[FFmpeg-devel] [PATCH] Optimize QTRLE encoding

[Malcolm Bechard]

On Tue, Feb 12, 2013 at 10:09 AM, Paul B Mahol <onemda at gmail.com> wrote:

> On 2/12/13, Malcolm Bechard <malcolm.bechard at gmail.com> wrote:
> > Attached is the base64 encoded patch file.
> > The goal is to remove this loop which causes a 1->127 loop for every
> pixel
> >
> > for (j = 1; j <= limit; j++) {
> >     if (s->length_table[i + j] + temp_cost < total_bulk_cost) {
> >         /* We have found a better bulk copy ... */
> >         total_bulk_cost = s->length_table[i + j] + temp_cost;
> >         bulkcount = j;
> >     }
> >     temp_cost += s->pixel_size;
> > }
> >
> > Output video files should be identical to the old algorithm in both size
> > and binary content.
> >
> > Performance gains may not be as strong on gcc since I was comparing (old
> > code) gcc vs. (new code) VS2010 in my initial comparisons. I expect 2-4x
> > speedups with gcc.
> >
> > Feedback is appreciated since this is my first patch.
> >
>
> Please read: http://ffmpeg.org/developer.html#toc-Contributing
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>

I'm sorry, I have. No sure what I've done wrong...