[FFmpeg-devel] [PATCH 13/39] lavc/ffv1: drop redundant PlaneContext.quant_table

[Anton Khirnov]

Quoting Paul B Mahol (2024-07-18 17:31:50)
> On Thu, Jul 18, 2024 at 10:20 AM Anton Khirnov <anton at khirnov.net> wrote:
> 
> > Quoting Michael Niedermayer (2024-07-18 00:32:38)
> > > the data for each decoder task should be together and not scattered
> > around
> > > more than needed, reducing cache efficiency
> > >
> > > putting all this extra code in the inner per pixel loop is not ok
> > > especially not for the sake of avoiding a memcpy of a few hundread bytes
> > multiple levels of loops outside
> >
> > A nice theory, but in practice this patchset makes single-threaded
> > decoding about 4% faster overall, on a 1920x1080 10bit sample. That's
> > just the ffv1 parts (up to patch 28), full set also improves frame
> > threading performance as follows:
> > threads         improvement
> > ---------------------------
> > 2                  52% (yes really)
> >
> 
> What?

Current code is effectively serial with 2 threads.

-- 
Anton Khirnov