+/* fill lookup tables for intensity compensation */
+#define INIT_LUT(lumscale, lumshift, luty, lutuv, chain) do { \
+ int scale, shift, i; \
+ if (!lumscale) { \
+ scale = -64; \
+ shift = (255 - lumshift * 2) << 6; \
+ if (lumshift > 31) \
+ shift += 128 << 6; \
+ } else { \
+ scale = lumscale + 32; \
+ if (lumshift > 31) \
+ shift = (lumshift - 64) << 6; \
+ else \
+ shift = lumshift << 6; \
+ } \
+ for (i = 0; i < 256; i++) { \
+ int iy = chain ? luty[i] : i; \
+ int iu = chain ? lutuv[i] : i; \
+ luty[i] = av_clip_uint8((scale * iy + shift + 32) >> 6); \
+ lutuv[i] = av_clip_uint8((scale * (iu - 128) + 128*64 + 32) >> 6);\
+ } \
+ } while(0)
+
+static void rotate_luts(VC1Context *v)
+{
+#define ROTATE(DEF, L, N, C, A) do { \
+ if (v->s.pict_type == AV_PICTURE_TYPE_BI || v->s.pict_type == AV_PICTURE_TYPE_B) { \
+ C = A; \
+ } else { \
+ DEF; \
+ memcpy(&tmp, &L , sizeof(tmp)); \
+ memcpy(&L , &N , sizeof(tmp)); \
+ memcpy(&N , &tmp, sizeof(tmp)); \
+ C = N; \
+ } \
+ } while(0)
+
+ ROTATE(int tmp, v->last_use_ic, v->next_use_ic, v->curr_use_ic, v->aux_use_ic);
+ ROTATE(uint8_t tmp[2][256], v->last_luty, v->next_luty, v->curr_luty, v->aux_luty);
+ ROTATE(uint8_t tmp[2][256], v->last_lutuv, v->next_lutuv, v->curr_lutuv, v->aux_lutuv);
+
+ INIT_LUT(32, 0, v->curr_luty[0], v->curr_lutuv[0], 0);
+ INIT_LUT(32, 0, v->curr_luty[1], v->curr_lutuv[1], 0);
+ v->curr_use_ic = 0;
+ if (v->curr_luty == v->next_luty) {
+ // If we just initialized next_lut, clear next_use_ic to match.
+ v->next_use_ic = 0;
+ }
+}
+