FFMPEG video to FLV conversion optimization

Question

Would anyone have any tips on optimizing video to FLV conversion using ffmpeg so I would get a medium quality video which is not very large?

I have a video site where users can upload videos which will be converted to FLV and displayed. Those videos are shown at the size 420x350. I'm using FFMPEG to convert then to FLV, through the following command:

ffmpeg -i $in $out

I find the result to be pretty low quality and whenever I try to change settings, the output will be a very large file. For instance, I've tried this:

  ffmpeg -i $in -sameq -ar 11025 -ab 32 -deinterlace -nr 500 -r 20 -g 500 -s 420x350 -aspect 4:3 -me_range 20 -b 270k -f flv -y $out

Answer 1

For ffmpeg, I always recommend using -sameq. During testing you can create a smaller test source. I assume 420x350 is lower resolution than the source. Try creating a source matching this to speed up testing.

ffmpeg -i "$in" -sameq -s 420x350 -an "$testin"

Where $testin is a filename with the same extension as $in. ffmpeg should keep the video codec and container the same, but drop the audio stream and drop the resolution. This will speed up testing since the source video will be a little smaller and you can just focus on making the codec conversion work well. I can't find -me_range documented in my ffmpeg. I would focus on playing with different values of -b and -r and use of -sameq until you get an output file size and quality you want.

ffmpeg -i "$testin" -sameq -r 20 -b 270k "$out"