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• avcodec/prores_ks : use official quant_matrix (for proxy and xq codec luma and chroma...

  13 avril 2018, par Martin Vignali

  avcodec/prores_ks : use official quant_matrix (for proxy and xq codec luma and chroma quant matrix is not the same)
  disable the use of the official luma xq matrix for now (output
  
  appear to be desaturate)
  

  • [DH] libavcodec/proresenc_kostya.c

• Solved - FFMPEG to Youtube Live - YouTube is not currently receiving data [duplicate]

  14 mars 2018, par Mickael Tzanakakis

  This question already has an answer here :

  • How to Live Stream YouTube without Audio [closed]
    
    1 answer
    
  • YouTube live says not receiving data
    
    1 answer
    

  Since a while, I would like to stream a video to the Youtube Live with FFMPEG. I tried a lot of configurations differents but nothing to the Youtube Dashboard. Every time Youtube feel something :

  Launch in progress

  and finally :

  "YouTube is not currently receiving
  data for this stream. If you believe this is incorrect, ensure you’re
  sending a stream and that it is configured with the correct stream
  key."

  I tried those scripts :

  https://gist.github.com/olasd/9841772

  https://github.com/scivision/PyLivestream

  and a lot ffmpeg command but ... no result.

  Exemple :

  ffmpeg -r 24 -f image2 -s 1920x1080 -i test.mp4 -vcodec libx264 -crf 25 -pix_fmt yuv420p -f flv rtmp://a.rtmp.youtube.com/live2/KEY
  
  
  
  ffmpeg -re -i test.mp4 -c:v libx264 -preset veryfast -maxrate 3000k \ -bufsize 6000k -pix_fmt yuv420p -g 50 -c:a aac -b:a 160k -ac 2 \ -ar 44100 -f flv rtmp://a.rtmp.youtube.com/live2/KEY

  If I replace rtmp ://a.rtmp.youtube.com/live2/ by "stream.flv" for exemple, I have the good result in this file.

  Unfortunately the differents topic on this didn’t help me ;
  Any idea please ?

  Thank you !

  PS : I success only with a desktop software : OBS Studio but is not my goal.

• Trying to fix VPlayer's seeking ability, need some guidance [Android FFmpeg]

  1er juin 2016, par vxh.viet

  I’m trying to fix the currently broken seeking ability of VPlayer which is a FFmpeg player for Android. Being a Java developer, C code looks like alien language to me so can only fix it using common logic (which could make any C veteran have a good laugh).

  The relevant file is player.c and I’ll try my best to point out the relevant modification.

  So the basic idea is because FFmpeg’s av_seek_frame is very inaccurate even with AVSEEK_FLAG_ANY so I’m trying to follow this suggestion to seek backward to the nearest keyframe and then decode to the frame I want. One addition note is since I want to seek based on millisecond while the said solution show the way to seek by frame which is potentially a source of problem.

  In the Player I add the following fields :

  struct Player{
  
  ....
  
  AVFrame *frame;
  
  int64_t current_time_stamp;
  
  }; 

  In the player_read_from_stream I modify the seeking part as :

  void * player_read_from_stream(void *data) {
  
      ...
  
      struct DecoderData *decoder_data = data;
  
      int stream_no = decoder_data->stream_no;
  
      AVCodecContext * ctx = player->input_codec_ctxs[stream_no];
  
      ...
  
      // seeking, start my stuff
  
      if(av_seek_frame(player->input_format_ctx, seek_input_stream_number, seek_target, AVSEEK_FLAG_BACKWARD) >= 0){
  
          //seek to key frame success, now need to read every frame from the key frame to our target time stamp
  
  
  
  
  
          while(player->current_time_stamp < seek_target){
  
  
  
              int frame_done;
  
  
  
              while (av_read_frame(player->input_format_ctx, &packet) >= 0) {
  
                  if (packet.stream_index == seek_input_stream_number) {
  
  
  
                      avcodec_decode_video2(ctx, player->frame, &frame_done, &packet);
  
                      LOGI(1,"testing_stuff ctx %d", *ctx);
  
                      if (frame_done) {
  
  
  
                          player->current_time_stamp = packet.dts;
  
                          LOGI(1,"testing_stuff current_time_stamp: %"PRId64, player->current_time_stamp);
  
                          av_free_packet(&packet);
  
                          return;
  
                      }
  
                  }
  
                  av_free_packet(&packet);
  
              }
  
          }
  
  
  
  
  
      }
  
      //end my stuff
  
  
  
      LOGI(3, "player_read_from_stream seeking success");
  
  
  
      int64_t current_time = av_gettime();
  
      player->start_time = current_time - player->seek_position;
  
      player->pause_time = current_time;        
  
  }

  And in player_alloc_frames I allocate the memory for my frame as :

  int player_alloc_frames(struct Player *player) {
  
      int capture_streams_no = player->caputre_streams_no;
  
      int stream_no;
  
      for (stream_no = 0; stream_no < capture_streams_no; ++stream_no) {
  
          player->input_frames[stream_no] = av_frame_alloc();
  
  
  
          //todo: test my stuff
  
          player->frame = av_frame_alloc();
  
          //end test
  
  
  
          if (player->input_frames[stream_no] == NULL) {
  
              return -ERROR_COULD_NOT_ALLOC_FRAME;
  
          }
  
      }
  
      return 0;
  
  }

  Currently it just keep crashing and being a typical Android NDK’s "feature", it just provide a super helpful stack trace :

  libc: Fatal signal 11 (SIGSEGV), code 1, fault addr 0x40 in tid 2717 (FFmpegReadFromS)

  I very much appreciate if anyone could help me solve this problem. Thank you for your time.