[FFmpeg-devel] [PATCH]lavc/libvpxenc: Avaoid vp8 transparency encoding with auto-alt-ref

[James Zern]

On Fri, Sep 16, 2016 at 4:50 PM, Carl Eugen Hoyos <ceffmpeg at gmail.com> wrote:
> 2016-09-17 1:48 GMT+02:00 James Zern:
>> On Fri, Sep 16, 2016 at 5:23 AM, Carl Eugen Hoyos wrote:
>
>>> Attached patch fixes ticket #5815.
>>
>>> +    if (ctx->auto_alt_ref && ctx->is_alpha && avctx->codec_id == AV_CODEC_ID_VP8) {
>>> +        av_log(avctx, AV_LOG_ERROR, "Transparency encoding with auto_alt_ref does not work\n");
>>> +        return AVERROR(EINVAL);
>>> +    }
>>> +
>>>
>>
>> This is a bit drastic, but might be necessary if the bug is reliably
>
> It only occurs if you try to encode with transparency and
> auto_alt_ref.
>

Thanks for the easy repro. It may have something to do with the fact
that in vp8 the alt-ref is a separate frame, this needs a closer look.
Feel free to apply the change in the meantime.

>> occurring. This sounds like a libvpx bug, I'll try to reproduce
>> locally when I get a chance.
>
> Please do!
>
> Carl Eugen
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel