VP8: simplify lf_delta mb mode logic

(cherry picked from commit dd18c9a050ac1f1437151ceb2d2afbc96c5602d8)

1 files changed, 11 insertions, 25 deletions

diff --git a/libavcodec/vp8.c b/libavcodec/vp8.c
index effeb4ed2f..bcf623790c 100644
--- a/libavcodec/vp8.c
+++ b/libavcodec/vp8.c
@@ -162,13 +162,14 @@ typedef struct {
 
         /**
          * filter strength adjustment for the following macroblock modes:
-         * [0] - i4x4
-         * [1] - zero mv
-         * [2] - inter modes except for zero or split mv
-         * [3] - split mv
+         * [0-3] - i16x16 (always zero)
+         * [4]   - i4x4
+         * [5]   - zero mv
+         * [6]   - inter modes except for zero or split mv
+         * [7]   - split mv
          *  i16x16 modes never have any adjustment
          */
-        int8_t mode[4];
+        int8_t mode[VP8_MVMODE_SPLIT+1];
 
         /**
          * filter strength adjustment for macroblocks that reference:
@@ -278,7 +279,7 @@ static void update_lf_deltas(VP8Context *s)
     for (i = 0; i < 4; i++)
         s->lf_delta.ref[i]  = vp8_rac_get_sint(c, 6);
 
-    for (i = 0; i < 4; i++)
+    for (i = MODE_I4x4; i <= VP8_MVMODE_SPLIT; i++)
         s->lf_delta.mode[i] = vp8_rac_get_sint(c, 6);
 }
 
@@ -762,6 +763,7 @@ void decode_mb_mode(VP8Context *s, VP8Macroblock *mb, int mb_x, int mb_y, uint8_
         // motion vectors, 16.3
         find_near_mvs(s, mb, near, &best, cnt);
         if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[0]][0])) {
+            mb->mode = VP8_MVMODE_MV;
             if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[1]][1])) {
                 if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[2]][2])) {
                     if (vp56_rac_get_prob_branchy(c, vp8_mode_contexts[cnt[3]][3])) {
@@ -769,19 +771,14 @@ void decode_mb_mode(VP8Context *s, VP8Macroblock *mb, int mb_x, int mb_y, uint8_
                         clamp_mv(s, &mb->mv, &mb->mv, mb_x, mb_y);
                         mb->mv = mb->bmv[decode_splitmvs(s, c, mb) - 1];
                     } else {
-                        mb->mode = VP8_MVMODE_NEW;
                         clamp_mv(s, &mb->mv, &mb->mv, mb_x, mb_y);
                         mb->mv.y += read_mv_component(c, s->prob->mvc[0]);
                         mb->mv.x += read_mv_component(c, s->prob->mvc[1]);
                     }
-                } else {
-                    mb->mode = VP8_MVMODE_NEAR;
+                } else
                     clamp_mv(s, &mb->mv, &near[1], mb_x, mb_y);
-                }
-            } else {
-                mb->mode = VP8_MVMODE_NEAREST;
+            } else
                 clamp_mv(s, &mb->mv, &near[0], mb_x, mb_y);
-            }
         } else {
             mb->mode = VP8_MVMODE_ZERO;
             AV_ZERO32(&mb->mv);
@@ -1481,18 +1478,7 @@ static av_always_inline void filter_level_for_mb(VP8Context *s, VP8Macroblock *m
 
     if (s->lf_delta.enabled) {
         filter_level += s->lf_delta.ref[mb->ref_frame];
-
-        if (mb->ref_frame == VP56_FRAME_CURRENT) {
-            if (mb->mode == MODE_I4x4)
-                filter_level += s->lf_delta.mode[0];
-        } else {
-            if (mb->mode == VP8_MVMODE_ZERO)
-                filter_level += s->lf_delta.mode[1];
-            else if (mb->mode == VP8_MVMODE_SPLIT)
-                filter_level += s->lf_delta.mode[3];
-            else
-                filter_level += s->lf_delta.mode[2];
-        }
+        filter_level += s->lf_delta.mode[mb->mode];
     }
     filter_level = av_clip(filter_level, 0, 63);