eaidct.c File Reference

Electronic Arts TGQ/TQI/MAD IDCT algorithm. More...

#include "eaidct.h"
#include "libavutil/common.h"

Macros
#define	ASQRT   181 /* (1/sqrt(2))<<8 */
#define	A4   669 /* cos(pi/8)*sqrt(2)<<9 */
#define	A2   277 /* sin(pi/8)*sqrt(2)<<9 */
#define	A5   196 /* sin(pi/8)<<9 */
#define	IDCT_TRANSFORM(dest, s0, s1, s2, s3, s4, s5, s6, s7, d0, d1, d2, d3, d4, d5, d6, d7, munge, src)
#define	MUNGE_NONE(x)   (x)
#define	IDCT_COL(dest, src)   IDCT_TRANSFORM(dest,0,8,16,24,32,40,48,56,0,8,16,24,32,40,48,56,MUNGE_NONE,src)
#define	MUNGE_8BIT(x)   av_clip_uint8((x)>>4)
#define	IDCT_ROW(dest, src)   IDCT_TRANSFORM(dest,0,1,2,3,4,5,6,7,0,1,2,3,4,5,6,7,MUNGE_8BIT,src)

Functions
void	ff_ea_idct_put_c (uint8_t *dest, ptrdiff_t linesize, int16_t *block)

Detailed Description

Electronic Arts TGQ/TQI/MAD IDCT algorithm.

Author

Peter Ross pross.nosp@m.@xvi.nosp@m.d.org

Macro Definition Documentation

IDCT_TRANSFORM

#define IDCT_TRANSFORM	(		dest,
			s0,
			s1,
			s2,
			s3,
			s4,
			s5,
			s6,
			s7,
			d0,
			d1,
			d2,
			d3,
			d4,
			d5,
			d6,
			d7,
			munge,
			src
	)

Value:

{\
    const int a1 = (src)[s1] + (src)[s7]; \
    const int a7 = (src)[s1] - (src)[s7]; \
    const int a5 = (src)[s5] + (src)[s3]; \
    const int a3 = (src)[s5] - (src)[s3]; \
    const int a2 = (src)[s2] + (src)[s6]; \
    const int a6 = (ASQRT*((src)[s2] - (src)[s6]))>>8; \
    const int a0 = (src)[s0] + (src)[s4]; \
    const int a4 = (src)[s0] - (src)[s4]; \
    const int b0 = (((A4-A5)*a7 - A5*a3)>>9) + a1+a5; \
    const int b1 = (((A4-A5)*a7 - A5*a3)>>9) + ((ASQRT*(a1-a5))>>8); \
    const int b2 = (((A2+A5)*a3 + A5*a7)>>9) + ((ASQRT*(a1-a5))>>8); \
    const int b3 =  ((A2+A5)*a3 + A5*a7)>>9; \
    (dest)[d0] = munge(a0+a2+a6+b0); \
    (dest)[d1] = munge(a4+a6   +b1); \
    (dest)[d2] = munge(a4-a6   +b2); \
    (dest)[d3] = munge(a0-a2-a6+b3); \
    (dest)[d4] = munge(a0-a2-a6-b3); \
    (dest)[d5] = munge(a4-a6   -b2); \
    (dest)[d6] = munge(a4+a6   -b1); \
    (dest)[d7] = munge(a0+a2+a6-b0); \
}