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

[YIRAN LI]

Hi Hendrik,

I had a quick test, and seems it doesn't work.

I guess that's because crf is longer a member of AVCodecContext. I'll try
to set AVOptions when opening codecs.

Thanks


2013/5/20 YIRAN LI <mrfun.china at gmail.com>

> 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/20130520/3b32c556/attachment.html>