Update encoder to use fb_idx_ref_cnt

Do reference counting the same way on the encoder as the decoder does,
rather than maintaining the 'flags' member of YV12_BUFFER_CONFIG.

Change-Id: I91dc210ffca081acaf9d5c09a06e7461b3c3139c

vp9/common/vp9_alloccommon.c

@@ -80,7 +80,6 @@ int vp9_alloc_frame_buffers(VP9_COMMON *oci, int width, int height) {
 
   for (i = 0; i < NUM_YV12_BUFFERS; i++) {
     oci->fb_idx_ref_cnt[i] = 0;
-    oci->yv12_fb[i].flags = 0;
     if (vp8_yv12_alloc_frame_buffer(&oci->yv12_fb[i], width, height,
                                     VP9BORDERINPIXELS) < 0) {
       vp9_de_alloc_frame_buffers(oci);

vp9/common/vp9_onyxc_int.h

@@ -271,4 +271,24 @@ typedef struct VP9Common {
 
 } VP9_COMMON;
 
+static int get_free_fb(VP9_COMMON *cm) {
+  int i;
+  for (i = 0; i < NUM_YV12_BUFFERS; i++)
+    if (cm->fb_idx_ref_cnt[i] == 0)
+      break;
+
+  assert(i < NUM_YV12_BUFFERS);
+  cm->fb_idx_ref_cnt[i] = 1;
+  return i;
+}
+
+static void ref_cnt_fb(int *buf, int *idx, int new_idx) {
+  if (buf[*idx] > 0)
+    buf[*idx]--;
+
+  *idx = new_idx;
+
+  buf[new_idx]++;
+}
+
 #endif  // VP9_COMMON_VP9_ONYXC_INT_H_

vp9/decoder/vp9_onyxd_if.c

@@ -30,9 +30,6 @@
 #include "vp9/decoder/vp9_detokenize.h"
 #include "./vpx_scale_rtcd.h"
 
-static int get_free_fb(VP9_COMMON *cm);
-static void ref_cnt_fb(int *buf, int *idx, int new_idx);
-
 #define WRITE_RECON_BUFFER 0
 #if WRITE_RECON_BUFFER == 1
 static void recon_write_yuv_frame(char *name, YV12_BUFFER_CONFIG *s) {
@@ -234,26 +231,6 @@ vpx_codec_err_t vp9_set_reference_dec(VP9D_PTR ptr, VP9_REFFRAME ref_frame_flag,
 }
 
 
-static int get_free_fb(VP9_COMMON *cm) {
-  int i;
-  for (i = 0; i < NUM_YV12_BUFFERS; i++)
-    if (cm->fb_idx_ref_cnt[i] == 0)
-      break;
-
-  assert(i < NUM_YV12_BUFFERS);
-  cm->fb_idx_ref_cnt[i] = 1;
-  return i;
-}
-
-static void ref_cnt_fb(int *buf, int *idx, int new_idx) {
-  if (buf[*idx] > 0)
-    buf[*idx]--;
-
-  *idx = new_idx;
-
-  buf[new_idx]++;
-}
-
 /* If any buffer copy / swapping is signalled it should be done here. */
 static int swap_frame_buffers(VP9_COMMON *cm) {
   int err = 0;

vp9/encoder/vp9_onyx_if.c

@@ -2564,36 +2564,24 @@ static int recode_loop_test(VP9_COMP *cpi,
 }
 
 static void update_reference_frames(VP9_COMMON *cm) {
-  YV12_BUFFER_CONFIG *yv12_fb = cm->yv12_fb;
-
   // At this point the new frame has been encoded.
   // If any buffer copy / swapping is signaled it should be done here.
 
   if (cm->frame_type == KEY_FRAME) {
-    yv12_fb[cm->new_fb_idx].flags |= VP9_GOLD_FLAG | VP9_ALT_FLAG;
-
-    yv12_fb[cm->gld_fb_idx].flags &= ~VP9_GOLD_FLAG;
-    yv12_fb[cm->alt_fb_idx].flags &= ~VP9_ALT_FLAG;
-
-    cm->alt_fb_idx = cm->gld_fb_idx = cm->new_fb_idx;
+    ref_cnt_fb(cm->fb_idx_ref_cnt, &cm->gld_fb_idx, cm->new_fb_idx);
+    ref_cnt_fb(cm->fb_idx_ref_cnt, &cm->alt_fb_idx, cm->new_fb_idx);
   } else { /* For non key frames */
     if (cm->refresh_alt_ref_frame) {
-      cm->yv12_fb[cm->new_fb_idx].flags |= VP9_ALT_FLAG;
-      cm->yv12_fb[cm->alt_fb_idx].flags &= ~VP9_ALT_FLAG;
-      cm->alt_fb_idx = cm->new_fb_idx;
+      ref_cnt_fb(cm->fb_idx_ref_cnt, &cm->alt_fb_idx, cm->new_fb_idx);
     }
 
     if (cm->refresh_golden_frame) {
-      cm->yv12_fb[cm->new_fb_idx].flags |= VP9_GOLD_FLAG;
-      cm->yv12_fb[cm->gld_fb_idx].flags &= ~VP9_GOLD_FLAG;
-      cm->gld_fb_idx = cm->new_fb_idx;
+      ref_cnt_fb(cm->fb_idx_ref_cnt, &cm->gld_fb_idx, cm->new_fb_idx);
     }
   }
 
   if (cm->refresh_last_frame) {
-    cm->yv12_fb[cm->new_fb_idx].flags |= VP9_LAST_FLAG;
-    cm->yv12_fb[cm->lst_fb_idx].flags &= ~VP9_LAST_FLAG;
-    cm->lst_fb_idx = cm->new_fb_idx;
+    ref_cnt_fb(cm->fb_idx_ref_cnt, &cm->lst_fb_idx, cm->new_fb_idx);
   }
 }
 
@@ -3914,18 +3902,13 @@ int vp9_get_compressed_data(VP9_PTR ptr, unsigned int *frame_flags,
   }
 
 #endif
-  /* find a free buffer for the new frame */
-  {
-    int i = 0;
-    for (; i < NUM_YV12_BUFFERS; i++) {
-      if (!cm->yv12_fb[i].flags) {
-        cm->new_fb_idx = i;
-        break;
-      }
-    }
 
-    assert(i < NUM_YV12_BUFFERS);
-  }
+  /* find a free buffer for the new frame, releasing the reference previously
+   * held.
+   */
+  cm->fb_idx_ref_cnt[cm->new_fb_idx]--;
+  cm->new_fb_idx = get_free_fb(cm);
+
   if (cpi->pass == 1) {
     Pass1Encode(cpi, size, dest, frame_flags);
   } else if (cpi->pass == 2) {