[FFmpeg-devel] rough PATCH: reducing the memory copies

[Michael Niedermayer]

Hi

On Tue, Jun 26, 2007 at 08:33:34PM -0400, Marc Hoffman wrote:
> On 6/26/07, Marc Hoffman <mmhoffm at gmail.com> wrote:
> >
> >
> >
> > On 6/25/07, mmh <mmh at pleasantst.com> wrote:
> > >
> > > Michael Niedermayer writes:
> > > > Hi
> > > >
> > > > On Mon, Jun 25, 2007 at 08:01:15PM -0400, mmh wrote:
> > > > Content-Description: message body text
> > > > >
> > > > > This saves me about 50MIPS + reduce cache stress, by elliminating
> > > this
> > > > > memory copy, which I guess happens later anyways again.
> > > > >
> > > > > I know that I need to creat a new function in utils.c for this like
> > > > > av_new_packet probably av_ref_packet which does the work in the if
> > > variant.
> > > > >
> > > > > What are the problems with this and, other ideas that comes to mind?
> > > >
> > > > there probably wont be any problems, it should work fine though
> > > > as you suspected it will sometimes tough not always cause a memcpy()
> > > > to be done later ...
> > > >
> > > >
> > > > [...]
> > > > > -
> > > > > +    PROF_BEGIN();
> > > >
> > > > this doesnt belong in here, the code is messy enough as is
> > > >
> > > >
> > > > >      ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame];
> > > > > -    memcpy(buf, ptr, s->frame_size);
> > > > >
> > > > > +    if (s->gb_buffers.frames > 1) {
> > > > > +        av_free (pkt->data);
> > > >
> > > > alloc+free is not ok, dont malloc()
> > > >
> > > >
> > > > > +        pkt->destruct= av_destruct_packet_nofree;
> > > > > +        pkt->data = ptr;
> > > > > +  pkt->size = s->frame_size;
> > > >
> > > > tab
> > > >
> > > >
> > >
> > > Trivial prototype correction.. Sorry for the confusion.
> >
> >
> >
> > Any objections to this patch being applied?
> >
> 
> I'm going to appy this tomorrow morning if there are no objections.

please wait until someone reviewed it

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The worst form of inequality is to try to make unequal things equal.
-- Aristotle
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