I would like to convert some videos to WebM format using Debian Squeeze. I prefer command line tool(s) although gui applications are also welcome.
Video formats to convert from would most probably be .avi, .mp4 or .mkv but support for converting all known video formats would be nice. The ability to convert from video CD/DVD to WebM would also be cool.
It looks like ffmpeg 0.6 and up will output webm format files (source, source). However, the ffmpeg in a stock Debian Squeeze/6.0 is currently a 0.5.6 build. That said, if you can build ffmpeg from source, or use ffmpeg from squeeze-backports (where it is currently at a 0.7.2), it should do the job. If you are ok with trusting third-party builds, Debian-Multimedia (FAQ)has an apt repository which you can use (It has builds for ffmpeg, with many features which are disabled in the stock builds.)
GStreamer's gst-launch can convert video to webm from the command line.
The following converted a test mp4 to webm (vp8). I've never used it before, and I haven't got the audio options right (no audio), but the video works fine.
This info is basically from a Stack Overflow post.. The mux arg in that example caused a syntax error, so I tried oggmux as shown in a man gst-launch example... It ran, but without audio, so it needs some audio option tweaking.
ifile="test.mp4"
gst-launch \
filesrc location="$ifile" ! \
decodebin name=demux ! \
queue ! \
ffmpegcolorspace ! \
vp8enc ! \
webmmux name=mux ! \
filesink location="$ifile".webm demux. ! \
queue ! \
progressreport ! \
audioconvert ! \
audioresample ! \
vorbisenc ! \
oggmux
