Re: [PATCH v3 3/9] DocBook/v4l: Add compressed video formats used on MT8173 codec driver

From: Nicolas Dufresne
Date: Tue Jul 12 2016 - 15:08:41 EST


Le mardi 12 juillet 2016 Ã 16:16 +0800, Wu-Cheng Li (æåè) a ÃcritÂ:
> Decoder hardware produces MT21 (compressed). Image processor can
> convert it to a format that can be input of display driver. Tiffany.
> When do you plan to upstream image processor (mtk-mdp)?
> >
> > It can be as input format for encoder, MDP and display drivers in
> our
> > platform.
> I remember display driver can only accept uncompressed MT21. Right?
> Basically V4L2_PIX_FMT_MT21 is compressed and is like an opaque
> format. It's not usable until it's decompressed and converted by
> image
> processor.

Previously it was described as MediaTek block mode, and now as a
MediaTek compressed format. It makes me think you have no idea what
this pixel format really is. Is that right ?

The main reason why I keep asking, is that we often find similarities
between what vendor like to call their proprietary formats. Doing the
proper research helps not creating a mess like in Android where you
have a lot of formats that all point to the same format. I believe
there was the same concern when Samsung wanted to introduce their Z-
flip-Z NV12 tile format. In the end they simply provided sufficient
documentation so we could document it and implement software converters
for test and validation purpose.

regards,
Nicolas