[XviD-devel] Hadamard Transform

[Marco Al]

peter ross wrote:

>> More seriously, whenever you need the real ASM 1D/2D code
>> (not the C-like one I sent before), just tell me...
>> I'll take time to finish it for good...
>
> imho development should always work like this:
> 1. propose idea, discuss design
> 2. implement in c, do some testing to decide if its really needed
> 3. implement in asm

Since the steps were skipped anyway, and you now have asm implementations could
someone benchmark it against the DCT now? (Working from cache.)

Personally I dont see it the hadamard transform making much sense in software
with the amount of mode decisions in MPEG-4. AFAICS the number of DCT transforms
needed if you wanted to make the intra and 4v mode decisions in the DCT domain
would only take a couple of percent of running time if those DCTs could all work
from cache. In reality it will be slower of course, but the reasons behind that
have nothing to do with the arithmetic of the transform and will hit you just as
hard with the hadamard transform so it's of no concern.

Marco