libvpx: Add VP9 decoder.

source/libvpx/vpx_mem/memory_manager/hmm_shrink.c

 /*
  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 
 /* This code is in the public domain.
 ** Version: 1.1  Author: Walt Karas
 */
 
 #include "hmm_intrnl.h"
 
-void U(shrink_chunk)(U(descriptor) *desc, U(size_bau) n_baus_to_shrink)
-{
-    head_record *dummy_end_block = (head_record *)
-                                   BAUS_BACKWARD(desc->end_of_shrinkable_chunk, DUMMY_END_BLOCK_BAUS);
+void U(shrink_chunk)(U(descriptor) *desc, U(size_bau) n_baus_to_shrink) {
+  head_record *dummy_end_block = (head_record *)
+                                 BAUS_BACKWARD(desc->end_of_shrinkable_chunk, DUMMY_END_BLOCK_BAUS);
 
 #ifdef HMM_AUDIT_FAIL
 
-    if (dummy_end_block->block_size != 0)
-        /* Chunk does not have valid dummy end block. */
-        HMM_AUDIT_FAIL
+  if (dummy_end_block->block_size != 0)
+    /* Chunk does not have valid dummy end block. */
+    HMM_AUDIT_FAIL
 
 #endif
 
-        if (n_baus_to_shrink)
-        {
-            head_record *last_block = (head_record *)
-                                      BAUS_BACKWARD(
-                                          dummy_end_block, dummy_end_block->previous_block_size);
+    if (n_baus_to_shrink) {
+      head_record *last_block = (head_record *)
+                                BAUS_BACKWARD(
+                                  dummy_end_block, dummy_end_block->previous_block_size);
 
 #ifdef HMM_AUDIT_FAIL
-            AUDIT_BLOCK(last_block)
+      AUDIT_BLOCK(last_block)
 #endif
 
-            if (last_block == desc->last_freed)
-            {
-                U(size_bau) bs = BLOCK_BAUS(last_block);
+      if (last_block == desc->last_freed) {
+        U(size_bau) bs = BLOCK_BAUS(last_block);
 
-                /* Chunk will not be shrunk out of existence if
-                ** 1.  There is at least one allocated block in the chunk
-                **     and the amount to shrink is exactly the size of the
-                **     last block, OR
-                ** 2.  After the last block is shrunk, there will be enough
-                **     BAUs left in it to form a minimal size block. */
-                int chunk_will_survive =
-                    (PREV_BLOCK_BAUS(last_block) && (n_baus_to_shrink == bs)) ||
-                    (n_baus_to_shrink <= (U(size_bau))(bs - MIN_BLOCK_BAUS));
+        /* Chunk will not be shrunk out of existence if
+        ** 1.  There is at least one allocated block in the chunk
+        **     and the amount to shrink is exactly the size of the
+        **     last block, OR
+        ** 2.  After the last block is shrunk, there will be enough
+        **     BAUs left in it to form a minimal size block. */
+        int chunk_will_survive =
+          (PREV_BLOCK_BAUS(last_block) && (n_baus_to_shrink == bs)) ||
+          (n_baus_to_shrink <= (U(size_bau))(bs - MIN_BLOCK_BAUS));
 
-                if (chunk_will_survive ||
-                    (!PREV_BLOCK_BAUS(last_block) &&
-                     (n_baus_to_shrink ==
-                      (U(size_bau))(bs + DUMMY_END_BLOCK_BAUS))))
-                {
-                    desc->last_freed = 0;
+        if (chunk_will_survive ||
+            (!PREV_BLOCK_BAUS(last_block) &&
+             (n_baus_to_shrink ==
+              (U(size_bau))(bs + DUMMY_END_BLOCK_BAUS)))) {
+          desc->last_freed = 0;
 
-                    if (chunk_will_survive)
-                    {
-                        bs -= n_baus_to_shrink;
+          if (chunk_will_survive) {
+            bs -= n_baus_to_shrink;
 
-                        if (bs)
-                        {
-                            /* The last (non-dummy) block was not completely
-                            ** eliminated by the shrink. */
+            if (bs) {
+              /* The last (non-dummy) block was not completely
+              ** eliminated by the shrink. */
 
-                            last_block->block_size = bs;
+              last_block->block_size = bs;
 
-                            /* Create new dummy end record.
-                            */
-                            dummy_end_block =
-                                (head_record *) BAUS_FORWARD(last_block, bs);
-                            dummy_end_block->previous_block_size = bs;
-                            dummy_end_block->block_size = 0;
+              /* Create new dummy end record.
+              */
+              dummy_end_block =
+                (head_record *) BAUS_FORWARD(last_block, bs);
+              dummy_end_block->previous_block_size = bs;
+              dummy_end_block->block_size = 0;
 
 #ifdef HMM_AUDIT_FAIL
 
-                            if (desc->avl_tree_root)
-                                AUDIT_BLOCK(PTR_REC_TO_HEAD(desc->avl_tree_root))
+              if (desc->avl_tree_root)
+                AUDIT_BLOCK(PTR_REC_TO_HEAD(desc->avl_tree_root))
 #endif
 
-                                U(into_free_collection)(desc, last_block);
-                        }
-                        else
-                        {
-                            /* The last (non-dummy) block was completely
-                            ** eliminated by the shrink.  Make its head
-                            ** the new dummy end block.
-                            */
-                            last_block->block_size = 0;
-                            last_block->previous_block_size &= ~HIGH_BIT_BAU_SIZE;
-                        }
-                    }
-                }
+                U(into_free_collection)(desc, last_block);
+            } else {
+              /* The last (non-dummy) block was completely
+              ** eliminated by the shrink.  Make its head
+              ** the new dummy end block.
+              */
+              last_block->block_size = 0;
+              last_block->previous_block_size &= ~HIGH_BIT_BAU_SIZE;
+            }
+          }
+        }
 
 #ifdef HMM_AUDIT_FAIL
-                else
-                    HMM_AUDIT_FAIL
+        else
+          HMM_AUDIT_FAIL
 #endif
-                }
+        }
 
 #ifdef HMM_AUDIT_FAIL
-            else
-                HMM_AUDIT_FAIL
+      else
+        HMM_AUDIT_FAIL
 #endif
-            }
+      }
 }