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• ffmpeg - how to handle video and audio URL's streams separately ?

  13 mai 2022, par Rubem Pacelli

  I am trying to create a zsh function that uses youtube-dl and ffmpeg to download a portion of a YouTube video. I did achieve this goal with the following function :

  


  # $1 - youtube URL
# $2 - start position in hh:mm:ss.msms format (ms=miliseconds)
# $3 - final position in hh:mm:ss.msms format (ms=miliseconds)
# $4 - output file name (optional)
function youtubedl_snippet()(
  local url_stream=$(youtube-dl -f best --get-url $1)
  local output_name=$(youtube-dl --get-title $1)

  ffmpeg -ss $2 -to $3 -i $url_stream -c:v copy -c:a copy ${4:-"$output_name.mp4"}
)


  


  The command youtube-dl -f best --get-url $1 return a single URL with the best possible quality. In order to understand better how ffmpeg works, I tried to create another function with the same goal but with a different approach :

  


  # $1 - youtube URL
# $2 - start position in hh:mm:ss.msms format (ms=miliseconds)
# $3 - final position in hh:mm:ss.msms format (ms=miliseconds)
# $4 - output file name (optional)
# $5 - output video codec type (optional, for instance: libx264)
# $6 - output audio codec type (optional, for instance: aac)
function youtubedl_snippet2()(
  local url_streams=$(youtube-dl --get-url $1)
  local output_name=$(youtube-dl --get-title $1)

  local url_array=(${(f)url_streams}) # expand urls by lines url_array[1] -> video stream url_array[2] -> audio stream

  ffmpeg -ss $2 -to $3 -i ${url_array[1]} -ss $2 -to $3 -i ${url_array[2]} -map 0:v -map 1:a -c:v ${5:-copy} -c:a ${6:-copy} ${4:-"$output_name.mp4"}
)


  


  What I suppose that is going on here :

  


  

  1. url_streams is a line-separated URL. url_array[1] is the video URL and url_array[2] is the audio URL.

  


  2. I am setting both audio and video to the same intervals.

  


  3. I mapped the first stream to video, and the second to audio

  


  4. If $5 and $6 does not give different codecs, ffmpeg just copy from the original source.

  


  


  Well, it seems that everything is ok. But when I try

  


  start=$SECONDS; youtubedl_snippet2 'https://www.youtube.com/watch?v=g-_hVXzkn0o' 00:00:05.00 00:00:15.00; echo "it takes $(( SECONDS - start )) seconds"


  


  It will take 368 seconds. Moreover, I cannot open it in my android (only audio works)

  


  

  


  On the other hand,

  


  start=$SECONDS; youtubedl_snippet 'https://www.youtube.com/watch?v=g-_hVXzkn0o' 00:00:05.00 00:00:15.00; echo "it takes $(( SECONDS - start )) seconds"


  


  takes only 40 seconds, and the video can be played on Android.

  


  Here is the youtubedl_snippet log file. And here is the youtubedl_snippet2 log file.

  


• ffmpeg hangs when muxing longer videos

  11 août 2020, par 492357816

  I am using ffmpeg with Janus WebRTC server for muxing video conference recordings. For video conferences under approximaately 5 minutes duration, existing code works well. If the source files are longer than that the process appears to hang without returning either an error or a completed file.
Any advice/suggestions would be most welcome.

  


      var recordingsPath = exports.recordingsPath;
    var videoRecordingPath = `${recordingsPath}/${filename}-video.mjr`;
    var audioRecordingPath = `${recordingsPath}/${filename}-audio.mjr`;
    var videoOutputPath = `${recordingsPath}/${filename}-output1.mp4`;
    var audioOutputPath = `${recordingsPath}/${filename}-output1.wav`;
    var finalOutputPath = `${recordingsPath}/${filename}-final.mp4`;
    var rawConverterPath = "/opt/janus/bin/janus-pp-rec";
    var audioRecordingByteSize = exports.getFileSizeInBytes(audioRecordingPath);
    var audioIsValid = audioRecordingByteSize > 8;

    if (audioIsValid) {
        //turn audio and video mjr files into .wav and mp4 respectively
        exports.runBashSync([ rawConverterPath, videoRecordingPath, videoOutputPath]);
        exports.runBashSync([ rawConverterPath, audioRecordingPath, audioOutputPath]);
        return exports.mergeMp4AndWav(
            audioOutputPath, videoOutputPath, finalOutputPath
        ).then(function(result) {
            // remove source data for audio & video
            exports.runBashSync([ "rm", audioOutputPath]);
            exports.runBashSync([ "rm", videoOutputPath]);
            exports.runBashSync([ "rm", audioRecordingPath]);
            exports.runBashSync([ "rm", videoRecordingPath]);
        });
    } else {
        // handle cases where audio is not available
        feedback("no audio");
        return new Promise(function(resolve) {
            exports.runBashSync([ rawConverterPath, videoRecordingPath, finalOutputPath], true);
            if (Number.isInteger(audioRecordingByteSize)) {
                exports.runBashSync([ "rm", audioRecordingPath]);
            }
            exports.runBashSync([ "rm", videoRecordingPath]);
            resolve(true);
        });
    }
};

exports.joinMp4s = function(mp4Filenames, outputPath) {
    feedback("joining mp4s");
    if (mp4Filenames.length === 1) {
        feedback("single-stream case");
        exports.runBashSync(["mv", mp4Filenames[0], outputPath]);
        return new Promise(function(resolve) { resolve(true); });
    }
    feedback("multi-stream case");
    var joinCmd = ["ffmpeg"];
    mp4Filenames.forEach(function(filename) {
        joinCmd.push(`-i ${filename}`);
    });
    joinCmd.push("-strict -2");
    var totalHeight = 960;
    var totalWidth = 1280;

    joinCmd.push(`-filter_complex "color=size=${totalWidth}x${totalHeight}:c=Black [base];`);

    // var numStrms = mp4Filenames.length;
    var streamsPattern = exports.setStreamsPattern(mp4Filenames);
    var strmHeight = streamsPattern.height;
    var strmWidth = streamsPattern.width;
    var strmDmns = `${strmWidth}x${strmHeight}`;
    feedback("streamDimensions: " + strmDmns);

    var i;
    for (i = 0; i < mp4Filenames.length; i++) {
        joinCmd.push(`[${i}:v] setpts=PTS-STARTPTS, scale=${strmDmns} [temp${i}];`);
    }
    for (i = 0; i < mp4Filenames.length; i++) {
        var xCoord;
        var yCoord;
        if (i === 0) {
            xCoord = streamsPattern.coords[i].xCoord;
            yCoord = streamsPattern.coords[i].yCoord;
            joinCmd.push(`[base][temp${i}] overlay=shortest=1:x=${xCoord}:y=${yCoord} [tmp${i + 1}];`);
            // joinCmd.push(`[base][temp${i}] overlay=shortest=1 [tmp${i + 1}];`);
        } else {
            var cmd = `[tmp${i}][temp${i}] overlay=shortest=1`;
            xCoord = streamsPattern.coords[i].xCoord;
            yCoord = streamsPattern.coords[i].yCoord;

            if (xCoord) { cmd += ":x=" + xCoord; }
            if (yCoord) { cmd += ":y=" + yCoord; }

            if (i + 1 !== mp4Filenames.length) { cmd += ` [tmp${i + 1}];`; }
            joinCmd.push(cmd);
        }
    }

    joinCmd.push(`" ${outputPath}`);
    feedback("join command: " + joinCmd);
    return exports.runBashAsync(joinCmd).then(function(result) {

        mp4Filenames.forEach(function(filename) {
            feedback("removing: " + filename);
            exports.runBashSync(`rm ${filename}`);
        });
    });
};



  


• FFMPEG hangs when trying to receive rtp/udp stream

  22 décembre 2016, par NathanK

  I am trying to receive a udp stream encoded as h264. The exact command I am using is :

  ffmpeg -v 9 -loglevel 99 -re -i "udp://239.192.1.2:1234" outfile.h264

  The output I receive is :

  ffmpeg version 3.2.2-1 Copyright (c) 2000-2016 the FFmpeg developers
  
    built with gcc 6.2.1 (Debian 6.2.1-5) 20161124
  
  
  
  
  
  configuration: --prefix=/usr --extra-version=1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libebur128 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librubberband --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-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libiec61883 --enable-libopencv --enable-frei0r --enable-libx264 --enable-chromaprint --enable-shared
  
    libavutil      55. 34.100 / 55. 34.100
  
    libavcodec     57. 64.101 / 57. 64.101
  
    libavformat    57. 56.100 / 57. 56.100
  
    libavdevice    57.  1.100 / 57.  1.100
  
    libavfilter     6. 65.100 /  6. 65.100
  
    libavresample   3.  1.  0 /  3.  1.  0
  
    libswscale      4.  2.100 /  4.  2.100
  
    libswresample   2.  3.100 /  2.  3.100
  
    libpostproc    54.  1.100 / 54.  1.100
  
  Splitting the commandline.
  
  Reading option '-v' ... matched as option 'v' (set logging level) with argument '9'.
  
  Reading option '-loglevel' ... matched as option 'loglevel' (set logging level) with argument '99'.
  
  Reading option '-re' ... matched as option 're' (read input at native frame rate) with argument '1'.
  
  Reading option '-i' ... matched as input url with argument 'udp://@239.192.1.2:1234'.
  
  Reading option 'outffff.h264' ... matched as output url.
  
  Finished splitting the commandline.
  
  Parsing a group of options: global .
  
  Applying option v (set logging level) with argument 9.
  
  Successfully parsed a group of options.
  
  Parsing a group of options: input url udp://@239.192.1.2:1234.
  
  Applying option re (read input at native frame rate) with argument 1.
  
  Successfully parsed a group of options.
  
  Opening an input file: udp://@239.192.1.2:1234.
  
  [udp @ 0x7f6638a36280] No default whitelist set
  
  [udp @ 0x7f6638a36280] end receive buffer size reported is 131072
  
  [AVIOContext @ 0x7f6638a56840] Statistics: 0 bytes read, 0 seeks

  The problem with this is, obviously, that the ffmpeg process isn’t detecting any incoming packets on that address which causes the process to hang.
  I am, however, able to receive the stream using vlc, so I know that the packets are arriving. Here is a link to a similar problem.

  I thought, perhaps, it was a problem with reverse path filtering (as is mentioned in the link), but rp_filter is not set in /etc/sysctl.conf. I’m not quite sure what to do from here, any help is appreciated.

  Edit : I removed the @, however this changes nothing.

  The vlc command that works is :

  vlc --miface eth1 rtp://@239.192.1.2:1234