[FFmpeg-devel] [PATCH 1/5] Shrink the size of vp56_mv

[Måns Rullgård]

"Ronald S. Bultje" <rsbultje at gmail.com> writes:

> Hi,
>
> On Tue, Jun 15, 2010 at 2:52 PM, Reimar D?ffinger
> <Reimar.Doeffinger at gmx.de> wrote:
>> On Tue, Jun 15, 2010 at 04:58:14PM +0200, Aurelien Jacobs wrote:
>>> On Tue, Jun 15, 2010 at 09:02:14AM -0400, David Conrad wrote:
>>> > ---
>>> > ?libavcodec/vp56.h | ? ?4 ++--
>>> > ?1 files changed, 2 insertions(+), 2 deletions(-)
>>> >
>>> > diff --git a/libavcodec/vp56.h b/libavcodec/vp56.h
>>> > index 89eba05..3d98b9e 100644
>>> > --- a/libavcodec/vp56.h
>>> > +++ b/libavcodec/vp56.h
>>> > @@ -60,8 +60,8 @@ typedef struct {
>>> > ?} VP56RefDc;
>>> >
>>> > ?struct vp56_mv {
>>> > - ? ?int x;
>>> > - ? ?int y;
>>> > + ? ?int16_t x;
>>> > + ? ?int16_t y;
>>> > ?};
>>>
>>> Looks OK. Apply if you're sure that it can't overflow.
>>
>> Hm, might make sense to benchmark a bit, it might be slower e.g.
>> if it means a lot of sign extension is added to the code...
>
> Did someone benchmark this? I mean, I'm quite sure any difference on
> general decoding would be unnoticeable so I might need some pointers
> on what exactly to benchmark, to prevent me wasting my time.

A simple test is to compare the size of .text on vp[56]+.o before and
after.  More instructions would make it bigger.

-- 
M?ns Rullg?rd
mans at mansr.com