ffmpeg by default aims for the lowest bitrate it can manage for a video when
encoding webm. I have been happy with this so far, but the video I grabbed of a
waterfall today does not look good in this mode. I tried changing the bitrate
options as discussed on the ffmpeg wiki, I thought I would show what you
can expect with a couple of differnet rates.
The original mov file generated from my camera was 21MB.
$ ffmpeg -i INPUT.mov -an output-default.webm
The original ultra low, 443kb/s that ffmpeg generates, file is 369KB.
$ ffmpeg -i DSC_3536.MOV -an -c:v libvpx -b:v 1M output-1M.webm
Doubling the rate, file is 976KB. Still a lot of artifacts in the video.
$ ffmpeg -i DSC_3536.MOV -an -c:v libvpx -b:v 10M output-10M.webm
This passed the smell test for me, I think it looks good enough for its size, this file is 5.6MB roughly the size of a jpeg of the same scene.