[Spice-devel] libjpeg performance

[Uri Lublin]

On 04/12/2010 09:57 PM, Alexander Larsson wrote:
> I did some simple testing of the new mjpeg encoder.
> Showing the youtube "will it blend - ipad" video i got quite better
> compression (24k per frame average as opposed to 35k before), but the
> code used a bit more cpu (9.8 msec per frame where it was 4.2 before). I
> made a simple change in the libjpeg code to make it a bit faster, but we
> might still be able to tweak this a bit in favour of performance rather
> than compression if thats what we want.
>

Hi Alex,

Nice.

In  client/mjpeg_decoder.cpp -> decode_data(), there is a code that memmove data 
to the beginning of the buffer.

Do you think we can gain better performance by actually implementing _cinfo.src 
functions ? This way we may be able to avoid (some) memory copying, e.g. by 
using a circular-buffer (and modulo calculation) or maybe even with no internal 
buffer.

Regards,
     Uri.