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• What is the best way to merge .mkv and .mka files using ffmpeg ?

  28 juin 2017, par Robert

  I’m using ffmpeg to merge .mkv and .mka files into .mp4 files. My current command looks like this :

  ffmpeg -i video.mkv -i audio.mka output_path.mp4

  The audio and video files are pre-signed urls from Amazon S3. Even on a server with sufficient resources, this process is going very slowly. I’ve researched situations where you can tell ffmpeg to skip re-encoding each frame, but I think that in my situation it actually does need to re-encode each frame.

  I’ve downloaded 2 sample files to my macbook pro and have installed ffmpeg locally via homebrew. When I run the command

  ffmpeg -i video.mkv -i audio.mka -c copy output.mp4

  I get the following output :

  ffmpeg version 3.3.2 Copyright (c) 2000-2017 the FFmpeg developers
  
    built with Apple LLVM version 8.1.0 (clang-802.0.42)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.3.2 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-vda
  
    libavutil      55. 58.100 / 55. 58.100
  
    libavcodec     57. 89.100 / 57. 89.100
  
    libavformat    57. 71.100 / 57. 71.100
  
    libavdevice    57.  6.100 / 57.  6.100
  
    libavfilter     6. 82.100 /  6. 82.100
  
    libavresample   3.  5.  0 /  3.  5.  0
  
    libswscale      4.  6.100 /  4.  6.100
  
    libswresample   2.  7.100 /  2.  7.100
  
    libpostproc    54.  5.100 / 54.  5.100
  
  Input #0, matroska,webm, from '319_audio_1498590673766.mka':
  
    Metadata:
  
      encoder         : GStreamer matroskamux version 1.8.1.1
  
      creation_time   : 2017-06-27T19:10:58.000000Z
  
    Duration: 00:00:03.53, start: 2.831000, bitrate: 50 kb/s
  
      Stream #0:0(eng): Audio: opus, 48000 Hz, stereo, fltp (default)
  
      Metadata:
  
        title           : Audio
  
  Input #1, matroska,webm, from '319_video_1498590673766.mkv':
  
    Metadata:
  
      encoder         : GStreamer matroskamux version 1.8.1.1
  
      creation_time   : 2017-06-27T19:10:58.000000Z
  
    Duration: 00:00:03.97, start: 2.851000, bitrate: 224 kb/s
  
      Stream #1:0(eng): Video: vp8, yuv420p(progressive), 640x480, SAR 1:1 DAR 4:3, 30 tbr, 1k tbn, 1k tbc (default)
  
      Metadata:
  
        title           : Video
  
  [mp4 @ 0x7fa4f0806800] Could not find tag for codec vp8 in stream #0, codec not currently supported in container
  
  Could not write header for output file #0 (incorrect codec parameters ?): Invalid argument
  
  Stream mapping:
  
    Stream #1:0 -> #0:0 (copy)
  
    Stream #0:0 -> #0:1 (copy)
  
      Last message repeated 1 times

  So it appears that the specific encodings I’m working with are vp8 videos and opus audio files, which I believe are incompatible with the .mp4 output container. I would appreciate answers that cover ways of optimally merging vp8 and opus into .mp4 output or answers that point me in the direction of output media formats that are both compatible with vp8 & opus and are playable on web and mobile devices so that I can bypass the re-encoding step altogether.

  EDIT :

  Just wanted to provide a benchmark after following LordNeckbeard’s advice :

  4 min 41 second video transcoded locally on my mac
  
  
  
  LordNeckbeard’s approach : 15 mins 55 seconds (955 seconds)
  
  Current approach : 18 mins 49 seconds (1129 seconds)
  
  
  
  18% speed increase

• Use Java FFmpeg wrapper, or simply use Java runtime to execute FFmpeg ?

  8 décembre 2024, par Beier

  I'm pretty new to Java, and need to write a program that listens to video conversion instructions and convert the video once a new instruction arrives (instructions are stored in Amazon SQS, but it's irrelevant to my question).

  


  I'm facing a choice, either use Java runtime to exec FFmpeg conversion (like from command line), or I can use an FFmpeg wrapper written in Java.

  


  http://fmj-sf.net/ffmpeg-java/getting_started.php

  


  I'd much prefer using Java runtime to exec FFmpeg directly, and avoid using java-ffmpeg wrapper as I have to learn the library.

  


  So my question is this : Are there any benefits using java-ffmpeg wrapper over exec FFmpeg directly using Runtime ?

  


  I don't need FFmpeg to play videos, just convert videos.

  


• AWS Lambda function for modify video

  4 février 2017, par Gold Fish

  I want to create a Lambda function that invoked whenever someone uploads to the S3 bucket. The purpose of the function is to take the uploaded file and if its a video file (mp4) so make a new file which is a preview of the last one (using ffmpeg). The Lambda function is written in nodejs.
  I took the code here for reference, but I do something wrong for I get an error saying that no input specified for SetStartTime :

  //dependecies
  
  var async = require('async');
  
  var AWS = require('aws-sdk');
  
  var util = require('util');
  
  var ffmpeg = require('fluent-ffmpeg');
  
  
  
  // get reference to S3 client 
  
  var s3 = new AWS.S3();
  
  
  
  
  
  exports.handler = function(event, context, callback) {
  
      // Read options from the event.
  
      console.log("Reading options from event:\n", util.inspect(event, {depth: 5}));
  
      var srcBucket = event.Records[0].s3.bucket.name;
  
      // Object key may have spaces or unicode non-ASCII characters.
  
      var srcKey    =
  
      decodeURIComponent(event.Records[0].s3.object.key.replace(/\+/g, " "));  
  
      var dstBucket = srcBucket;
  
      var dstKey    = "preview_" + srcKey;
  
  
  
      // Sanity check: validate that source and destination are different buckets.
  
      if (srcBucket == dstBucket) {
  
          callback("Source and destination buckets are the same.");
  
          return;
  
      }
  
  
  
      // Infer the video type.
  
      var typeMatch = srcKey.match(/\.([^.]*)$/);
  
      if (!typeMatch) {
  
          callback("Could not determine the video type.");
  
          return;
  
      }
  
      var videoType = typeMatch[1];
  
      if (videoType != "mp4") {
  
          callback('Unsupported video type: ${videoType}');
  
          return;
  
      }
  
  
  
      // Download the video from S3, transform, and upload to a different S3 bucket.
  
      async.waterfall([
  
          function download(next) {
  
              // Download the video from S3 into a buffer.
  
              s3.getObject({
  
                      Bucket: srcBucket,
  
                      Key: srcKey
  
                  },
  
                  next);
  
              },
  
          function transform(response, next) {
  
          console.log("response.Body:\n", response.Body);
  
          ffmpeg(response.Body)
  
              .setStartTime('00:00:03')
  
              .setDuration('10')   //.output('public/videos/test/test.mp4')
  
          .toBuffer(videoType, function(err, buffer) {
  
                          if (err) {
  
                              next(err);
  
                          } else {
  
                              next(null, response.ContentType, buffer);
  
                          }
  
                   });
  
          },
  
          function upload(contentType, data, next) {
  
              // Stream the transformed image to a different S3 bucket.
  
              s3.putObject({
  
                      Bucket: dstBucket,
  
                      Key: dstKey,
  
                      Body: data,
  
                      ContentType: contentType
  
                  },
  
                  next);
  
              }
  
          ], function (err) {
  
              if (err) {
  
                  console.error(
  
                      'Unable to modify ' + srcBucket + '/' + srcKey +
  
                      ' and upload to ' + dstBucket + '/' + dstKey +
  
                      ' due to an error: ' + err
  
                  );
  
              } else {
  
                  console.log(
  
                      'Successfully modify ' + srcBucket + '/' + srcKey +
  
                      ' and uploaded to ' + dstBucket + '/' + dstKey
  
                  );
  
              }
  
  
  
              callback(null, "message");
  
          }
  
      );
  
  };

  So what am I doing wrong ?