commit 2eada612bfc4c7440f8ab48fdacafe62bae61944
author Debargha Mukherjee <debargha@google.com> Fri Sep 22 15:37:39 2017 -0700
committer Debargha Mukherjee <debargha@google.com> Mon Sep 25 18:13:33 2017 -0700
tree 2ce343637e67cbaf06d1ea90cf317a42abb5135a
parent 8f4b21679e00ce19f4881bbec3483bd223ff3595

Add experiment to restrict compressed header

The compressed header is now used only when the refresh
type is set as forward, i.e. in error resilience and
frame parallel modes. As long as backward updates are
used the header is disabled thereby saving bits.

Change-Id: Iee9f66ffbd30ef3552ea41b75e4b51537cd9ff97

av1/decoder/decodeframe.c

diff --git a/av1/decoder/decodeframe.c b/av1/decoder/decodeframe.c
index 8b74350..c85ecb7 100644
--- a/av1/decoder/decodeframe.c
+++ b/av1/decoder/decodeframe.c
@@ -5071,11 +5071,14 @@
 #endif
 
   read_tile_info(pbi, rb);
-  sz = aom_rb_read_literal(rb, 16);
-
-  if (sz == 0)
-    aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
-                       "Invalid header size");
+  if (use_compressed_header(cm)) {
+    sz = aom_rb_read_literal(rb, 16);
+    if (sz == 0)
+      aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
+                         "Invalid header size");
+  } else {
+    sz = 0;
+  }
   return sz;
 }
 
@@ -5194,6 +5197,7 @@
 
   return aom_reader_has_error(&r);
 }
+
 #ifdef NDEBUG
 #define debug_check_frame_counts(cm) (void)0
 #else  // !NDEBUG
@@ -5419,16 +5423,17 @@
 #endif  // CONFIG_HIGHBITDEPTH
 #endif  // CONFIG_INTRABC
 
-  if (!first_partition_size) {
+  if (cm->show_existing_frame) {
     // showing a frame directly
     *p_data_end = data + aom_rb_bytes_read(&rb);
     return;
   }
 
   data += aom_rb_bytes_read(&rb);
-  if (!read_is_valid(data, first_partition_size, data_end))
-    aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
-                       "Truncated packet or corrupt header length");
+  if (first_partition_size)
+    if (!read_is_valid(data, first_partition_size, data_end))
+      aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
+                         "Truncated packet or corrupt header length");
 
   cm->setup_mi(cm);
 
@@ -5495,10 +5500,12 @@
   av1_zero(cm->counts);
 
   xd->corrupted = 0;
-  new_fb->corrupted = read_compressed_header(pbi, data, first_partition_size);
-  if (new_fb->corrupted)
-    aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
-                       "Decode failed. Frame data header is corrupted.");
+  if (first_partition_size) {
+    new_fb->corrupted = read_compressed_header(pbi, data, first_partition_size);
+    if (new_fb->corrupted)
+      aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
+                         "Decode failed. Frame data header is corrupted.");
+  }
 
 #if CONFIG_LOOP_RESTORATION
   if (cm->rst_info[0].frame_restoration_type != RESTORE_NONE ||
@@ -5711,16 +5718,17 @@
 #endif  // CONFIG_HIGHBITDEPTH
 #endif  // CONFIG_INTRABC
 
-  if (!first_partition_size) {
+  if (cm->show_existing_frame) {
     // showing a frame directly
     *p_data_end = data + aom_rb_bytes_read(&rb);
     return 0;
   }
 
   data += aom_rb_bytes_read(&rb);
-  if (!read_is_valid(data, first_partition_size, data_end))
-    aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
-                       "Truncated packet or corrupt header length");
+  if (first_partition_size)
+    if (!read_is_valid(data, first_partition_size, data_end))
+      aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
+                         "Truncated packet or corrupt header length");
 
   cm->setup_mi(cm);
 
@@ -5787,11 +5795,12 @@
   av1_zero(cm->counts);
 
   xd->corrupted = 0;
-  new_fb->corrupted = read_compressed_header(pbi, data, first_partition_size);
-  if (new_fb->corrupted)
-    aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
-                       "Decode failed. Frame data header is corrupted.");
-
+  if (first_partition_size) {
+    new_fb->corrupted = read_compressed_header(pbi, data, first_partition_size);
+    if (new_fb->corrupted)
+      aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
+                         "Decode failed. Frame data header is corrupted.");
+  }
   return first_partition_size;
 }