IDCT input permutation.
Several optimized IDCTs need a permutated input (relative to the
normal order of the reference IDCT).
This permutation must be performed before the idct_put/add.
Note, normally this can be merged with the zigzag/alternate scan<br>
An example to avoid confusion:
- (->decode coeffs -> zigzag reorder -> dequant -> reference IDCT -> ...)
- (x -> reference DCT -> reference IDCT -> x)
- (x -> reference DCT -> simple_mmx_perm = idct_permutation
-> simple_idct_mmx -> x)
- (-> decode coeffs -> zigzag reorder -> simple_mmx_perm -> dequant
-> simple_idct_mmx -> ...)
IDCT input permutation. Several optimized IDCTs need a permutated input (relative to the normal order of the reference IDCT). This permutation must be performed before the idct_put/add. Note, normally this can be merged with the zigzag/alternate scan<br> An example to avoid confusion: - (->decode coeffs -> zigzag reorder -> dequant -> reference IDCT -> ...) - (x -> reference DCT -> reference IDCT -> x) - (x -> reference DCT -> simple_mmx_perm = idct_permutation -> simple_idct_mmx -> x) - (-> decode coeffs -> zigzag reorder -> simple_mmx_perm -> dequant -> simple_idct_mmx -> ...)