ffmpeg on Heroku: unrecognized option 'preset'

Question

I'm using ffmpeg version 1.2.4 in my local Rails app to convert video files. Everything works as expected when I run the app locally. When I deployed to heroku, I added a buildpack for ffmpeg:

https://github.com/shunjikonishi/heroku-buildpack-ffmpeg

This installs ffmpeg version git-2013-06-02-5711e4f. When I try to transcode a video to mp4, I get the following error:

Unrecognized option 'preset'. Error splitting the argument list: Option not found

Here is the complete log:

2013-11-17T19:45:05.255059+00:00 app[web.1]: Running transcoding...
2013-11-17T19:45:05.255059+00:00 app[web.1]: ffmpeg -y -i /app/public/uploads/tmp/1384717504-2-9158/Untitled.mov -vcodec libx264 -acodec libfaac -s 640x360  -qscale 0 -preset slow -g 30 -aspect 1.7777777777777777 /app/public/uploads/tmp/1384717504-2-9158/tmpfile.mp4
2013-11-17T19:45:05.255059+00:00 app[web.1]: 
2013-11-17T19:45:05.317895+00:00 app[web.1]: Failed encoding...
2013-11-17T19:45:05.317895+00:00 app[web.1]: ffmpeg -y -i /app/public/uploads/tmp/1384717504-2-9158/Untitled.mov -vcodec libx264 -acodec libfaac -s 640x360  -qscale 0 -preset slow -g 30 -aspect 1.7777777777777777 /app/public/uploads/tmp/1384717504-2-9158/tmpfile.mp4
2013-11-17T19:45:05.317895+00:00 app[web.1]: 
2013-11-17T19:45:05.317895+00:00 app[web.1]: ffmpeg version git-2013-06-02-5711e4f Copyright (c) 2000-2013 the FFmpeg developers
2013-11-17T19:45:05.317895+00:00 app[web.1]:   built on Jun  2 2013 07:38:40 with gcc 4.4.3 (Ubuntu 4.4.3-4ubuntu5.1)
2013-11-17T19:45:05.317895+00:00 app[web.1]:   configuration: --enable-shared --disable-asm --prefix=/app/vendor/ffmpeg
2013-11-17T19:45:05.317895+00:00 app[web.1]:   libavutil      52. 34.100 / 52. 34.100
2013-11-17T19:45:05.317895+00:00 app[web.1]:   libavcodec     55. 13.100 / 55. 13.100
2013-11-17T19:45:05.317895+00:00 app[web.1]:   libavformat    55.  8.102 / 55.  8.102
2013-11-17T19:45:05.317895+00:00 app[web.1]:   libavdevice    55.  2.100 / 55.  2.100
2013-11-17T19:45:05.318137+00:00 app[web.1]:   libavfilter     3. 74.101 /  3. 74.101
2013-11-17T19:45:05.318137+00:00 app[web.1]:   libswscale      2.  3.100 /  2.  3.100
2013-11-17T19:45:05.318137+00:00 app[web.1]:   libswresample   0. 17.102 /  0. 17.102
2013-11-17T19:45:05.318137+00:00 app[web.1]: Unrecognized option 'preset'.
2013-11-17T19:45:05.318137+00:00 app[web.1]: Error splitting the argument list: Option not found
2013-11-17T19:45:05.318137+00:00 app[web.1]: 
2013-11-17T19:45:05.318137+00:00 app[web.1]: Errors: no output file created. 

I think that the error may be a result of differences in the version of ffmpeg that I'm using locally and on Heroku. Does anyone have suggestions for how to resolve this issue?

Answer 1

You're trying to use the encoders libfaac and libx264, but your ffmpeg was not compiled to support these encoders. libfaac requires ffmpeg configure options --enable-nonfree --enable-libfaac and libx264 requires --enable-gpl --enable-libx264. Using --disable-asm is not recommended and can significantly affect encoding time.

If you need help compiling see How to Compile FFmpeg on Ubuntu. Compilation is recommended because the so-called "ffmpeg" package in the repository is a fake, old, buggy, and outdated version from a fork and it does not supply a good AAC encoder.

As for the ffmpeg command options:

• -qscale is ambiguous. You should tell ffmpeg if it should apply to the audio (-qscale:a or -q:a) or the video (-qscale:v or -q:v) but note that libx264 ignores -qscale and you should use the default settings or -crf as shown in the FFmpeg and x264 Encoding Guide.

• No need to add -g 30 -aspect 1.7777777777777777. The default setting for -g should suffice and I don't see why you want to force a seemingly arbitrary aspect ratio.

• Consider using -vf scale=640:-1 instead of explicitly forcing a hard size since this can change the aspect ratio and cause a squished or stretched look. The -1 tells ffmpeg to automatically calculate the value while preserving the aspect ratio.

• If you compile ffmpeg, then use -codec:a libfdk_aac instead of libfaac. It will provide better quality per bitrate. See the FFmpeg and AAC Encoding Guide for more info.

• I'm guessing you are making videos for display on the web. If yes, then add -movflags +faststart as an output option to allow the client to begin playback before the file is completely downloaded. This is only available with real ffmpeg and not the fake junk.