[FFmpeg-devel] pre discussion around Blackfin dct_quantize_bfin routine

Marc Hoffman mmh
Tue Jun 12 04:58:00 CEST 2007


This is my rough draft it works well with the small precision errors  
due to 16bit arithmetic, actually its the same (as far as I can tell)  
as the MMX quantizer. I ran my reference fixpoint against the mmx and  
it seems to work on the cases I tried, its 1 bit off which seems  
about right considering the truncation of the coeffs from 22 to  
16bits.  Can someone look over my shoulder and give a peak. I know I  
have to clean up the codes a bit but I wanted to get someone else to  
review my work up until now.  I have used inline asm, Michael this  
should be pretty straight forward for you to get your head around.   
This doubles the performance roughly.

Also can you comment on me keeping the reference version and  
profiling apparatus in the module?

Thanks I appreciate your help

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