Start with video file off my smartphone, portrait, h264 inside mp4. Goal: shrink it to a size small enough to be emailable, and natively plays on Microsoft Windows Media Player without having to download extra codecs.
Install libavcodec-extra-53 for ubuntu oneiric to get the libmp3lame audio encoder.
ffmpeg -i input.mp4 -vf scale=iw/2:ih/2,transpose=1 -vcodec msmpeg4v2 -acodec libmp3lame -qscale 20 -r 30.06 output.avi
Setting the rate correctly (-r 30.06, matching the input rate) was important, or otherwise the rate of the AVI container becomes 1000, and WMP fails to play it. But I still occasionally see a dropped frame; maybe it's not exactly 30.06?
The instructions for wmv2 didn't work enough to shrink the file. Not even "-q 31" seemed to significantly work.
For previewing the file
mplayer -really-quiet -vf pp=de -fs $file
was nice, which runs a deblocking filter.
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