vc1dec: Redesign the intensity compensation

Use the intensity-compensated reference frame for subsequent
fields/B-frames.

Since we currently don't change the reference frame we have to
maintain lookup tables for intensity compensation in the following
dependent frames.

Signed-off-by: Martin Storsjö <martin@martin.st>

1 files changed, 68 insertions, 19 deletions

diff --git a/libavcodec/vc1.c b/libavcodec/vc1.c
index 23012cdc63..7d09234f9b 100644
--- a/libavcodec/vc1.c
+++ b/libavcodec/vc1.c
@@ -571,7 +571,7 @@ int ff_vc1_decode_entry_point(AVCodecContext *avctx, VC1Context *v, GetBitContex
 }
 
 /* fill lookup tables for intensity compensation */
-#define INIT_LUT(lumscale, lumshift, luty, lutuv) do {                        \
+#define INIT_LUT(lumscale, lumshift, luty, lutuv, chain) do {                 \
         int scale, shift, i;                                                  \
         if (!lumscale) {                                                      \
             scale = -64;                                                      \
@@ -586,11 +586,36 @@ int ff_vc1_decode_entry_point(AVCodecContext *avctx, VC1Context *v, GetBitContex
                 shift = lumshift << 6;                                        \
         }                                                                     \
         for (i = 0; i < 256; i++) {                                           \
-            luty[i]  = av_clip_uint8((scale * i + shift + 32) >> 6);          \
-            lutuv[i] = av_clip_uint8((scale * (i - 128) + 128*64 + 32) >> 6); \
+            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;
+}
+
 int ff_vc1_parse_frame_header(VC1Context *v, GetBitContext* gb)
 {
     int pqindex, lowquant, status;
@@ -677,8 +702,8 @@ int ff_vc1_parse_frame_header(VC1Context *v, GetBitContext* gb)
             (v->s.pict_type == AV_PICTURE_TYPE_P) ? 'P' : ((v->s.pict_type == AV_PICTURE_TYPE_I) ? 'I' : 'B'),
             pqindex, v->pq, v->halfpq, v->rangeredfrm);
 
-    if (v->s.pict_type == AV_PICTURE_TYPE_I || v->s.pict_type == AV_PICTURE_TYPE_P)
-        v->use_ic = 0;
+    if (v->first_pic_header_flag)
+        rotate_luts(v);
 
     switch (v->s.pict_type) {
     case AV_PICTURE_TYPE_P:
@@ -692,9 +717,10 @@ int ff_vc1_parse_frame_header(VC1Context *v, GetBitContext* gb)
             v->mv_mode2 = ff_vc1_mv_pmode_table2[lowquant][get_unary(gb, 1, 3)];
             v->lumscale = get_bits(gb, 6);
             v->lumshift = get_bits(gb, 6);
-            v->use_ic   = 1;
+            v->last_use_ic = 1;
             /* fill lookup tables for intensity compensation */
-            INIT_LUT(v->lumscale, v->lumshift, v->luty, v->lutuv);
+            INIT_LUT(v->lumscale, v->lumshift, v->last_luty[0], v->last_lutuv[0], 1);
+            INIT_LUT(v->lumscale, v->lumshift, v->last_luty[1], v->last_lutuv[1], 1);
         }
         v->qs_last = v->s.quarter_sample;
         if (v->mv_mode == MV_PMODE_1MV_HPEL || v->mv_mode == MV_PMODE_1MV_HPEL_BILIN)
@@ -942,12 +968,12 @@ int ff_vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb)
     if (v->postprocflag)
         v->postproc = get_bits(gb, 2);
 
-    if (v->s.pict_type == AV_PICTURE_TYPE_I || v->s.pict_type == AV_PICTURE_TYPE_P)
-        v->use_ic = 0;
-
     if (v->parse_only)
         return 0;
 
+    if (v->first_pic_header_flag)
+        rotate_luts(v);
+
     switch (v->s.pict_type) {
     case AV_PICTURE_TYPE_I:
     case AV_PICTURE_TYPE_BI:
@@ -998,7 +1024,9 @@ int ff_vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb)
                 if (v->intcomp) {
                     v->lumscale = get_bits(gb, 6);
                     v->lumshift = get_bits(gb, 6);
-                    INIT_LUT(v->lumscale, v->lumshift, v->luty, v->lutuv);
+                    INIT_LUT(v->lumscale, v->lumshift, v->last_luty[0], v->last_lutuv[0], 1);
+                    INIT_LUT(v->lumscale, v->lumshift, v->last_luty[1], v->last_lutuv[1], 1);
+                    v->last_use_ic = 1;
                 }
                 status = bitplane_decoding(v->s.mbskip_table, &v->skip_is_raw, v);
                 av_log(v->s.avctx, AV_LOG_DEBUG, "SKIPMB plane encoding: "
@@ -1041,17 +1069,38 @@ int ff_vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb)
                 int mvmode2;
                 mvmode2 = get_unary(gb, 1, 3);
                 v->mv_mode2 = ff_vc1_mv_pmode_table2[lowquant][mvmode2];
-                if (v->field_mode)
-                    v->intcompfield = decode210(gb);
-                v->lumscale = get_bits(gb, 6);
-                v->lumshift = get_bits(gb, 6);
-                INIT_LUT(v->lumscale, v->lumshift, v->luty, v->lutuv);
-                if ((v->field_mode) && !v->intcompfield) {
+                if (v->field_mode) {
+                    v->intcompfield = decode210(gb) ^ 3;
+                } else
+                    v->intcompfield = 3;
+
+                v->lumscale2 = v->lumscale = 32;
+                v->lumshift2 = v->lumshift =  0;
+                if (v->intcompfield & 1) {
+                    v->lumscale = get_bits(gb, 6);
+                    v->lumshift = get_bits(gb, 6);
+                }
+                if ((v->intcompfield & 2) && v->field_mode) {
                     v->lumscale2 = get_bits(gb, 6);
                     v->lumshift2 = get_bits(gb, 6);
-                    INIT_LUT(v->lumscale2, v->lumshift2, v->luty2, v->lutuv2);
+                } else if(!v->field_mode) {
+                    v->lumscale2 = v->lumscale;
+                    v->lumshift2 = v->lumshift;
+                }
+                if (v->field_mode && v->second_field) {
+                    if (v->cur_field_type) {
+                        INIT_LUT(v->lumscale , v->lumshift , v->curr_luty[v->cur_field_type^1], v->curr_lutuv[v->cur_field_type^1], 0);
+                        INIT_LUT(v->lumscale2, v->lumshift2, v->last_luty[v->cur_field_type  ], v->last_lutuv[v->cur_field_type  ], 1);
+                    } else {
+                        INIT_LUT(v->lumscale2, v->lumshift2, v->curr_luty[v->cur_field_type^1], v->curr_lutuv[v->cur_field_type^1], 0);
+                        INIT_LUT(v->lumscale , v->lumshift , v->last_luty[v->cur_field_type  ], v->last_lutuv[v->cur_field_type  ], 1);
+                    }
+                    v->next_use_ic = v->curr_use_ic = 1;
+                } else {
+                    INIT_LUT(v->lumscale , v->lumshift , v->last_luty[0], v->last_lutuv[0], 1);
+                    INIT_LUT(v->lumscale2, v->lumshift2, v->last_luty[1], v->last_lutuv[1], 1);
                 }
-                v->use_ic = 1;
+                v->last_use_ic = 1;
             }
             v->qs_last = v->s.quarter_sample;
             if (v->mv_mode == MV_PMODE_1MV_HPEL || v->mv_mode == MV_PMODE_1MV_HPEL_BILIN)