Handling frame references and scale factors in one for loop.

Using ALLOWED_REFS_PER_FRAME constants instead of hard coded 3, replacing
memcpy with plain struct assignment.

Change-Id: Ibc86f5d175fcb3f3a3eddacf593525370f1f854c

2 files changed, 21 insertions, 25 deletions

diff --git a/vp9/common/vp9_onyxc_int.h b/vp9/common/vp9_onyxc_int.h
index 3e09c864c..730021a56 100644
--- a/vp9/common/vp9_onyxc_int.h
+++ b/vp9/common/vp9_onyxc_int.h
@@ -181,12 +181,14 @@ typedef struct VP9Common {
   int fb_idx_ref_cnt[NUM_YV12_BUFFERS]; /* reference counts */
   int ref_frame_map[NUM_REF_FRAMES]; /* maps fb_idx to reference slot */
 
-  /* TODO(jkoleszar): could expand active_ref_idx to 4, with 0 as intra, and
-   * roll new_fb_idx into it.
-   */
-  int active_ref_idx[3]; /* each frame can reference 3 buffers */
+  // TODO(jkoleszar): could expand active_ref_idx to 4, with 0 as intra, and
+  // roll new_fb_idx into it.
+
+  // Each frame can reference ALLOWED_REFS_PER_FRAME buffers
+  int active_ref_idx[ALLOWED_REFS_PER_FRAME];
+  struct scale_factors active_ref_scale[ALLOWED_REFS_PER_FRAME];
   int new_fb_idx;
-  struct scale_factors active_ref_scale[3];
+
 
   YV12_BUFFER_CONFIG post_proc_buffer;
   YV12_BUFFER_CONFIG temp_scale_frame;
diff --git a/vp9/decoder/vp9_decodframe.c b/vp9/decoder/vp9_decodframe.c
index a3445c03a..d5bfe647f 100644
--- a/vp9/decoder/vp9_decodframe.c
+++ b/vp9/decoder/vp9_decodframe.c
@@ -1517,10 +1517,18 @@ int vp9_decode_frame(VP9D_COMP *pbi, const uint8_t **p_data_end) {
     // Should the GF or ARF be updated from the current frame
     pbi->refresh_frame_flags = vp9_read_literal(&header_bc, NUM_REF_FRAMES);
 
-    // Select active reference frames
+    // Select active reference frames and calculate scaling factors
     for (i = 0; i < ALLOWED_REFS_PER_FRAME; ++i) {
-      int ref_frame_num = vp9_read_literal(&header_bc, NUM_REF_FRAMES_LG2);
-      pc->active_ref_idx[i] = pc->ref_frame_map[ref_frame_num];
+      const int ref = vp9_read_literal(&header_bc, NUM_REF_FRAMES_LG2);
+      const int mapped_ref = pc->ref_frame_map[ref];
+      YV12_BUFFER_CONFIG *const fb = &pc->yv12_fb[mapped_ref];
+      struct scale_factors *const sf = &pc->active_ref_scale[i];
+
+      pc->active_ref_idx[i] = mapped_ref;
+      if (mapped_ref >= NUM_YV12_BUFFERS)
+        memset(sf, 0, sizeof(*sf));
+      else
+        vp9_setup_scale_factors_for_frame(sf, fb, pc->width, pc->height);
     }
 
     pc->ref_frame_sign_bias[GOLDEN_FRAME] = vp9_read_bit(&header_bc);
@@ -1532,17 +1540,6 @@ int vp9_decode_frame(VP9D_COMP *pbi, const uint8_t **p_data_end) {
     pc->use_interintra = vp9_read_bit(&header_bc);
 #endif
 
-    // Calculate scaling factors for each of the 3 available references
-    for (i = 0; i < ALLOWED_REFS_PER_FRAME; ++i) {
-      const int idx = pc->active_ref_idx[i];
-      struct scale_factors *sf = &pc->active_ref_scale[i];
-      if (idx >= NUM_YV12_BUFFERS)
-        memset(sf, 0, sizeof(*sf));
-      else
-        vp9_setup_scale_factors_for_frame(sf, &pc->yv12_fb[idx],
-                                          pc->width, pc->height);
-    }
-
     // To enable choice of different interpolation filters
     vp9_setup_interp_filters(xd, pc->mcomp_filter_type, pc);
   }
@@ -1556,8 +1553,7 @@ int vp9_decode_frame(VP9D_COMP *pbi, const uint8_t **p_data_end) {
   }
 
   pc->frame_context_idx = vp9_read_literal(&header_bc, NUM_FRAME_CONTEXTS_LG2);
-  vpx_memcpy(&pc->fc, &pc->frame_contexts[pc->frame_context_idx],
-             sizeof(pc->fc));
+  pc->fc = pc->frame_contexts[pc->frame_context_idx];
 
   setup_segmentation(pc, xd, &header_bc);
 
@@ -1645,10 +1641,8 @@ int vp9_decode_frame(VP9D_COMP *pbi, const uint8_t **p_data_end) {
   }
 #endif
 
-  if (pc->refresh_entropy_probs) {
-    vpx_memcpy(&pc->frame_contexts[pc->frame_context_idx], &pc->fc,
-               sizeof(pc->fc));
-  }
+  if (pc->refresh_entropy_probs)
+    pc->frame_contexts[pc->frame_context_idx] = pc->fc;
 
   *p_data_end = vp9_reader_find_end(&residual_bc);
   return 0;