libmpdemux/parse_es.c

   1 /*
   2  * MPEG-ES video parser
   3  *
   4  * This file is part of MPlayer.
   5  *
   6  * MPlayer is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * MPlayer is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24
  25 #include "config.h"
  26 #include "mp_msg.h"
  27
  28 #include "stream/stream.h"
  29 #include "demuxer.h"
  30 #include "parse_es.h"
  31
  32 //static unsigned char videobuffer[MAX_VIDEO_PACKET_SIZE];
  33 unsigned char* videobuffer=NULL;
  34 int videobuf_len=0;
  35 int next_nal = -1;
  36 ///! legacy variable, 4 if stream is synced, 0 if not
  37 int videobuf_code_len=0;
  38
  39 #define MAX_SYNCLEN (10 * 1024 * 1024)
  40 // sync video stream, and returns next packet code
  41 int sync_video_packet(demux_stream_t *ds){
  42   if (!videobuf_code_len) {
  43   int skipped=0;
  44     if (!demux_pattern_3(ds, NULL, MAX_SYNCLEN, &skipped, 0x100)) {
  45       if (skipped == MAX_SYNCLEN)
  46       mp_msg(MSGT_DEMUXER, MSGL_ERR, "parse_es: could not sync video stream!\n");
  47       goto eof_out;
  48     }
  49     next_nal = demux_getc(ds);
  50     if (next_nal < 0)
  51       goto eof_out;
  52     videobuf_code_len = 4;
  53   if(skipped) mp_dbg(MSGT_PARSEES,MSGL_DBG2,"videobuf: %d bytes skipped  (next: 0x1%02X)\n",skipped,next_nal);
  54   }
  55   return 0x100|next_nal;
  56
  57 eof_out:
  58   next_nal = -1;
  59   videobuf_code_len = 0;
  60   return 0;
  61 }
  62
  63 // return: packet length
  64 int read_video_packet(demux_stream_t *ds){
  65 int packet_start;
  66   int res, read;
  67
  68   if (VIDEOBUFFER_SIZE - videobuf_len < 5)
  69     return 0;
  70   // SYNC STREAM
  71 //  if(!sync_video_packet(ds)) return 0; // cannot sync (EOF)
  72
  73   // COPY STARTCODE:
  74   packet_start=videobuf_len;
  75   videobuffer[videobuf_len+0]=0;
  76   videobuffer[videobuf_len+1]=0;
  77   videobuffer[videobuf_len+2]=1;
  78   videobuffer[videobuf_len+3]=next_nal;
  79   videobuf_len+=4;
  80
  81   // READ PACKET:
  82   res = demux_pattern_3(ds, &videobuffer[videobuf_len],
  83           VIDEOBUFFER_SIZE - videobuf_len, &read, 0x100);
  84   videobuf_len += read;
  85   if (!res)
  86     goto eof_out;
  87
  88   videobuf_len-=3;
  89
  90   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);
  91
  92   // Save next packet code:
  93   next_nal = demux_getc(ds);
  94   if (next_nal < 0)
  95     goto eof_out;
  96   videobuf_code_len=4;
  97
  98   return videobuf_len-packet_start;
  99
 100 eof_out:
 101   next_nal = -1;
 102   videobuf_code_len = 0;
 103   return videobuf_len - packet_start;
 104 }
 105
 106 // return: next packet code
 107 int skip_video_packet(demux_stream_t *ds){
 108
 109   // SYNC STREAM
 110 //  if(!sync_video_packet(ds)) return 0; // cannot sync (EOF)
 111
 112   videobuf_code_len=0; // force resync
 113
 114   // SYNC AGAIN:
 115   return sync_video_packet(ds);
 116 }