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• Writing decoded YUV420P data into a file with FFmpeg ?

  9 mai 2016, par Sir DrinksCoffeeALot

  I’ve read frame which is encoded with H264, decoded it, and converted it to YUV420P and the data is stored in frameYUV420->data, (type of frame is AVFrame). I want to save that data into a file that can be displayed with GIMP for example.

  I know how to save RGB25 pixel format but i’m not quite sure how to do YUV420P. Though i know that Y component will take width x height , and Cb/Cr will take (width/2) x (height/2) amount of space needed to save the data. So i’m guessing i need to first write Y data, and after that i need to write Cb and Cr data. Does anyone have finished code that i could take a look at ?

• Save the recording video chunk (Segment) into system

  10 mars 2014, par user3156324

  I am recording the video using (Logitech) webcam, and after that store this recorded mp4 format video into the device. But if recording is going on and in the middle I directly turn off the device then the video is not get recorded means it is not saved into device. Means I think it is corrupted I am not sure about that but I think.

  So I want to save the recording into the device with the video chunk when recording is going on. I don't want to save the recording into device after completion of recording. But I want to save the recording continuously when recording is going on.

  I am using ubuntu system.

  Please tell me how can I do this.

• FFmpeg decode h.264 mp4 video and save it to desktop in any format

  22 août 2016, par esadcelik

  By following ffmpeg examples i realised they don’t provide an example that decodes h.264 and save it to desktop in any way. I can decode h.264 but i cannot save it to desktop. How can i do this ?

  I can get this point but now how can i save it as a video ?

  while (1) {
  
      if ((ret = av_read_frame(fmt_ctx, &packet)) < 0)
  
          break;
  
      if (packet.stream_index == video_stream_index) {
  
          got_frame = 0;
  
          ret = avcodec_decode_video2(dec_ctx, frame, &got_frame, &packet);
  
          if (ret < 0) {
  
              av_log(NULL, AV_LOG_ERROR, "Error decoding video\n");
  
              break;
  
          }
  
          if (got_frame) {
  
              frame->pts = av_frame_get_best_effort_timestamp(frame);
  
                 .
  
                 .
  
                 .
  
                 .
  
                 .
  
                 .        
  
                 .
  
                 }
  
                  av_frame_unref(frame);
  
              }
  
          }
  
          av_packet_unref(&packet);
  
      }