[FFmpeg-devel] [PATCH] avcodec/internal: improve min_size documentation for ff_alloc_packet2()

[wm4]

On Tue, 4 Aug 2015 00:51:17 +0200
Michael Niedermayer <michael at niedermayer.cc> wrote:

> On Tue, Aug 04, 2015 at 12:12:24AM +0200, wm4 wrote:

> > > As well as benchmark results in some commits like
> > > 4302a92835313000d4bf8030baae32c2b130d8a1
> > 
> >     avcodec/pcm: Better min_size for ff_alloc_packet2()
> >     
> >     33318 -> 30601 decicycles
> > 
> > That doesn't look convincing at all. So you save ~3000 decicycles for
> > a task that isn't CPU bound, but which might blocks entire milliseconds
> > on I/O.
> 
> There was a bug report of a overall (aka time ffmpeg) speedloss
> in the % values with high res rawvideo

Was it fixed?

> > > i do intend to fine tune this for more codecs but i spend more time
> > > in such disussions than working on the code and having people tell me
> > > to do it differently each time i take a step kind of slows it down
> > > and turns it into a mess
> > 
> > We also must take care of not turning the codebase into a mess.
> 
> I want to fix the mess

I don't mind, but...

> and i would suggest that we first test if any / which encoders benefit
> from the static buffer.
> It where quite a few long ago but it seems from a few quick tests that
> this is not so anymore.
> Can someone confirm ?
> if it has become useless then I could drop quite a bit of code

Do you have to do your experiments on the live codebase? If you just
want to try something, you could do that in a branch. If it gives good
results, merge, if not, it's a failed experiment.