demux_mpg.c

君正早期ucos系统(只有早期的才不没有打包成库),MPLAYER,文件系统,图片解码,浏览,电子书,录音,想学ucos,识货的人就下吧 russblock fmradio explore set

      head|=c;
      if(mp_check_mp3_header(head)) ++num_mp3audio_packets;
      ++skipped; //++demux->filepos;
      continue;
    }
    head|=c;
    break;
   }
   demux->filepos+=skipped;
  }
  if(stream_eof(demux->stream)) break;
  // sure: head=0x000001XX
  mp_dbg(MSGT_DEMUX,MSGL_DBG4,"*** head=0x%X\n",head);
  if(demux->synced==0){
    if(head==0x1BA) demux->synced=1; //else
//    if(head==0x1BD || (head>=0x1C0 && head<=0x1EF)) demux->synced=3; // PES?
  } else
  if(demux->synced==1){
    if(head==0x1BB || head==0x1BD || (head>=0x1C0 && head<=0x1EF)){
      demux->synced=2;
      mp_msg(MSGT_DEMUX,MSGL_V,"system stream synced at 0x%"PRIX64" (%"PRId64")!\n",(int64_t)demux->filepos,(int64_t)demux->filepos);
      num_elementary_packets100=0; // requires for re-sync!
      num_elementary_packets101=0; // requires for re-sync!
    } else demux->synced=0;
  } // else
  if(demux->synced>=2){
      ret=demux_mpg_read_packet(demux,head);
      if(!ret)
        if(--max_packs==0){
          demux->stream->eof=1;
          mp_msg(MSGT_DEMUX,MSGL_ERR,MSGTR_DoesntContainSelectedStream);
          return 0;
        }
      if(demux->synced==3) demux->synced=(ret==1)?2:0; // PES detect
  } else {
    update_stats(head);
    if(head>=0x100 && head<0x1B0)
      mp_msg(MSGT_DEMUX,MSGL_DBG3,"Opps... elementary video packet found: %03X\n",head);
    else if((head>=0x1C0 && head<0x1F0) || head==0x1BD)
      mp_msg(MSGT_DEMUX,MSGL_DBG3,"Opps... PES packet found: %03X\n",head);

    if(((num_elementary_packets100>50 && num_elementary_packets101>50) ||
        (num_elementary_packetsPES>50)) && skipped>4000000){
        mp_msg(MSGT_DEMUX,MSGL_V,"sync_mpeg_ps: seems to be ES/PES stream...\n");
        demux->stream->eof=1;
        break;
    }
    if(num_mp3audio_packets>100 && num_elementary_packets100<10){
        mp_msg(MSGT_DEMUX,MSGL_V,"sync_mpeg_ps: seems to be MP3 stream...\n");
        demux->stream->eof=1;
        break;
    }
  }
} while(ret!=1);
  mp_dbg(MSGT_DEMUX,MSGL_DBG2,"demux: %d bad bytes skipped\n",skipped);
  if(demux->stream->eof){
    mp_msg(MSGT_DEMUX,MSGL_V,"MPEG Stream reached EOF\n");
    return 0;
  }
  return 1;
}

extern void skip_audio_frame(sh_audio_t *sh_audio);

void demux_seek_mpg(demuxer_t *demuxer,float rel_seek_secs,float audio_delay, int flags){
    demux_stream_t *d_audio=demuxer->audio;
    demux_stream_t *d_video=demuxer->video;
    sh_audio_t *sh_audio=d_audio->sh;
    sh_video_t *sh_video=d_video->sh;
    mpg_demuxer_t *mpg_d=(mpg_demuxer_t*)demuxer->priv;
    int precision = 1;
    float oldpts = 0;
    off_t oldpos = demuxer->filepos;
    float newpts = 0; 
    off_t newpos = (flags & 1) ? demuxer->movi_start : oldpos;

    if(mpg_d)
      oldpts = mpg_d->last_pts;
    newpts = (flags & 1) ? 0.0 : oldpts;
  //================= seek in MPEG ==========================
  //calculate the pts to seek to
    if(flags & 2) {
      if (mpg_d && mpg_d->first_to_final_pts_len > 0.0)
        newpts += mpg_d->first_to_final_pts_len * rel_seek_secs;
      else
        newpts += rel_seek_secs * (demuxer->movi_end - demuxer->movi_start) * oldpts / oldpos;
    } else
      newpts += rel_seek_secs;
    if (newpts < 0) newpts = 0;
	
    if(flags&2){
	// float seek 0..1
	newpos+=(demuxer->movi_end-demuxer->movi_start)*rel_seek_secs;
    } else {
	// time seek (secs)
        if (mpg_d && mpg_d->has_valid_timestamps) {
          if (mpg_d->first_to_final_pts_len > 0.0)
            newpos += rel_seek_secs * (demuxer->movi_end - demuxer->movi_start) / mpg_d->first_to_final_pts_len;
          else if (oldpts > 0.0)
            newpos += rel_seek_secs * (oldpos - demuxer->movi_start) / oldpts;
        } else if(!sh_video || !sh_video->i_bps) // unspecified or VBR
          newpos+=2324*75*rel_seek_secs; // 174.3 kbyte/sec
        else
          newpos+=sh_video->i_bps*rel_seek_secs;
    }

    while (1) {
        if(newpos<demuxer->movi_start){
	    if(demuxer->stream->type!=STREAMTYPE_VCD) demuxer->movi_start=0; // for VCD
	    if(newpos<demuxer->movi_start) newpos=demuxer->movi_start;
	}

        stream_seek(demuxer->stream,newpos);

        // re-sync video:
        videobuf_code_len=0; // reset ES stream buffer

	ds_fill_buffer(d_video);
	if(sh_audio){
	  ds_fill_buffer(d_audio);
	}

	while(1){
	  int i;
          if(sh_audio && !d_audio->eof && d_video->pts && d_audio->pts){
	    float a_pts=d_audio->pts;
            a_pts+=(ds_tell_pts(d_audio)-sh_audio->a_in_buffer_len)/(float)sh_audio->i_bps;
	    if(d_video->pts>a_pts){
	      skip_audio_frame(sh_audio);  // sync audio
	      continue;
	    }
          }
	  if(!sh_video) break;
          i=sync_video_packet(d_video);
          if(sh_video->format == mmioFOURCC('W', 'V', 'C', '1')) {
            if(i==0x10E || i==0x10F) //entry point or sequence header
              break;
          } else
          if(sh_video->format == 0x10000004) {	//mpeg4
            if(i==0x1B6) {			//vop (frame) startcode
	      int pos = videobuf_len;
	      if(!read_video_packet(d_video)) break; // EOF
	      if((videobuffer[pos+4] & 0x3F) == 0) break;	//I-frame
	    }
          } else if(sh_video->format == 0x10000005){	//h264
            if((i & ~0x60) == 0x105) break;
          } else { 	//default mpeg1/2
	    if(i==0x1B3 || i==0x1B8) break; // found it!
	  }
          if(!i || !skip_video_packet(d_video)) break; // EOF?
        }
	if(!mpg_d)
          break;
        if (!precision || abs(newpts - mpg_d->last_pts) < 0.5 || (mpg_d->last_pts == oldpts)) break;
        if ((newpos - oldpos) * (mpg_d->last_pts - oldpts) < 0) { // invalid timestamps
          mpg_d->has_valid_timestamps = 0;
          break;
        }
        precision--;
        //prepare another seek because we are off by more than 0.5s
	if(mpg_d) {
        newpos += (newpts - mpg_d->last_pts) * (newpos - oldpos) / (mpg_d->last_pts - oldpts);
        ds_free_packs(d_audio);
        ds_free_packs(d_video);
        ds_free_packs(demuxer->sub);
        demuxer->stream->eof=0; // clear eof flag
        d_video->eof=0;
        d_audio->eof=0;
	}
    }
}

int demux_mpg_control(demuxer_t *demuxer,int cmd, void *arg){
    mpg_demuxer_t *mpg_d=(mpg_demuxer_t*)demuxer->priv;

    switch(cmd) {
	case DEMUXER_CTRL_GET_TIME_LENGTH:
            if(stream_control(demuxer->stream, STREAM_CTRL_GET_TIME_LENGTH, arg) != STREAM_UNSUPPORTED) {
              mp_msg(MSGT_DEMUXER,MSGL_DBG2,"\r\nDEMUX_MPG_CTRL, (%.3lf)\r\n", *((double*)arg));
              return DEMUXER_CTRL_GUESS;
            }
            if (mpg_d && mpg_d->has_valid_timestamps) {
              *((double *)arg)=(double)mpg_d->first_to_final_pts_len;
              return DEMUXER_CTRL_OK;
            }
    		return DEMUXER_CTRL_DONTKNOW;

	case DEMUXER_CTRL_GET_PERCENT_POS:
            if (mpg_d && mpg_d->has_valid_timestamps && mpg_d->first_to_final_pts_len > 0.0) {
              *((int *)arg)=(int)(100 * (mpg_d->last_pts-mpg_d->first_pts) / mpg_d->first_to_final_pts_len);
              return DEMUXER_CTRL_OK;
            }
	    return DEMUXER_CTRL_DONTKNOW;

	case DEMUXER_CTRL_SWITCH_AUDIO:
            if(! (mpg_d && mpg_d->num_a_streams > 1 && demuxer->audio && demuxer->audio->sh))
	      return DEMUXER_CTRL_NOTIMPL; 
	    else {
              demux_stream_t *d_audio = demuxer->audio;
              sh_audio_t *sh_audio = d_audio->sh;
              sh_audio_t *sh_a = sh_audio;
              int i;
	      if(!sh_audio)
	        return DEMUXER_CTRL_NOTIMPL;
              if (*((int*)arg) < 0)
              {
              for (i = 0; i < mpg_d->num_a_streams; i++) {
                if (d_audio->id == mpg_d->a_stream_ids[i]) break;
              }
                i = (i+1) % mpg_d->num_a_streams;
                sh_a = (sh_audio_t*)demuxer->a_streams[mpg_d->a_stream_ids[i]];
              }
              else {
                for (i = 0; i < mpg_d->num_a_streams; i++)
                  if (*((int*)arg) == mpg_d->a_stream_ids[i]) break;
                if (i < mpg_d->num_a_streams)
                  sh_a = (sh_audio_t*)demuxer->a_streams[*((int*)arg)];
              }
              if (i < mpg_d->num_a_streams && d_audio->id != mpg_d->a_stream_ids[i]) {
                d_audio->id = mpg_d->a_stream_ids[i];
                d_audio->sh = sh_a;
                ds_free_packs(d_audio);
              }
            }
            *((int*)arg) = demuxer->audio->id;
            return DEMUXER_CTRL_OK;

	default:
	    return DEMUXER_CTRL_NOTIMPL;
    }
}


static int demux_mpg_pes_probe(demuxer_t *demuxer) {
   demuxer->synced = 3;
   return (demux_mpg_probe(demuxer) == DEMUXER_TYPE_MPEG_PS) ? DEMUXER_TYPE_MPEG_PES : 0;
}


static demuxer_t* demux_mpg_es_open(demuxer_t* demuxer)
{
    sh_video_t *sh_video=NULL;

    demuxer->audio->sh = NULL;   // ES streams has no audio channel
    demuxer->video->sh = new_sh_video(demuxer,0); // create dummy video stream header, id=0
    sh_video=demuxer->video->sh;sh_video->ds=demuxer->video;

    return demuxer;
}

static demuxer_t *demux_mpg_gxf_open(demuxer_t *demuxer) {
  demuxer->audio->sh = NULL;
  demuxer->video->sh = new_sh_video(demuxer,0);
  ((sh_video_t *)demuxer->video->sh)->ds = demuxer->video;
  demuxer->priv = (void *) 0xffffffff;
  return demuxer;
}

static demuxer_t* demux_mpg_ps_open(demuxer_t* demuxer)
{
    sh_audio_t *sh_audio=NULL;
    sh_video_t *sh_video=NULL;

    sh_video=demuxer->video->sh;sh_video->ds=demuxer->video;

    if(demuxer->audio->id!=-2) {
        if(!ds_fill_buffer(demuxer->audio)){
            mp_msg(MSGT_DEMUXER,MSGL_INFO,"MPEG: " MSGTR_MissingAudioStream);
            demuxer->audio->sh=NULL;
        } else {
            sh_audio=demuxer->audio->sh;sh_audio->ds=demuxer->audio;
        }
    }

    if(!sh_video->format && ps_probe > 0) {
        int head;
        off_t pos = stream_tell(demuxer->stream);

        clear_stats();
        do {
            head=sync_video_packet(demuxer->video);
            if(!head) break;
            update_stats(head);
            skip_video_packet(demuxer->video);
        } while(stream_tell(demuxer->stream) < pos + ps_probe && !demuxer->stream->eof);

        ds_free_packs(demuxer->video);
        demuxer->stream->eof=0;
        stream_seek(demuxer->stream, pos);
        mp_msg(MSGT_DEMUX,MSGL_INFO,"MPEG packet stats: p100: %d  p101: %d p1B6: %d p12x: %d sli: %d a: %d b: %d c: %d idr: %d sps: %d pps: %d\n",
            num_elementary_packets100, num_elementary_packets101,
            num_elementary_packets1B6, num_elementary_packets12x,
            num_h264_slice, num_h264_dpa, num_h264_dpb, num_h264_dpc,
            num_h264_idr, num_h264_sps, num_h264_pps);

        if(num_elementary_packets1B6>3 && num_elementary_packets12x>=1 &&
            num_elementary_packets100<=num_elementary_packets12x)
            sh_video->format = 0x10000004;
        else if((num_h264_slice>3 || (num_h264_dpa>3 && num_h264_dpb>3 && num_h264_dpc>3)) &&
            num_h264_sps>=1 && num_h264_pps>=1 && num_h264_idr>=1 &&
            num_elementary_packets1B6==0)
                sh_video->format = 0x10000005;
        else sh_video->format = 0x10000002;
    }

    return demuxer;
}


demuxer_desc_t demuxer_desc_mpeg_ps = {
  "MPEG PS demuxer",
  "mpegps",
  "MPEG-PS",
  "Arpi?",
  "Mpeg",
  DEMUXER_TYPE_MPEG_PS,
  0, // unsafe autodetect
  demux_mpg_probe,
  demux_mpg_fill_buffer,
  demux_mpg_ps_open,
  demux_close_mpg,
  demux_seek_mpg,
  demux_mpg_control,
};


demuxer_desc_t demuxer_desc_mpeg_pes = {
  "MPEG PES demuxer",
  "mpegpes",
  "MPEG-PES",
  "Arpi?",
  "Mpeg",
  DEMUXER_TYPE_MPEG_PES,
  0, // unsafe autodetect
  demux_mpg_pes_probe,
  demux_mpg_fill_buffer,
  demux_mpg_ps_open,
  demux_close_mpg,
  demux_seek_mpg,
  demux_mpg_control,
};


demuxer_desc_t demuxer_desc_mpeg_gxf = {
  "MPEG ES in GXF demuxer",
  "mpeggxf",
  "MPEG-ES in GXF",
  "Reimar Doeffinger",
  "Mpeg",
  DEMUXER_TYPE_MPEG_GXF,
  0, // hack autodetection
  NULL,
  demux_mpg_gxf_fill_buffer,
  demux_mpg_gxf_open,
  NULL,
  NULL,
  NULL
};

demuxer_desc_t demuxer_desc_mpeg_es = {
  "MPEG ES demuxer",
  "mpeges",
  "MPEG-ES",
  "Arpi?",
  "Mpeg",
  DEMUXER_TYPE_MPEG_ES,
  0, // hack autodetection
  NULL,
  demux_mpg_es_fill_buffer,
  demux_mpg_es_open,
  demux_close_mpg,
  demux_seek_mpg,
  demux_mpg_control,
};


demuxer_desc_t demuxer_desc_mpeg4_es = {
  "MPEG4 ES demuxer",
  "mpeg4es",
  "MPEG-ES",
  "Arpi?",
  "Mpeg",
  DEMUXER_TYPE_MPEG4_ES,
  0, // hack autodetection
  NULL,
  demux_mpg_es_fill_buffer,
  demux_mpg_es_open,
  demux_close_mpg,
  demux_seek_mpg,
  demux_mpg_control,
};


demuxer_desc_t demuxer_desc_h264_es = {
  "H.264 ES demuxer",
  "h264es",
  "H264-ES",
  "Arpi?",
  "Mpeg",
  DEMUXER_TYPE_H264_ES,
  0, // hack autodetection
  NULL,
  demux_mpg_es_fill_buffer,
  demux_mpg_es_open,
  demux_close_mpg,
  demux_seek_mpg,
  demux_mpg_control,
};