[FFmpeg-user] Need help converting videos for on-demand-streaming

Boštjan Strojan bostjan.strojan at gmail.com
Fri Mar 30 08:48:52 CEST 2012

> 3. -tune animation
> What exactly is this for? Since the videos are animated I think this
> is a good option?

Depends, it is not meant for 3d animation, this is more for old
fashioned 2d anim/cartoonish stuff.
maybe check http://doom10.org/index.php?topic=253.0

> 4. What is a good value for -crf?
> I tried 20, 21 and 22 and couldn't notice a difference. I want small
> files so it's possible to watch the videos without buffering but you
> shouldn't notice (much) difference in video quality.

My usual default is 21, bigger number = worse quality. Also people
seems to use higher values (worse quality) for higher resolutions.

> 5. Faster conversion?
> If I need the conversion faster, should I change -preset slow to
> -preset medium or something else? Will the file get larger or the
> quality worse?

afaik they are not directly comparable, but i could be wrong, my
default is -preset medium.

> 7. I'm not sure if this is related to ffmpeg but I can't seek when
> streamed over HTTP (I do use qt-faststart after ffmpeg!). Other vids I
> converted some months ago however work. The only difference I know of
> is that I used that -partitions parameter from the question above.

how are you streaming? progressive download or real streaming? For
progressive download  qt-faststart  is working for me.


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