[FFmpeg-devel] [PATCH 1/5] lavc : yami : add libyami decoder/encoder

[Jun Zhao]

On 2016/8/16 15:37, Chao Liu wrote:
> On Mon, Aug 15, 2016 at 7:44 PM, Jun Zhao <mypopydev at gmail.com> wrote:
> 
>>
>>
>> On 2016/8/16 10:14, Chao Liu wrote:
>>> On Mon, Aug 15, 2016 at 6:00 PM, Jun Zhao <mypopydev at gmail.com> wrote:
>>>
>>>>
>>>>
>>>> On 2016/8/16 1:48, Jean-Baptiste Kempf wrote:
>>>>> On 15 Aug, Hendrik Leppkes wrote :
>>>>>>> On Mon, Aug 15, 2016 at 10:22 AM, Jun Zhao <mypopydev at gmail.com>
>>>> wrote:
>>>>>>>>> add libyami decoder/encoder/vpp in ffmpeg, about build step,
>>>>>>>>> please refer to the link: https://github.com/01org/
>>>> ffmpeg_libyami/wiki/Build
>>>>>>>>>
>>>>>>>
>>>>>>> We've had patches for yami before, and they were not applied because
>>>>>>> many developers did not agree with adding more wrappers for the same
>>>>>>> hardware decoders which we already support.
>>>>>>> Please refer to the discussion in this thread:
>>>>>>> https://ffmpeg.org/pipermail/ffmpeg-devel/2015-January/167388.html
>>>>>>>
>>>>>>> The concerns and reasons brought up there should not really have
>>>> changed.
>>>>> I still object very strongly against yami.
>>>>>
>>>>> It is a library that does not bring much that we could not do
>> ourselves,
>>>>> it duplicates a lot of our code, it is the wrong level of abstraction
>>>>> for libavcodec, it is using a bad license and there is no guarantee of
>>>>> maintainership in the future.
>>>>
>>>> I know the worry after read the above thread.For Intel GPU HW accelerate
>>>> decode/encode,
>>>> now have 3 options in ffmpeg:
>>>>
>>>> 1. ffmpeg and QSV (Media SDK)
>>>> 2. ffmpeg vaapi hw accelerate decoder/native vaapi encoder
>>>> 3. ffmpeg and libyami
>>>>
>>> Sorry for this little diversion: what are the differences between QSV and
>>> vaapi?
>>> My understanding is that QSV has better performance, while vaapi supports
>>> more decoders / encoders. Is that correct?
>>> It would be nice if there are some data showing the speed of these HW
>>> accelerated decoders / encoders.
>>
>> QSV has better performance is right, but libyami have more
>> decoders/encoders than
>> vaapi hw accel decoder/encoder. :)
>>
>> According our profile, the speed of QSV/Libyami/vaapi-hw accel decoder and
>> native
>> vaapi encoder are: QSV > ffmpeg and libyami > vaapi-hw accel decoder and
>> native
>> vaapi encoder
>>
>>>
>>>>
>>>> And I know the guys prefer option 2 than 3, but I have a little
>> question,
>>>> what's the
>>>> difference about ffmpeg/libyami and the other external codec library(e,g
>>>> openh264,
>>>> videotoolbox...)?
>>>>
>>> Is 2 available in ffmpeg today or is it sth. planned?
>>>
>>
>> Option 2 is available today :), I think the wiki page (
>> https://wiki.libav.org/Hardware/vaapi)
>> is good refer to for option 2, if you want to try. :)
> 
> Thanks. But that's for libav. These decoders and encoders are not available
> for ffmpeg.
> 

I can run ffmpeg vaapi hw accel decoder and vaapi encoder with zero-copy mode for
transcode case, I don't know why you can't succeed.

Do you re-build intel-driver/libva with master branch?