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• how to combine an image stream and an audio stream together with transcoding

  11 novembre 2020, par SolskGaer

  I tried the method mentioned in this link to capture audio stream from an iPhone, and want to combine the audio stream with an image stream(10 fps) which can be acquired via http. But the output I got has messed up audio and the video speed is way faster than the input, here is the command I used to generate the video ffmpeg -f avfoundation -i ":4" -f mjpeg -i http://127.0.0.1:8888 -c:a aac -c:v libx264 out.mp4, how do I fix the problem ? By the way, when I transcoding audio/video only, it worked exactually as expected.

  


• Is there a good set of ffmpeg presets to target multiple platforms available anywere ?

  17 mai 2012, par Prody

  I'm working on a web app that would let users upload a video.

  The user's video should then be played on apps on a few platforms :

  • web, via flash
  • iOS native player
  • Android phones - hopefully all players, even low-end devices

  I plan to do the encoding with ffmpeg which has this very cool preset feature.

  I'm sure I'm not the only one to find this out, but when I Google ffmpeg encode for iPhone, I get as many different parameter sets on people's blogs as results.

  Furthermore, people sometimes use parameters which are not even documented.

  Since ffmpeg supports these presets, I can't believe we don't have a "preset database" somewhere which has such presets as iPhone_low_quality, Android_low_end_device_low_quality, etc.

  Am I just failing to find it ?

• FFMPEG fails in node exec but succeeds on OSX

  10 avril 2015, par rrrkren

  So I’m trying to get a thumbnail of a mov video using ffmpeg.
  Here is the command :

  ffmpeg -i video.mov -vf scale=-1:100 -r 1 -an -vframes 1 -f mjpeg thumb.jpg

  it works fine when I type it in terminal. But once I do it in javascript (node) :
  (thumbPath, destPath, and thumbname are all defined earlier, and I doubt they are the problem)

  var command = "ffmpeg -i "+ destPath +" -vf scale=-1:100 -ss 00:01 -r 1 -an -vframes 1  -f mjpeg "+thumbPath+thumbname;
  
  exec(command,function(err){
  
      if(err){
  
          console.log(err);
  
      };
  
  });

  The console logs :

  { [Error: Command failed: ffmpeg version 2.4.1-tessus Copyright (c) 2000-2014 the FFmpeg developers
  
    built on Sep 22 2014 23:16:01 with Apple LLVM version 6.0 (clang-600.0.51) (based on LLVM 3.5svn)
  
    configuration: --cc=/usr/bin/clang --prefix=/Users/tessus/data/ext/ffmpeg/sw --as=yasm --extra-version=tessus --disable-shared --enable-static --disable-ffplay --enable-gpl --enable-pthreads --enable-postproc --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libx265 --enable-libxvid --enable-libspeex --enable-bzlib --enable-zlib --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libxavs --enable-libsoxr --enable-libwavpack --enable-version3 --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvpx --enable-libgsm --enable-libopus --enable-libmodplug --enable-fontconfig --enable-libfreetype --enable-libass --enable-libbluray --enable-filters --disable-indev=qtkit --enable-runtime-cpudetect
  
    libavutil      54.  7.100 / 54.  7.100
  
    libavcodec     56.  1.100 / 56.  1.100
  
    libavformat    56.  4.101 / 56.  4.101
  
    libavdevice    56.  0.100 / 56.  0.100
  
    libavfilter     5.  1.100 /  5.  1.100
  
    libswscale      3.  0.100 /  3.  0.100
  
    libswresample   1.  1.100 /  1.  1.100
  
    libpostproc    53.  0.100 / 53.  0.100
  
  [mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fe29c817000] moov atom not found
  
  video.mov: Invalid data found when processing input
  
  ] killed: false, code: 1, signal: null }

  I’ve looked up online and apparently the "moov atom not found error" is caused by the video being corrupted. But the command works fine when I type it in terminal. What’s wrong with my code ?

  Edit : This code works for mp4 videos, and the mov video was from an iPhone. I tried using a .mov file downloaded elsewhere and it works. Seems to be an issue with mov file shot with iPhone ?