[XviD-devel] Performance questions

[Radek Czyz]

Hi,

 >     xvid_gbl_init.cpu_flags = XVID_CPU_SSE2;

This disables anything BUT SSE2. Since there's very little SSE2-only 
code in XviD, you end up with almost pure C.

Leave it at zero to auto-detect, it's your best option unless you really 
want to *disable* something.

 > 2.  Why Xvid decore () setting RGB565 is slower than BGRA8888?

RGB16 are the slowest colourspaces in existence. They are also very 
rarely used so xvid only has "for completeness", unoptimized code for them.

Radek

steve wrote:
> Hi:
> First I would like to thank you all in this forum.
> The program I made to play back avi file is running fine.
> 
> My test machine is 
> PC: Intel P4 3.0GHz, Intel 915, DDR2-667 MHz, 
> Video file: 1024x768
> Xvid setting: BGRA8888, MMX, SSE, SSE2
> Ogre Engine Display: resolution 1024 x 768, pixel format: RGB565
> 
> The result is
> Average FPS: 36, (Xvid Decode only, no pixel conversion) 47
> 
> My code:
>     xvid_gbl_init_t   xvid_gbl_init;
>     memset (&xvid_gbl_init, 0, sizeof (xvid_gbl_init_t));
>     xvid_gbl_init.version = XVID_VERSION;
>     xvid_gbl_init.cpu_flags = XVID_CPU_SSE2; 
>     xvid_global (NULL,  XVID_GBL_INIT, &xvid_gbl_init, NULL);
> 
> I have a couple of questions regarding performance.
> 1.  Is the result fps reasonable? I expected faster frame rate.
> 2.  Why Xvid decore () setting RGB565 is slower than BGRA8888?
> 3.  Why MMX, MMXEX, SSE, SSE2 perforamce are all the same?
> 
> Thank you very much.
> Steve
> 
> 
> 
> 
> _______________________________________________
> XviD-devel mailing list
> XviD-devel at xvid.org
> http://list.xvid.org/mailman/listinfo/xvid-devel
> 
>