[Ffmpeg-devel] ADI Blackfin port and optimization
Michael Benjamin
neuroptik
Wed Aug 23 22:54:18 CEST 2006
On 8/23/06, Michael Niedermayer <michaelni at gmx.at> wrote:
>
> > + fdctCoef[0] = 0x5a82; // C4
> > + fdctCoef[1] = 0x5a82; // C4
> > + fdctCoef[2] = 0x30Fb; //cos(3pi/8) C6
> > + fdctCoef[3] = 0x7641; //cos(pi/8) C2
> > + fdctCoef[4] = 0x18F8; //cos(7pi/16)
> > + fdctCoef[5] = 0x7D8A; //cos(pi/16)
> > + fdctCoef[6] = 0x471c; //cos(5pi/16)
> > + fdctCoef[7] = 0x6A6d; //cos(3pi/16)
> > +
> > + r8x8dct_bfin( block, fdctCoef, computeTemp );
>
> what is computeTemp good for ?
ideally, computeTemp would be in L1 SRAM (in core clock domain) on the
Blackfin (along with DCT/IDCT) for fast execution. right now whole code/data
segments can be put into L1 SRAM, putting specific functions/data with gcc
attributes is not yet implemented.
[...]
> > + if(idct_algo==FF_IDCT_AUTO||idct_algo==FF_IDCT_BFIN){
> > + c->idct = simple_idct_bfin;
> > + }
>
> IDCTs which are selected automatically by default (especially for
> encoding)
> must
> 1. provide a binary identical portable implementation in C
true for DCT too?
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