From: Minghai Shang <minghai@google.com>
Date: Wed, 20 May 2015 23:43:27 +0000 (-0700)
Subject: [svc] Make size of empty frame to be 16x16 all the time
X-Git-Tag: v1.5.0~650^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=15353216c5b345e9df8500ce4f8fbba659a7f131;p=platform%2Fupstream%2Flibvpx.git

[svc] Make size of empty frame to be 16x16 all the time

Change-Id: Ibab09aa0e8c69cf5efea2f0ec035e5da9cc894b0
---

diff --git a/vp9/encoder/vp9_encoder.c b/vp9/encoder/vp9_encoder.c
index e89ee5e..f99bd14 100644
--- a/vp9/encoder/vp9_encoder.c
+++ b/vp9/encoder/vp9_encoder.c
@@ -3474,11 +3474,18 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
     }
   }
   if (is_two_pass_svc(cpi) && cm->error_resilient_mode == 0) {
-    // Use the last frame context for the empty frame.
+    // Use context 0 for intra only empty frame, but the last frame context
+    // for other empty frames.
+    if (cpi->svc.encode_empty_frame_state == ENCODING) {
+      if (cpi->svc.encode_intra_empty_frame != 0)
+        cm->frame_context_idx = 0;
+      else
+        cm->frame_context_idx = FRAME_CONTEXTS - 1;
+    } else {
     cm->frame_context_idx =
-        (cpi->svc.encode_empty_frame_state == ENCODING) ? FRAME_CONTEXTS - 1 :
         cpi->svc.spatial_layer_id * cpi->svc.number_temporal_layers +
         cpi->svc.temporal_layer_id;
+    }
 
     // The probs will be updated based on the frame type of its previous
     // frame if frame_parallel_decoding_mode is 0. The type may vary for
@@ -3966,6 +3973,7 @@ int vp9_get_compressed_data(VP9_COMP *cpi, unsigned int *frame_flags,
       }
 
       cm->show_frame = 0;
+      cm->intra_only = 0;
       cpi->refresh_alt_ref_frame = 1;
       cpi->refresh_golden_frame = 0;
       cpi->refresh_last_frame = 0;
@@ -4308,8 +4316,10 @@ int vp9_get_compressed_data(VP9_COMP *cpi, unsigned int *frame_flags,
 #endif
 
   if (is_two_pass_svc(cpi)) {
-    if (cpi->svc.encode_empty_frame_state == ENCODING)
+    if (cpi->svc.encode_empty_frame_state == ENCODING) {
       cpi->svc.encode_empty_frame_state = ENCODED;
+      cpi->svc.encode_intra_empty_frame = 0;
+    }
 
     if (cm->show_frame) {
       ++cpi->svc.spatial_layer_to_encode;
diff --git a/vp9/encoder/vp9_firstpass.c b/vp9/encoder/vp9_firstpass.c
index 88b1030..49b009d 100644
--- a/vp9/encoder/vp9_firstpass.c
+++ b/vp9/encoder/vp9_firstpass.c
@@ -2581,9 +2581,8 @@ void vp9_rc_get_second_pass_params(VP9_COMP *cpi) {
         cpi->ref_frame_flags &=
             (~VP9_LAST_FLAG & ~VP9_GOLD_FLAG & ~VP9_ALT_FLAG);
         lc->frames_from_key_frame = 0;
-        // Reset the empty frame resolution since we have a key frame.
-        cpi->svc.empty_frame_width = cm->width;
-        cpi->svc.empty_frame_height = cm->height;
+        // Encode an intra only empty frame since we have a key frame.
+        cpi->svc.encode_intra_empty_frame = 1;
       }
     } else {
       cm->frame_type = INTER_FRAME;
diff --git a/vp9/encoder/vp9_svc_layercontext.c b/vp9/encoder/vp9_svc_layercontext.c
index b3491a2..2d2e95d 100644
--- a/vp9/encoder/vp9_svc_layercontext.c
+++ b/vp9/encoder/vp9_svc_layercontext.c
@@ -15,6 +15,8 @@
 #include "vp9/encoder/vp9_extend.h"
 
 #define SMALL_FRAME_FB_IDX 7
+#define SMALL_FRAME_WIDTH  16
+#define SMALL_FRAME_HEIGHT 16
 
 void vp9_init_layer_context(VP9_COMP *const cpi) {
   SVC *const svc = &cpi->svc;
@@ -33,7 +35,7 @@ void vp9_init_layer_context(VP9_COMP *const cpi) {
 
     if (cpi->oxcf.error_resilient_mode == 0 && cpi->oxcf.pass == 2) {
       if (vp9_realloc_frame_buffer(&cpi->svc.empty_frame.img,
-                                   cpi->common.width, cpi->common.height,
+                                   SMALL_FRAME_WIDTH, SMALL_FRAME_HEIGHT,
                                    cpi->common.subsampling_x,
                                    cpi->common.subsampling_y,
 #if CONFIG_VP9_HIGHBITDEPTH
@@ -48,8 +50,6 @@ void vp9_init_layer_context(VP9_COMP *const cpi) {
 
       memset(cpi->svc.empty_frame.img.buffer_alloc, 0x80,
              cpi->svc.empty_frame.img.buffer_alloc_sz);
-      cpi->svc.empty_frame_width = cpi->common.width;
-      cpi->svc.empty_frame_height = cpi->common.height;
     }
   }
 
@@ -362,20 +362,11 @@ int vp9_svc_start_frame(VP9_COMP *const cpi) {
         cpi->lst_fb_idx =
             cpi->gld_fb_idx = cpi->alt_fb_idx = SMALL_FRAME_FB_IDX;
 
-        // Gradually make the empty frame smaller to save bits. Make it half of
-        // its previous size because of the scaling factor restriction.
-        cpi->svc.empty_frame_width >>= 1;
-        cpi->svc.empty_frame_width = (cpi->svc.empty_frame_width + 1) & ~1;
-        if (cpi->svc.empty_frame_width < 16)
-          cpi->svc.empty_frame_width = 16;
+        if (cpi->svc.encode_intra_empty_frame != 0)
+          cpi->common.intra_only = 1;
 
-        cpi->svc.empty_frame_height >>= 1;
-        cpi->svc.empty_frame_height = (cpi->svc.empty_frame_height + 1) & ~1;
-        if (cpi->svc.empty_frame_height < 16)
-          cpi->svc.empty_frame_height = 16;
-
-        width = cpi->svc.empty_frame_width;
-        height = cpi->svc.empty_frame_height;
+        width = SMALL_FRAME_WIDTH;
+        height = SMALL_FRAME_HEIGHT;
       }
     }
   }
diff --git a/vp9/encoder/vp9_svc_layercontext.h b/vp9/encoder/vp9_svc_layercontext.h
index e9645ce..5063d52 100644
--- a/vp9/encoder/vp9_svc_layercontext.h
+++ b/vp9/encoder/vp9_svc_layercontext.h
@@ -57,8 +57,7 @@ typedef struct {
     NEED_TO_ENCODE
   }encode_empty_frame_state;
   struct lookahead_entry empty_frame;
-  int empty_frame_width;
-  int empty_frame_height;
+  int encode_intra_empty_frame;
 
   // Store scaled source frames to be used for temporal filter to generate
   // a alt ref frame.