[FFmpeg-user] Which parameter for WEBM VP8/Vorbis quality depending on resolution?

Tom Evans tevans.uk at googlemail.com
Wed Apr 3 17:09:15 CEST 2013


On Wed, Apr 3, 2013 at 3:35 PM, Timm Ganske <tag at gmx.com> wrote:
> Using my smartphone I sometimes do videos. It is very convenient that they can be played directly in Firefox. Currently I am using ffmpeg2theora to create Theora videos, but I want to change to webm (VP8/vorbis) because it uses less space for same quality resp. better quality for same space. The videos are in different resolutions, and sometimes I crop them. I want to have the bitrate adopting to what is reasonable for the resolution. If I set a fixed bitrate let us say 800 kb/s, it is too much for low resolutions (some are below 320x240) and not enough for high resolutions (my S3 is capable of Full HD). But I want to convert them using a single command line for all of them.
>
> Is there a parameter for ffmpeg which lets me choose -video-quality (low, reasonable, good, excellent) which depends on the resolution? If not, is it possible to support such an option in the future? Or do I need some script which analyzes the video and sets the bitrate accordingly?

Please, line breaks are free on the internet, use them every 80
characters or so!

You can use the -crf argument, which sets a quality setting for the
final video, not a bitrate. I believe this works with libvpx.

Cheers

Tom


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