int lowres
low resolution decoding, 1-> 1/2 size, 2->1/4 size
int idct_algo
IDCT algorithm, see FF_IDCT_* below.
main external API structure.
void(* idct_add)(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
block -> idct -> add dest -> clip to unsigned 8 bit -> dest.
void(* idct_put)(uint8_t *dest, ptrdiff_t line_size, int16_t *block)
block -> idct -> clip to unsigned 8 bit -> dest.
enum idct_permutation_type perm_type
void(* idct)(int16_t *block)