libmpdemux/parse_es.c

   1 //=================== MPEG-ES VIDEO PARSER =========================
   2
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <unistd.h>
   6
   7 #include "config.h"
   8 #include "mp_msg.h"
   9 #include "help_mp.h"
  10
  11 #include "stream/stream.h"
  12 #include "demuxer.h"
  13 #include "parse_es.h"
  14
  15 //static unsigned char videobuffer[MAX_VIDEO_PACKET_SIZE];
  16 unsigned char* videobuffer=NULL;
  17 int videobuf_len=0;
  18 int next_nal = -1;
  19 ///! legacy variable, 4 if stream is synced, 0 if not
  20 int videobuf_code_len=0;
  21
  22 #define MAX_SYNCLEN (10 * 1024 * 1024)
  23 // sync video stream, and returns next packet code
  24 int sync_video_packet(demux_stream_t *ds){
  25   if (!videobuf_code_len) {
  26   int skipped=0;
  27     if (!demux_pattern_3(ds, NULL, MAX_SYNCLEN, &skipped, 0x100)) {
  28       if (skipped == MAX_SYNCLEN)
  29       mp_msg(MSGT_DEMUXER, MSGL_ERR, "parse_es: could not sync video stream!\n");
  30       goto eof_out;
  31     }
  32     next_nal = demux_getc(ds);
  33     if (next_nal < 0)
  34       goto eof_out;
  35     videobuf_code_len = 4;
  36   if(skipped) mp_dbg(MSGT_PARSEES,MSGL_DBG2,"videobuf: %d bytes skipped  (next: 0x1%02X)\n",skipped,next_nal);
  37   }
  38   return 0x100|next_nal;
  39
  40 eof_out:
  41   next_nal = -1;
  42   videobuf_code_len = 0;
  43   return 0;
  44 }
  45
  46 // return: packet length
  47 int read_video_packet(demux_stream_t *ds){
  48 int packet_start;
  49   int res, read;
  50
  51   if (VIDEOBUFFER_SIZE - videobuf_len < 5)
  52     return 0;
  53   // SYNC STREAM
  54 //  if(!sync_video_packet(ds)) return 0; // cannot sync (EOF)
  55
  56   // COPY STARTCODE:
  57   packet_start=videobuf_len;
  58   videobuffer[videobuf_len+0]=0;
  59   videobuffer[videobuf_len+1]=0;
  60   videobuffer[videobuf_len+2]=1;
  61   videobuffer[videobuf_len+3]=next_nal;
  62   videobuf_len+=4;
  63
  64   // READ PACKET:
  65   res = demux_pattern_3(ds, &videobuffer[videobuf_len],
  66           VIDEOBUFFER_SIZE - videobuf_len, &read, 0x100);
  67   videobuf_len += read;
  68   if (!res)
  69     goto eof_out;
  70
  71   videobuf_len-=3;
  72
  73   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);
  74
  75   // Save next packet code:
  76   next_nal = demux_getc(ds);
  77   if (next_nal < 0)
  78     goto eof_out;
  79   videobuf_code_len=4;
  80
  81   return videobuf_len-packet_start;
  82
  83 eof_out:
  84   next_nal = -1;
  85   videobuf_code_len = 0;
  86   return videobuf_len - packet_start;
  87 }
  88
  89 // return: next packet code
  90 int skip_video_packet(demux_stream_t *ds){
  91
  92   // SYNC STREAM
  93 //  if(!sync_video_packet(ds)) return 0; // cannot sync (EOF)
  94
  95   videobuf_code_len=0; // force resync
  96
  97   // SYNC AGAIN:
  98   return sync_video_packet(ds);
  99 }