[FFmpeg-devel] [PATCH] lavc/cuvid: fail early if GPU can't handle given video resolution

[Pavel Koshevoy]

On Mon, Jan 2, 2017 at 9:37 AM, Philip Langdale <philipl at overt.org> wrote:
> On Mon, 2 Jan 2017 00:56:18 -0700
> Pavel Koshevoy <pkoshevoy at gmail.com> wrote:

>> Perhaps a more comprehensive solution is needed.  I've run into the
>> same problem again (avcodec_open2 succeeds, decoding spits errors)
>> when I tried to play back an mpeg2 stream with YUV422P pixel format.
>>
>> I have a new patch but I'd like to test it on a Pascal GPU first.  I
>> am still hoping that 422 decoding will work.  It looks like it should
>> be supported, but I've observed on Geforce GT 730 that even though I
>> can instantiate a cuvid decoder with cudaVideoChromaFormat_422 without
>> error -- the decoded video is garbage everywhere except for 16-pixel
>> wide column along the left edge of the frame.
>>
>> In ee88dcb2 cuvid_handle_video_sequence was hard-coded to error-out if
>> the chroma format is not 420.  This looks like an NVIDIA driver/cuvid
>> bug... does anyone know how to bring it to their attention?
>
> It is documented as only supporting 420, even though it doesn't return
> an error, so it's not a bug per-se - it's just that they don't detect
> and return an error, so we do it ourselves.
>
> --phil


I don't recall seeing it mentioned that they do not support 422 and
444 in nvidia docs, but I haven't looked very hard yet.  I find it odd
that they have enum values to represent these chroma formats, yet they
don't work...  I'll see if I can file a bug with nvidia about this,
tomorrow.  I'll send another patch in about an hour to address the
original problem that got me looking in cuvid.c.

    Pavel.