[FFmpeg-devel] [PATCH] avcodec/mfenc: expose more properties of the media foundation encoder

Mark Thompson sw at jkqxz.net
Tue Apr 2 23:54:37 EEST 2024


On 01/04/2024 19:55, Mark Thompson wrote:
> On 01/04/2024 17:25, Mark Samuelson wrote:
>> On Mon, Apr 1, 2024 at 10:06 AM Mark Thompson <sw at jkqxz.net> wrote:
>>
>>>> On 28/03/2024 12:34, Mark Samuelson wrote:
>>>>> Thank you for the notes, here is a new patch that incorporates your
>>> suggestions.  You are right, the default value of 12 for gop_size is
>>> suprising, I didn't know about it before now.
>>>>>
>>>>> ---
>>>>>    libavcodec/mf_utils.h |  5 +++++
>>>>>    libavcodec/mfenc.c    | 33 +++++++++++++++++++++++++++------
>>>>>    2 files changed, 32 insertions(+), 6 deletions(-)
>>>>
>>>> Patch looks good.
>>>>
>>>> I did a bit of testing with the Microsoft H.264 MFT: GOP size and
>>> compression level work as expected, and VBV parameters seem to be doing
>>> something sensible.
>>>>
>>>> Under what conditions are you expecting global_quality ->
>>> AVEncVideoEncodeQP to do anything, though?  When I set it alone the output
>>> was always identical regardless of what value I set > it to.  (Including
>>> with "-rate_control quality".)
>>>>
>>>> Thanks,
>>>>
>>>> - Mark
>>>
>>
>> I have also had issues making the Media Foundation encoder respect that
>> value.  I put it in there so that I could easily test it, because I was
>> having issues with the existing opt_enc_quality -> AVEncCommonQuality.  I
>> figured it was better to leave it in so people can experiment with it.
> 
> Fair, these options are not particularly consistent between different encoder MFT implementations.
> 
> I will apply this patch tomorrow unless there are any more comments on it.

Applied.

(git hint for emails: write email commentary below the "---" line - everything above that ends up in the commit message.  I edited this out of the patch.)

Thanks,

- Mark


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