[FFmpeg-devel] lavc/libvpxenc: Deprecate lossless option

[Carl Eugen Hoyos]

2019-02-07 21:21 GMT+01:00, James Almer <jamrial at gmail.com>:
> On 2/7/2019 5:08 PM, Carl Eugen Hoyos wrote:
>> 2019-02-07 20:57 GMT+01:00, James Almer <jamrial at gmail.com>:
>>> On 2/7/2019 4:53 PM, Carl Eugen Hoyos wrote:
>>>> Hi!
>>>>
>>>> Lossless libvpx encoding is possible with "-crf 0".
>>>
>>> Does that work with all supported versions, or was it a recent change?
>>
>> No, it needs a newer version than 1.4.0
>>
>> Sorry, Carl Eugen
>
> What's the first version where this works?

It works with 1.6.0 but not with 1.5.0.

> We could bump the minimum required version. It would
> also let us remove a considerable amount of ifdeffery.
>
> Debian Oldstable has a libvpx 1.6.1 package in the official backports
> repository, and Ubuntu Xenial (oldest LTS) ships with 1.5.0. And if it
> was added after those, an argument could also be made that if you're
> compiling latest ffmpeg you can also compile its popular dependencies.
> Not to mention libvpx is a library that's best to have as up to date as
> possible.

No strong opinion here, I hadn't realized that -crf 0 only works with
newer versions.

Can you explain why crf alone has no effect and needs -b:v 0?
Isn't this a bug both with libvpx and libaom?

Carl Eugen