[FFmpeg-devel] [PATCH] avcodec: only warn about hwaccel with frame threads

[Ronald S. Bultje]

Hi,

On Mon, Jan 25, 2016 at 4:01 AM, wm4 <nfxjfg at googlemail.com> wrote:

> On Sun, 24 Jan 2016 20:03:01 -0500
> "Ronald S. Bultje" <rsbultje at gmail.com> wrote:
>
> > Hi,
> >
> > On Sun, Jan 24, 2016 at 6:49 PM, Hendrik Leppkes <h.leppkes at gmail.com>
> > wrote:
>
>
> > > Unfortunately that doesn't alleviate the other issues, like the
> > > complexity needed in the decoders during frame threading, or the extra
> > > resources needed (extra image surfaces for every thread).
> > >
> >
> > So, the extra code is just in the decoders, which already need it anyway
> > (because they implement frame-mt), right? Or do hwaccels need extra code
> > also?
> >
> > The extra resources aren't a big deal IMO. Memory use isn't typically a
> big
> > issue, we're adding a fw kb extra for contexts but practically all memory
> > is in framebuffers regardless.
>
> It's can be a big deal for hardware decoding, because hw surfaces
> might be a more constrained resource than system RAM. Also, you often
> have to preallocate _all_ surfaces you're going to use, so you'll have
> to add the exact number of additionally needed surfaces to the
> preallocation.


If only one thread is active, the rest never has to be inited and thus
contains no surfaces (or framebuffers, or anything), right? If not, that
should be a trivial win.

Ronald