Pipeline not working with gdkpixbufoverlay and vaapi using JPEG 4:2:2 streams, bug #158

[Wolfgang Grandegger]

Hello,

Am 20.12.19 um 20:00 schrieb Nicolas Dufresne:
> Le jeudi 19 décembre 2019 à 14:20 +0100, Wolfgang Grandegger a écrit :
>> Hello,
>>
>> this issue [1] is still present in 1.16.2. Any idea what the problem
>> could be and where to start debugging at.
>>
>> [1] https://gitlab.freedesktop.org/gstreamer/gstreamer-vaapi/issues/158
> 
> Aren't you just missing vaapipostproc after the jpeg decoder ?

As I wrote, it works with "vaapipostproc format=i420". I thin tt does
not work without "format=i420", but I need to double-check. Anyway, if I
use clockoverlay, the vaapipostproc is not necessary.

The i420 is a 4:2:0 format, while the camera sends 4:2:2. Converting to
4:2:0 means worse image quality, which is not desirable, IIUC.

Do you say, that VAAPI does not support 4:2:2? How can I find out, what
formats are supported by the VAAPI (Intel Graphics) JPGEG decoder?

Wolfgang