Re: [Open2x-devel] libmpeg2 update

[John W. <Joh...@Di...>]

Hi Matt,

Sorry for the late response.

>I still have not been able to get the FDC to respond no matter what I send 
>to it.  So I decided to try a different approach and have the 2nd CPU (940)

>convert the YV12 surface to YUY2 for me.  This has proven pretty successful

>and I have also got hardware blitting working to speed up copying the 
>converted YUY2 surface from the 940 to the place where SDL wants the YUY2 
>image (it would be even cooler to not have to do this copy at all but that 
>is an optimization for the future).

That's a real shame about using the FDC. I guess we will have to put that
idea to one side until we better understand it. Anyway, onto the 940 MPEG
lib, in a few simple words, really sweet :). Running the YV12 conversion on
the 940 is a great idea. Out of interest how close is the lib to the
original API's? Just pondering reuse in other apps. 

>I am currently able to get about 30 FPS (ie full speed) using a very low 
>bitrate 320x240 mpeg1/mpeg2 file (250kbps-500kbps), with the mpeg decoding 
>and YV12->YUY2 conversion all being done on the 940.

That is very credible performance, I assume that is an all C implementation,
is the YV12>YUY2 conversion code also C, would it benefit from some ASM
work?

Regards,

John Willis