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-rw-r--r--code/libspeex/bits.c372
1 files changed, 372 insertions, 0 deletions
diff --git a/code/libspeex/bits.c b/code/libspeex/bits.c
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+++ b/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);
+}
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