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

[Marc Hoffman]

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.

Thanks
Marc