Re: transcoding flv to mp4
On 10/05/2010 03:40 PM, Celejar wrote:
I'm dabbling in transcoding flvs (e.g., from YouTube) to mp4s (for
uploading to a service (Snapfish) which doesn't support flv. I'm doing
something like this:
ffmpeg -i example.flv example.mp4
I find that the above command line reduces the size of the video to
about a third of the original, but at the cost of egregious degradation
of the video quality. If I use the 'sameq' option:
ffmpeg -sameq -i example.flv example.mp4
the resulting video seems to retain the quality, but now the file size
is increased by a factor of four (I've only tested one file so far -
the original flv was about 20MB, the first mp4 was about 8MB, and the
second about 80MB).
Why is this, and is there a happy medium, i.e., a way to keep the size
roughly constant, but to retain quality?
I just made one quick experiment with ffmpeg.
For testing purpose I was grab first video I found
ffmpeg -i input.flv -vcodec libx264 -vpre max -acodec copy output.mp4
Rezult you can see here dobosevic.com/nix/The.mp4.tar.gz
I think tha video quality is almost as original and output is 2.7 x
smaller in size.
More about ffmpeg presets you can find in
/usr/share/doc/ffmpeg/ffmpeg-doc.html (3.10 Preset files) and presets
are in /usr/share/ffmpeg/
You can also write your one presets or change default one.
Registered Linux User #503414