[FFmpeg-devel] [PATCH] Setup for extracting quantization parameters from encoded streams

[Lynne]

Jul 23, 2019, 12:23 AM by juandl-at-google.com at ffmpeg.org:

>> On Mon, Jul 22, 2019 at 12:17 PM Lynne <dev at lynne.ee> wrote:
>> You can't hack a decoder in any nice and performant way for it to output
>>
> data to an analyzer.
> Hi, Lynne
> I hear your concern about the decoder performance.
> I believe that the way we would like to modify the decoder should not
> affect its performance, since
> AV_FRAME_QUANTIZATION_PARAMS will be disabled by default; the extraction is
> done optionally with a flag.
> I would be glad to verify that by running tests and measuring performance
> with and without my changes.
> If you have in mind any tests I should run, please let me know.
>
>> I've explained why this is a bad idea and why you should maintain
>>
> it internally.
> FFmpeg already has a lot of analyzing tools, I disagree that this change
> does not belong to ffmpeg.
>

Switches like these only make code slower, not faster. And they don't erase code either.
I'll not accept this API without a decoder patch either.