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• Why frame->pts increases by 20, rather than by 1 ?

  19 mars 2013, par user1914692

  Following the exmaples of ffmpeg : decoding_encoding.c and filtering_video.c, I process one video file taken by iPhone. The video file : .mov, video dimensions ; 480x272, video Codec : H.264/AVC, 30 frames per second, bitrate : 605 kbps.

  I first extract each frame, which is YUV.
  I convert YUV to RGB24, and process the RGB24, then write the RGB24 to a .ppm file. It shows the .ppm file is correct.

  Then I plan to encode processed RGB24 frames to a video file.
  Since MPEG does not support RGB24 picture format, I used AV_CODEC_ID_HUFFYUV.
  But the output video file (showing 18.5 MB) does not play. Movie Player on Ubuntu claims an error : Could not determine type of stream.
  I also tried it on VCL. It simply does not work, without any error information.

  My second questions is :
  For each extracted fram from the input video file, I get its pts as follows according to filtering_video.c :

  frame->pts = av_frame_get_best_effort_timestamp(frame);

  I print out each frame's pts, and find that it increases by 20, like below :

  pFrameRGB_count: 0,  frame->pts: 0
  
  pFrameRGB_count: 1,  frame->pts: 20
  
  pFrameRGB_count: 2,  frame->pts: 40
  
  pFrameRGB_count: 3,  frame->pts: 60

  Where frame is the extracted frame from the input video, and pFrameRGB_count is the count for processed frame in RGB24 form.

  Why are they wrong ?

• ffmpeg stream video file from ubuntu to youtube

  14 mars 2018, par user3010452

  I’m trying to create a stream to youtube. I could see how preview button changes into enable state. However it never actually changes from offline.
  And it gives me several error. What am I doing wrong ?

       ffmpeg -i video.flv -f flv rtmp://a.rtmp.youtube.com/live2/XXXXXX
  
  
  
  
  
    ffmpeg version 2.8.11-0ubuntu0.16.04.1 Copyright (c) 2000-2017 the FFmpeg developers
  
  
  
        built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.4) 20160609
  
        configuration: --prefix=/usr --extra-version=0ubuntu0.16.04.1 --build-suffix=-ffmpeg --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --cc=cc --cxx=g++ --enable-gpl --enable-shared --disable-stripping --disable-decoder=libopenjpeg --disable-decoder=libschroedinger --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzvbi --enable-openal --enable-opengl --enable-x11grab --enable-libdc1394 --enable-libiec61883 --enable-libzmq --enable-frei0r --enable-libx264 --enable-libopencv
  
        libavutil      54. 31.100 / 54. 31.100
  
        libavcodec     56. 60.100 / 56. 60.100
  
        libavformat    56. 40.101 / 56. 40.101
  
        libavdevice    56.  4.100 / 56.  4.100
  
        libavfilter     5. 40.101 /  5. 40.101
  
        libavresample   2.  1.  0 /  2.  1.  0
  
        libswscale      3.  1.101 /  3.  1.101
  
        libswresample   1.  2.101 /  1.  2.101
  
        libpostproc    53.  3.100 / 53.  3.100
  
      Input #0, flv, from 'video.flv':
  
        Metadata:
  
          major_brand     : qt  
  
          minor_version   : 0
  
          compatible_brands: qt  
  
          com.apple.quicktime.creationdate: 2017-07-20T21:44:12+0700
  
          com.apple.quicktime.make: Apple
  
          com.apple.quicktime.model: iPhone 6s Plus
  
          com.apple.quicktime.software: 10.3.2
  
          encoder         : Lavf57.83.100
  
        Duration: 00:01:15.24, start: 0.000000, bitrate: 4454 kb/s
  
          Stream #0:0: Video: flv1, yuv420p, 1920x1080, 200 kb/s, 29.97 fps, 29.97 tbr, 1k tbn, 1k tbc
  
          Stream #0:1: Audio: adpcm_swf, 44100 Hz, mono, s16, 176 kb/s
  
      Output #0, flv, to 'rtmp://a.rtmp.youtube.com/XXXXXX':
  
        Metadata:
  
          major_brand     : qt  
  
          minor_version   : 0
  
          compatible_brands: qt  
  
          com.apple.quicktime.creationdate: 2017-07-20T21:44:12+0700
  
          com.apple.quicktime.make: Apple
  
          com.apple.quicktime.model: iPhone 6s Plus
  
          com.apple.quicktime.software: 10.3.2
  
          encoder         : Lavf56.40.101
  
          Stream #0:0: Video: flv1 (flv) ([2][0][0][0] / 0x0002), yuv420p, 1920x1080, q=2-31, 200 kb/s, 29.97 fps, 1k tbn, 29.97 tbc
  
          Metadata:
  
            encoder         : Lavc56.60.100 flv
  
          Stream #0:1: Audio: mp3 (libmp3lame) ([2][0][0][0] / 0x0002), 44100 Hz, mono, s16p
  
          Metadata:
  
            encoder         : Lavc56.60.100 libmp3lame
  
      Stream mapping:
  
        Stream #0:0 -> #0:0 (flv1 (flv) -> flv1 (flv))
  
        Stream #0:1 -> #0:1 (adpcm_swf (native) -> mp3 (libmp3lame))
  
      Press [q] to stop, [?] for help
  
      [flv @ 0x162bac0] Failed to update header with correct duration.ate=4125.4kbits/s    
  
      [flv @ 0x162bac0] Failed to update header with correct filesize.
  
      frame= 2255 fps=114 q=31.0 Lsize=   37863kB time=00:01:15.24 bitrate=4122.0kbits/s    
  
      video:37194kB audio:588kB subtitle:0kB other streams:0kB global 

  headers:0kB mixing overhead : 0.213941%

• ffmpeg : Continiously encode and append base64 data chunks into output file

  11 février 2021, par O.O

  I have a .mov file thats being written into by my iphone cam saved as input.mov and I have a script that's reading the currently updating file and I am trying to encode the video and audio codec into a .mkv container.

  


  I have little knowledge of this tool, but looking at similar Q/A's around ffmpeg usage I have found little on using base64 as input. But it is documented by ffmpeg for images, so I assume it is possible and I have also used data:video/mp4 since these file types are very similar.

  


  I have :

  


  const ifRecordingStream = await fs.readStream('input.mov', 'base64', 4095);
ifRecordingStream.open();

ifRecordingStream.onData((chunk) => 
    execute(`ffmpeg -f concat -i "data:video/mp4;base64,${chunk} -c:v h264 -c:a aac output.mkv")
);


  


  onData() currently throws Line {}: unknown keyword {}

  


  Is my command wrong ?

  


  ffmpeg -f concat -i "data:video/mp4;base64,${chunk}" -c:v h264 -c:a aac output.mkv

  


  Any help at all is welcomed.