cog/Frameworks/WavPack/Files/bits.c

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2006-04-21 20:43:47 +00:00
////////////////////////////////////////////////////////////////////////////
// **** WAVPACK **** //
// Hybrid Lossless Wavefile Compressor //
// Copyright (c) 1998 - 2005 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 <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <sys/stat.h>
#if defined(WIN32)
#include <io.h>
#else
#include <unistd.h>
#endif
////////////////////////// Bitstream functions ////////////////////////////////
#if defined(UNPACK) || defined(INFO_ONLY)
// 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)
{
bs->error = bs->sr = bs->bc = 0;
bs->ptr = (bs->buf = buffer_start) - 1;
bs->end = buffer_end;
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)
{
bs->ptr = bs->buf - 1;
bs->error = 1;
}
// This function is called to close the bitstream. It returns the number of
// full bytes actually read as bits.
uint32_t bs_close_read (Bitstream *bs)
{
uint32_t bytes_read;
if (bs->bc < 8)
bs->ptr++;
if ((bs->buf - bs->ptr) & 1)
bs->ptr++;
bytes_read = bs->ptr - bs->buf;
CLEAR (*bs);
return bytes_read;
}
#endif
#ifdef PACK
// Open the specified BitStream using the specified buffer pointers. It is
// assumed that enough buffer space has been allocated for all data that will
// be written, otherwise an error will be generated.
static void bs_write (Bitstream *bs);
void bs_open_write (Bitstream *bs, uchar *buffer_start, uchar *buffer_end)
{
bs->error = bs->sr = bs->bc = 0;
bs->ptr = bs->buf = buffer_start;
bs->end = buffer_end;
bs->wrap = bs_write;
}
// This function is only called from the putbit() and putbits() macros when
// the buffer is full, which is now flagged as an error.
static void bs_write (Bitstream *bs)
{
bs->ptr = bs->buf;
bs->error = 1;
}
// This function forces a flushing write of the specified BitStream, and
// returns the total number of bytes written into the buffer.
uint32_t bs_close_write (Bitstream *bs)
{
uint32_t bytes_written;
if (bs->error)
return (uint32_t) -1;
while (bs->bc || ((bs->ptr - bs->buf) & 1)) putbit_1 (bs);
bytes_written = bs->ptr - bs->buf;
CLEAR (*bs);
return bytes_written;
}
#endif
/////////////////////// 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++;
}
}
////////////////////////// Debug Wrapper for Malloc ///////////////////////////
#ifdef DEBUG_ALLOC
void *vptrs [512];
static void *add_ptr (void *ptr)
{
int i;
for (i = 0; i < 512; ++i)
if (!vptrs [i]) {
vptrs [i] = ptr;
break;
}
if (i == 512)
error_line ("too many mallocs!");
return ptr;
}
static void *del_ptr (void *ptr)
{
int i;
for (i = 0; i < 512; ++i)
if (vptrs [i] == ptr) {
vptrs [i] = NULL;
break;
}
if (i == 512)
error_line ("free invalid ptr!");
return ptr;
}
void *malloc_db (uint32_t size)
{
if (size)
return add_ptr (malloc (size));
else
return NULL;
}
void free_db (void *ptr)
{
if (ptr)
free (del_ptr (ptr));
}
void *realloc_db (void *ptr, uint32_t size)
{
if (ptr && size)
return add_ptr (realloc (del_ptr (ptr), size));
else if (size)
return malloc_db (size);
else
free_db (ptr);
return NULL;
}
int32_t dump_alloc (void)
{
int i, j;
for (j = i = 0; i < 512; ++i)
if (vptrs [i])
j++;
return j;
}
#endif