[Libav-user] how to set crf for vp8 encoder in ffmpeg programmatically?

YIRAN LI mrfun.china at gmail.com
Mon May 20 11:35:36 CEST 2013


Thanks Hendrik!

And I found that member variable crf has been removed from AVCodecContext,
so I assume that unless I add that back to AVCodecConetxt, using
av_option_set is the only way to set that.

Great thanks!


2013/5/20 Hendrik Leppkes <h.leppkes at gmail.com>

> On Mon, May 20, 2013 at 10:23 AM, YIRAN LI <mrfun.china at gmail.com> wrote:
> > Hi guys,
> >
> > I've downloaded latest libvpx code and built it into ffmpeg, so that my
> > application can use ffmpeg dlls.
> >
> > Vp8 encoding works correctly and my application can generate webm videos.
> >
> > But what I want to know is, how can I set crf when encoding?
> >
> > What I do in my application is just calling ffmpeg interface
> > 1. AVStream* pVideoStream = av_new_stream(pFormatCtx, 0);
> > 2. AVCodec* pVideoCodec = avcodec_find_encoder(AVCODE_ID_VP8)
> > 3. AVCodecContext* pVideoCodecCtx = pVideoStream->codec;
> >
> >    pVideoCodexCtx->bit_rate =
> >                            ->rc_min_rate=
> >                            ->rc_max_rate=   (set all these bit rate
> control
> > param)
> >
> >   I checked libvpxenc.c under libavcodec and seems when initing the
> encoder,
> > it doesn't directly refer to any member
> >  of AVCodecContext to set crf.
> >
> >  So could anyone tell me, how to set crf when open vp8 encoder
> > programmatically?
> >
> >  Great thanks!
> >
>
> This should do it:
> av_opt_set_int(pVideoCodexCtx, "crf", 10, AV_OPT_SEARCH_CHILDREN)
> _______________________________________________
> Libav-user mailing list
> Libav-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/libav-user
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://ffmpeg.org/pipermail/libav-user/attachments/20130520/c9ff25c6/attachment.html>


More information about the Libav-user mailing list