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• Minimal sample of muxing two streams with no reencoding (av_interleaved_write_frame fails)

  19 juillet 2022, par Alvein

  What I'm trying to do : having two files, one is video-only and the other is audio-only, with identical durations, I want to "join" them in a single container.

  


  I previously made a routine which just copied all the streams inside a container to another one. No reencoding, etc. This works perfectly :

  


  while(true) {
    pkIn=av_packet_alloc();
    if(NULL==pkIn) {
        fprintf(stderr,"av_packet_alloc() failed");
        break;
    }
    iError=av_read_frame(fcIn,pkIn);
    if(0>iError)
        if(AVERROR_EOF==iError)
            break;
        else {
            fprintf(stderr,"av_read_frame() failed");
            break;
        }
    stIn=fcIn->streams[pkIn->stream_index];
    stOut=fcOut->streams[pkIn->stream_index];
    log_packet(fcIn,pkIn,"in");
    av_packet_rescale_ts(pkIn,stIn->time_base,stOut->time_base);
    pkIn->pos=-1;
    log_packet(fcOut,pkIn,"out");
    iError=av_interleaved_write_frame(fcOut,pkIn);
    if(0>iError) {
        fprintf(stderr,"av_interleaved_write_frame() failed");
        break;
    }
    av_packet_free(&pkIn);
}


  


  I just did the analogy and tried to do the same, but taking each stream from a distinct container, like this :

  


  while(true) {
    if(!bVideoInEOF) {
        pkVideoIn=av_packet_alloc();
        if(NULL==pkVideoIn) {
            fprintf(stderr,"av_packet_alloc(video in) failed");
            break;
        }
        iError=av_read_frame(fcVideoIn,pkVideoIn);
        if(0>iError)
            if(AVERROR_EOF==iError)
                bVideoInEOF=true;
            else {
                fprintf(stderr,"av_read_frame(video in) failed");
                break;
            }
        if(!bVideoInEOF) {
            log_packet(fcVideoIn,pkVideoIn,"video in");
            av_packet_rescale_ts(pkVideoIn,stVideoIn->time_base,stVideoOut->time_base);
            pkVideoIn->pos=-1;
            pkVideoIn->stream_index=stVideoOut->index; // Edit (2022-07-19)
            log_packet(fcVideoIn,pkVideoIn,"video out");
            iError=av_interleaved_write_frame(fcOut,pkVideoIn);
            if(0>iError) {
                fprintf(stderr,"av_interleaved_write_frame(video out) failed");
                break;
            }
        }
        av_packet_free(&pkVideoIn);
    }
    if(!bAudioInEOF) {
        pkAudioIn=av_packet_alloc();
        if(NULL==pkAudioIn) {
            fprintf(stderr,"av_packet_alloc(audio in) failed");
            break;
        }
        iError=av_read_frame(fcAudioIn,pkAudioIn);
        if(0>iError)
            if(AVERROR_EOF==iError)
                bAudioInEOF=true;
            else {
                fprintf(stderr,"av_read_frame(audio in) failed");
                break;
            }
        if(!bAudioInEOF) {
            log_packet(fcAudioIn,pkAudioIn,"audio in");
            av_packet_rescale_ts(pkAudioIn,stAudioIn->time_base,stAudioOut->time_base);
            pkAudioIn->pos=-1;
            pkAudioIn->stream_index=stAudioOut->index; // Edit (2022-07-19)
            log_packet(fcAudioIn,pkAudioIn,"audio out");
            iError=av_interleaved_write_frame(fcOut,pkAudioIn);
            if(0>iError) {
                fprintf(stderr,"av_interleaved_write_frame(audio out) failed");
                break;
            }
        }
        av_packet_free(&pkAudioIn);
    }
    if(bVideoInEOF&&bAudioInEOF)
        break;
}


  


  I know the previous code looks like redundant but I wanted to leave both streams "processing" separated the way you understand my plans.

  


  Anyway, that code ends quickly with "av_interleaved_write_frame(audio out) failed".

  


  The error detail is "Invalid argument", and the debugger shows this :

  


  


  Application provided invalid, non monotonically increasing dts to
muxer in stream 0.

  


  


  If I disable any of the main blocks "if(!bVideoInEOF)" / "if(!bAudioInEOF)", the file is written successfully, with the obvious lack of the disabled stream.

  


  I'm new into using this library so probably I'm doing something really stupid, or missing something obvious.

  


  Suggestions ?

  


  Edit (2022-07-19) :

  


  By checking the logs, I noticed I was writing every frame to the stream #0. Hence, the horrible jumps in PTS/DTS.

  


  Code edited by adding the corresponding "...->stream_index=" before each call to av_interleaved_write_frame().

  


  ...

  


  Though it works, I still think my code is far from perfect. Comments are welcome.

  


• FFMPEG Screen record using AMD GPU encoder in Arch linux

  23 décembre 2020, par Lucas Martins Soares

  I am trying to record my screen with the GPU encoder using the following command :

  


  ffmpeg -vaapi_device /dev/dri/renderD128 -f x11grab -video_size 1440x900 -i :0 -vf 'hwupload,scale_vaapi=format=nv12' -c:v h264_vaapi -qp 24 output.mp4

  


  But I get the following error :

  


  [h264_vaapi @ 0x565330f47580] Driver does not support some wanted packed headers (wanted 0xd,
found 0x1).

  


  the recording starts well but when i finish a 3 second video it takes 3 minutes to process and the
result is an almost slow motion video.

  


  My drivers :

  


  xf86-video-amdgpu 19.1.0-2
xf86-video-ati 1:19.1.0-2
xf86-video-fbdev 0.5.0-2
xf86-video-vesa 2.5.0-1
libva-mesa-driver 20.3.1-1
mesa 20.3.1-1
opencl-mesa 20.3.1-1


  


  vainfo :

  


  
vainfo: VA-API version: 1.10 (libva 2.10.0)
vainfo: Driver version: Mesa Gallium driver 20.3.1 for AMD VERDE (DRM 2.50.0, 5.9.14-arch1-1, LLVM 11.0.0)
vainfo: Supported profile and entrypoints
      VAProfileMPEG2Simple            : VAEntrypointVLD
      VAProfileMPEG2Main              : VAEntrypointVLD
      VAProfileVC1Simple              : VAEntrypointVLD
      VAProfileVC1Main                : VAEntrypointVLD
      VAProfileVC1Advanced            : VAEntrypointVLD
      VAProfileH264ConstrainedBaseline: VAEntrypointVLD
      VAProfileH264ConstrainedBaseline: VAEntrypointEncSlice
      VAProfileH264Main               : VAEntrypointVLD
      VAProfileH264Main               : VAEntrypointEncSlice
      VAProfileH264High               : VAEntrypointVLD
      VAProfileH264High               : VAEntrypointEncSlice
      VAProfileNone                   : VAEntrypointVideoProc



  


• Combining audio and multiple videos with FFMPEG [closed]

  6 novembre 2023, par Lee P

  I am working on a ffmpeg script to combine two videos with one audio file. The first video file should start after about 6 seconds and the second after about 40 seconds, and there should be a padding with a black screen between the two videos.
However, it only seems to add the first video clones the final frame as the padding.

  


  Here is my current script :

  


  ffmpeg -i video_0.mp4 -i video_1.mp4 -i audio.mp4 -filter_complex "[0:v] tpad=start_duration=5927ms:start_mode=add:color=black:stop_mode=add:color=black; [1:v] tpad=start_duration=44901ms:start_mode=add:color=black:stop_mode=add:color=blackconcat=n=2" -map 2:a -f mp4 -movflags +faststart composite_recording.mp4


  


  The final video timing should be :

  


  00:00-00:06 — black screen
  
00:06-00:24 — first video
  
00:24-00:40 — black screen
  
00:40-00:48 — second video

  


  I tried setting different values for the tpad start_duration for the second video and expected it to start the second video at around 40 seconds into the audio, however it didn't change anything.