Implement software fallback for PPB_VideoDecoder.

content/renderer/pepper/video_decoder_proxy.h

+// Copyright (c) 2014 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 CONTENT_RENDERER_PEPPER_VIDEO_DECODER_PROXY_H_
+#define CONTENT_RENDERER_PEPPER_VIDEO_DECODER_PROXY_H_
+
+#include <queue>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/containers/hash_tables.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop/message_loop_proxy.h"
+#include "gpu/command_buffer/common/mailbox.h"
+#include "media/base/decoder_buffer.h"
+#include "media/base/video_decoder.h"
+#include "media/base/video_decoder_config.h"
+
+#include "ppapi/c/pp_codecs.h"
+
+namespace gpu {
+namespace gles2 {
+class GLES2Interface;
+}
+}
+
+namespace webkit {
+namespace gpu {
+class ContextProviderWebContext;
+}
+}
+
+namespace content {
+
+class PepperVideoDecoderHost;
+
+// This class proxies calls to a media::VideoDecoder on the media thread.
+// Instances should be constructed, used, and destructed on the main (render)
+// thread.
+class VideoDecoderProxy {
+ public:
+  explicit VideoDecoderProxy(PepperVideoDecoderHost* host);
+
+  void Initialize(media::VideoCodecProfile profile);
+  void Decode(uint32_t decode_id, const uint8_t* buffer, uint32_t size);
+  void AssignTextures(const std::vector<uint32_t>& texture_ids);
+  void RecycleTexture(uint32_t texture_id);
+  void Flush();
+  void Reset();
+  void Destroy();
+
+ protected:
+  // Do not delete directly; use Destroy() or own it with a scoped_ptr, which
+  // will Destroy() it properly by default.
+  ~VideoDecoderProxy();
+
+ private:
+  enum State {
+    UNINITIALIZED,
+    DECODING,
+    FLUSHING,
+    RESETTING,
+  };
+
+  struct PendingDecode {
+    PendingDecode(uint32_t decode_id,
+                  const scoped_refptr<media::DecoderBuffer>& buffer);
+    ~PendingDecode();
+
+    uint32_t decode_id;
+    scoped_refptr<media::DecoderBuffer> buffer;
+  };
+
+  struct PendingFrame {
+    PendingFrame(uint32_t decode_id, const gfx::Size& size);
+    ~PendingFrame();
+
+    uint32_t decode_id;
+    gfx::Size size;
+    std::vector<uint8_t> pixels;
+  };
+
+  // This class is constructed and destructed on the main (render) thread, but
+  // used only on the media thread.
+  class Delegate {
+   public:
+    Delegate(VideoDecoderProxy* proxy);
+    ~Delegate();
+
+    void Initialize(media::VideoDecoderConfig config,
+                    scoped_ptr<media::VideoDecoder> decoder);
+    void ReceiveBuffer(uint32_t decode_id,
+                       scoped_refptr<media::DecoderBuffer> buffer);
+    void Decode();
+    void Reset();
+    void Destroy();
+
+   private:
+    void OnPipelineStatus(media::PipelineStatus status);
+    void ConvertFrame(uint32_t decode_id,
+                      media::VideoDecoder::Status status,
+                      const scoped_refptr<media::VideoFrame>& frame);
+    void OnResetComplete();
+
+    VideoDecoderProxy* proxy_;
+    scoped_ptr<media::VideoDecoder> decoder_;
+    scoped_refptr<base::MessageLoopProxy> main_message_loop_;
+    // Queue of decodes waiting for the decoder.
+    typedef std::queue<PendingDecode> PendingDecodeQueue;
+    PendingDecodeQueue pending_decodes_;
+
+    DISALLOW_COPY_AND_ASSIGN(Delegate);
+  };
+
+  void OnPipelineStatus(media::PipelineStatus status);
+  void ReceiveFrame(media::VideoDecoder::Status status,
+                    scoped_ptr<PendingFrame> frame);
+  void SendPictures();
+  void OnResetComplete();
+  void OnDestroyComplete();
+  void DismissTexture(uint32_t texture_id);
+  void DeleteTexture(uint32_t texture_id);
+  void FlushCommandBuffer();
+
+  Delegate delegate_;
+  State state_;
+
+  PepperVideoDecoderHost* host_;
+  scoped_refptr<base::MessageLoopProxy> media_message_loop_;
+  scoped_refptr<webkit::gpu::ContextProviderWebContext> context_provider_;
+
+  // The current decoded frame size.
+  gfx::Size texture_size_;
+  // Map that takes the plugin's GL texture id to the renderer's GL texture id.
+  typedef base::hash_map<uint32_t, uint32_t> TextureIdMap;
+  TextureIdMap texture_id_map_;
+  // Available textures (these are plugin ids.)
+  std::vector<uint32_t> available_textures_;
+  // Track textures that are no longer needed (these are plugin ids.)
+  typedef base::hash_set<uint32_t> TextureIdSet;
+  TextureIdSet textures_to_dismiss_;
+  // Mailboxes for pending texture requests, to write to plugin's textures.
+  std::vector<gpu::Mailbox> pending_texture_mailboxes_;
+  // Queue of pending decoded frames. These have been converted to RGB, and
+  // await upload to a GL texture.
+  typedef std::queue<PendingFrame*> PendingFrameQueue;
+  PendingFrameQueue pending_frames_;
+  uint32_t num_pending_decodes_;
+
+  DISALLOW_COPY_AND_ASSIGN(VideoDecoderProxy);
+};
+
+}  // namespace content
+
+namespace base {
+
+template <class T>
+struct DefaultDeleter;
+
+// Specialize DefaultDeleter so that scoped_ptr<content::VideoDecoderProxy>
+// always uses "Destroy()" instead of trying to use the destructor.
+template <>
+struct DefaultDeleter<content::VideoDecoderProxy> {
+ public:
+  inline void operator()(void* video_decoder) const {
+    static_cast<content::VideoDecoderProxy*>(video_decoder)->Destroy();
+  }
+};
+
+}  // namespace base
+
+#endif  // CONTENT_RENDERER_PEPPER_VIDEO_DECODER_PROXY_H_