transcoder_example.c

mediastreamer2是开源的网络传输媒体流的库

    ttc->LastKeyFrame-1;

  return 0;
}

//static void _tp_writebuffer(oggpack_buffer *opb, const char *buf, const long len)

int theora_transcoder_init(theora_info * ti, TC_INSTANCE * ttc){
  memset(ttc, 0, sizeof(*ttc));
  ttc->granulepos = -1;
  ttc->keyframe_granule_shift=_ilog(ti->keyframe_frequency_force-1);
  ttc->LastKeyFrame  = 0;
  ttc->KeyFrameCount = 0;
  ttc->ThisIsFirstFrame = 1;
  ttc->ThisIsKeyFrame = 0;
  ttc->CurrentFrame = 1; 
  ttc->in_bytes = 0;
  ttc->in_bytecount  = 0;
  ttc->fps_denominator = ti->fps_denominator;
  ttc->fps_numerator = ti->fps_numerator;
  oggpackB_writeinit(&ttc->opb_out);
  return 0;
}

int fetch_and_process_video(FILE *video,ogg_page *videopage,
                            ogg_stream_state *to,
                            TC_INSTANCE *ttc,
                            int videoflag){
  /* You'll go to Hell for using static variables */
  static int          state=-1;
  ogg_packet          op;
  int i;
  int keyframeflag, framelength;


  if(state==-1){
        /* initialize the double frame buffer */
    state=0;
  }

  /* is there a video page flushed?  If not, work until there is. */
  while(!videoflag){
    spinnit();

    if(ogg_stream_pageout(to,videopage)>0) return 1;
    if(ogg_stream_eos(to)) return 0;

    {
      /* read and process more video */
      /* video strategy reads one frame ahead so we know when we're
         at end of stream and can mark last video frame as such
         (vorbis audio has to flush one frame past last video frame
         due to overlap and thus doesn't need this extra work */

      /* have two frame buffers full (if possible) before
         proceeding.  after first pass and until eos, one will
         always be full when we get here */

      for(i=state;i<2;i++){
        char c,frame[6];
        int ret=fread(frame,1,6,video);
        
	/* match and skip the frame header */
        if(ret<6)break;
        if(memcmp(frame,"FRAME",5)){
          fprintf(stderr,"Loss of framing in VP31 input data\n");
          exit(1);
        }
        if(frame[5]!='\n'){
          int j;
          for(j=0;j<79;j++)
            if(fread(&c,1,1,video)&&c=='\n')break;
          if(j==79){
            fprintf(stderr,"Error parsing VP31 frame header\n");
            exit(1);
          }
        }

        /*read the length*/
        ret=fread(&framelength, sizeof(int), 1, video);

        /*read the keyframeflag*/
        ret=fread(&keyframeflag, sizeof(int), 1, video);

        vp3frame[i] = malloc(framelength);
        framebytecount[i] = framelength;
        frameiskey[i] = keyframeflag;

        /* read the frame */
        ret=fread((char *) vp3frame[i], sizeof(char), framelength, video);
            if(ret!=framelength) break;
        
        state++;
      }

      if(state<1){
        /* can't get here unless VP31 stream has no video */
        fprintf(stderr,"Video input contains no frames.\n");
        exit(1);
      }

      /* Theora is a one-frame-in,one-frame-out system; submit a frame
         for compression and pull out the packet */

      //theora_encode_YUVin(td,&yuv);
      theora_transcode_bufferin( ttc, frameiskey[0], vp3frame[0], framebytecount[0]);

      /* if there's only one frame, it's the last in the stream */
      if(state<2)
        theora_transcode_packetout(ttc,1,&op);
      else
        theora_transcode_packetout(ttc,0,&op);

      ogg_stream_packetin(to,&op);

      {
        signed char *temp=vp3frame[0];
        vp3frame[0]=vp3frame[1];
        vp3frame[1] = temp;
        free(temp);
        
        framebytecount[0]= framebytecount[1];
        frameiskey[0] = frameiskey[1];
        state--;
      }
    }
  }
  return videoflag;
}

/* returns, in seconds, absolute time of current packet in given
   logical stream */
double transcode_granule_time(TC_INSTANCE *ttc,ogg_int64_t granulepos){
  if(granulepos>=0){
    ogg_int64_t iframe=granulepos>>ttc->keyframe_granule_shift;
    ogg_int64_t pframe=granulepos-(iframe<<ttc->keyframe_granule_shift);

    return (iframe+pframe)*
      ((double)ttc->fps_denominator/ttc->fps_numerator);

  }
  return(-1);
}

int main(int argc,char *argv[]){
  int c,long_option_index,ret;

  ogg_stream_state to; /* take physical pages, weld into a logical
                           stream of packets */
  ogg_stream_state vo; /* take physical pages, weld into a logical
                           stream of packets */
  ogg_page         og; /* one Ogg bitstream page.  Vorbis packets are inside */
  ogg_packet       op; /* one raw packet of data for decode */

  theora_state     td;
  theora_info      ti;
  theora_comment   tc;

  vorbis_info      vi; /* struct that stores all the static vorbis bitstream
                          settings */
  vorbis_comment   vc; /* struct that stores all the user comments */

  vorbis_dsp_state vd; /* central working state for the packet->PCM decoder */
  vorbis_block     vb; /* local working space for packet->PCM decode */

  int audioflag=0;
  int videoflag=0;
  int akbps=0;
  int vkbps=0;

  ogg_int64_t audio_bytesout=0;
  ogg_int64_t video_bytesout=0;
  double timebase;

  FILE* outfile = stdout;

  TC_INSTANCE ttc;

#ifdef _WIN32 /* We need to set stdin/stdout to binary mode. Damn windows. */
  /* if we were reading/writing a file, it would also need to in
     binary mode, eg, fopen("file.wav","wb"); */
  /* Beware the evil ifdef. We avoid these where we can, but this one we
     cannot. Don't add any more, you'll probably go to hell if you do. */
  _setmode( _fileno( stdin ), _O_BINARY );
  _setmode( _fileno( stdout ), _O_BINARY );
#endif

  while((c=getopt_long(argc,argv,optstring,options,&long_option_index))!=EOF){
    switch(c){
    case 'o':
      outfile=fopen(optarg,"wb");
      if(outfile==NULL){
        fprintf(stderr,"Unable to open output file '%s'\n", optarg);
        exit(1);
      }
      break;;

    case 'a':
      audio_q=atof(optarg)*.099;
      if(audio_q<-.1 || audio_q>1){
        fprintf(stderr,"Illegal audio quality (choose -1 through 10)\n");
        exit(1);
      }
      audio_r=-1;
      break;

    case 'v':
      video_q=rint(atof(optarg)*6.3);
      if(video_q<0 || video_q>63){
        fprintf(stderr,"Illegal video quality (choose 0 through 10)\n");
        exit(1);
      }
      video_r=0;
      break;

    case 'A':
      audio_r=atof(optarg)*1000;
      if(audio_q<0){
        fprintf(stderr,"Illegal audio quality (choose > 0 please)\n");
        exit(1);
      }
      audio_q=-99;
      break;

    case 'V':
      video_r=rint(atof(optarg)*1000);
      if(video_r<45000 || video_r>2000000){
        fprintf(stderr,"Illegal video bitrate (choose 45kbps through 2000kbps)\n");
        exit(1);
      }
      video_q=0;
     break;
    default:
      usage();
    }
  }

  while(optind<argc){
    /* assume that anything following the options must be a filename */
    id_file(argv[optind]);
    optind++;
  }

  /* yayness.  Set up Ogg output stream */
  srand(time(NULL));
  ogg_stream_init(&vo,rand());
  ogg_stream_init(&to,rand()); /* oops, add one ot the above */

  /* Set up Theora encoder */
  if(!video){
    fprintf(stderr,"No video files submitted for compression?\n");
    exit(1);
  }
  /* Theora has a divisible-by-sixteen restriction for the encoded video size */
  /* scale the frame size up to the nearest /16 and calculate offsets */
  video_x=((frame_x + 15) >>4)<<4;
  video_y=((frame_y + 15) >>4)<<4;
  frame_x_offset=(video_x-frame_x)/2;
  frame_y_offset=(video_y-frame_y)/2;

  theora_info_init(&ti);
  ti.width=video_x;
  ti.height=video_y;
  ti.frame_width=frame_x;
  ti.frame_height=frame_y;
  ti.offset_x=frame_x_offset;
  ti.offset_y=frame_y_offset;
  ti.fps_numerator=video_hzn;
  ti.fps_denominator=video_hzd;
  ti.aspect_numerator=video_an;
  ti.aspect_denominator=video_ad;
  ti.colorspace=OC_CS_UNSPECIFIED;
  ti.target_bitrate=video_r;
  ti.quality=video_q;

  ti.dropframes_p=0;
  ti.quick_p=1;
  ti.keyframe_auto_p=1;
  ti.keyframe_frequency=32768;
  ti.keyframe_frequency_force=32768;
  ti.keyframe_data_target_bitrate=video_r*1.5;
  ti.keyframe_auto_threshold=80;
  ti.keyframe_mindistance=8;
  ti.noise_sensitivity=1;

  theora_encode_init(&td,&ti);
  theora_transcoder_init(&ti, &ttc);
  theora_info_clear(&ti);

  /* initialize Vorbis too, assuming we have audio to compress. */
  if(audio){
    vorbis_info_init(&vi);
    if(audio_q>-99)
      ret = vorbis_encode_init_vbr(&vi,audio_ch,audio_hz,audio_q);
    else
      ret = vorbis_encode_init(&vi,audio_ch,audio_hz,-1,audio_r,-1);
    if(ret){
      fprintf(stderr,"The Vorbis encoder could not set up a mode according to\n"
              "the requested quality or bitrate.\n\n");
      exit(1);
    }

    vorbis_comment_init(&vc);
    vorbis_analysis_init(&vd,&vi);
    vorbis_block_init(&vd,&vb);
  }

  /* write the bitstream header packets with proper page interleave */

  /* first packet will get its own page automatically */
  theora_encode_header(&td,&op);
  ogg_stream_packetin(&to,&op);
  if(ogg_stream_pageout(&to,&og)!=1){
    fprintf(stderr,"Internal Ogg library error.\n");
    exit(1);
  }
  fwrite(og.header,1,og.header_len,outfile);
  fwrite(og.body,1,og.body_len,outfile);

  /* create the remaining theora headers */
  theora_comment_init(&tc);
  theora_encode_comment(&tc,&op);
  ogg_stream_packetin(&to,&op);
  theora_encode_tables(&td,&op);
  ogg_stream_packetin(&to,&op);

  if(audio){
    ogg_packet header;
    ogg_packet header_comm;
    ogg_packet header_code;

    vorbis_analysis_headerout(&vd,&vc,&header,&header_comm,&header_code);
    ogg_stream_packetin(&vo,&header); /* automatically placed in its own
                                         page */
    if(ogg_stream_pageout(&vo,&og)!=1){
      fprintf(stderr,"Internal Ogg library error.\n");
      exit(1);
    }
    fwrite(og.header,1,og.header_len,outfile);
    fwrite(og.body,1,og.body_len,outfile);

    /* remaining vorbis header packets */
    ogg_stream_packetin(&vo,&header_comm);
    ogg_stream_packetin(&vo,&header_code);
  }

  /* Flush the rest of our headers. This ensures
     the actual data in each stream will start
     on a new page, as per spec. */
  while(1){
    int result = ogg_stream_flush(&to,&og);
      if(result<0){
        /* can't get here */
        fprintf(stderr,"Internal Ogg library error.\n");
        exit(1);
      }
    if(result==0)break;
    fwrite(og.header,1,og.header_len,outfile);
    fwrite(og.body,1,og.body_len,outfile);
  }
  if(audio){
    while(1){
      int result=ogg_stream_flush(&vo,&og);
      if(result<0){
        /* can't get here */
        fprintf(stderr,"Internal Ogg library error.\n");
        exit(1);
      }
      if(result==0)break;
      fwrite(og.header,1,og.header_len,outfile);
      fwrite(og.body,1,og.body_len,outfile);
    }
  }

  /* setup complete.  Raw processing loop */
  fprintf(stderr,"Compressing....\n");
  while(1){


    /* is there an audio page flushed?  If not, fetch one if possible */
    audioflag=fetch_and_process_audio(audio,&audiopage,&vo,&vd,&vb,audioflag);

    /* is there a video page flushed?  If not, fetch one if possible */
    videoflag=fetch_and_process_video(video,&videopage,&to,&ttc,videoflag);

    /* no pages of either?  Must be end of stream. */
    if(!audioflag && !videoflag)break;

    /* which is earlier; the end of the audio page or the end of the
       video page? Flush the earlier to stream */
    {
      int audio_or_video=-1;
      double audiotime=
        audioflag?vorbis_granule_time(&vd,ogg_page_granulepos(&audiopage)):-1;
      double videotime=
        videoflag?transcode_granule_time(&ttc,ogg_page_granulepos(&videopage)):-1;

      if(!audioflag){
        audio_or_video=1;
      } else if(!videoflag) {
        audio_or_video=0;
      } else {
        if(audiotime<videotime)
          audio_or_video=0;
        else
          audio_or_video=1;
      }

      if(audio_or_video==1){
        /* flush a video page */
        video_bytesout+=fwrite(videopage.header,1,videopage.header_len,outfile);
        video_bytesout+=fwrite(videopage.body,1,videopage.body_len,outfile);
        videoflag=0;
        timebase=videotime;
        
      }else{
        /* flush an audio page */
        audio_bytesout+=fwrite(audiopage.header,1,audiopage.header_len,outfile);
        audio_bytesout+=fwrite(audiopage.body,1,audiopage.body_len,outfile);
        audioflag=0;
        timebase=audiotime;
      }
      {
        int hundredths=timebase*100-(long)timebase*100;
        int seconds=(long)timebase%60;
        int minutes=((long)timebase/60)%60;
        int hours=(long)timebase/3600;
        
        if(audio_or_video)
          vkbps=rint(video_bytesout*8./timebase*.001);
        else
          akbps=rint(audio_bytesout*8./timebase*.001);
        
        fprintf(stderr,
                "\n      %d:%02d:%02d.%02d audio: %dkbps video: %dkbps                 ",
                hours,minutes,seconds,hundredths,akbps,vkbps);
      }
    }

  }

  /* clear out state */

  if(audio){
    ogg_stream_clear(&vo);
    vorbis_block_clear(&vb);
    vorbis_dsp_clear(&vd);
    vorbis_comment_clear(&vc);
    vorbis_info_clear(&vi);
  }
  if(video){
    ogg_stream_clear(&to);
    theora_clear(&td);
  }

  if(outfile && outfile!=stdout)fclose(outfile);

  fprintf(stderr,"\r   \ndone.\n\n");

  return(0);

}