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Re: [OpenDivX] OpenDivX optimalization: +30-40%



Had a quick look and it seems that IntraBlock() runs clearblock and an iDCT
on each block even if it was not coded!  I think we need to fix this, well
spotted.

So, where's the cleanest place to make the change:  as indicated below, or
inside IntraBlock()?

This might take a couple of days to get into CVS as e7abe7a's away today and
he should approve this first as this is his code.

Thanks again,

John (eagle)


----- Original Message -----
From: Andrew Woznytsa <[email protected]>
To: <[email protected]>
Sent: Wednesday, March 14, 2001 10:46 AM
Subject: [OpenDivX] OpenDivX optimalization: +30-40%


> Hi All,
>
> I'm quite confused...
>
> look below and compare these algorithms.. results will be the same but
> perfomance gain will be 30-40%..
>
> regards,
>
> Andrew
>
> decoder/mp4_mblock.c/macroblock(), line 120:
>
> 1. original algorithm:
>
>   // motion compensation
>   if (interFlag)
>   {
>    reconstruct(mp4_hdr.mb_xpos, mp4_hdr.mb_ypos, mp4_hdr.derived_mb_type);
>
>    // texture decoding add
>    for (j = 0; j < 6; j++) {
>     int coded = mp4_hdr.cbp & (1 << (5 - j));
>
>     blockInter(j, (coded != 0));
>     addblockInter(j, mp4_hdr.mb_xpos, mp4_hdr.mb_ypos);
>    }
>   }
>   else
>   {
>    // texture decoding add
> [skiped]
>
> 2. my version
>
>   // motion compensation
>   if (interFlag)
>   {
>    reconstruct(mp4_hdr.mb_xpos, mp4_hdr.mb_ypos, mp4_hdr.derived_mb_type);
>
>    // texture decoding add
>    for (j = 0; j < 6; j++) {
>     int coded = mp4_hdr.cbp & (1 << (5 - j));
>     if(coded){
>          blockInter(j, (coded != 0));
>          addblockInter(j, mp4_hdr.mb_xpos, mp4_hdr.mb_ypos);
>     }
>   }
>   else
>   {
>    // texture decoding add
> [skiped]
>
>
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