avcodec/vc1: cleanup and simplification

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 97 insertions, 112 deletions

diff --git a/libavcodec/vc1.c b/libavcodec/vc1.c
index 19657ed690..22eb358dae 100644
--- a/libavcodec/vc1.c
+++ b/libavcodec/vc1.c
@@ -234,37 +234,34 @@ static int vop_dquant_decoding(VC1Context *v)
     int pqdiff;
 
     //variable size
-    if (v->dquant == 2) {
-        pqdiff = get_bits(gb, 3);
-        if (pqdiff == 7)
-            v->altpq = get_bits(gb, 5);
-        else
-            v->altpq = v->pq + pqdiff + 1;
-    } else {
+    if (v->dquant != 2) {
         v->dquantfrm = get_bits1(gb);
-        if (v->dquantfrm) {
-            v->dqprofile = get_bits(gb, 2);
-            switch (v->dqprofile) {
-            case DQPROFILE_SINGLE_EDGE:
-            case DQPROFILE_DOUBLE_EDGES:
-                v->dqsbedge = get_bits(gb, 2);
-                break;
-            case DQPROFILE_ALL_MBS:
-                v->dqbilevel = get_bits1(gb);
-                if (!v->dqbilevel)
-                    v->halfpq = 0;
-            default:
-                break; //Forbidden ?
-            }
-            if (v->dqbilevel || v->dqprofile != DQPROFILE_ALL_MBS) {
-                pqdiff = get_bits(gb, 3);
-                if (pqdiff == 7)
-                    v->altpq = get_bits(gb, 5);
-                else
-                    v->altpq = v->pq + pqdiff + 1;
+        if (!v->dquantfrm)
+            return 0;
+
+        v->dqprofile = get_bits(gb, 2);
+        switch (v->dqprofile) {
+        case DQPROFILE_SINGLE_EDGE:
+        case DQPROFILE_DOUBLE_EDGES:
+            v->dqsbedge = get_bits(gb, 2);
+            break;
+        case DQPROFILE_ALL_MBS:
+            v->dqbilevel = get_bits1(gb);
+            if (!v->dqbilevel) {
+                v->halfpq = 0;
+                return 0;
             }
+        default:
+            break; //Forbidden ?
         }
     }
+
+    pqdiff = get_bits(gb, 3);
+    if (pqdiff == 7)
+        v->altpq = get_bits(gb, 5);
+    else
+        v->altpq = v->pq + pqdiff + 1;
+
     return 0;
 }
 
@@ -335,8 +332,7 @@ int ff_vc1_decode_sequence_header(AVCodecContext *avctx, VC1Context *v, GetBitCo
         return -1;
     }
     v->extended_mv     = get_bits1(gb); //common
-    if (!v->profile && v->extended_mv)
-    {
+    if (!v->profile && v->extended_mv) {
         av_log(avctx, AV_LOG_ERROR,
                "Extended MVs unavailable in Simple Profile\n");
         return -1;
@@ -345,8 +341,7 @@ int ff_vc1_decode_sequence_header(AVCodecContext *avctx, VC1Context *v, GetBitCo
     v->vstransform     = get_bits1(gb); //common
 
     v->res_transtab    = get_bits1(gb);
-    if (v->res_transtab)
-    {
+    if (v->res_transtab) {
         av_log(avctx, AV_LOG_ERROR,
                "1 for reserved RES_TRANSTAB is forbidden\n");
         return -1;
@@ -649,17 +644,14 @@ int ff_vc1_parse_frame_header(VC1Context *v, GetBitContext* gb)
     v->rangeredfrm = 0;
     if (v->rangered)
         v->rangeredfrm = get_bits1(gb);
-    v->s.pict_type = get_bits1(gb);
-    if (v->s.avctx->max_b_frames) {
-        if (!v->s.pict_type) {
-            if (get_bits1(gb))
-                v->s.pict_type = AV_PICTURE_TYPE_I;
-            else
-                v->s.pict_type = AV_PICTURE_TYPE_B;
+    if (get_bits1(gb)) {
+        v->s.pict_type = AV_PICTURE_TYPE_P;
+    } else {
+        if (v->s.avctx->max_b_frames && !get_bits1(gb)) {
+            v->s.pict_type = AV_PICTURE_TYPE_B;
         } else
-            v->s.pict_type = AV_PICTURE_TYPE_P;
-    } else
-        v->s.pict_type = v->s.pict_type ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
+            v->s.pict_type = AV_PICTURE_TYPE_I;
+    }
 
     v->bi_type = 0;
     if (v->s.pict_type == AV_PICTURE_TYPE_B) {
@@ -689,19 +681,25 @@ int ff_vc1_parse_frame_header(VC1Context *v, GetBitContext* gb)
         v->pq = ff_vc1_pquant_table[0][pqindex];
     else
         v->pq = ff_vc1_pquant_table[1][pqindex];
-
-    v->pquantizer = 1;
-    if (v->quantizer_mode == QUANT_FRAME_IMPLICIT)
-        v->pquantizer = pqindex < 9;
-    if (v->quantizer_mode == QUANT_NON_UNIFORM)
-        v->pquantizer = 0;
     v->pqindex = pqindex;
     if (pqindex < 9)
         v->halfpq = get_bits1(gb);
     else
         v->halfpq = 0;
-    if (v->quantizer_mode == QUANT_FRAME_EXPLICIT)
+    switch (v->quantizer_mode) {
+    case QUANT_FRAME_IMPLICIT:
+        v->pquantizer = pqindex < 9;
+        break;
+    case QUANT_NON_UNIFORM:
+        v->pquantizer = 0;
+        break;
+    case QUANT_FRAME_EXPLICIT:
         v->pquantizer = get_bits1(gb);
+        break;
+    default:
+        v->pquantizer = 1;
+        break;
+    }
     v->dquantfrm = 0;
     if (v->extended_mv == 1)
         v->mvrange = get_unary(gb, 0, 3);
@@ -725,9 +723,7 @@ int ff_vc1_parse_frame_header(VC1Context *v, GetBitContext* gb)
 
     switch (v->s.pict_type) {
     case AV_PICTURE_TYPE_P:
-        if (v->pq < 5)       v->tt_index = 0;
-        else if (v->pq < 13) v->tt_index = 1;
-        else                 v->tt_index = 2;
+        v->tt_index = (v->pq > 4) + (v->pq > 12);
 
         lowquant = (v->pq > 12) ? 0 : 1;
         v->mv_mode = ff_vc1_mv_pmode_table[lowquant][get_unary(gb, 1, 4)];
@@ -741,16 +737,15 @@ int ff_vc1_parse_frame_header(VC1Context *v, GetBitContext* gb)
             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)
-            v->s.quarter_sample = 0;
-        else if (v->mv_mode == MV_PMODE_INTENSITY_COMP) {
-            if (v->mv_mode2 == MV_PMODE_1MV_HPEL || v->mv_mode2 == MV_PMODE_1MV_HPEL_BILIN)
-                v->s.quarter_sample = 0;
-            else
-                v->s.quarter_sample = 1;
-        } else
-            v->s.quarter_sample = 1;
-        v->s.mspel = !(v->mv_mode == MV_PMODE_1MV_HPEL_BILIN || (v->mv_mode == MV_PMODE_INTENSITY_COMP && v->mv_mode2 == MV_PMODE_1MV_HPEL_BILIN));
+        if (v->mv_mode == MV_PMODE_INTENSITY_COMP) {
+            v->s.quarter_sample = (v->mv_mode2 != MV_PMODE_1MV_HPEL &&
+                                   v->mv_mode2 != MV_PMODE_1MV_HPEL_BILIN);
+            v->s.mspel          = (v->mv_mode2 != MV_PMODE_1MV_HPEL_BILIN);
+        } else {
+            v->s.quarter_sample = (v->mv_mode != MV_PMODE_1MV_HPEL &&
+                                   v->mv_mode != MV_PMODE_1MV_HPEL_BILIN);
+            v->s.mspel          = (v->mv_mode != MV_PMODE_1MV_HPEL_BILIN);
+        }
 
         if ((v->mv_mode  == MV_PMODE_INTENSITY_COMP &&
              v->mv_mode2 == MV_PMODE_MIXED_MV)      ||
@@ -779,21 +774,19 @@ int ff_vc1_parse_frame_header(VC1Context *v, GetBitContext* gb)
             vop_dquant_decoding(v);
         }
 
-        v->ttfrm = 0; //FIXME Is that so ?
         if (v->vstransform) {
             v->ttmbf = get_bits1(gb);
             if (v->ttmbf) {
                 v->ttfrm = ff_vc1_ttfrm_to_tt[get_bits(gb, 2)];
-            }
+            } else
+                v->ttfrm = 0; //FIXME Is that so ?
         } else {
             v->ttmbf = 1;
             v->ttfrm = TT_8X8;
         }
         break;
     case AV_PICTURE_TYPE_B:
-        if (v->pq < 5)       v->tt_index = 0;
-        else if (v->pq < 13) v->tt_index = 1;
-        else                 v->tt_index = 2;
+        v->tt_index = (v->pq > 4) + (v->pq > 12);
 
         v->mv_mode          = get_bits1(gb) ? MV_PMODE_1MV : MV_PMODE_1MV_HPEL_BILIN;
         v->qs_last          = v->s.quarter_sample;
@@ -819,12 +812,12 @@ int ff_vc1_parse_frame_header(VC1Context *v, GetBitContext* gb)
             vop_dquant_decoding(v);
         }
 
-        v->ttfrm = 0;
         if (v->vstransform) {
             v->ttmbf = get_bits1(gb);
             if (v->ttmbf) {
                 v->ttfrm = ff_vc1_ttfrm_to_tt[get_bits(gb, 2)];
-            }
+            } else
+                v->ttfrm = 0;
         } else {
             v->ttmbf = 1;
             v->ttfrm = TT_8X8;
@@ -859,11 +852,12 @@ int ff_vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb)
     v->numref          = 0;
     v->p_frame_skipped = 0;
     if (v->second_field) {
-        if(v->fcm!=2 || v->field_mode!=1)
+        if (v->fcm != ILACE_FIELD || v->field_mode!=1)
             return -1;
-        v->s.pict_type = (v->fptype & 1) ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
         if (v->fptype & 4)
             v->s.pict_type = (v->fptype & 1) ? AV_PICTURE_TYPE_BI : AV_PICTURE_TYPE_B;
+        else
+            v->s.pict_type = (v->fptype & 1) ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
         v->s.current_picture_ptr->f->pict_type = v->s.pict_type;
         if (!v->pic_header_flag)
             goto parse_common_info;
@@ -889,10 +883,10 @@ int ff_vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb)
     if (v->field_mode) {
         v->s.mb_height = FFALIGN(v->s.height + 15 >> 4, 2);
         v->fptype = get_bits(gb, 3);
-        v->s.pict_type = (v->fptype & 2) ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
         if (v->fptype & 4) // B-picture
             v->s.pict_type = (v->fptype & 2) ? AV_PICTURE_TYPE_BI : AV_PICTURE_TYPE_B;
-
+        else
+            v->s.pict_type = (v->fptype & 2) ? AV_PICTURE_TYPE_P : AV_PICTURE_TYPE_I;
     } else {
         v->s.mb_height = v->s.height + 15 >> 4;
         switch (get_unary(gb, 0, 4)) {
@@ -974,24 +968,29 @@ int ff_vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb)
     pqindex = get_bits(gb, 5);
     if (!pqindex)
         return -1;
-    v->pqindex = pqindex;
     if (v->quantizer_mode == QUANT_FRAME_IMPLICIT)
         v->pq = ff_vc1_pquant_table[0][pqindex];
     else
         v->pq = ff_vc1_pquant_table[1][pqindex];
-
-    v->pquantizer = 1;
-    if (v->quantizer_mode == QUANT_FRAME_IMPLICIT)
-        v->pquantizer = pqindex < 9;
-    if (v->quantizer_mode == QUANT_NON_UNIFORM)
-        v->pquantizer = 0;
     v->pqindex = pqindex;
     if (pqindex < 9)
         v->halfpq = get_bits1(gb);
     else
         v->halfpq = 0;
-    if (v->quantizer_mode == QUANT_FRAME_EXPLICIT)
+    switch (v->quantizer_mode) {
+    case QUANT_FRAME_IMPLICIT:
+        v->pquantizer = pqindex < 9;
+        break;
+    case QUANT_NON_UNIFORM:
+        v->pquantizer = 0;
+        break;
+    case QUANT_FRAME_EXPLICIT:
         v->pquantizer = get_bits1(gb);
+        break;
+    default:
+        v->pquantizer = 1;
+        break;
+    }
     if (v->postprocflag)
         v->postproc = get_bits(gb, 2);
 
@@ -1081,12 +1080,7 @@ int ff_vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb)
         v->range_x = 1 << (v->k_x - 1);
         v->range_y = 1 << (v->k_y - 1);
 
-        if (v->pq < 5)
-            v->tt_index = 0;
-        else if (v->pq < 13)
-            v->tt_index = 1;
-        else
-            v->tt_index = 2;
+        v->tt_index = (v->pq > 4) + (v->pq > 12);
         if (v->fcm != ILACE_FRAME) {
             int mvmode;
             mvmode     = get_unary(gb, 1, 4);
@@ -1130,18 +1124,15 @@ int ff_vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb)
                 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)
-                v->s.quarter_sample = 0;
-            else if (v->mv_mode == MV_PMODE_INTENSITY_COMP) {
-                if (v->mv_mode2 == MV_PMODE_1MV_HPEL || v->mv_mode2 == MV_PMODE_1MV_HPEL_BILIN)
-                    v->s.quarter_sample = 0;
-                else
-                    v->s.quarter_sample = 1;
-            } else
-                v->s.quarter_sample = 1;
-            v->s.mspel = !(v->mv_mode == MV_PMODE_1MV_HPEL_BILIN
-                           || (v->mv_mode == MV_PMODE_INTENSITY_COMP
-                               && v->mv_mode2 == MV_PMODE_1MV_HPEL_BILIN));
+            if (v->mv_mode == MV_PMODE_INTENSITY_COMP) {
+                v->s.quarter_sample = (v->mv_mode2 != MV_PMODE_1MV_HPEL &&
+                                       v->mv_mode2 != MV_PMODE_1MV_HPEL_BILIN);
+                v->s.mspel          = (v->mv_mode2 != MV_PMODE_1MV_HPEL_BILIN);
+            } else {
+                v->s.quarter_sample = (v->mv_mode != MV_PMODE_1MV_HPEL &&
+                                       v->mv_mode != MV_PMODE_1MV_HPEL_BILIN);
+                v->s.mspel          = (v->mv_mode != MV_PMODE_1MV_HPEL_BILIN);
+            }
         }
         if (v->fcm == PROGRESSIVE) { // progressive
             if ((v->mv_mode == MV_PMODE_INTENSITY_COMP &&
@@ -1192,12 +1183,12 @@ int ff_vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb)
             vop_dquant_decoding(v);
         }
 
-        v->ttfrm = 0; //FIXME Is that so ?
         if (v->vstransform) {
             v->ttmbf = get_bits1(gb);
             if (v->ttmbf) {
                 v->ttfrm = ff_vc1_ttfrm_to_tt[get_bits(gb, 2)];
-            }
+            } else
+                v->ttfrm = 0; //FIXME Is that so ?
         } else {
             v->ttmbf = 1;
             v->ttfrm = TT_8X8;
@@ -1220,12 +1211,7 @@ int ff_vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb)
         v->range_x = 1 << (v->k_x - 1);
         v->range_y = 1 << (v->k_y - 1);
 
-        if (v->pq < 5)
-            v->tt_index = 0;
-        else if (v->pq < 13)
-            v->tt_index = 1;
-        else
-            v->tt_index = 2;
+        v->tt_index = (v->pq > 4) + (v->pq > 12);
 
         if (v->field_mode) {
             int mvmode;
@@ -1313,12 +1299,12 @@ int ff_vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb)
             vop_dquant_decoding(v);
         }
 
-        v->ttfrm = 0;
         if (v->vstransform) {
             v->ttmbf = get_bits1(gb);
             if (v->ttmbf) {
                 v->ttfrm = ff_vc1_ttfrm_to_tt[get_bits(gb, 2)];
-            }
+            } else
+                v->ttfrm = 0;
         } else {
             v->ttmbf = 1;
             v->ttfrm = TT_8X8;
@@ -1344,11 +1330,10 @@ int ff_vc1_parse_frame_header_adv(VC1Context *v, GetBitContext* gb)
         vop_dquant_decoding(v);
     }
 
-    v->bi_type = 0;
-    if (v->s.pict_type == AV_PICTURE_TYPE_BI) {
+    v->bi_type = (v->s.pict_type == AV_PICTURE_TYPE_BI);
+    if (v->bi_type)
         v->s.pict_type = AV_PICTURE_TYPE_B;
-        v->bi_type = 1;
-    }
+
     return 0;
 }