[FFmpeg-devel] [PATCH] QSV MJPEG video decoder has been added.

Hendrik Leppkes h.leppkes at gmail.com
Sun Aug 2 23:58:28 CEST 2015


On Sun, Aug 2, 2015 at 11:52 PM, wm4 <nfxjfg at googlemail.com> wrote:
> On Sun, 2 Aug 2015 23:45:36 +0200
> Hendrik Leppkes <h.leppkes at gmail.com> wrote:
>
>> On Sun, Aug 2, 2015 at 11:27 PM, Ivan Uskov <ivan.uskov at nablet.com> wrote:
>> > Hello Michael,
>> >
>> > Sunday, August 2, 2015, 9:46:23 PM, you wrote:
>> >>> MN> it appears the file was not in mfx_dispatch previously
>> >>> MN> so a check in confgure might be needed
>> >>> As I can see here
>> >>> https://github.com/lu-zero/mfx_dispatch/tree/master/mfx
>> >>> The mfxjpeg.h was added 17 days ago and marked  part of API 1.16.
>> >>> But really mfxjpeg.h was introduced by Intel at old-old API 1.3 (decoder)
>> >>> I do not use mfx_dispatch by myself at all, only native Intel Media
>> >>> SDK and patch compiles fine at my side.
>> >>> Looks like here some mess from mfx_dispatch side.
>> >>>
>> >
>> >>> Is there any similar case existing in ffpeg which I can use as
>> >>> template to implement own check in configure?
>> >
>> > MN> its very simple, see any code using check_header and related functions
>> > MN> in configure
>> > MN> and HAVE_*_H defines
>> >
>> > MN> [...]
>> >
>> > I have added simple check for mfxjpeg.h to configure, please review
>> > the attached update.
>> >
>> >
>>
>> The decoder should depend on the header in configure directly already,
>> so its not built at all when the header is not available.
>>
>> Secondly, why is there a AVHWAccel in there? It doesn't have any
>> callable functions, nor do we support AVHWAccel for mjpeg.
>> For some reason the other QSV codecs also have this, but also without
>> any functions in them - those serve no purpose and are likely to even
>> cause problems if a user accidentally tries to use it. I'll send a
>> patch to remove them, unless you can name a reason for them to exist.
>
> Because if it's missing, ff_get_format() refuses to return the QSV
> opaque format. I think. So you need AVHWAccels for every codec/decoder
> combination.

But if you use the normal h264 decoder and select the QSV format in
get_format (because you don't know any better), it will probably end
up in unhappiness of all.

- Hendrik


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