[FFmpeg-devel] [PATCH 1/2] lavc/h264dsp: remove MMI 8-bit chroma DC dequant

[Rémi Denis-Courmont]

Le sunnuntaina 7. heinäkuuta 2024, 14.44.47 EEST Rémi Denis-Courmont a écrit :
> The function is exactly identical to the C reference, only with the
> constant propagated manually. It does not optimise anything.

There are presently no (other) implementations for 
`H264DSPContext.h264_chroma_dc_dequant_idct`, which is used by H.264 and SVQ3 
decoders. I don't know if we should keep the pointers anyway or just hard-code 
the calls to the C implementation.

I am not sure if it would be possible to marginally optimise the functions 
with scalar product or matrix extensions... at least those extensions that do 
support widening 16x16 multiplications. (This is unfortunately not a given. 
With the AI/ML hype,16-bit floats, 8-bit and/or 4-bit integers are the more 
commonly supported types.)

-- 
Rémi Denis-Courmont
http://www.remlab.net/