1 files changed, 140 insertions, 0 deletions
diff --git a/src/wavpack/bits.c b/src/wavpack/bits.c
new file mode 100644
index 00000000..dbfa0cae
--- /dev/null
+++ b/src/wavpack/bits.c
@@ -0,0 +1,140 @@
+////////////////////////////////////////////////////////////////////////////
+//                           **** WAVPACK ****                            //
+//                  Hybrid Lossless Wavefile Compressor                   //
+//              Copyright (c) 1998 - 2006 Conifer Software.               //
+//                          All Rights Reserved.                          //
+//      Distributed under the BSD Software License (see license.txt)      //
+////////////////////////////////////////////////////////////////////////////
+
+// bits.c
+
+// This module provides utilities to support the BitStream structure which is
+// used to read and write all WavPack audio data streams. It also contains a
+// wrapper for the stream I/O functions and a set of functions dealing with
+// endian-ness, both for enhancing portability. Finally, a debug wrapper for
+// the malloc() system is provided.
+
+#include "wavpack.h"
+
+#include <string.h>
+#include <ctype.h>
+
+////////////////////////// Bitstream functions ////////////////////////////////
+
+// Open the specified BitStream and associate with the specified buffer.
+
+static void bs_read (Bitstream *bs);
+
+void bs_open_read (Bitstream *bs, uchar *buffer_start, uchar *buffer_end, read_stream file, uint32_t file_bytes)
+{
+    CLEAR (*bs);
+    bs->buf = buffer_start;
+    bs->end = buffer_end;
+
+    if (file) {
+        bs->ptr = bs->end - 1;
+        bs->file_bytes = file_bytes;
+        bs->file = file;
+    }
+    else
+        bs->ptr = bs->buf - 1;
+
+    bs->wrap = bs_read;
+}
+
+// This function is only called from the getbit() and getbits() macros when
+// the BitStream has been exhausted and more data is required. Sinve these
+// bistreams no longer access files, this function simple sets an error and
+// resets the buffer.
+
+static void bs_read (Bitstream *bs)
+{
+    if (bs->file && bs->file_bytes) {
+        uint32_t bytes_read, bytes_to_read = bs->end - bs->buf;
+
+        if (bytes_to_read > bs->file_bytes)
+            bytes_to_read = bs->file_bytes;
+
+        bytes_read = bs->file (bs->buf, bytes_to_read);
+
+        if (bytes_read) {
+            bs->end = bs->buf + bytes_read;
+            bs->file_bytes -= bytes_read;
+        }
+        else {
+            memset (bs->buf, -1, bs->end - bs->buf);
+            bs->error = 1;
+        }
+    }
+    else
+        bs->error = 1;
+
+    if (bs->error)
+        memset (bs->buf, -1, bs->end - bs->buf);
+
+    bs->ptr = bs->buf;
+}
+
+/////////////////////// Endian Correction Routines ////////////////////////////
+
+void little_endian_to_native (void *data, char *format)
+{
+    uchar *cp = (uchar *) data;
+    int32_t temp;
+
+    while (*format) {
+        switch (*format) {
+            case 'L':
+                temp = cp [0] + ((int32_t) cp [1] << 8) + ((int32_t) cp [2] << 16) + ((int32_t) cp [3] << 24);
+                * (int32_t *) cp = temp;
+                cp += 4;
+                break;
+
+            case 'S':
+                temp = cp [0] + (cp [1] << 8);
+                * (short *) cp = (short) temp;
+                cp += 2;
+                break;
+
+            default:
+                if (isdigit (*format))
+                    cp += *format - '0';
+
+                break;
+        }
+
+        format++;
+    }
+}
+
+void native_to_little_endian (void *data, char *format)
+{
+    uchar *cp = (uchar *) data;
+    int32_t temp;
+
+    while (*format) {
+        switch (*format) {
+            case 'L':
+                temp = * (int32_t *) cp;
+                *cp++ = (uchar) temp;
+                *cp++ = (uchar) (temp >> 8);
+                *cp++ = (uchar) (temp >> 16);
+                *cp++ = (uchar) (temp >> 24);
+                break;
+
+            case 'S':
+                temp = * (short *) cp;
+                *cp++ = (uchar) temp;
+                *cp++ = (uchar) (temp >> 8);
+                break;
+
+            default:
+                if (isdigit (*format))
+                    cp += *format - '0';
+
+                break;
+        }
+
+        format++;
+    }
+}