Add PP_VideoFrame, PPB_VideoReader, and PPB_VideoWriter APIs to Pepper.

ppapi/cpp/video.h

Index: ppapi/cpp/video.h
diff --git a/ppapi/cpp/video.h b/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 {

[dmichael (off chromium), 2013/04/03 22:17:06]

I second moving these to their own files. video.h and video.cc just seems so
broad that I'm afraid it might be confusing. Especially since we have other
interfaces that also deal with video (video decoding, video capture, and content
decryption modules)

[bbudge, 2013/04/04 17:58:05]

Done.

+ 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,

[dmichael (off chromium), 2013/04/03 22:17:06]

I think we could just use std::string here.

[bbudge, 2013/04/04 17:58:05]

Done.

+               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,

[dmichael (off chromium), 2013/04/03 22:17:06]

ditto std::string

[bbudge, 2013/04/04 17:58:05]

Done.

+               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_