libvpx: Pull from upstream

source/libvpx/vp9/encoder/vp9_lookahead.c

 /*
  *  Copyright (c) 2011 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.
  */
 #include <assert.h>
 #include <stdlib.h>
 
 #include "./vpx_config.h"
 
 #include "vp9/common/vp9_common.h"
 
 #include "vp9/encoder/vp9_encoder.h"
 #include "vp9/encoder/vp9_extend.h"
 #include "vp9/encoder/vp9_lookahead.h"
 
-// The max of past frames we want to keep in the queue.
-#define MAX_PRE_FRAMES 1
-
-struct lookahead_ctx {
-  unsigned int max_sz;         /* Absolute size of the queue */
-  unsigned int sz;             /* Number of buffers currently in the queue */
-  unsigned int read_idx;       /* Read index */
-  unsigned int write_idx;      /* Write index */
-  struct lookahead_entry *buf; /* Buffer list */
-};
-
-
 /* Return the buffer at the given absolute index and increment the index */
 static struct lookahead_entry *pop(struct lookahead_ctx *ctx,
                                    unsigned int *idx) {
   unsigned int index = *idx;
   struct lookahead_entry *buf = ctx->buf + index;
 
   assert(index < ctx->max_sz);
   if (++index >= ctx->max_sz)
     index -= ctx->max_sz;
   *idx = index;
@@ skipping 155 matching lines @@
       buf = ctx->buf + index;
     }
   }
 
   return buf;
 }
 
 unsigned int vp9_lookahead_depth(struct lookahead_ctx *ctx) {
   return ctx->sz;
 }