[FFmpeg-devel] [PATCH 2/2] avcodec/dnxuc_parser: rework DNXUC parser

[Marton Balint]

On Fri, 22 Nov 2024, martin schitter wrote:

>
>
> On 20.11.24 22:03, Marton Balint wrote:
>
>>  The parser's primary job is to packetize a non-packetized stream and maybe
>>  get some basic information about the packets which normally the container
>>  has.
>
> As long as we only support single component variants there isn't much use of 
> saving the unmodified `pack` structure, because nearly all contained metadata 
> is more or less redundant and also available one layer above in the MXF CDCI 
> and RGBA Picture Essence Descriptors.
>
> That's why I just passed along the `sinf`.packet_type and `sdat` frame 
> content as the only useful information relevant for further processing. 
> That's also enough information to recreate a functional equivalent DNxUC 
> `pack` structure later again, if needed.
>
> Nevertheless, I do not have any serious objections against your proposal. It 
> simply makes sense for more efficient pass-through.

Actually if you change where the packet starts in the parser, the generic 
demuxing code will likely do a memcpy on the packet data... So the most 
efficient is to not change that... You also have to think not just the 
decoding use case, but re-muxing as well, so the codec having a 
well-defined packet format which works for all cases is important.

I will apply this in 1-2 days then.

Thanks,
Marton