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diff --git a/media/libvpx/libvpx/vp9/encoder/vp9_lookahead.h b/media/libvpx/libvpx/vp9/encoder/vp9_lookahead.h
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+++ b/media/libvpx/libvpx/vp9/encoder/vp9_lookahead.h
@@ -0,0 +1,127 @@
+/*
+ *  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.
+ */
+
+#ifndef VPX_VP9_ENCODER_VP9_LOOKAHEAD_H_
+#define VPX_VP9_ENCODER_VP9_LOOKAHEAD_H_
+
+#include "vpx_scale/yv12config.h"
+#include "vpx/vpx_encoder.h"
+#include "vpx/vpx_integer.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define MAX_LAG_BUFFERS 25
+
+struct lookahead_entry {
+  YV12_BUFFER_CONFIG img;
+  int64_t ts_start;
+  int64_t ts_end;
+  int show_idx; /*The show_idx of this frame*/
+  vpx_enc_frame_flags_t flags;
+};
+
+// The max of past frames we want to keep in the queue.
+#define MAX_PRE_FRAMES 1
+
+struct lookahead_ctx {
+  int max_sz;        /* Absolute size of the queue */
+  int sz;            /* Number of buffers currently in the queue */
+  int read_idx;      /* Read index */
+  int write_idx;     /* Write index */
+  int next_show_idx; /* The show_idx that will be assigned to the next frame
+                        being pushed in the queue*/
+  struct lookahead_entry *buf; /* Buffer list */
+};
+
+/**\brief Initializes the lookahead stage
+ *
+ * The lookahead stage is a queue of frame buffers on which some analysis
+ * may be done when buffers are enqueued.
+ */
+struct lookahead_ctx *vp9_lookahead_init(unsigned int width,
+                                         unsigned int height,
+                                         unsigned int subsampling_x,
+                                         unsigned int subsampling_y,
+#if CONFIG_VP9_HIGHBITDEPTH
+                                         int use_highbitdepth,
+#endif
+                                         unsigned int depth);
+
+/**\brief Destroys the lookahead stage
+ */
+void vp9_lookahead_destroy(struct lookahead_ctx *ctx);
+
+/**\brief Check if lookahead is full
+ *
+ * \param[in] ctx         Pointer to the lookahead context
+ *
+ * Return 1 if lookahead is full, otherwise return 0.
+ */
+int vp9_lookahead_full(const struct lookahead_ctx *ctx);
+
+/**\brief Return the next_show_idx
+ *
+ * \param[in] ctx         Pointer to the lookahead context
+ *
+ * Return the show_idx that will be assigned to the next
+ * frame pushed by vp9_lookahead_push()
+ */
+int vp9_lookahead_next_show_idx(const struct lookahead_ctx *ctx);
+
+/**\brief Enqueue a source buffer
+ *
+ * This function will copy the source image into a new framebuffer with
+ * the expected stride/border.
+ *
+ * \param[in] ctx         Pointer to the lookahead context
+ * \param[in] src         Pointer to the image to enqueue
+ * \param[in] ts_start    Timestamp for the start of this frame
+ * \param[in] ts_end      Timestamp for the end of this frame
+ * \param[in] flags       Flags set on this frame
+ */
+int vp9_lookahead_push(struct lookahead_ctx *ctx, YV12_BUFFER_CONFIG *src,
+                       int64_t ts_start, int64_t ts_end, int use_highbitdepth,
+                       vpx_enc_frame_flags_t flags);
+
+/**\brief Get the next source buffer to encode
+ *
+ *
+ * \param[in] ctx       Pointer to the lookahead context
+ * \param[in] drain     Flag indicating the buffer should be drained
+ *                      (return a buffer regardless of the current queue depth)
+ *
+ * \retval NULL, if drain set and queue is empty
+ * \retval NULL, if drain not set and queue not of the configured depth
+ */
+struct lookahead_entry *vp9_lookahead_pop(struct lookahead_ctx *ctx, int drain);
+
+/**\brief Get a future source buffer to encode
+ *
+ * \param[in] ctx       Pointer to the lookahead context
+ * \param[in] index     Index of the frame to be returned, 0 == next frame
+ *
+ * \retval NULL, if no buffer exists at the specified index
+ */
+struct lookahead_entry *vp9_lookahead_peek(struct lookahead_ctx *ctx,
+                                           int index);
+
+/**\brief Get the number of frames currently in the lookahead queue
+ *
+ * \param[in] ctx       Pointer to the lookahead context
+ */
+unsigned int vp9_lookahead_depth(struct lookahead_ctx *ctx);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // VPX_VP9_ENCODER_VP9_LOOKAHEAD_H_