ioq3quest/code/libspeex/bits.c

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/* Copyright (C) 2002 Jean-Marc Valin
File: speex_bits.c
Handles bit packing/unpacking
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
- Neither the name of the Xiph.org Foundation nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <speex/speex_bits.h>
#include "arch.h"
#include "os_support.h"
/* Maximum size of the bit-stream (for fixed-size allocation) */
#ifndef MAX_CHARS_PER_FRAME
#define MAX_CHARS_PER_FRAME (2000/BYTES_PER_CHAR)
#endif
void speex_bits_init(SpeexBits *bits)
{
bits->chars = (char*)speex_alloc(MAX_CHARS_PER_FRAME);
if (!bits->chars)
return;
bits->buf_size = MAX_CHARS_PER_FRAME;
bits->owner=1;
speex_bits_reset(bits);
}
void speex_bits_init_buffer(SpeexBits *bits, void *buff, int buf_size)
{
bits->chars = (char*)buff;
bits->buf_size = buf_size;
bits->owner=0;
speex_bits_reset(bits);
}
void speex_bits_set_bit_buffer(SpeexBits *bits, void *buff, int buf_size)
{
bits->chars = (char*)buff;
bits->buf_size = buf_size;
bits->owner=0;
bits->nbBits=buf_size<<LOG2_BITS_PER_CHAR;
bits->charPtr=0;
bits->bitPtr=0;
bits->overflow=0;
}
void speex_bits_destroy(SpeexBits *bits)
{
if (bits->owner)
speex_free(bits->chars);
/* Will do something once the allocation is dynamic */
}
void speex_bits_reset(SpeexBits *bits)
{
/* We only need to clear the first byte now */
bits->chars[0]=0;
bits->nbBits=0;
bits->charPtr=0;
bits->bitPtr=0;
bits->overflow=0;
}
void speex_bits_rewind(SpeexBits *bits)
{
bits->charPtr=0;
bits->bitPtr=0;
bits->overflow=0;
}
void speex_bits_read_from(SpeexBits *bits, char *chars, int len)
{
int i;
int nchars = len / BYTES_PER_CHAR;
if (nchars > bits->buf_size)
{
speex_notify("Packet is larger than allocated buffer");
if (bits->owner)
{
char *tmp = (char*)speex_realloc(bits->chars, nchars);
if (tmp)
{
bits->buf_size=nchars;
bits->chars=tmp;
} else {
nchars=bits->buf_size;
speex_warning("Could not resize input buffer: truncating input");
}
} else {
speex_warning("Do not own input buffer: truncating oversize input");
nchars=bits->buf_size;
}
}
#if (BYTES_PER_CHAR==2)
/* Swap bytes to proper endian order (could be done externally) */
#define HTOLS(A) ((((A) >> 8)&0xff)|(((A) & 0xff)<<8))
#else
#define HTOLS(A) (A)
#endif
for (i=0;i<nchars;i++)
bits->chars[i]=HTOLS(chars[i]);
bits->nbBits=nchars<<LOG2_BITS_PER_CHAR;
bits->charPtr=0;
bits->bitPtr=0;
bits->overflow=0;
}
static void speex_bits_flush(SpeexBits *bits)
{
int nchars = ((bits->nbBits+BITS_PER_CHAR-1)>>LOG2_BITS_PER_CHAR);
if (bits->charPtr>0)
SPEEX_MOVE(bits->chars, &bits->chars[bits->charPtr], nchars-bits->charPtr);
bits->nbBits -= bits->charPtr<<LOG2_BITS_PER_CHAR;
bits->charPtr=0;
}
void speex_bits_read_whole_bytes(SpeexBits *bits, char *chars, int nbytes)
{
int i,pos;
int nchars = nbytes/BYTES_PER_CHAR;
if (((bits->nbBits+BITS_PER_CHAR-1)>>LOG2_BITS_PER_CHAR)+nchars > bits->buf_size)
{
/* Packet is larger than allocated buffer */
if (bits->owner)
{
char *tmp = (char*)speex_realloc(bits->chars, (bits->nbBits>>LOG2_BITS_PER_CHAR)+nchars+1);
if (tmp)
{
bits->buf_size=(bits->nbBits>>LOG2_BITS_PER_CHAR)+nchars+1;
bits->chars=tmp;
} else {
nchars=bits->buf_size-(bits->nbBits>>LOG2_BITS_PER_CHAR)-1;
speex_warning("Could not resize input buffer: truncating oversize input");
}
} else {
speex_warning("Do not own input buffer: truncating oversize input");
nchars=bits->buf_size;
}
}
speex_bits_flush(bits);
pos=bits->nbBits>>LOG2_BITS_PER_CHAR;
for (i=0;i<nchars;i++)
bits->chars[pos+i]=HTOLS(chars[i]);
bits->nbBits+=nchars<<LOG2_BITS_PER_CHAR;
}
int speex_bits_write(SpeexBits *bits, char *chars, int max_nbytes)
{
int i;
int max_nchars = max_nbytes/BYTES_PER_CHAR;
int charPtr, bitPtr, nbBits;
/* Insert terminator, but save the data so we can put it back after */
bitPtr=bits->bitPtr;
charPtr=bits->charPtr;
nbBits=bits->nbBits;
speex_bits_insert_terminator(bits);
bits->bitPtr=bitPtr;
bits->charPtr=charPtr;
bits->nbBits=nbBits;
if (max_nchars > ((bits->nbBits+BITS_PER_CHAR-1)>>LOG2_BITS_PER_CHAR))
max_nchars = ((bits->nbBits+BITS_PER_CHAR-1)>>LOG2_BITS_PER_CHAR);
for (i=0;i<max_nchars;i++)
chars[i]=HTOLS(bits->chars[i]);
return max_nchars*BYTES_PER_CHAR;
}
int speex_bits_write_whole_bytes(SpeexBits *bits, char *chars, int max_nbytes)
{
int max_nchars = max_nbytes/BYTES_PER_CHAR;
int i;
if (max_nchars > ((bits->nbBits)>>LOG2_BITS_PER_CHAR))
max_nchars = ((bits->nbBits)>>LOG2_BITS_PER_CHAR);
for (i=0;i<max_nchars;i++)
chars[i]=HTOLS(bits->chars[i]);
if (bits->bitPtr>0)
bits->chars[0]=bits->chars[max_nchars];
else
bits->chars[0]=0;
bits->charPtr=0;
bits->nbBits &= (BITS_PER_CHAR-1);
return max_nchars*BYTES_PER_CHAR;
}
void speex_bits_pack(SpeexBits *bits, int data, int nbBits)
{
unsigned int d=data;
if (bits->charPtr+((nbBits+bits->bitPtr)>>LOG2_BITS_PER_CHAR) >= bits->buf_size)
{
speex_notify("Buffer too small to pack bits");
if (bits->owner)
{
int new_nchars = ((bits->buf_size+5)*3)>>1;
char *tmp = (char*)speex_realloc(bits->chars, new_nchars);
if (tmp)
{
bits->buf_size=new_nchars;
bits->chars=tmp;
} else {
speex_warning("Could not resize input buffer: not packing");
return;
}
} else {
speex_warning("Do not own input buffer: not packing");
return;
}
}
while(nbBits)
{
int bit;
bit = (d>>(nbBits-1))&1;
bits->chars[bits->charPtr] |= bit<<(BITS_PER_CHAR-1-bits->bitPtr);
bits->bitPtr++;
if (bits->bitPtr==BITS_PER_CHAR)
{
bits->bitPtr=0;
bits->charPtr++;
bits->chars[bits->charPtr] = 0;
}
bits->nbBits++;
nbBits--;
}
}
int speex_bits_unpack_signed(SpeexBits *bits, int nbBits)
{
unsigned int d=speex_bits_unpack_unsigned(bits,nbBits);
/* If number is negative */
if (d>>(nbBits-1))
{
d |= (-1)<<nbBits;
}
return d;
}
unsigned int speex_bits_unpack_unsigned(SpeexBits *bits, int nbBits)
{
unsigned int d=0;
if ((bits->charPtr<<LOG2_BITS_PER_CHAR)+bits->bitPtr+nbBits>bits->nbBits)
bits->overflow=1;
if (bits->overflow)
return 0;
while(nbBits)
{
d<<=1;
d |= (bits->chars[bits->charPtr]>>(BITS_PER_CHAR-1 - bits->bitPtr))&1;
bits->bitPtr++;
if (bits->bitPtr==BITS_PER_CHAR)
{
bits->bitPtr=0;
bits->charPtr++;
}
nbBits--;
}
return d;
}
unsigned int speex_bits_peek_unsigned(SpeexBits *bits, int nbBits)
{
unsigned int d=0;
int bitPtr, charPtr;
char *chars;
if ((bits->charPtr<<LOG2_BITS_PER_CHAR)+bits->bitPtr+nbBits>bits->nbBits)
bits->overflow=1;
if (bits->overflow)
return 0;
bitPtr=bits->bitPtr;
charPtr=bits->charPtr;
chars = bits->chars;
while(nbBits)
{
d<<=1;
d |= (chars[charPtr]>>(BITS_PER_CHAR-1 - bitPtr))&1;
bitPtr++;
if (bitPtr==BITS_PER_CHAR)
{
bitPtr=0;
charPtr++;
}
nbBits--;
}
return d;
}
int speex_bits_peek(SpeexBits *bits)
{
if ((bits->charPtr<<LOG2_BITS_PER_CHAR)+bits->bitPtr+1>bits->nbBits)
bits->overflow=1;
if (bits->overflow)
return 0;
return (bits->chars[bits->charPtr]>>(BITS_PER_CHAR-1 - bits->bitPtr))&1;
}
void speex_bits_advance(SpeexBits *bits, int n)
{
if (((bits->charPtr<<LOG2_BITS_PER_CHAR)+bits->bitPtr+n>bits->nbBits) || bits->overflow){
bits->overflow=1;
return;
}
bits->charPtr += (bits->bitPtr+n) >> LOG2_BITS_PER_CHAR; /* divide by BITS_PER_CHAR */
bits->bitPtr = (bits->bitPtr+n) & (BITS_PER_CHAR-1); /* modulo by BITS_PER_CHAR */
}
int speex_bits_remaining(SpeexBits *bits)
{
if (bits->overflow)
return -1;
else
return bits->nbBits-((bits->charPtr<<LOG2_BITS_PER_CHAR)+bits->bitPtr);
}
int speex_bits_nbytes(SpeexBits *bits)
{
return ((bits->nbBits+BITS_PER_CHAR-1)>>LOG2_BITS_PER_CHAR);
}
void speex_bits_insert_terminator(SpeexBits *bits)
{
if (bits->bitPtr)
speex_bits_pack(bits, 0, 1);
while (bits->bitPtr)
speex_bits_pack(bits, 1, 1);
}