mpv/libmpdemux/parse_es.c

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/*
* MPEG-ES video parser
*
* This file is part of MPlayer.
*
* MPlayer 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.
*
* MPlayer 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 MPlayer; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "config.h"
#include "mp_msg.h"
#include "stream/stream.h"
#include "demuxer.h"
#include "parse_es.h"
//static unsigned char videobuffer[MAX_VIDEO_PACKET_SIZE];
unsigned char* videobuffer=NULL;
int videobuf_len=0;
int next_nal = -1;
///! legacy variable, 4 if stream is synced, 0 if not
int videobuf_code_len=0;
#define MAX_SYNCLEN (10 * 1024 * 1024)
// sync video stream, and returns next packet code
int sync_video_packet(demux_stream_t *ds){
if (!videobuf_code_len) {
int skipped=0;
if (!demux_pattern_3(ds, NULL, MAX_SYNCLEN, &skipped, 0x100)) {
if (skipped == MAX_SYNCLEN)
mp_msg(MSGT_DEMUXER, MSGL_ERR, "parse_es: could not sync video stream!\n");
goto eof_out;
}
next_nal = demux_getc(ds);
if (next_nal < 0)
goto eof_out;
videobuf_code_len = 4;
if(skipped) mp_dbg(MSGT_PARSEES,MSGL_DBG2,"videobuf: %d bytes skipped (next: 0x1%02X)\n",skipped,next_nal);
}
return 0x100|next_nal;
eof_out:
next_nal = -1;
videobuf_code_len = 0;
return 0;
}
// return: packet length
int read_video_packet(demux_stream_t *ds){
int packet_start;
int res, read;
if (VIDEOBUFFER_SIZE - videobuf_len < 5)
return 0;
// SYNC STREAM
// if(!sync_video_packet(ds)) return 0; // cannot sync (EOF)
// COPY STARTCODE:
packet_start=videobuf_len;
videobuffer[videobuf_len+0]=0;
videobuffer[videobuf_len+1]=0;
videobuffer[videobuf_len+2]=1;
videobuffer[videobuf_len+3]=next_nal;
videobuf_len+=4;
// READ PACKET:
res = demux_pattern_3(ds, &videobuffer[videobuf_len],
VIDEOBUFFER_SIZE - videobuf_len, &read, 0x100);
videobuf_len += read;
if (!res)
goto eof_out;
videobuf_len-=3;
mp_dbg(MSGT_PARSEES,MSGL_DBG2,"videobuf: packet 0x1%02X len=%d (total=%d)\n",videobuffer[packet_start+3],videobuf_len-packet_start,videobuf_len);
// Save next packet code:
next_nal = demux_getc(ds);
if (next_nal < 0)
goto eof_out;
videobuf_code_len=4;
return videobuf_len-packet_start;
eof_out:
next_nal = -1;
videobuf_code_len = 0;
return videobuf_len - packet_start;
}
// return: next packet code
int skip_video_packet(demux_stream_t *ds){
// SYNC STREAM
// if(!sync_video_packet(ds)) return 0; // cannot sync (EOF)
videobuf_code_len=0; // force resync
// SYNC AGAIN:
return sync_video_packet(ds);
}
/* stripped down version of a52_syncinfo() from liba52
* copyright belongs to Michel Lespinasse <walken@zoy.org>
* and Aaron Holtzman <aholtzma@ess.engr.uvic.ca> */
int mp_a52_framesize(uint8_t * buf, int *srate)
{
int rate[] = { 32, 40, 48, 56, 64, 80, 96, 112,
128, 160, 192, 224, 256, 320, 384, 448,
512, 576, 640
};
uint8_t halfrate[12] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3 };
int frmsizecod, bitrate, half;
if ((buf[0] != 0x0b) || (buf[1] != 0x77)) /* syncword */
return 0;
if (buf[5] >= 0x60) /* bsid >= 12 */
return 0;
half = halfrate[buf[5] >> 3];
frmsizecod = buf[4] & 63;
if (frmsizecod >= 38)
return 0;
bitrate = rate[frmsizecod >> 1];
switch (buf[4] & 0xc0) {
case 0: /* 48 KHz */
*srate = 48000 >> half;
return 4 * bitrate;
case 0x40: /* 44.1 KHz */
*srate = 44100 >> half;
return 2 * (320 * bitrate / 147 + (frmsizecod & 1));
case 0x80: /* 32 KHz */
*srate = 32000 >> half;
return 6 * bitrate;
}
return 0;
}