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• C++, FFmpeg, save AVPacket infomation into videostate structure in ffplay.c

  28 mai 2015, par Yoohoo

  I am currently working on a project that tests video streaming. In the project, video stream is encoded with H.264 before send and decoded after receive, using FFmpeg codec and functions.

  I can encode video stream by

  init_video_encode(AV_CODEC_ID_H264);

  where

  static void init_video_encode(AVCodecID codec_id){
  
  codec = avcodec_find_encoder(codec_id);
  
  if (!codec) {
  
      fprintf(stderr, "Codec not found\n");
  
      exit(1);
  
  }
  
  
  
  c = avcodec_alloc_context3(codec);
  
  if (!c) {
  
      fprintf(stderr, "Could not allocate video codec context\n");
  
      exit(1);
  
  }
  
  
  
  /* put sample parameters */
  
  c->bit_rate = 400000;
  
  /* resolution must be a multiple of two */
  
  c->width = 640;
  
  c->height = 480;
  
  /* frames per second */
  
  c->time_base= (AVRational){1,25};
  
  c->gop_size = 10; /* emit one intra frame every ten frames */
  
  c->max_b_frames=max_f;
  
  c->pix_fmt = AV_PIX_FMT_YUV420P;
  
  
  
  if(codec_id == AV_CODEC_ID_H264)
  
      av_opt_set(c->priv_data, "preset", "slow", 0);
  
  
  
  /* open it */
  
  if (avcodec_open2(c, codec, NULL) < 0) {
  
      fprintf(stderr, "Could not open codec\n");
  
      exit(1);
  
  }
  
  
  
  frame = avcodec_alloc_frame();
  
  if (!frame) {
  
      fprintf(stderr, "Could not allocate video frame\n");
  
      exit(1);
  
  }
  
  frame->format = c->pix_fmt;
  
  frame->width  = c->width;
  
  frame->height = c->height;
  
  
  
  /* the image can be allocated by any means and av_image_alloc() is
  
   * just the most convenient way if av_malloc() is to be used */
  
  ret = av_image_alloc(frame->data, frame->linesize, c->width, c->height,
  
                       c->pix_fmt, 32);
  
  
  
  /* get the delayed frames */
  
  if (ret < 0) {
  
      fprintf(stderr, "Could not allocate raw picture buffer\n");
  
      exit(1);
  
  }
  
      av_init_packet(&pkt);
  
  
  
  //}
  
  
  
      pkt.data = NULL;    // packet data will be allocated by the encoder
  
      pkt.size = 0;
  
      //cout<<"\nBefore YUV\n";
  
      if(count == 0)
  
      read_yuv420(frame->data[0]);
  
      count ++;
  
     // cout<<"\nAfter YUV\n";
  
      if(count == SUBSITY) {
  
      count = 0;
  
      }
  
  
  
      frame->pts = i++;
  
  
  
      /* encode the image */
  
      ret = avcodec_encode_video2(c, &pkt, frame, &got_output);
  
      if (ret < 0) {
  
           fprintf(stderr, "Error encoding frame\n");
  
           return -1;
  
      }
  
      //cout<<"\nRecord the Video\n";
  
      if (got_output) {
  
           //printf("Write frame %3d (size=%5d)\n", i, pkt.size);
  
           //cout<<"\nBefore Memcpy\n\n\n";
  
  
  
           memcpy(inbufout+totalSize,pkt.data,pkt.size);
  
           //cout<<"\nAfter Memcpy\n\n\n";
  
           totalSize+=pkt.size;

  The video encoder works very well, if I write the encoded packet into a .h264 file, it can be played. But at the decoder side, I cannot decode the received packet with :

      codec = avcodec_find_decoder(AV_CODEC_ID_H264);
  
      if (!codec) {
  
          fprintf(stderr, "Codec not found\n");
  
          exit(1);
  
      }
  
  
  
      c = avcodec_alloc_context3(codec);
  
      if (!c) {
  
          fprintf(stderr, "Could not allocate video codec context\n");
  
          exit(1);
  
      }
  
  
  
      if(codec->capabilities&CODEC_CAP_TRUNCATED)
  
          c->flags|= CODEC_FLAG_TRUNCATED; 
  
  
  
      /* open it */
  
      if (avcodec_open2(c, codec, NULL) < 0) {
  
          fprintf(stderr, "Could not open codec\n");
  
          exit(1);
  
      }
  
  
  
      frame = avcodec_alloc_frame();
  
      if (!frame) {
  
          fprintf(stderr, "Could not allocate video frame\n");
  
          exit(1);
  
      }
  
  len = avcodec_decode_video2(avctx, frame, &got_frame, pkt);
  
      if (len < 0) {
  
          fprintf(stderr, "Error while decoding frame %d\n", *frame_count);
  
          return len;
  
      }

  The reason of failure is lacking parser, I have tried to build a parser but failed......

  Therefore I am wondering using ffplay.c as a header file in my receiver program so that I can use it as the decoder and player.

  I have took a look at ffplay.c, it actually fetch file into a videostate structure and processing it. The fetching part is from line 3188 of ffplay.c :

  VideoState *is;
  
  
  
      is = av_mallocz(sizeof(VideoState));
  
      if (!is)
  
          return NULL;
  
      av_strlcpy(is->filename, filename, sizeof(is->filename));
  
      is->iformat = iformat;
  
      is->ytop    = 0;
  
      is->xleft   = 0;
  
  
  
      /* start video display */
  
      if (frame_queue_init(&is->pictq, &is->videoq, VIDEO_PICTURE_QUEUE_SIZE, 1) < 0)
  
          goto fail;
  
      if (frame_queue_init(&is->subpq, &is->subtitleq, SUBPICTURE_QUEUE_SIZE, 0) < 0)
  
          goto fail;
  
      if (frame_queue_init(&is->sampq, &is->audioq, SAMPLE_QUEUE_SIZE, 1) < 0)
  
          goto fail;
  
  
  
      packet_queue_init(&is->videoq);
  
      packet_queue_init(&is->audioq);
  
      packet_queue_init(&is->subtitleq);
  
  
  
      is->continue_read_thread = SDL_CreateCond();
  
  
  
      init_clock(&is->vidclk, &is->videoq.serial);
  
      init_clock(&is->audclk, &is->audioq.serial);
  
      init_clock(&is->extclk, &is->extclk.serial);
  
      is->audio_clock_serial = -1;
  
      is->av_sync_type = av_sync_type;
  
      is->read_tid     = SDL_CreateThread(read_thread, is);
  
      if (!is->read_tid) {
  
  fail:
  
          stream_close(is);
  
          return NULL;
  
      }

  Now instead of fetching file, I want to modify ffplay.c code so that let it fetch the received packet, I can save received packet to AVPacket by

  static AVPacket avpkt;
  
  avpkt.data = inbuf;

  My question is : how to put AVPacket information into videostate structure ?

• FFmpeg Stream RTSP input and save to file at the same time using nodejs

  26 juin 2015, par Ofir Attia

  I am using node-rtsp-stream module to stream RTSP to web with nodejs.
  I am streaming RTSP source with ffmpeg, for example RTSP SOURCE - EXAMPLE

  I know that I can save one or many inputs to many outputs but I dont know if there is option to stream the input and save it to file at the same time without executing two process of ffmpeg.
  With the following example I am able to stream the RTSP source
  

  ffmpeg -i rtsp-url -rtsp_transport tcp -f  mpeg1video -b:v 800k -r 30  

  On the module is look like that :
  

  this.stream = child_process.spawn("ffmpeg", [ "-i", this.url, "-rtsp_transport", "tcp",'-f', 'mpeg1video', '-b:v', '800k', '-r', '30', '-'], {
  
        detached: false
  
      });
  
      ff =child_process.spawn("ffmpeg", [ "-i", this.url,  '-b:v', '800k', '-r', '30', '1.mp4'], {
  
        detached: false
  
      });
  
      this.inputStreamStarted = true;
  
      this.stream.stdout.on('data', function(data) {
  
        return self.emit('mpeg1data', data);
  
      });
  
      this.stream.stderr.on('data', function(data) {
  
        return self.emit('ffmpegError', data);
  
      });

  As you can see I am using two process of ffmpeg to do what I want but
  If anyone faced with this issue and solve it with one command ( process ), I would like to get some suggestions.
  How to stream RTSP source and save it to file at the same time.

  for more information about the module I use :
  node-rtsp-stream
  

• Fluent ffmpeg how to user save callback

  7 août 2018, par Desert P

  I am using fluent-ffmpeg
  GIT
  I want to further process the saved file. But save do not have any callback. how can I use the saved file with promise.
  My code is

  ffmpeg(filename)
  
      .toFormat('mp3')
  
      .on('error', (err) => {
  
         console.log('An error occurred: ' + err.message);
  
      })
  
      .on('progress', (progress) => {
  
          console.log('Processing: ' + progress.targetSize + ' KB converted');
  
  })
  
  .on('end', () => {
  
          console.log('Processing finished !');
  
  })
  
  .save(`./${newname}.mp3`)

  My problem is "save" function do not have a callback. so how could I save the output on S3 again ?