[Libav-user] Encoding with no compression with OpenH264

Stefano Sabatini stefasab at gmail.com
Tue Mar 8 18:29:44 CET 2016

In date Tuesday 2016-03-08 08:48:44 -0800, Arthur Muller wrote:
> > What is your problem? Please test current FFmpeg git head and
> > provide the command line you tested together with the complete,
> > uncut console output and explain what goes wrong.
> Carl,
> Fair request.

> I can't use the latest version of FFmpeg because it fails to compile
> if I include openH264. In a previous post I asked about this and was
> told to use a previous version of FFmpeg. And that worked! I'm using
> v1.5.1. So I assume this is the best I can do as far as using the
> latest version of FFmpeg.

I posted a patch yesterday to fix that, see:

> And - believe it or not - after using libav for a few months now I'm
> more familiar with the libav API than with the command line. I do
> have a series of 18 png files sent by the customer. I can rename
> them to conform to ffmpeg command line program so I can use the
> proper formatting.

> I hope I'm not asking too much if I ask for help here. Can you tell
> me what arguments I should pass to ffmpeg (built with openh264!) to
> generate a high quality, openh264-encoded mp4 file from these files?
> If it turns out the quality is acceptable then it's a matter of
> going to my program to see what I may be missing there.

The only parameters used by FFmpeg/libavcodec which affect the quality
are the bitrate and the max_bitrate. I don't know if it possible to
use other parameters exposed by the openh264 API, if that's the case
patches are welcome (TM). So in order to increase the quality you
simply increase the bitrate.

You can have a look at the wrapper code libavcodec/libopenh264enc.c to
see how FFmpeg uses the openh264 API.


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