminates individual StreamComponents. + */ +static void PaAlsaStream_Terminate( PaAlsaStream *self ) +{ + assert( self ); + + if( self->capture.pcm ) + { + PaAlsaStreamComponent_Terminate( &self->capture ); + } + if( self->playback.pcm ) + { + PaAlsaStreamComponent_Terminate( &self->playback ); + } + + PaUtil_FreeMemory( self->pfds ); + ASSERT_CALL_( PaUnixMutex_Terminate( &self->stateMtx ), paNoError ); + + PaUtil_FreeMemory( self ); +} + +/** Calculate polling timeout + * + * @param frames Time to wait + * @return Polling timeout in milliseconds + */ +static int CalculatePollTimeout( const PaAlsaStream *stream, unsigned long frames ) +{ + assert( stream->streamRepresentation.streamInfo.sampleRate > 0.0 ); + /* Period in msecs, rounded up */ + return (int)ceil( 1000 * frames / stream->streamRepresentation.streamInfo.sampleRate ); +} + +/** Determine size per host buffer. + * + * During this method call, the component's framesPerBuffer attribute gets computed, and the corresponding period size + * gets configured for the device. + * @param accurate: If the configured period size is non-integer, this will be set to 0. + */ +static PaError PaAlsaStreamComponent_DetermineFramesPerBuffer( PaAlsaStreamComponent* self, const PaStreamParameters* params, + unsigned long framesPerUserBuffer, double sampleRate, snd_pcm_hw_params_t* hwParams, int* accurate ) +{ + PaError result = paNoError; + unsigned long bufferSize = params->suggestedLatency * sampleRate, framesPerHostBuffer; + int dir = 0; + + { + snd_pcm_uframes_t tmp; + snd_pcm_hw_params_get_buffer_size_min( hwParams, &tmp ); + bufferSize = PA_MAX( bufferSize, tmp ); + snd_pcm_hw_params_get_buffer_size_max( hwParams, &tmp ); + bufferSize = PA_MIN( bufferSize, tmp ); + } + + assert( bufferSize > 0 ); + + if( framesPerUserBuffer != paFramesPerBufferUnspecified ) + { + /* Preferably the host buffer size should be a multiple of the user buffer size */ + + if( bufferSize > framesPerUserBuffer ) + { + snd_pcm_uframes_t remainder = bufferSize % framesPerUserBuffer; + if( remainder > framesPerUserBuffer / 2. ) + bufferSize += framesPerUserBuffer - remainder; + else + bufferSize -= remainder; + + assert( bufferSize % framesPerUserBuffer == 0 ); + } + else if( framesPerUserBuffer % bufferSize != 0 ) + { + /* Find a good compromise between user specified latency and buffer size */ + if( bufferSize > framesPerUserBuffer * .75 ) + { + bufferSize = framesPerUserBuffer; + } + else + { + snd_pcm_uframes_t newSz = framesPerUserBuffer; + while( newSz / 2 >= bufferSize ) + { + if( framesPerUserBuffer % (newSz / 2) != 0 ) + { + /* No use dividing any further */ + break; + } + newSz /= 2; + } + bufferSize = newSz; + } + + assert( framesPerUserBuffer % bufferSize == 0 ); + } + } + + /* Using 5 as a base number of periods, we try to approximate the suggested latency (+1 period), + finding a combination of period/buffer size which best fits these constraints */ + { + unsigned numPeriods = 4, maxPeriods = 0; + /* It may be that the device only supports 2 periods for instance */ + dir = 0; + ENSURE_( snd_pcm_hw_params_get_periods_max( hwParams, &maxPeriods, &dir ), paUnanticipatedHostError ); + assert( maxPeriods > 1 ); + /* One period is not counted as latency */ + maxPeriods -= 1; + numPeriods = PA_MIN( maxPeriods, numPeriods ); + + if( framesPerUserBuffer != paFramesPerBufferUnspecified ) + { + framesPerHostBuffer = framesPerUserBuffer; + if( framesPerHostBuffer < bufferSize ) + { + while( bufferSize / framesPerHostBuffer > numPeriods ) + { + framesPerHostBuffer *= 2; + } + } + else + { + while( bufferSize / framesPerHostBuffer < numPeriods ) + { + if( framesPerUserBuffer % (framesPerHostBuffer / 2) != 0 ) + { + /* Can't be divided any further */ + break; + } + framesPerHostBuffer /= 2; + } + } + + if( framesPerHostBuffer < framesPerUserBuffer ) + { + assert( framesPerUserBuffer % framesPerHostBuffer == 0 ); + if( snd_pcm_hw_params_test_period_size( self->pcm, hwParams, framesPerHostBuffer, 0 ) < 0 ) + { + if( snd_pcm_hw_params_test_period_size( self->pcm, hwParams, framesPerHostBuffer * 2, 0 ) == 0 ) + framesPerHostBuffer *= 2; + else if( snd_pcm_hw_params_test_period_size( self->pcm, hwParams, framesPerHostBuffer / 2, 0 ) == 0 ) + framesPerHostBuffer /= 2; + } + } + else + { + assert( framesPerHostBuffer % framesPerUserBuffer == 0 ); + if( snd_pcm_hw_params_test_period_size( self->pcm, hwParams, framesPerHostBuffer, 0 ) < 0 ) + { + if( snd_pcm_hw_params_test_period_size( self->pcm, hwParams, framesPerHostBuffer + framesPerUserBuffer, 0 ) == 0 ) + framesPerHostBuffer += framesPerUserBuffer; + else if( snd_pcm_hw_params_test_period_size( self->pcm, hwParams, framesPerHostBuffer - framesPerUserBuffer, 0 ) == 0 ) + framesPerHostBuffer -= framesPerUserBuffer; + } + } + } + else + { + framesPerHostBuffer = bufferSize / numPeriods; + } + } + + assert( framesPerHostBuffer > 0 ); + { + snd_pcm_uframes_t min = 0, max = 0; + ENSURE_( snd_pcm_hw_params_get_period_size_min( hwParams, &min, NULL ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_get_period_size_max( hwParams, &max, NULL ), paUnanticipatedHostError ); + + if( framesPerHostBuffer < min ) + { + framesPerHostBuffer = min; + PA_DEBUG(( "%s: The determined period size (%lu) is less than minimum (%lu)\n", __FUNCTION__, + framesPerHostBuffer, min )); + } + else if( framesPerHostBuffer > max ) + { + framesPerHostBuffer = max; + PA_DEBUG(( "%s: The determined period size (%lu) is greater than maximum (%lu)\n", __FUNCTION__, + framesPerHostBuffer, max )); + } + + assert( framesPerHostBuffer >= min && framesPerHostBuffer <= max ); + dir = 0; + ENSURE_( snd_pcm_hw_params_set_period_size_near( self->pcm, hwParams, &framesPerHostBuffer, &dir ), + paUnanticipatedHostError ); + if( dir != 0 ) + { + PA_DEBUG(( "%s: The configured period size is non-integer.\n", __FUNCTION__, dir )); + *accurate = 0; + } + } + self->framesPerBuffer = framesPerHostBuffer; + +error: + return result; +} + +/* We need to determine how many frames per host buffer (period) to use. Our + * goals are to provide the best possible performance, but also to + * honor the requested latency settings as closely as we can. Therefore this + * decision is based on: + * + * - the period sizes that playback and/or capture support. The + * host buffer size has to be one of these. + * - the number of periods that playback and/or capture support. + * + * We want to make period_size*(num_periods-1) to be as close as possible + * to latency*rate for both playback and capture. + * + * This method will determine suitable period sizes for capture and playback handles, and report the maximum number of + * frames per host buffer. The latter is relevant, in case we should be so unfortunate that the period size differs + * between capture and playback. If this should happen, the stream's hostBufferSizeMode attribute will be set to + * paUtilBoundedHostBufferSize, because the best we can do is limit the size of individual host buffers to the upper + * bound. The size of host buffers scheduled for processing should only matter if the user has specified a buffer size, + * but when he/she does we must strive for an optimal configuration. By default we'll opt for a fixed host buffer size, + * which should be fine if the period size is the same for capture and playback. In general, if there is a specified user + * buffer size, this method tries it best to determine a period size which is a multiple of the user buffer size. + * + * The framesPerBuffer attributes of the individual capture and playback components of the stream are set to corresponding + * values determined here. Since these should be reported as + * + * This is one of those blocks of code that will just take a lot of + * refinement to be any good. + * + * In the full-duplex case it is possible that the routine was unable + * to find a number of frames per buffer acceptable to both devices + * TODO: Implement an algorithm to find the value closest to acceptance + * by both devices, to minimize difference between period sizes? + * + * @param determinedFramesPerHostBuffer: The determined host buffer size. + */ +static PaError PaAlsaStream_DetermineFramesPerBuffer( PaAlsaStream* self, double sampleRate, const PaStreamParameters* inputParameters, + const PaStreamParameters* outputParameters, unsigned long framesPerUserBuffer, snd_pcm_hw_params_t* hwParamsCapture, + snd_pcm_hw_params_t* hwParamsPlayback, PaUtilHostBufferSizeMode* hostBufferSizeMode ) +{ + PaError result = paNoError; + unsigned long framesPerHostBuffer = 0; + int dir = 0; + int accurate = 1; + + if( self->capture.pcm && self->playback.pcm ) + { + if( framesPerUserBuffer == paFramesPerBufferUnspecified ) + { + snd_pcm_uframes_t desiredLatency, e, minPeriodSize, maxPeriodSize, optimalPeriodSize, periodSize, + minCapture, minPlayback, maxCapture, maxPlayback; + + /* Come up with a common desired latency */ + + dir = 0; + ENSURE_( snd_pcm_hw_params_get_period_size_min( hwParamsCapture, &minCapture, &dir ), paUnanticipatedHostError ); + dir = 0; + ENSURE_( snd_pcm_hw_params_get_period_size_min( hwParamsPlayback, &minPlayback, &dir ), paUnanticipatedHostError ); + dir = 0; + ENSURE_( snd_pcm_hw_params_get_period_size_max( hwParamsCapture, &maxCapture, &dir ), paUnanticipatedHostError ); + dir = 0; + ENSURE_( snd_pcm_hw_params_get_period_size_max( hwParamsPlayback, &maxPlayback, &dir ), paUnanticipatedHostError ); + minPeriodSize = PA_MAX( minPlayback, minCapture ); + maxPeriodSize = PA_MIN( maxPlayback, maxCapture ); + PA_UNLESS( minPeriodSize <= maxPeriodSize, paBadIODeviceCombination ); + + desiredLatency = (snd_pcm_uframes_t)(PA_MIN( outputParameters->suggestedLatency, inputParameters->suggestedLatency ) + * sampleRate); + /* Clamp desiredLatency */ + { + snd_pcm_uframes_t maxBufferSize; + snd_pcm_uframes_t maxBufferSizeCapture, maxBufferSizePlayback; + ENSURE_( snd_pcm_hw_params_get_buffer_size_max( hwParamsCapture, &maxBufferSizeCapture ), paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_get_buffer_size_max( hwParamsPlayback, &maxBufferSizePlayback ), paUnanticipatedHostError ); + maxBufferSize = PA_MIN( maxBufferSizeCapture, maxBufferSizePlayback ); + + desiredLatency = PA_MIN( desiredLatency, maxBufferSize ); + } + + /* Find the closest power of 2 */ + e = ilogb( minPeriodSize ); + if( minPeriodSize & (minPeriodSize - 1) ) + e += 1; + periodSize = (snd_pcm_uframes_t)pow( 2, e ); + + while( periodSize <= maxPeriodSize ) + { + if( snd_pcm_hw_params_test_period_size( self->playback.pcm, hwParamsPlayback, periodSize, 0 ) >= 0 && + snd_pcm_hw_params_test_period_size( self->capture.pcm, hwParamsCapture, periodSize, 0 ) >= 0 ) + break; /* Ok! */ + + periodSize *= 2; + } + + /* 4 periods considered optimal */ + optimalPeriodSize = PA_MAX( desiredLatency / 4, minPeriodSize ); + optimalPeriodSize = PA_MIN( optimalPeriodSize, maxPeriodSize ); + + /* Find the closest power of 2 */ + e = ilogb( optimalPeriodSize ); + if( optimalPeriodSize & (optimalPeriodSize - 1) ) + e += 1; + optimalPeriodSize = (snd_pcm_uframes_t)pow( 2, e ); + + while( optimalPeriodSize >= periodSize ) + { + if( snd_pcm_hw_params_test_period_size( self->capture.pcm, hwParamsCapture, optimalPeriodSize, 0 ) < 0 ) + continue; + if( snd_pcm_hw_params_test_period_size( self->playback.pcm, hwParamsPlayback, optimalPeriodSize, 0 ) >= 0 ) + break; + optimalPeriodSize /= 2; + } + if( optimalPeriodSize > periodSize ) + periodSize = optimalPeriodSize; + + if( periodSize <= maxPeriodSize ) + { + /* Looks good, the periodSize _should_ be acceptable by both devices */ + ENSURE_( snd_pcm_hw_params_set_period_size( self->capture.pcm, hwParamsCapture, periodSize, 0 ), + paUnanticipatedHostError ); + ENSURE_( snd_pcm_hw_params_set_period_size( self->playback.pcm, hwParamsPlayback, periodSize, 0 ), + paUnanticipatedHostError ); + self->capture.framesPerBuffer = self->playback.framesPerBuffer = periodSize; + framesPerHostBuffer = periodSize; + } + else + { + /* Unable to find a common period size, oh well */ + optimalPeriodSize = PA_MAX( desiredLatency / 4, minPeriodSize ); + optimalPeriodSize = PA_MIN( optimalPeriodSize, maxPeriodSize ); + + self->capture.framesPerBuffer = optimalPeriodSize; + dir = 0; + ENSURE_( snd_pcm_hw_params_set_period_size_near( self->capture.pcm, hwParamsCapture, &self->capture.framesPerBuffer, &dir ), + paUnanticipatedHostError ); + self->playback.framesPerBuffer = optimalPeriodSize; + dir = 0; + ENSURE_( snd_pcm_hw_params_set_period_size_near( self->playback.pcm, hwParamsPlayback, &self->playback.framesPerBuffer, &dir ), + paUnanticipatedHostError ); + framesPerHostBuffer = PA_MAX( self->capture.framesPerBuffer, self->playback.framesPerBuffer ); + *hostBufferSizeMode = paUtilBoundedHostBufferSize; + } + } + else + { + /* We choose the simple route and determine a suitable number of frames per buffer for one component of + * the stream, then we hope that this will work for the other component too (it should!). + */ + + unsigned maxPeriods = 0; + PaAlsaStreamComponent* first = &self->capture, * second = &self->playback; + const PaStreamParameters* firstStreamParams = inputParameters; + snd_pcm_hw_params_t* firstHwParams = hwParamsCapture, * secondHwParams = hwParamsPlayback; + + dir = 0; + ENSURE_( snd_pcm_hw_params_get_periods_max( hwParamsPlayback, &maxPeriods, &dir ), paUnanticipatedHostError ); + if( maxPeriods < 4 ) + { + /* The playback component is trickier to get right, try that first */ + first = &self->playback; + second = &self->capture; + firstStreamParams = outputParameters; + firstHwParams = hwParamsPlayback; + secondHwParams = hwParamsCapture; + } + + PA_ENSURE( PaAlsaStreamComponent_DetermineFramesPerBuffer( first, firstStreamParams, framesPerUserBuffer, + sampleRate, firstHwParams, &accurate ) ); + + second->framesPerBuffer = first->framesPerBuffer; + dir = 0; + ENSURE_( snd_pcm_hw_params_set_period_size_near( second->pcm, secondHwParams, &second->framesPerBuffer, &dir ), + paUnanticipatedHostError ); + if( self->capture.framesPerBuffer == self->playback.framesPerBuffer ) + { + framesPerHostBuffer = self->capture.framesPerBuffer; + } + else + { + framesPerHostBuffer = PA_MAX( self->capture.framesPerBuffer, self->playback.framesPerBuffer ); + *hostBufferSizeMode = paUtilBoundedHostBufferSize; + } + } + } + else /* half-duplex is a slightly simpler case */ + { + if( self->capture.pcm ) + { + PA_ENSURE( PaAlsaStreamComponent_DetermineFramesPerBuffer( &self->capture, inputParameters, framesPerUserBuffer, + sampleRate, hwParamsCapture, &accurate) ); + framesPerHostBuffer = self->capture.framesPerBuffer; + } + else + { + assert( self->playback.pcm ); + PA_ENSURE( PaAlsaStreamComponent_DetermineFramesPerBuffer( &self->playback, outputParameters, framesPerUserBuffer, + sampleRate, hwParamsPlayback, &accurate ) ); + framesPerHostBuffer = self->playback.framesPerBuffer; + } + } + + PA_UNLESS( framesPerHostBuffer != 0, paInternalError ); + self->maxFramesPerHostBuffer = framesPerHostBuffer; + + if( !accurate ) + { + /* Don't know the exact size per host buffer */ + *hostBufferSizeMode = paUtilBoundedHostBufferSize; + /* Raise upper bound */ + ++self->maxFramesPerHostBuffer; + } + +error: + return result; +} + +/** Set up ALSA stream parameters. + * + */ +static PaError PaAlsaStream_Configure( PaAlsaStream *self, const PaStreamParameters *inParams, const PaStreamParameters* + outParams, double sampleRate, unsigned long framesPerUserBuffer, double* inputLatency, double* outputLatency, + PaUtilHostBufferSizeMode* hostBufferSizeMode ) +{ + PaError result = paNoError; + double realSr = sampleRate; + snd_pcm_hw_params_t* hwParamsCapture, * hwParamsPlayback; + + snd_pcm_hw_params_alloca( &hwParamsCapture ); + snd_pcm_hw_params_alloca( &hwParamsPlayback ); + + if( self->capture.pcm ) + PA_ENSURE( PaAlsaStreamComponent_InitialConfigure( &self->capture, inParams, self->primeBuffers, hwParamsCapture, + &realSr ) ); + if( self->playback.pcm ) + PA_ENSURE( PaAlsaStreamComponent_InitialConfigure( &self->playback, outParams, self->primeBuffers, hwParamsPlayback, + &realSr ) ); + + PA_ENSURE( PaAlsaStream_DetermineFramesPerBuffer( self, realSr, inParams, outParams, framesPerUserBuffer, + hwParamsCapture, hwParamsPlayback, hostBufferSizeMode ) ); + + if( self->capture.pcm ) + { + assert( self->capture.framesPerBuffer != 0 ); + PA_ENSURE( PaAlsaStreamComponent_FinishConfigure( &self->capture, hwParamsCapture, inParams, self->primeBuffers, realSr, + inputLatency ) ); + PA_DEBUG(( "%s: Capture period size: %lu, latency: %f\n", __FUNCTION__, self->capture.framesPerBuffer, *inputLatency )); + } + if( self->playback.pcm ) + { + assert( self->playback.framesPerBuffer != 0 ); + PA_ENSURE( PaAlsaStreamComponent_FinishConfigure( &self->playback, hwParamsPlayback, outParams, self->primeBuffers, realSr, + outputLatency ) ); + PA_DEBUG(( "%s: Playback period size: %lu, latency: %f\n", __FUNCTION__, self->playback.framesPerBuffer, *outputLatency )); + } + + /* Should be exact now */ + self->streamRepresentation.streamInfo.sampleRate = realSr; + + /* this will cause the two streams to automatically start/stop/prepare in sync. + * We only need to execute these operations on one of the pair. + * A: We don't want to do this on a blocking stream. + */ + if( self->callbackMode && self->capture.pcm && self->playback.pcm ) + { + int err = snd_pcm_link( self->capture.pcm, self->playback.pcm ); + if( err == 0 ) + self->pcmsSynced = 1; + else + PA_DEBUG(( "%s: Unable to sync pcms: %s\n", __FUNCTION__, snd_strerror( err ) )); + } + + { + unsigned long minFramesPerHostBuffer = PA_MIN( self->capture.pcm ? self->capture.framesPerBuffer : ULONG_MAX, + self->playback.pcm ? self->playback.framesPerBuffer : ULONG_MAX ); + self->pollTimeout = CalculatePollTimeout( self, minFramesPerHostBuffer ); /* Period in msecs, rounded up */ + + /* Time before watchdog unthrottles realtime thread == 1/4 of period time in msecs */ + /* self->threading.throttledSleepTime = (unsigned long) (minFramesPerHostBuffer / sampleRate / 4 * 1000); */ + } + + if( self->callbackMode ) + { + /* If the user expects a certain number of frames per callback we will either have to rely on block adaption + * (framesPerHostBuffer is not an integer multiple of framesPerBuffer) or we can simply align the number + * of host buffer frames with what the user specified */ + if( self->framesPerUserBuffer != paFramesPerBufferUnspecified ) + { + /* self->alignFrames = 1; */ + + /* Unless the ratio between number of host and user buffer frames is an integer we will have to rely + * on block adaption */ + /* + if( framesPerHostBuffer % framesPerBuffer != 0 || (self->capture.pcm && self->playback.pcm && + self->capture.framesPerBuffer != self->playback.framesPerBuffer) ) + self->useBlockAdaption = 1; + else + self->alignFrames = 1; + */ + } + } + +error: + return result; +} + +static PaError OpenStream( struct PaUtilHostApiRepresentation *hostApi, + PaStream** s, + const PaStreamParameters *inputParameters, + const PaStreamParameters *outputParameters, + double sampleRate, + unsigned long framesPerBuffer, + PaStreamFlags streamFlags, + PaStreamCallback* callback, + void *userData ) +{ + PaError result = paNoError; + PaAlsaHostApiRepresentation *alsaHostApi = (PaAlsaHostApiRepresentation*)hostApi; + PaAlsaStream *stream = NULL; + PaSampleFormat hostInputSampleFormat = 0, hostOutputSampleFormat = 0; + PaSampleFormat inputSampleFormat = 0, outputSampleFormat = 0; + int numInputChannels = 0, numOutputChannels = 0; + PaTime inputLatency, outputLatency; + /* Operate with fixed host buffer size by default, since other modes will invariably lead to block adaption */ + /* XXX: Use Bounded by default? Output tends to get stuttery with Fixed ... */ + PaUtilHostBufferSizeMode hostBufferSizeMode = paUtilFixedHostBufferSize; + + if( (streamFlags & paPlatformSpecificFlags) != 0 ) + return paInvalidFlag; + + if( inputParameters ) + { + PA_ENSURE( ValidateParameters( inputParameters, hostApi, StreamDirection_In ) ); + + numInputChannels = inputParameters->channelCount; + inputSampleFormat = inputParameters->sampleFormat; + } + if( outputParameters ) + { + PA_ENSURE( ValidateParameters( outputParameters, hostApi, StreamDirection_Out ) ); + + numOutputChannels = outputParameters->channelCount; + outputSampleFormat = outputParameters->sampleFormat; + } + + /* XXX: Why do we support this anyway? */ + if( framesPerBuffer == paFramesPerBufferUnspecified && getenv( "PA_ALSA_PERIODSIZE" ) != NULL ) + { + PA_DEBUG(( "%s: Getting framesPerBuffer from environment\n", __FUNCTION__ )); + framesPerBuffer = atoi( getenv("PA_ALSA_PERIODSIZE") ); + } + + PA_UNLESS( stream = (PaAlsaStream*)PaUtil_AllocateMemory( sizeof(PaAlsaStream) ), paInsufficientMemory ); + PA_ENSURE( PaAlsaStream_Initialize( stream, alsaHostApi, inputParameters, outputParameters, sampleRate, + framesPerBuffer, callback, streamFlags, userData ) ); + + PA_ENSURE( PaAlsaStream_Configure( stream, inputParameters, outputParameters, sampleRate, framesPerBuffer, + &inputLatency, &outputLatency, &hostBufferSizeMode ) ); + hostInputSampleFormat = stream->capture.hostSampleFormat; + hostOutputSampleFormat = stream->playback.hostSampleFormat; + + PA_ENSURE( PaUtil_InitializeBufferProcessor( &stream->bufferProcessor, + numInputChannels, inputSampleFormat, hostInputSampleFormat, + numOutputChannels, outputSampleFormat, hostOutputSampleFormat, + sampleRate, streamFlags, framesPerBuffer, stream->maxFramesPerHostBuffer, + hostBufferSizeMode, callback, userData ) ); + + /* Ok, buffer processor is initialized, now we can deduce it's latency */ + if( numInputChannels > 0 ) + stream->streamRepresentation.streamInfo.inputLatency = inputLatency + PaUtil_GetBufferProcessorInputLatency( + &stream->bufferProcessor ); + if( numOutputChannels > 0 ) + stream->streamRepresentation.streamInfo.outputLatency = outputLatency + PaUtil_GetBufferProcessorOutputLatency( + &stream->bufferProcessor ); + + *s = (PaStream*)stream; + + return result; + +error: + if( stream ) + { + PA_DEBUG(( "%s: Stream in error, terminating\n", __FUNCTION__ )); + PaAlsaStream_Terminate( stream ); + } + + return result; +} + +static PaError CloseStream( PaStream* s ) +{ + PaError result = paNoError; + PaAlsaStream *stream = (PaAlsaStream*)s; + + PaUtil_TerminateBufferProcessor( &stream->bufferProcessor ); + PaUtil_TerminateStreamRepresentation( &stream->streamRepresentation ); + + PaAlsaStream_Terminate( stream ); + + return result; +} + +static void SilenceBuffer( PaAlsaStream *stream ) +{ + const snd_pcm_channel_area_t *areas; + snd_pcm_uframes_t frames = (snd_pcm_uframes_t)snd_pcm_avail_update( stream->playback.pcm ), offset; + + snd_pcm_mmap_begin( stream->playback.pcm, &areas, &offset, &frames ); + snd_pcm_areas_silence( areas, offset, stream->playback.numHostChannels, frames, stream->playback.nativeFormat ); + snd_pcm_mmap_commit( stream->playback.pcm, offset, frames ); +} + +/** Start/prepare pcm(s) for streaming. + * + * Depending on wether the stream is in callback or blocking mode, we will respectively start or simply + * prepare the playback pcm. If the buffer has _not_ been primed, we will in callback mode prepare and + * silence the buffer before starting playback. In blocking mode we simply prepare, as the playback will + * be started automatically as the user writes to output. + * + * The capture pcm, however, will simply be prepared and started. + */ +static PaError AlsaStart( PaAlsaStream *stream, int priming ) +{ + PaError result = paNoError; + + if( stream->playback.pcm ) + { + if( stream->callbackMode ) + { + if( !priming ) + { + /* Buffer isn't primed, so prepare and silence */ + ENSURE_( snd_pcm_prepare( stream->playback.pcm ), paUnanticipatedHostError ); + SilenceBuffer( stream ); + } + ENSURE_( snd_pcm_start( stream->playback.pcm ), paUnanticipatedHostError ); + } + else + ENSURE_( snd_pcm_prepare( stream->playback.pcm ), paUnanticipatedHostError ); + } + if( stream->capture.pcm && !stream->pcmsSynced ) + { + ENSURE_( snd_pcm_prepare( stream->capture.pcm ), paUnanticipatedHostError ); + /* For a blocking stream we want to start capture as well, since nothing will happen otherwise */ + ENSURE_( snd_pcm_start( stream->capture.pcm ), paUnanticipatedHostError ); + } + +end: + return result; +error: + goto end; +} + +/** Utility function for determining if pcms are in running state. + * + */ +#if 0 +static int IsRunning( PaAlsaStream *stream ) +{ + int result = 0; + + PA_ENSURE( PaUnixMutex_Lock( &stream->stateMtx ) ); + if( stream->capture.pcm ) + { + snd_pcm_state_t capture_state = snd_pcm_state( stream->capture.pcm ); + + if( capture_state == SND_PCM_STATE_RUNNING || capture_state == SND_PCM_STATE_XRUN + || capture_state == SND_PCM_STATE_DRAINING ) + { + result = 1; + goto end; + } + } + + if( stream->playback.pcm ) + { + snd_pcm_state_t playback_state = snd_pcm_state( stream->playback.pcm ); + + if( playback_state == SND_PCM_STATE_RUNNING || playback_state == SND_PCM_STATE_XRUN + || playback_state == SND_PCM_STATE_DRAINING ) + { + result = 1; + goto end; + } + } + +end: + ASSERT_CALL_( PaUnixMutex_Unlock( &stream->stateMtx ), paNoError ); + return result; +error: + goto error; +} +#endif + +static PaError StartStream( PaStream *s ) +{ + PaError result = paNoError; + PaAlsaStream* stream = (PaAlsaStream*)s; + int streamStarted = 0; /* So we can know wether we need to take the stream down */ + + /* Ready the processor */ + PaUtil_ResetBufferProcessor( &stream->bufferProcessor ); + + /* Set now, so we can test for activity further down */ + stream->isActive = 1; + + if( stream->callbackMode ) + { + PA_ENSURE( PaUnixThread_New( &stream->thread, &CallbackThreadFunc, stream, 1., 0 ) ); + } + else + { + PA_ENSURE( AlsaStart( stream, 0 ) ); + streamStarted = 1; + } + +end: + return result; +error: + if( streamStarted ) + { + AbortStream( stream ); + } + stream->isActive = 0; + + goto end; +} + +/** Stop PCM handle, either softly or abruptly. + */ +static PaError AlsaStop( PaAlsaStream *stream, int abort ) +{ + PaError result = paNoError; + + if( abort ) + { + if( stream->playback.pcm ) + { + ENSURE_( snd_pcm_drop( stream->playback.pcm ), paUnanticipatedHostError ); + } + if( stream->capture.pcm && !stream->pcmsSynced ) + { + ENSURE_( snd_pcm_drop( stream->capture.pcm ), paUnanticipatedHostError ); + } + + PA_DEBUG(( "%s: Dropped frames\n", __FUNCTION__ )); + } + else + { + if( stream->playback.pcm ) + { + ENSURE_( snd_pcm_nonblock( stream->playback.pcm, 0 ), paUnanticipatedHostError ); + if( snd_pcm_drain( stream->playback.pcm ) < 0 ) + { + PA_DEBUG(( "%s: Draining playback handle failed!\n", __FUNCTION__ )); + } + } + if( stream->capture.pcm && !stream->pcmsSynced ) + { + /* We don't need to retrieve any remaining frames */ + if( snd_pcm_drop( stream->capture.pcm ) < 0 ) + { + PA_DEBUG(( "%s: Draining capture handle failed!\n", __FUNCTION__ )); + } + } + } + +end: + return result; +error: + goto end; +} + +/** Stop or abort stream. + * + * If a stream is in callback mode we will have to inspect wether the background thread has + * finished, or we will have to take it out. In either case we join the thread before + * returning. In blocking mode, we simply tell ALSA to stop abruptly (abort) or finish + * buffers (drain) + * + * Stream will be considered inactive (!PaAlsaStream::isActive) after a call to this function + */ +static PaError RealStop( PaAlsaStream *stream, int abort ) +{ + PaError result = paNoError; + + /* First deal with the callback thread, cancelling and/or joining + * it if necessary + */ + if( stream->callbackMode ) + { + PaError threadRes; + stream->callbackAbort = abort; + + if( !abort ) + { + PA_DEBUG(( "Stopping callback\n" )); + } + PA_ENSURE( PaUnixThread_Terminate( &stream->thread, !abort, &threadRes ) ); + if( threadRes != paNoError ) + { + PA_DEBUG(( "Callback thread returned: %d\n", threadRes )); + } +#if 0 + if( watchdogRes != paNoError ) + PA_DEBUG(( "Watchdog thread returned: %d\n", watchdogRes )); +#endif + + stream->callback_finished = 0; + } + else + { + PA_ENSURE( AlsaStop( stream, abort ) ); + } + + stream->isActive = 0; + +end: + return result; + +error: + goto end; +} + +static PaError StopStream( PaStream *s ) +{ + return RealStop( (PaAlsaStream *) s, 0 ); +} + +static PaError AbortStream( PaStream *s ) +{ + return RealStop( (PaAlsaStream * ) s, 1 ); +} + +/** The stream is considered stopped before StartStream, or AFTER a call to Abort/StopStream (callback + * returning !paContinue is not considered) + * + */ +static PaError IsStreamStopped( PaStream *s ) +{ + PaAlsaStream *stream = (PaAlsaStream *)s; + + /* callback_finished indicates we need to join callback thread (ie. in Abort/StopStream) */ + return !IsStreamActive( s ) && !stream->callback_finished; +} + +static PaError IsStreamActive( PaStream *s ) +{ + PaAlsaStream *stream = (PaAlsaStream*)s; + return stream->isActive; +} + +static PaTime GetStreamTime( PaStream *s ) +{ + PaAlsaStream *stream = (PaAlsaStream*)s; + + snd_timestamp_t timestamp; + snd_pcm_status_t* status; + snd_pcm_status_alloca( &status ); + + /* TODO: what if we have both? does it really matter? */ + + /* TODO: if running in callback mode, this will mean + * libasound routines are being called from multiple threads. + * need to verify that libasound is thread-safe. */ + + if( stream->capture.pcm ) + { + snd_pcm_status( stream->capture.pcm, status ); + } + else if( stream->playback.pcm ) + { + snd_pcm_status( stream->playback.pcm, status ); + } + + snd_pcm_status_get_tstamp( status, ×tamp ); + return timestamp.tv_sec + (PaTime)timestamp.tv_usec / 1e6; +} + +static double GetStreamCpuLoad( PaStream* s ) +{ + PaAlsaStream *stream = (PaAlsaStream*)s; + + return PaUtil_GetCpuLoad( &stream->cpuLoadMeasurer ); +} + +static int SetApproximateSampleRate( snd_pcm_t *pcm, snd_pcm_hw_params_t *hwParams, double sampleRate ) +{ + unsigned long approx = (unsigned long) sampleRate; + int dir = 0; + double fraction = sampleRate - approx; + + assert( pcm && hwParams ); + + if( fraction > 0.0 ) + { + if( fraction > 0.5 ) + { + ++approx; + dir = -1; + } + else + dir = 1; + } + + return snd_pcm_hw_params_set_rate( pcm, hwParams, approx, dir ); +} + +/* Return exact sample rate in param sampleRate */ +static int GetExactSampleRate( snd_pcm_hw_params_t *hwParams, double *sampleRate ) +{ + unsigned int num, den; + int err; + + assert( hwParams ); + + err = snd_pcm_hw_params_get_rate_numden( hwParams, &num, &den ); + *sampleRate = (double) num / den; + + return err; +} + +/* Utility functions for blocking/callback interfaces */ + +/* Atomic restart of stream (we don't want the intermediate state visible) */ +static PaError AlsaRestart( PaAlsaStream *stream ) +{ + PaError result = paNoError; + + PA_ENSURE( PaUnixMutex_Lock( &stream->stateMtx ) ); + PA_ENSURE( AlsaStop( stream, 0 ) ); + PA_ENSURE( AlsaStart( stream, 0 ) ); + + PA_DEBUG(( "%s: Restarted audio\n", __FUNCTION__ )); + +error: + PA_ENSURE( PaUnixMutex_Unlock( &stream->stateMtx ) ); + + return result; +} + +/** Recover from xrun state. + * + */ +static PaError PaAlsaStream_HandleXrun( PaAlsaStream *self ) +{ + PaError result = paNoError; + snd_pcm_status_t *st; + PaTime now = PaUtil_GetTime(); + snd_timestamp_t t; + + snd_pcm_status_alloca( &st ); + + if( self->playback.pcm ) + { + snd_pcm_status( self->playback.pcm, st ); + if( snd_pcm_status_get_state( st ) == SND_PCM_STATE_XRUN ) + { + snd_pcm_status_get_trigger_tstamp( st, &t ); + self->underrun = now * 1000 - ((PaTime) t.tv_sec * 1000 + (PaTime) t.tv_usec / 1000); + } + } + if( self->capture.pcm ) + { + snd_pcm_status( self->capture.pcm, st ); + if( snd_pcm_status_get_state( st ) == SND_PCM_STATE_XRUN ) + { + snd_pcm_status_get_trigger_tstamp( st, &t ); + self->overrun = now * 1000 - ((PaTime) t.tv_sec * 1000 + (PaTime) t.tv_usec / 1000); + } + } + + PA_ENSURE( AlsaRestart( self ) ); + +end: + return result; +error: + goto end; +} + +/** Decide if we should continue polling for specified direction, eventually adjust the poll timeout. + * + */ +static PaError ContinuePoll( const PaAlsaStream *stream, StreamDirection streamDir, int *pollTimeout, int *continuePoll ) +{ + PaError result = paNoError; + snd_pcm_sframes_t delay, margin; + int err; + const PaAlsaStreamComponent *component = NULL, *otherComponent = NULL; + + *continuePoll = 1; + + if( StreamDirection_In == streamDir ) + { + component = &stream->capture; + otherComponent = &stream->playback; + } + else + { + component = &stream->playback; + otherComponent = &stream->capture; + } + + /* ALSA docs say that negative delay should indicate xrun, but in my experience snd_pcm_delay returns -EPIPE */ + if( (err = snd_pcm_delay( otherComponent->pcm, &delay )) < 0 ) + { + if( err == -EPIPE ) + { + /* Xrun */ + *continuePoll = 0; + goto error; + } + + ENSURE_( err, paUnanticipatedHostError ); + } + + if( StreamDirection_Out == streamDir ) + { + /* Number of eligible frames before capture overrun */ + delay = otherComponent->bufferSize - delay; + } + margin = delay - otherComponent->framesPerBuffer / 2; + + if( margin < 0 ) + { + PA_DEBUG(( "%s: Stopping poll for %s\n", __FUNCTION__, StreamDirection_In == streamDir ? "capture" : "playback" )); + *continuePoll = 0; + } + else if( margin < otherComponent->framesPerBuffer ) + { + *pollTimeout = CalculatePollTimeout( stream, margin ); + PA_DEBUG(( "%s: Trying to poll again for %s frames, pollTimeout: %d\n", + __FUNCTION__, StreamDirection_In == streamDir ? "capture" : "playback", *pollTimeout )); + } + +error: + return result; +} + +/* Callback interface */ + +static void OnExit( void *data ) +{ + PaAlsaStream *stream = (PaAlsaStream *) data; + + assert( data ); + + PaUtil_ResetCpuLoadMeasurer( &stream->cpuLoadMeasurer ); + + stream->callback_finished = 1; /* Let the outside world know stream was stopped in callback */ + PA_DEBUG(( "%s: Stopping ALSA handles\n", __FUNCTION__ )); + AlsaStop( stream, stream->callbackAbort ); + + PA_DEBUG(( "%s: Stoppage\n", __FUNCTION__ )); + + /* Eventually notify user all buffers have played */ + if( stream->streamRepresentation.streamFinishedCallback ) + { + stream->streamRepresentation.streamFinishedCallback( stream->streamRepresentation.userData ); + } + stream->isActive = 0; +} + +static void CalculateTimeInfo( PaAlsaStream *stream, PaStreamCallbackTimeInfo *timeInfo ) +{ + snd_pcm_status_t *capture_status, *playback_status; + snd_timestamp_t capture_timestamp, playback_timestamp; + PaTime capture_time = 0., playback_time = 0.; + + snd_pcm_status_alloca( &capture_status ); + snd_pcm_status_alloca( &playback_status ); + + if( stream->capture.pcm ) + { + snd_pcm_sframes_t capture_delay; + + snd_pcm_status( stream->capture.pcm, capture_status ); + snd_pcm_status_get_tstamp( capture_status, &capture_timestamp ); + + capture_time = capture_timestamp.tv_sec + + ((PaTime)capture_timestamp.tv_usec / 1000000.0); + timeInfo->currentTime = capture_time; + + capture_delay = snd_pcm_status_get_delay( capture_status ); + timeInfo->inputBufferAdcTime = timeInfo->currentTime - + (PaTime)capture_delay / stream->streamRepresentation.streamInfo.sampleRate; + } + if( stream->playback.pcm ) + { + snd_pcm_sframes_t playback_delay; + + snd_pcm_status( stream->playback.pcm, playback_status ); + snd_pcm_status_get_tstamp( playback_status, &playback_timestamp ); + + playback_time = playback_timestamp.tv_sec + + ((PaTime)playback_timestamp.tv_usec / 1000000.0); + + if( stream->capture.pcm ) /* Full duplex */ + { + /* Hmm, we have both a playback and a capture timestamp. + * Hopefully they are the same... */ + if( fabs( capture_time - playback_time ) > 0.01 ) + PA_DEBUG(("Capture time and playback time differ by %f\n", fabs(capture_time-playback_time))); + } + else + timeInfo->currentTime = playback_time; + + playback_delay = snd_pcm_status_get_delay( playback_status ); + timeInfo->outputBufferDacTime = timeInfo->currentTime + + (PaTime)playback_delay / stream->streamRepresentation.streamInfo.sampleRate; + } +} + +/** Called after buffer processing is finished. + * + * A number of mmapped frames is committed, it is possible that an xrun has occurred in the meantime. + * + * @param numFrames The number of frames that has been processed + * @param xrun Return whether an xrun has occurred + */ +static PaError PaAlsaStreamComponent_EndProcessing( PaAlsaStreamComponent *self, unsigned long numFrames, int *xrun ) +{ + PaError result = paNoError; + int res; + + /* @concern FullDuplex It is possible that only one direction is marked ready after polling, and processed + * afterwards + */ + if( !self->ready ) + goto end; + + res = snd_pcm_mmap_commit( self->pcm, self->offset, numFrames ); + if( res == -EPIPE || res == -ESTRPIPE ) + { + *xrun = 1; + } + else + { + ENSURE_( res, paUnanticipatedHostError ); + } + +end: +error: + return result; +} + +/* Extract buffer from channel area */ +static unsigned char *ExtractAddress( const snd_pcm_channel_area_t *area, snd_pcm_uframes_t offset ) +{ + return (unsigned char *) area->addr + (area->first + offset * area->step) / 8; +} + +/** Do necessary adaption between user and host channels. + * + @concern ChannelAdaption Adapting between user and host channels can involve silencing unused channels and + duplicating mono information if host outputs come in pairs. + */ +static PaError PaAlsaStreamComponent_DoChannelAdaption( PaAlsaStreamComponent *self, PaUtilBufferProcessor *bp, int numFrames ) +{ + PaError result = paNoError; + unsigned char *p; + int i; + int unusedChans = self->numHostChannels - self->numUserChannels; + unsigned char *src, *dst; + int convertMono = (self->numHostChannels % 2) == 0 && (self->numUserChannels % 2) != 0; + + assert( StreamDirection_Out == self->streamDir ); + + if( self->hostInterleaved ) + { + int swidth = snd_pcm_format_size( self->nativeFormat, 1 ); + unsigned char *buffer = ExtractAddress( self->channelAreas, self->offset ); + + /* Start after the last user channel */ + p = buffer + self->numUserChannels * swidth; + + if( convertMono ) + { + /* Convert the last user channel into stereo pair */ + src = buffer + (self->numUserChannels - 1) * swidth; + for( i = 0; i < numFrames; ++i ) + { + dst = src + swidth; + memcpy( dst, src, swidth ); + src += self->numHostChannels * swidth; + } + + /* Don't touch the channel we just wrote to */ + p += swidth; + --unusedChans; + } + + if( unusedChans > 0 ) + { + /* Silence unused output channels */ + for( i = 0; i < numFrames; ++i ) + { + memset( p, 0, swidth * unusedChans ); + p += self->numHostChannels * swidth; + } + } + } + else + { + /* We extract the last user channel */ + if( convertMono ) + { + ENSURE_( snd_pcm_area_copy( self->channelAreas + self->numUserChannels, self->offset, self->channelAreas + + (self->numUserChannels - 1), self->offset, numFrames, self->nativeFormat ), paUnanticipatedHostError ); + --unusedChans; + } + if( unusedChans > 0 ) + { + snd_pcm_areas_silence( self->channelAreas + (self->numHostChannels - unusedChans), self->offset, unusedChans, numFrames, + self->nativeFormat ); + } + } + +error: + return result; +} + +static PaError PaAlsaStream_EndProcessing( PaAlsaStream *self, unsigned long numFrames, int *xrunOccurred ) +{ + PaError result = paNoError; + int xrun = 0; + + if( self->capture.pcm ) + { + PA_ENSURE( PaAlsaStreamComponent_EndProcessing( &self->capture, numFrames, &xrun ) ); + } + if( self->playback.pcm ) + { + if( self->playback.numHostChannels > self->playback.numUserChannels ) + { + PA_ENSURE( PaAlsaStreamComponent_DoChannelAdaption( &self->playback, &self->bufferProcessor, numFrames ) ); + } + PA_ENSURE( PaAlsaStreamComponent_EndProcessing( &self->playback, numFrames, &xrun ) ); + } + +error: + *xrunOccurred = xrun; + return result; +} + +/** Update the number of available frames. + * + */ +static PaError PaAlsaStreamComponent_GetAvailableFrames( PaAlsaStreamComponent *self, unsigned long *numFrames, int *xrunOccurred ) +{ + PaError result = paNoError; + snd_pcm_sframes_t framesAvail = snd_pcm_avail_update( self->pcm ); + *xrunOccurred = 0; + + if( -EPIPE == framesAvail ) + { + *xrunOccurred = 1; + framesAvail = 0; + } + else + { + ENSURE_( framesAvail, paUnanticipatedHostError ); + } + + *numFrames = framesAvail; + +error: + return result; +} + +/** Fill in pollfd objects. + */ +static PaError PaAlsaStreamComponent_BeginPolling( PaAlsaStreamComponent* self, struct pollfd* pfds ) +{ + PaError result = paNoError; + int ret = snd_pcm_poll_descriptors( self->pcm, pfds, self->nfds ); + (void)ret; /* Prevent unused variable warning if asserts are turned off */ + assert( ret == self->nfds ); + + self->ready = 0; + + return result; +} + +/** Examine results from poll(). + * + * @param pfds pollfds to inspect + * @param shouldPoll Should we continue to poll + * @param xrun Has an xrun occurred + */ +static PaError PaAlsaStreamComponent_EndPolling( PaAlsaStreamComponent* self, struct pollfd* pfds, int* shouldPoll, int* xrun ) +{ + PaError result = paNoError; + unsigned short revents; + + ENSURE_( snd_pcm_poll_descriptors_revents( self->pcm, pfds, self->nfds, &revents ), paUnanticipatedHostError ); + if( revents != 0 ) + { + if( revents & POLLERR ) + { + *xrun = 1; + } + else + self->ready = 1; + + *shouldPoll = 0; + } + +error: + return result; +} + +/** Return the number of available frames for this stream. + * + * @concern FullDuplex The minimum available for the two directions is calculated, it might be desirable to ignore + * one direction however (not marked ready from poll), so this is controlled by queryCapture and queryPlayback. + * + * @param queryCapture Check available for capture + * @param queryPlayback Check available for playback + * @param available The returned number of frames + * @param xrunOccurred Return whether an xrun has occurred + */ +static PaError PaAlsaStream_GetAvailableFrames( PaAlsaStream *self, int queryCapture, int queryPlayback, unsigned long + *available, int *xrunOccurred ) +{ + PaError result = paNoError; + unsigned long captureFrames, playbackFrames; + *xrunOccurred = 0; + + assert( queryCapture || queryPlayback ); + + if( queryCapture ) + { + assert( self->capture.pcm ); + PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( &self->capture, &captureFrames, xrunOccurred ) ); + if( *xrunOccurred ) + { + goto end; + } + } + if( queryPlayback ) + { + assert( self->playback.pcm ); + PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( &self->playback, &playbackFrames, xrunOccurred ) ); + if( *xrunOccurred ) + { + goto end; + } + } + + if( queryCapture && queryPlayback ) + { + *available = PA_MIN( captureFrames, playbackFrames ); + /*PA_DEBUG(("capture: %lu, playback: %lu, combined: %lu\n", captureFrames, playbackFrames, *available));*/ + } + else if( queryCapture ) + { + *available = captureFrames; + } + else + { + *available = playbackFrames; + } + +end: +error: + return result; +} + +/** Wait for and report available buffer space from ALSA. + * + * Unless ALSA reports a minimum of frames available for I/O, we poll the ALSA filedescriptors for more. + * Both of these operations can uncover xrun conditions. + * + * @concern Xruns Both polling and querying available frames can report an xrun condition. + * + * @param framesAvail Return the number of available frames + * @param xrunOccurred Return whether an xrun has occurred + */ +static PaError PaAlsaStream_WaitForFrames( PaAlsaStream *self, unsigned long *framesAvail, int *xrunOccurred ) +{ + PaError result = paNoError; + int pollPlayback = self->playback.pcm != NULL, pollCapture = self->capture.pcm != NULL; + int pollTimeout = self->pollTimeout; + int xrun = 0; + + assert( self ); + assert( framesAvail ); + + if( !self->callbackMode ) + { + /* In blocking mode we will only wait if necessary */ + PA_ENSURE( PaAlsaStream_GetAvailableFrames( self, self->capture.pcm != NULL, self->playback.pcm != NULL, + framesAvail, &xrun ) ); + if( xrun ) + { + goto end; + } + + if( *framesAvail > 0 ) + { + /* Mark pcms ready from poll */ + if( self->capture.pcm ) + self->capture.ready = 1; + if( self->playback.pcm ) + self->playback.ready = 1; + + goto end; + } + } + + while( pollPlayback || pollCapture ) + { + int totalFds = 0; + struct pollfd *capturePfds = NULL, *playbackPfds = NULL; + + pthread_testcancel(); + + if( pollCapture ) + { + capturePfds = self->pfds; + PA_ENSURE( PaAlsaStreamComponent_BeginPolling( &self->capture, capturePfds ) ); + totalFds += self->capture.nfds; + } + if( pollPlayback ) + { + playbackPfds = self->pfds + (self->capture.pcm ? self->capture.nfds : 0); + PA_ENSURE( PaAlsaStreamComponent_BeginPolling( &self->playback, playbackPfds ) ); + totalFds += self->playback.nfds; + } + + if( poll( self->pfds, totalFds, pollTimeout ) < 0 ) + { + /* XXX: Depend on preprocessor condition? */ + if( errno == EINTR ) + { + /* gdb */ + continue; + } + + /* TODO: Add macro for checking system calls */ + PA_ENSURE( paInternalError ); + } + + /* check the return status of our pfds */ + if( pollCapture ) + { + PA_ENSURE( PaAlsaStreamComponent_EndPolling( &self->capture, capturePfds, &pollCapture, &xrun ) ); + } + if( pollPlayback ) + { + PA_ENSURE( PaAlsaStreamComponent_EndPolling( &self->playback, playbackPfds, &pollPlayback, &xrun ) ); + } + if( xrun ) + { + break; + } + + /* @concern FullDuplex If only one of two pcms is ready we may want to compromise between the two. + * If there is less than half a period's worth of samples left of frames in the other pcm's buffer we will + * stop polling. + */ + if( self->capture.pcm && self->playback.pcm ) + { + if( pollCapture && !pollPlayback ) + { + PA_ENSURE( ContinuePoll( self, StreamDirection_In, &pollTimeout, &pollCapture ) ); + } + else if( pollPlayback && !pollCapture ) + { + PA_ENSURE( ContinuePoll( self, StreamDirection_Out, &pollTimeout, &pollPlayback ) ); + } + } + } + + if( !xrun ) + { + /* Get the number of available frames for the pcms that are marked ready. + * @concern FullDuplex If only one direction is marked ready (from poll), the number of frames available for + * the other direction is returned. Output is normally preferred over capture however, so capture frames may be + * discarded to avoid overrun unless paNeverDropInput is specified. + */ + int captureReady = self->capture.pcm ? self->capture.ready : 0, + playbackReady = self->playback.pcm ? self->playback.ready : 0; + PA_ENSURE( PaAlsaStream_GetAvailableFrames( self, captureReady, playbackReady, framesAvail, &xrun ) ); + + if( self->capture.pcm && self->playback.pcm ) + { + if( !self->playback.ready && !self->neverDropInput ) + { + /* Drop input, a period's worth */ + assert( self->capture.ready ); + PaAlsaStreamComponent_EndProcessing( &self->capture, PA_MIN( self->capture.framesPerBuffer, + *framesAvail ), &xrun ); + *framesAvail = 0; + self->capture.ready = 0; + } + } + else if( self->capture.pcm ) + assert( self->capture.ready ); + else + assert( self->playback.ready ); + } + +end: +error: + if( xrun ) + { + /* Recover from the xrun state */ + PA_ENSURE( PaAlsaStream_HandleXrun( self ) ); + *framesAvail = 0; + } + else + { + if( 0 != *framesAvail ) + { + /* If we're reporting frames eligible for processing, one of the handles better be ready */ + PA_UNLESS( self->capture.ready || self->playback.ready, paInternalError ); + } + } + *xrunOccurred = xrun; + + return result; +} + +/** Register per-channel ALSA buffer information with buffer processor. + * + * Mmapped buffer space is acquired from ALSA, and registered with the buffer processor. Differences between the + * number of host and user channels is taken into account. + * + * @param numFrames On entrance the number of requested frames, on exit the number of contiguously accessible frames. + */ +static PaError PaAlsaStreamComponent_RegisterChannels( PaAlsaStreamComponent* self, PaUtilBufferProcessor* bp, + unsigned long* numFrames, int* xrun ) +{ + PaError result = paNoError; + const snd_pcm_channel_area_t *areas, *area; + void (*setChannel)(PaUtilBufferProcessor *, unsigned int, void *, unsigned int) = + StreamDirection_In == self->streamDir ? PaUtil_SetInputChannel : PaUtil_SetOutputChannel; + unsigned char *buffer, *p; + int i; + unsigned long framesAvail; + + /* This _must_ be called before mmap_begin */ + PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( self, &framesAvail, xrun ) ); + if( *xrun ) + { + *numFrames = 0; + goto end; + } + + ENSURE_( snd_pcm_mmap_begin( self->pcm, &areas, &self->offset, numFrames ), paUnanticipatedHostError ); + + if( self->hostInterleaved ) + { + int swidth = snd_pcm_format_size( self->nativeFormat, 1 ); + + p = buffer = ExtractAddress( areas, self->offset ); + for( i = 0; i < self->numUserChannels; ++i ) + { + /* We're setting the channels up to userChannels, but the stride will be hostChannels samples */ + setChannel( bp, i, p, self->numHostChannels ); + p += swidth; + } + } + else + { + for( i = 0; i < self->numUserChannels; ++i ) + { + area = areas + i; + buffer = ExtractAddress( area, self->offset ); + setChannel( bp, i, buffer, 1 ); + } + } + + /* @concern ChannelAdaption Buffer address is recorded so we can do some channel adaption later */ + self->channelAreas = (snd_pcm_channel_area_t *)areas; + +end: +error: + return result; +} + +/** Initiate buffer processing. + * + * ALSA buffers are registered with the PA buffer processor and the buffer size (in frames) set. + * + * @concern FullDuplex If both directions are being processed, the minimum amount of frames for the two directions is + * calculated. + * + * @param numFrames On entrance the number of available frames, on exit the number of received frames + * @param xrunOccurred Return whether an xrun has occurred + */ +static PaError PaAlsaStream_SetUpBuffers( PaAlsaStream* self, unsigned long* numFrames, int* xrunOccurred ) +{ + PaError result = paNoError; + unsigned long captureFrames = ULONG_MAX, playbackFrames = ULONG_MAX, commonFrames = 0; + int xrun = 0; + + if( *xrunOccurred ) + { + *numFrames = 0; + return result; + } + /* If we got here at least one of the pcm's should be marked ready */ + PA_UNLESS( self->capture.ready || self->playback.ready, paInternalError ); + + /* Extract per-channel ALSA buffer pointers and register them with the buffer processor. + * It is possible that a direction is not marked ready however, because it is out of sync with the other. + */ + if( self->capture.pcm && self->capture.ready ) + { + captureFrames = *numFrames; + PA_ENSURE( PaAlsaStreamComponent_RegisterChannels( &self->capture, &self->bufferProcessor, &captureFrames, + &xrun ) ); + } + if( self->playback.pcm && self->playback.ready ) + { + playbackFrames = *numFrames; + PA_ENSURE( PaAlsaStreamComponent_RegisterChannels( &self->playback, &self->bufferProcessor, &playbackFrames, + &xrun ) ); + } + if( xrun ) + { + /* Nothing more to do */ + assert( 0 == commonFrames ); + goto end; + } + + commonFrames = PA_MIN( captureFrames, playbackFrames ); + /* assert( commonFrames <= *numFrames ); */ + if( commonFrames > *numFrames ) + { + /* Hmmm ... how come there are more frames available than we requested!? Blah. */ + PA_DEBUG(( "%s: Common available frames are reported to be more than number requested: %lu, %lu, callbackMode: %d\n", __FUNCTION__, + commonFrames, *numFrames, self->callbackMode )); + if( self->capture.pcm ) + { + PA_DEBUG(( "%s: captureFrames: %lu, capture.ready: %d\n", __FUNCTION__, captureFrames, self->capture.ready )); + } + if( self->playback.pcm ) + { + PA_DEBUG(( "%s: playbackFrames: %lu, playback.ready: %d\n", __FUNCTION__, playbackFrames, self->playback.ready )); + } + + commonFrames = 0; + goto end; + } + + /* Inform PortAudio of the number of frames we got. + * @concern FullDuplex We might be experiencing underflow in either end; if its an input underflow, we go on + * with output. If its output underflow however, depending on the paNeverDropInput flag, we may want to simply + * discard the excess input or call the callback with paOutputOverflow flagged. + */ + if( self->capture.pcm ) + { + if( self->capture.ready ) + { + PaUtil_SetInputFrameCount( &self->bufferProcessor, commonFrames ); + } + else + { + /* We have input underflow */ + PaUtil_SetNoInput( &self->bufferProcessor ); + } + } + if( self->playback.pcm ) + { + if( self->playback.ready ) + { + PaUtil_SetOutputFrameCount( &self->bufferProcessor, commonFrames ); + } + else + { + /* We have output underflow, but keeping input data (paNeverDropInput) */ + assert( self->neverDropInput ); + assert( self->capture.pcm != NULL ); + PA_DEBUG(( "%s: Setting output buffers to NULL\n", __FUNCTION__ )); + PaUtil_SetNoOutput( &self->bufferProcessor ); + } + } + +end: + *numFrames = commonFrames; +error: + if( xrun ) + { + PA_ENSURE( PaAlsaStream_HandleXrun( self ) ); + *numFrames = 0; + } + *xrunOccurred = xrun; + + return result; +} + +/** Callback thread's function. + * + * Roughly, the workflow can be described in the following way: The number of available frames that can be processed + * directly is obtained from ALSA, we then request as much directly accessible memory as possible within this amount + * from ALSA. The buffer memory is registered with the PA buffer processor and processing is carried out with + * PaUtil_EndBufferProcessing. Finally, the number of processed frames is reported to ALSA. The processing can + * happen in several iterations untill we have consumed the known number of available frames (or an xrun is detected). + */ +static void *CallbackThreadFunc( void *userData ) +{ + PaError result = paNoError; + PaAlsaStream *stream = (PaAlsaStream*) userData; + PaStreamCallbackTimeInfo timeInfo = {0, 0, 0}; + snd_pcm_sframes_t startThreshold = 0; + int callbackResult = paContinue; + PaStreamCallbackFlags cbFlags = 0; /* We might want to keep state across iterations */ + int streamStarted = 0; + + assert( stream ); + + /* Execute OnExit when exiting */ + pthread_cleanup_push( &OnExit, stream ); + + /* Not implemented */ + assert( !stream->primeBuffers ); + + /* @concern StreamStart If the output is being primed the output pcm needs to be prepared, otherwise the + * stream is started immediately. The latter involves signaling the waiting main thread. + */ + if( stream->primeBuffers ) + { + snd_pcm_sframes_t avail; + + if( stream->playback.pcm ) + ENSURE_( snd_pcm_prepare( stream->playback.pcm ), paUnanticipatedHostError ); + if( stream->capture.pcm && !stream->pcmsSynced ) + ENSURE_( snd_pcm_prepare( stream->capture.pcm ), paUnanticipatedHostError ); + + /* We can't be certain that the whole ring buffer is available for priming, but there should be + * at least one period */ + avail = snd_pcm_avail_update( stream->playback.pcm ); + startThreshold = avail - (avail % stream->playback.framesPerBuffer); + assert( startThreshold >= stream->playback.framesPerBuffer ); + } + else + { + PA_ENSURE( PaUnixThread_PrepareNotify( &stream->thread ) ); + /* Buffer will be zeroed */ + PA_ENSURE( AlsaStart( stream, 0 ) ); + PA_ENSURE( PaUnixThread_NotifyParent( &stream->thread ) ); + + streamStarted = 1; + } + + while( 1 ) + { + unsigned long framesAvail, framesGot; + int xrun = 0; + + pthread_testcancel(); + + /* @concern StreamStop if the main thread has requested a stop and the stream has not been effectively + * stopped we signal this condition by modifying callbackResult (we'll want to flush buffered output). + */ + if( PaUnixThread_StopRequested( &stream->thread ) && paContinue == callbackResult ) + { + PA_DEBUG(( "Setting callbackResult to paComplete\n" )); + callbackResult = paComplete; + } + + if( paContinue != callbackResult ) + { + stream->callbackAbort = (paAbort == callbackResult); + if( stream->callbackAbort || + /** @concern BlockAdaption: Go on if adaption buffers are empty */ + PaUtil_IsBufferProcessorOutputEmpty( &stream->bufferProcessor ) ) + { + goto end; + } + + PA_DEBUG(( "%s: Flushing buffer processor\n", __FUNCTION__ )); + /* There is still buffered output that needs to be processed */ + } + + /* Wait for data to become available, this comes down to polling the ALSA file descriptors untill we have + * a number of available frames. + */ + PA_ENSURE( PaAlsaStream_WaitForFrames( stream, &framesAvail, &xrun ) ); + if( xrun ) + { + assert( 0 == framesAvail ); + continue; + + /* XXX: Report xruns to the user? A situation is conceivable where the callback is never invoked due + * to constant xruns, it might be desirable to notify the user of this. + */ + } + + /* Consume buffer space. Once we have a number of frames available for consumption we must retrieve the + * mmapped buffers from ALSA, this is contiguously accessible memory however, so we may receive smaller + * portions at a time than is available as a whole. Therefore we should be prepared to process several + * chunks successively. The buffers are passed to the PA buffer processor. + */ + while( framesAvail > 0 ) + { + xrun = 0; + + pthread_testcancel(); + + /** @concern Xruns Under/overflows are to be reported to the callback */ + if( stream->underrun > 0.0 ) + { + cbFlags |= paOutputUnderflow; + stream->underrun = 0.0; + } + if( stream->overrun > 0.0 ) + { + cbFlags |= paInputOverflow; + stream->overrun = 0.0; + } + if( stream->capture.pcm && stream->playback.pcm ) + { + /** @concern FullDuplex It's possible that only one direction is being processed to avoid an + * under- or overflow, this should be reported correspondingly */ + if( !stream->capture.ready ) + { + cbFlags |= paInputUnderflow; + PA_DEBUG(( "%s: Input underflow\n", __FUNCTION__ )); + } + else if( !stream->playback.ready ) + { + cbFlags |= paOutputOverflow; + PA_DEBUG(( "%s: Output overflow\n", __FUNCTION__ )); + } + } + +#if 0 + CallbackUpdate( &stream->threading ); +#endif + CalculateTimeInfo( stream, &timeInfo ); + PaUtil_BeginBufferProcessing( &stream->bufferProcessor, &timeInfo, cbFlags ); + cbFlags = 0; + + /* CPU load measurement should include processing activivity external to the stream callback */ + PaUtil_BeginCpuLoadMeasurement( &stream->cpuLoadMeasurer ); + + framesGot = framesAvail; + if( paUtilFixedHostBufferSize == stream->bufferProcessor.hostBufferSizeMode ) + { + /* We've committed to a fixed host buffer size, stick to that */ + framesGot = framesGot >= stream->maxFramesPerHostBuffer ? stream->maxFramesPerHostBuffer : 0; + } + else + { + /* We've committed to an upper bound on the size of host buffers */ + assert( paUtilBoundedHostBufferSize == stream->bufferProcessor.hostBufferSizeMode ); + framesGot = PA_MIN( framesGot, stream->maxFramesPerHostBuffer ); + } + PA_ENSURE( PaAlsaStream_SetUpBuffers( stream, &framesGot, &xrun ) ); + /* Check the host buffer size against the buffer processor configuration */ + framesAvail -= framesGot; + + if( framesGot > 0 ) + { + assert( !xrun ); + PaUtil_EndBufferProcessing( &stream->bufferProcessor, &callbackResult ); + PA_ENSURE( PaAlsaStream_EndProcessing( stream, framesGot, &xrun ) ); + } + PaUtil_EndCpuLoadMeasurement( &stream->cpuLoadMeasurer, framesGot ); + + if( 0 == framesGot ) + { + /* Go back to polling for more frames */ + break; + + } + + if( paContinue != callbackResult ) + break; + } + } + + /* Match pthread_cleanup_push */ + pthread_cleanup_pop( 1 ); + +end: + PA_DEBUG(( "%s: Thread %d exiting\n ", __FUNCTION__, pthread_self() )); + PaUnixThreading_EXIT( result ); +error: + goto end; +} + +/* Blocking interface */ + +static PaError ReadStream( PaStream* s, void *buffer, unsigned long frames ) +{ + PaError result = paNoError; + PaAlsaStream *stream = (PaAlsaStream*)s; + unsigned long framesGot, framesAvail; + void *userBuffer; + snd_pcm_t *save = stream->playback.pcm; + + assert( stream ); + + PA_UNLESS( stream->capture.pcm, paCanNotReadFromAnOutputOnlyStream ); + + /* Disregard playback */ + stream->playback.pcm = NULL; + + if( stream->overrun > 0. ) + { + result = paInputOverflowed; + stream->overrun = 0.0; + } + + if( stream->capture.userInterleaved ) + { + userBuffer = buffer; + } + else + { + /* Copy channels into local array */ + userBuffer = stream->capture.userBuffers; + memcpy( userBuffer, buffer, sizeof (void *) * stream->capture.numUserChannels ); + } + + /* Start stream if in prepared state */ + if( snd_pcm_state( stream->capture.pcm ) == SND_PCM_STATE_PREPARED ) + { + ENSURE_( snd_pcm_start( stream->capture.pcm ), paUnanticipatedHostError ); + } + + while( frames > 0 ) + { + int xrun = 0; + PA_ENSURE( PaAlsaStream_WaitForFrames( stream, &framesAvail, &xrun ) ); + framesGot = PA_MIN( framesAvail, frames ); + + PA_ENSURE( PaAlsaStream_SetUpBuffers( stream, &framesGot, &xrun ) ); + if( framesGot > 0 ) + { + framesGot = PaUtil_CopyInput( &stream->bufferProcessor, &userBuffer, framesGot ); + PA_ENSURE( PaAlsaStream_EndProcessing( stream, framesGot, &xrun ) ); + frames -= framesGot; + } + } + +end: + stream->playback.pcm = save; + return result; +error: + goto end; +} + +static PaError WriteStream( PaStream* s, const void *buffer, unsigned long frames ) +{ + PaError result = paNoError; + signed long err; + PaAlsaStream *stream = (PaAlsaStream*)s; + snd_pcm_uframes_t framesGot, framesAvail; + const void *userBuffer; + snd_pcm_t *save = stream->capture.pcm; + + assert( stream ); + + PA_UNLESS( stream->playback.pcm, paCanNotWriteToAnInputOnlyStream ); + + /* Disregard capture */ + stream->capture.pcm = NULL; + + if( stream->underrun > 0. ) + { + result = paOutputUnderflowed; + stream->underrun = 0.0; + } + + if( stream->playback.userInterleaved ) + userBuffer = buffer; + else /* Copy channels into local array */ + { + userBuffer = stream->playback.userBuffers; + memcpy( (void *)userBuffer, buffer, sizeof (void *) * stream->playback.numUserChannels ); + } + + while( frames > 0 ) + { + int xrun = 0; + snd_pcm_uframes_t hwAvail; + + PA_ENSURE( PaAlsaStream_WaitForFrames( stream, &framesAvail, &xrun ) ); + framesGot = PA_MIN( framesAvail, frames ); + + PA_ENSURE( PaAlsaStream_SetUpBuffers( stream, &framesGot, &xrun ) ); + if( framesGot > 0 ) + { + framesGot = PaUtil_CopyOutput( &stream->bufferProcessor, &userBuffer, framesGot ); + PA_ENSURE( PaAlsaStream_EndProcessing( stream, framesGot, &xrun ) ); + frames -= framesGot; + } + + /* Start stream after one period of samples worth */ + + /* Frames residing in buffer */ + PA_ENSURE( err = GetStreamWriteAvailable( stream ) ); + framesAvail = err; + hwAvail = stream->playback.bufferSize - framesAvail; + + if( snd_pcm_state( stream->playback.pcm ) == SND_PCM_STATE_PREPARED && + hwAvail >= stream->playback.framesPerBuffer ) + { + ENSURE_( snd_pcm_start( stream->playback.pcm ), paUnanticipatedHostError ); + } + } + +end: + stream->capture.pcm = save; + return result; +error: + goto end; +} + +/* Return frames available for reading. In the event of an overflow, the capture pcm will be restarted */ +static signed long GetStreamReadAvailable( PaStream* s ) +{ + PaError result = paNoError; + PaAlsaStream *stream = (PaAlsaStream*)s; + unsigned long avail; + int xrun; + + PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( &stream->capture, &avail, &xrun ) ); + if( xrun ) + { + PA_ENSURE( PaAlsaStream_HandleXrun( stream ) ); + PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( &stream->capture, &avail, &xrun ) ); + if( xrun ) + PA_ENSURE( paInputOverflowed ); + } + + return (signed long)avail; + +error: + return result; +} + +static signed long GetStreamWriteAvailable( PaStream* s ) +{ + PaError result = paNoError; + PaAlsaStream *stream = (PaAlsaStream*)s; + unsigned long avail; + int xrun; + + PA_ENSURE( PaAlsaStreamComponent_GetAvailableFrames( &stream->playback, &avail, &xrun ) ); + if( xrun ) + { + snd_pcm_sframes_t savail; + + PA_ENSURE( PaAlsaStream_HandleXrun( stream ) ); + savail = snd_pcm_avail_update( stream->playback.pcm ); + + /* savail should not contain -EPIPE now, since PaAlsaStream_HandleXrun will only prepare the pcm */ + ENSURE_( savail, paUnanticipatedHostError ); + + avail = (unsigned long) savail; + } + + return (signed long)avail; + +error: + return result; +} + +/* Extensions */ + +/* Initialize host api specific structure */ +void PaAlsa_InitializeStreamInfo( PaAlsaStreamInfo *info ) +{ + info->size = sizeof (PaAlsaStreamInfo); + info->hostApiType = paALSA; + info->version = 1; + info->deviceString = NULL; +} + +void PaAlsa_EnableRealtimeScheduling( PaStream *s, int enable ) +{ +#if 0 + PaAlsaStream *stream = (PaAlsaStream *) s; + stream->threading.rtSched = enable; +#endif +} + +void PaAlsa_EnableWatchdog( PaStream *s, int enable ) +{ +#if 0 + PaAlsaStream *stream = (PaAlsaStream *) s; + stream->threading.useWatchdog = enable; +#endif +} |