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• dts to m4a (aac) ffmpeg to qaac output issue

  10 avril 2014, par user8979

  Looking to encode 2 dts 5.1 audio sources (Sonic Landscape and The Digital Experience) to m4a (aac) 5.1 with qaac 2.35. Input piped to qaac using :

  ffmpeg -report -loglevel verbose -i "input.file" -vn -f wav -codec:a pcm_f32le - | qaac --cvbr 160 --quality 2 --rate=keep --ignorelength --no-delay - -o "output.m4a"

  • Sonic Landscape duration : 18.848s, qaac output duration : 18.859s

    • output .m4a duration mismatch
    • mediainfo reports output is 2ch while mediatab and ffmpeg report output is 5.1ch (lfe)
      
      

  • The Digital Experience duration : 32.875s, qaac output duration : 32.875s

    • mediainfo reports output is 2ch while mediatab and ffmpeg report output is 5.1ch (lfe)
      
      

  1. what caused the duration mismatch in the first one ? how can it be fixed ?
  2. is the output 2ch or 5.1ch ?
     
     • if it is 2ch, what qaac option(s) leave the channels in output same as input ?
     • if the output is 5.1ch, does qaac then always preserve channels unless explicitly told otherwise ?

• pyInstaller : Pack binary executable inside project's executable to run

  18 décembre 2023, par zur

  TLDR ;

  


  I would like to pack the ffmpeg executable inside my own executable. Currently I am getting

  


  FileNotFoundError: [Errno 2] No such file or directory: 'ffmpeg'
Skipping ./testFile202312061352.mp4 due to FileNotFoundError: [Errno 2] No such file or directory: 'ffmpeg'


  


  Details :

  


  I am creating executable file using following command :

  


  pyinstaller cli.py \&#xA;  --onefile \&#xA;  --add-binary /Users/<machineuser>/anaconda3/envs/my_env/bin/ffmpeg:bin&#xA;</machineuser>

  


  The code that uses ffmpeg is not authored by me. And I would like to keep that part the same.

  


  When I run from command line while conda environment is active I can successfully run it as python (or perhaps anaconda) knows where the binaries are. I have a pretty empty cli.py. That seems to be the entry point and I hope if it is possible I can set the bin directory's path there ...

  


  I am able to successfully run the application like following :

  


  (my_env) machineUser folder % "dist/cli_mac_001202312051431" ./testFile202312061352.mp4


  


  I would like to run like following :

  


  (base) machineUser folder % "dist/cli_mac_001202312051431" ./testFile202312061352.mp4


  


  I would like to keep the world out side my executable's tmp folder the same. I would not want to change something that will be "left behind" after the exec is terminated.

  


  Question :

  


  Can some one please mention how to modify the pyinstaller command or what to change in cli.py to achieve it successfully ?

  


• How to write a text in a frame using ffmpeg

  21 février 2024, par Jorge Augusto Wilchen

  I need to write a text in every frame before write in the video file, this text will be passed as a argument (std::string or char, whatever you want to best solution). For example, write "Hello World" 24px, color yellow, position 30x30.

  


  How can i do this ?

  


  This is my function that read frames to a AVPacket and write in the video file :

  


  bool VideoRecorder::record_video()
{
    if (recording) {
        AVPacket packet;

        while (recording && av_read_frame(inputFormatContext, &packet) >= 0) {
            AVStream* in_stream = inputFormatContext->streams[packet.stream_index];
            AVStream* out_stream = outputFormatContext->streams[0];

            // Adjustment of DTS and PTS to ensure increasing monoticity
            if (packet.pts != AV_NOPTS_VALUE) {
                packet.pts = av_rescale_q_rnd(packet.pts, in_stream->time_base, out_stream->time_base, AVRounding(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
            }

            if (packet.dts != AV_NOPTS_VALUE) {
                packet.dts = av_rescale_q_rnd(packet.dts, in_stream->time_base, out_stream->time_base, AVRounding(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
            }

            packet.duration = av_rescale_q(packet.duration, in_stream->time_base, out_stream->time_base);

            packet.stream_index = 0;

            av_interleaved_write_frame(outputFormatContext, &packet);

            av_packet_unref(&packet);
        }


        return true;
    }

    std::cerr << "Error recording video. Recording not started or already stopped." << std::endl;
    return false;
}