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• 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 ?

• FFMPEG/avconv option -c:a copy

  1er juin 2013, par b747fp

  I am converting a bunch of videos from FLV to MP4 (for iphone compatibility) and using AAC codec it kept throwing out "invalid audio bitrate" or similar errors. I tried "-c:a copy" option and it works, but I am wondering if that tells ffmpeg to use the original MP3 codec or just the original audio bitrates/frequencies ?

  /usr/bin/avconv -i /var/www/vhosts/domain.com/httpdocs/conversions/34649274.flv -s 640x480 -b 1248k -vcodec libx264 -acodec aac -strict experimental -c:a copy /var/www/vhosts/domain.com/httpdocs/conversions/34649274.mp4