From: Frank Galligan <fgalligan@google.com>
Date: Wed, 4 Dec 2013 23:11:00 +0000 (-0800)
Subject: Fix the initial references to frame buffers.
X-Git-Tag: v1.4.0~2902^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9ed616a56cc32399d992ca0a3553cec9c3f5e041;p=libvpx

Fix the initial references to frame buffers.

The old code would start in a mixed state, where all the reference
frames were pointing to frame buffer 0, but the reference counts
were 0. This is why we needed special code for the first frame.

Change-Id: I734961012917654ff8c0c8b317aac00ab75ded1a
---

diff --git a/vp9/common/vp9_onyxc_int.h b/vp9/common/vp9_onyxc_int.h
index 751accf02..6d14128a8 100644
--- a/vp9/common/vp9_onyxc_int.h
+++ b/vp9/common/vp9_onyxc_int.h
@@ -238,8 +238,10 @@ static int get_free_fb(VP9_COMMON *cm) {
 }
 
 static void ref_cnt_fb(int *buf, int *idx, int new_idx) {
-  if (buf[*idx] > 0)
-    buf[*idx]--;
+  const int ref_index = *idx;
+
+  if (ref_index > 0 && buf[ref_index] > 0)
+    buf[ref_index]--;
 
   *idx = new_idx;
 
diff --git a/vp9/decoder/vp9_decodeframe.c b/vp9/decoder/vp9_decodeframe.c
index 82bace00d..516aa88cb 100644
--- a/vp9/decoder/vp9_decodeframe.c
+++ b/vp9/decoder/vp9_decodeframe.c
@@ -687,12 +687,6 @@ static void apply_frame_size(VP9D_COMP *pbi, int width, int height) {
 
   if (cm->width != width || cm->height != height) {
     // Change in frame size.
-    if (cm->width == 0 || cm->height == 0) {
-      // Assign new frame buffer on first call.
-      cm->new_fb_idx = NUM_YV12_BUFFERS - 1;
-      cm->fb_idx_ref_cnt[cm->new_fb_idx] = 1;
-    }
-
     // TODO(agrange) Don't test width/height, check overall size.
     if (width > cm->width || height > cm->height) {
       // Rescale frame buffers only if they're not big enough already.
diff --git a/vp9/decoder/vp9_onyxd_if.c b/vp9/decoder/vp9_onyxd_if.c
index 25fb3d6d2..4c0cd45a9 100644
--- a/vp9/decoder/vp9_onyxd_if.c
+++ b/vp9/decoder/vp9_onyxd_if.c
@@ -125,6 +125,9 @@ VP9D_PTR vp9_create_decompressor(VP9D_CONFIG *oxcf) {
 
   vp9_zero(*pbi);
 
+  // Initialize the references to not point to any frame buffers.
+  memset(&cm->ref_frame_map, -1, sizeof(cm->ref_frame_map));
+
   if (setjmp(cm->error.jmp)) {
     cm->error.setjmp = 0;
     vp9_remove_decompressor(pbi);