Penguin
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FFmpeg is a multi-purpose multimedia tool which can convert between an amazing variety of different file formats and audio and video CoDecs. Its development is done in common with that of MPlayer.

FFmpeg is undergoing continual development. Hence, any copy included with your distro is guaranteed to be out of date. Instead, always get the latest version via SubVersion from the repository linked from the FFmpeg home page (below).

Basic usage:

ffmpeg input-spec [input-spec ...] output-spec [output-spec ...] [mapping-options]

where each input-spec consists of

-i input-filename

possibly preceded by options that apply to that input file (e.g. overriding format, sample rate etc if FFmpeg guesses wrong), and each output-spec consists of

output-filename

possibly preceded by options to be applied in generating that output file.

FFmpeg does not concatenate multiple input files, it multiplexes them. Thus, you can specify an input video-only file and an input audio-only file, and get a combined video-plus-audio output file. Or you can demultiplex the input into multiple output files, for example video-only into one output file, audio-only into another, or different encodings of the same video or audio input into different outputs.

The mapping-options allow the specification of which streams from whicn input file(s) are mapped onto which streams in the output file(s). These are only necessary if FFmpeg can't figure out the right thing to do.

Tips

Extract an audio file from a MP4 or other video file:

ffmpeg -i Videofile.mp4 -vn -acodec mp3 audiofile.mp3

Result on Ubuntu 9.04:

Unknown encoder 'mp3'

Fail!

You could follow the advice in this bug report, but why bother. Just do this:

ffmpeg -i Videofile.mp4 -vn -acodec vorbis audiofile.ogg

Extract a single video frame into a JPEG file:

 ffmpeg -ss hh:mm:ss:cc -t 00:00:00.01 -i input-filename -f mjpeg output-name.jpeg

For example, extract the frame at time 3 minutes and 51.04 seconds into the input video file:

 ffmpeg -ss 00:03:51.04 -t 00:00:00.01 -i my-doggie.mpg -f mjpeg my-doggie-thumbnail.jpeg

Generate a specified duration of silence:

 NrChannels=2
 SampleRate=48000
 NrSeconds=1
 # above parameters can be changed as appropriate
 ffmpeg -ar $SampleRate -acodec pcm_s16le -f s16le -ac $NrChannels \
    -i <(dd if=/dev/zero bs=$(($SampleRate * $NrChannels * 2)) count=$NrSeconds) \
    silence.wav

Generate a static background suitable for a non-animated DVD-Video menu.

This takes a single still frame (probably best to stick to JPEG format, certainly PNG didn't work) and turns it into an MPEG-2 output movie with a silent soundtrack. The movie is of one-second duration, which is sufficient because it can be set to loop during the DVD authoring process:

 ffmpeg -loop_input -t 1.0 -i stillframename \
    -ar 48000 -f s16le -i <(dd if=/dev/zero bs=192000 count=1) \
    -target pal-dvd outputmoviename

where pal-dvd can be replaced with ntsc-dvd if authoring an NTSC disc rather than PAL.

Fix audio/video sync in a movie

In this example, 64 seconds (determined by trial and error while observing lip sync) was trimmed from the start of the audio track. The video track happens to come first in the list; the source movie is specified twice, once with the appropriate offset applied, and the -map option is used to select the appropriate audio and video streams to combine into the output movie: the first -map specification says that the first (video) output stream is to come from the first stream of the second input file (stream 1.0), while the second -map specification says that the second (audio) output stream is to come from the second stream of the first input file (stream 0.1). Note the use also of -vcodec copy and -acodec copy to ensure that no re-encoding of audio or video data takes place:

 ffmpeg \
    -ss 00:01:04.00 -i srcmovie \
    -i srcmovie \
    -vcodec copy -acodec copy dstmovie \
    -map 1.0 -map 0.1

Links:

  • FFmpeg home
  • libamr home page -- needed for audio encoding if you're making 3GPP movies to play on cell phones. Recent versions of FFmpeg no longer expect the AMR source code to be inserted into the FFmpeg source tree.