Add PP_VideoFrame, PPB_VideoReader, and PPB_VideoWriter APIs to Pepper.

ppapi/cpp/video.h

Index: ppapi/cpp/video.h
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+// Copyright (c) 2013 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 PPAPI_CPP_VIDEO_H_
+#define PPAPI_CPP_VIDEO_H_
+
+#include "ppapi/c/pp_time.h"
+#include "ppapi/c/pp_video_frame.h"
+#include "ppapi/cpp/completion_callback.h"
+#include "ppapi/cpp/image_data.h"
+#include "ppapi/cpp/pass_ref.h"
+#include "ppapi/cpp/resource.h"
+
+/// @file
+/// This file defines the API to create and use video stream readers and
+/// writers.
+
+namespace pp {
+
+class InstanceHandle;
+
+// VideoFrame ------------------------------------------------------------------
+
+/// The <code>VideoFrame</code> class represents a frame of video in a stream.
+class VideoFrame {
+ public:
+  /// Default constructor for creating a <code>VideoFrame</code> object.
+  VideoFrame();
+  /// Constructor that takes an existing <code>PP_VideoFrame</code> structure.
+  /// The 'image_data' PP_Resource field in the structure will be managed by
+  /// this instance.
+  VideoFrame(PassRef, const PP_VideoFrame& pp_video_frame);
+  /// The copy constructor for <code>VideoFrame</code>.
+  ///
+  /// @param[in] other A reference to a <code>VideoFrame</code>.
+  VideoFrame(const VideoFrame& other);
+  ~VideoFrame();
+
+  VideoFrame& operator=(const VideoFrame& other);
+
+  const PP_VideoFrame& pp_video_frame() const {
+    return video_frame_;
+  }
+
+  ImageData image_data() const {
+    return image_data_;
+  }
+  void set_image_data(const ImageData& image_data) {
+    image_data_ = image_data;
+    // The assignment above manages the underlying PP_Resources. Copy the new
+    // one into our internal video frame struct.
+    video_frame_.image_data = image_data_.pp_resource();
+  }
+
+  PP_TimeTicks timestamp() const { return video_frame_.timestamp; }
+  void set_timestamp(PP_TimeTicks timestamp) {
+    video_frame_.timestamp = timestamp;
+  }
+
+ private:
+  ImageData image_data_;  // This manages the PP_Resource in video_frame_.
+  PP_VideoFrame video_frame_;
+};
+
+// VideoReader -----------------------------------------------------------------
+
+/// The <code>VideoReader</code> class represents a video reader resource.
+class VideoReader : public Resource {
+ public:
+  /// Default constructor for creating a <code>VideoReader</code> object.
+  VideoReader();
+
+  /// Constructor for creating a <code>VideoReader</code> for an instance.
+  explicit VideoReader(const InstanceHandle& instance);
+
+  /// The copy constructor for <code>VideoReader</code>.
+  ///
+  /// @param[in] other A reference to a <code>VideoReader</code>.
+  VideoReader(const VideoReader& other);
+
+  /// A constructor used when you have received a PP_Resource as a return
+  /// value that has had its reference count incremented for you.
+  ///
+  /// @param[in] resource A PP_Resource corresponding to a video reader.
+  VideoReader(PassRef, PP_Resource resource);
+
+  /// Opens a stream for reading video and associates it with the given id.
+  ///
+  /// @param[in] stream_id A <code>Var</code> uniquely identifying the stream
+  /// to read from.
+  /// @param[in] callback A <code>CompletionCallback</code> to be called upon
+  /// completion of Open.
+  ///
+  /// @return A return code from <code>pp_errors.h</code>.
+  int32_t Open(const pp::Var& stream_id,
+               const CompletionCallback& cc);
+
+  /// Gets the next frame of video from the reader's stream.
+  ///
+  /// @param[in] callback A <code>CompletionCallbackWithOutput</code> to be
+  /// called upon completion of GetNextFrame.
+  ///
+  /// @return A return code from <code>pp_errors.h</code>.
+  int32_t GetNextFrame(const CompletionCallbackWithOutput<VideoFrame>& cc);
+
+  /// Closes the reader's current stream.
+  void Close();
+};
+
+// VideoWriter -----------------------------------------------------------------
+
+/// The <code>VideoWriter</code> class represents a video writer resource.
+class VideoWriter : public Resource {
+ public:
+  /// Default constructor for creating a <code>VideoWriter</code> object.
+  VideoWriter();
+
+  /// Constructor for creating a <code>VideoWriter</code> for an instance.
+  explicit VideoWriter(const InstanceHandle& instance);
+
+  /// The copy constructor for <code>VideoWriter</code>.
+  ///
+  /// @param[in] other A reference to a <code>VideoWriter</code>.
+  VideoWriter(const VideoWriter& other);
+
+  /// A constructor used when you have received a PP_Resource as a return
+  /// value that has had its reference count incremented for you.
+  ///
+  /// @param[in] resource A PP_Resource corresponding to a video writer.
+  VideoWriter(PassRef, PP_Resource resource);
+
+  /// Opens a stream for writing video and associates it with the given id.
+  ///
+  /// @param[in] stream_id A <code>Var</code> uniquely identifying the stream
+  /// to write to.
+  /// @param[in] callback A <code>CompletionCallback</code> to be called upon
+  /// completion of Open.
+  ///
+  /// @return A return code from <code>pp_errors.h</code>.
+  int32_t Open(const pp::Var& stream_id,
+               const CompletionCallback& cc);
+
+  /// Emits the next frame of video to the writer's stream.
+  ///
+  /// @param[in] frame A <code>VideoFrame</code> containing the frame to write
+  /// to the open stream.
+  ///
+  /// @return A return code from <code>pp_errors.h</code>.
+  int32_t PutNextFrame(const VideoFrame& frame);
+
+  /// Closes the writer's current stream.
+  void Close();
+};
+
+namespace internal {
+
+// A specialization of CallbackOutputTraits to provide the callback system the
+// information on how to handle pp::VideoFrame. This converts PP_VideoFrame to
+// pp::VideoFrame when passing to the plugin, and specifically manages the
+// PP_Resource embedded in the video_frame_ field.
+template<>
+struct CallbackOutputTraits<pp::VideoFrame> {
+  typedef PP_VideoFrame* APIArgType;
+  typedef PP_VideoFrame StorageType;
+
+  static inline APIArgType StorageToAPIArg(StorageType& t) {
+    return &t;
+  }
+
+  static inline pp::VideoFrame StorageToPluginArg(StorageType& t) {
+    return pp::VideoFrame(PASS_REF, t);
+  }
+};
+
+}  // namespace internal
+
+}  // namespace pp
+
+#endif  // PPAPI_CPP_VIDEO_H_