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
an example to avoid confusion:
- (->decode coeffs -> zigzag reorder -> dequant -> reference idct ->...)
- (x -> referece dct -> reference idct -> x)
- (x -> referece dct -> simple_mmx_perm = idct_permutation -> simple_idct_mmx -> x)
- (->decode coeffs -> zigzag reorder -> simple_mmx_perm -> dequant -> simple_idct_mmx ->...)
Definition at line 333 of file dsputil.h.
Referenced by mpeg4_pred_ac().