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/*
* mad - MPEG audio decoder
* Copyright (C) 2000-2001 Robert Leslie
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* $Id: stream.c,v 1.1 2001/08/12 02:57:55 guenter Exp $
*/
# ifdef HAVE_CONFIG_H
# include "config.h"
# endif
# include "global.h"
# include <stdlib.h>
# include "bit.h"
# include "stream.h"
/*
* NAME: stream->init()
* DESCRIPTION: initialize stream struct
*/
void mad_stream_init(struct mad_stream *stream)
{
stream->buffer = 0;
stream->bufend = 0;
stream->skiplen = 0;
stream->sync = 0;
stream->freerate = 0;
stream->this_frame = 0;
stream->next_frame = 0;
mad_bit_init(&stream->ptr, 0);
mad_bit_init(&stream->anc_ptr, 0);
stream->anc_bitlen = 0;
stream->main_data = 0;
stream->md_len = 0;
stream->options = 0;
stream->error = 0;
}
/*
* NAME: stream->finish()
* DESCRIPTION: deallocate any dynamic memory associated with stream
*/
void mad_stream_finish(struct mad_stream *stream)
{
if (stream->main_data) {
free(stream->main_data);
stream->main_data = 0;
}
mad_bit_finish(&stream->anc_ptr);
mad_bit_finish(&stream->ptr);
}
/*
* NAME: stream->buffer()
* DESCRIPTION: set stream buffer pointers
*/
void mad_stream_buffer(struct mad_stream *stream,
unsigned char const *buffer, unsigned long length)
{
stream->buffer = buffer;
stream->bufend = buffer + length;
stream->this_frame = buffer;
stream->next_frame = buffer;
stream->sync = 1;
mad_bit_init(&stream->ptr, buffer);
}
/*
* NAME: stream->skip()
* DESCRIPTION: arrange to skip bytes before the next frame
*/
void mad_stream_skip(struct mad_stream *stream, unsigned long length)
{
stream->skiplen += length;
}
/*
* NAME: stream->sync()
* DESCRIPTION: locate the next stream sync word
*/
int mad_stream_sync(struct mad_stream *stream)
{
register unsigned char const *ptr, *end;
ptr = mad_bit_nextbyte(&stream->ptr);
end = stream->bufend;
while (ptr < end - 1 &&
!(ptr[0] == 0xff && (ptr[1] & 0xe0) == 0xe0))
++ptr;
if (end - ptr < MAD_BUFFER_GUARD)
return -1;
mad_bit_init(&stream->ptr, ptr);
return 0;
}
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