[chrome.displaySource][WiFi Display] Media pipeline infrastructure

extensions/renderer/api/display_source/wifi_display/wifi_display_video_encoder.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef EXTENSIONS_RENDERER_API_DISPLAY_SOURCE_WIFI_DISPLAY_WIFI_DISPLAY_VIDEO_ENCODER_H_
+#define EXTENSIONS_RENDERER_API_DISPLAY_SOURCE_WIFI_DISPLAY_WIFI_DISPLAY_VIDEO_ENCODER_H_
+
+#include <string>
+
+#include "base/memory/shared_memory.h"
+#include "base/stl_util.h"
+#include "media/base/video_frame.h"
+#include "media/video/video_encode_accelerator.h"
+#include "third_party/wds/src/libwds/public/video_format.h"
+
+namespace extensions {
+
+// This structure represents an encoded video frame.
+struct WiFiDisplayEncodedFrame {
+  const uint8_t* bytes() const {
+    return reinterpret_cast<uint8_t*>(
+        string_as_array(const_cast<std::string*>(&data)));
+  }
+  uint8_t* mutable_bytes() {
+    return reinterpret_cast<uint8_t*>(string_as_array(&data));
+  }
+
+  base::TimeTicks pts;  // Presentation timestamp.
+  base::TimeTicks dts;  // Decoder timestamp.
+  std::string data;
+  bool key_frame;
+};
+
+// This interface represents H.264 video encoder used by the
+// Wi-Fi Display media pipeline.
+// Threading: the client code should belong to a single thread.
+class WiFiDisplayVideoEncoder :
+    public base::RefCountedThreadSafe<WiFiDisplayVideoEncoder> {
+ public:
+  using EncodedFrameCallback =
+      base::Callback<void(const WiFiDisplayEncodedFrame&)>;
+
+  using VideoEncoderCallback =
+      base::Callback<void(scoped_refptr<WiFiDisplayVideoEncoder>)>;
+
+  using ReceiveVideoEncodeAcceleratorCallback =
+      base::Callback<void(scoped_refptr<base::SingleThreadTaskRunner>,
+      std::unique_ptr<media::VideoEncodeAccelerator>)>;
+  using CreateVideoEncodeAcceleratorCallback =
+      base::Callback<void(const ReceiveVideoEncodeAcceleratorCallback&)>;
+
+  using ReceiveEncodeMemoryCallback =
+      base::Callback<void(std::unique_ptr<base::SharedMemory>)>;
+  using CreateEncodeMemoryCallback =
+      base::Callback<void(size_t size, const ReceiveEncodeMemoryCallback&)>;
+
+  struct InitParameters {
+    InitParameters();
+    ~InitParameters();
+    gfx::Size frame_size;
+    int frame_rate;
+    int bit_rate;
+    wds::H264Profile profile;
+    wds::H264Level level;
+    // VEA-specific parameters.
+    CreateEncodeMemoryCallback create_memory_callback;
+    CreateVideoEncodeAcceleratorCallback vea_create_callback;
+  };
+
+  // A factory method that creates a new encoder instance from the given
+  // |params|, the encoder instance is returned as an argument of
+  // |result_callback| ('nullptr' argument means encoder creation failure).
+  static void Create(
+      const InitParameters& params,
+      const VideoEncoderCallback& encoder_callback);
+
+  // Encodes the given raw frame. The resulting encoded frame is passed
+  // as an |encoded_callback|'s argument which is set via 'SetCallbacks'
+  // method.
+  virtual void InsertRawVideoFrame(
+      const scoped_refptr<media::VideoFrame>& video_frame,
+      base::TimeTicks reference_time) = 0;
+
+  // Requests the next encoded frame to be an instantaneous decoding refresh
+  // (IDR) picture.
+  virtual void RequestIDRPicture() = 0;
+
+  // Sets callbacks for the obtained encoder instance:
+  // |encoded_callback| is invoked to return the next encoded frame
+  // |error_callback| is invoked to report a fatal encoder error
+  void SetCallbacks(const EncodedFrameCallback& encoded_callback,
+                    const base::Closure& error_callback);
+
+ protected:
+  friend class base::RefCountedThreadSafe<WiFiDisplayVideoEncoder>;
+  WiFiDisplayVideoEncoder();
+  virtual ~WiFiDisplayVideoEncoder();
+
+  EncodedFrameCallback encoded_callback_;
+  base::Closure error_callback_;
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_RENDERER_API_DISPLAY_SOURCE_WIFI_DISPLAY_WIFI_DISPLAY_VIDEO_ENCODER_H_