[FFmpeg-devel] [PATCH 2/3] avcodec/hevcdec: Export Dolby Vision RPUs as side data

[Derek Buitenhuis]

On 10/23/2021 7:15 PM, James Almer wrote:
>> Do'h, will fix.
> 
> That being said, would Dolby RPU NALUs like this using other values for 
> temporal and layer id be valid? Or can we just assume that's never 
> happening?

They also use 63 for an EL, according to other codebases an docs. I didn't
include it in this patch, since I have no such samples or way to test.


> No, i prefer having the side data be about Dolby Vision RPU. Who knows, 
> maybe in the future Dolby realizes they had the Unregistered and even 
> Registered User Data SEI readily available for this kind of proprietary 
> information and start using that instead...

OK.
>> Or, what we could do is check for the existence of stream side data containing
>> the DOVI configuration record, which is needed to use these RPUs, I think.
> 
> That sounds ideal, yes.

Will do.

> I guess it may be because there's one such NALU per AU in this sample, 
> so no frame depends on other threads having finished parsing/decoding 
> their own frames and syncing the stuff stored in their thread-specific 
> contexts.

There must be a exactly one RPU per AU, is my understanding - anything else is
malformed.

I guess malformed files would run into trouble, so this should be done regardless.

- Derek