[FFmpeg-user] need some help

Moritz Barsnick barsnick at gmx.net
Mon Apr 20 00:30:21 CEST 2015

On Sun, Apr 19, 2015 at 23:08:51 +0200, Henk D. Schoneveld wrote:
> > I am looking for someone who can help me with live streaming h264 quality
> > adjustments.  I have been trying for some time but can't seem to strike a
> > good balance between bandwidth and quality. I am willing to pay for it.

> I don’t know what you have been trying, but the crf function should
> exactly do what you want. You can try with values between 19 and 30,
> 23 being the default value. You should be able to trust your eyes for
> quality and can save files for a certain amount of time. So you see
> for yourself for what quality which average bitrate is needed.

Another factor for bandwidth can be set using the presets.

While crf defines the quality (at the cost of bandwidth of course), you
can balance CPU usage (or computation time, if you will) against this
constant quality by tuning from ultrafast to veryslow. In the slower
presets, x264 makes more effort to compress/reduce filesize, while
basically keeping the quality chosen. So you can experiment by choosing
slower presets, until your CPU can no longer cope for your live
streaming. As long as the CPU copes, each reduction of speed will bring
a reduction of bandwidth. (With some exceptions - you should really
experiment with this.)


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