Implement software fallback for PPB_VideoDecoder.

content/renderer/pepper/pepper_video_decoder_host.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_PEPPER_VIDEO_DECODER_HOST_H_
 #define CONTENT_RENDERER_PEPPER_PEPPER_VIDEO_DECODER_HOST_H_
 
 #include <map>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/containers/hash_tables.h"
-#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "content/common/content_export.h"
-#include "gpu/command_buffer/common/mailbox.h"
 #include "media/video/video_decode_accelerator.h"
 #include "ppapi/c/pp_codecs.h"
 #include "ppapi/host/host_message_context.h"
 #include "ppapi/host/resource_host.h"
 #include "ppapi/proxy/resource_message_params.h"
 
 namespace base {
 class SharedMemory;
 }
 
 namespace content {
 
 class PPB_Graphics3D_Impl;
 class RendererPpapiHost;
 class RenderViewImpl;
+class VideoDecoderShim;
 
 class CONTENT_EXPORT PepperVideoDecoderHost
     : public ppapi::host::ResourceHost,
       public media::VideoDecodeAccelerator::Client {
  public:
   PepperVideoDecoderHost(RendererPpapiHost* host,
                          PP_Instance instance,
                          PP_Resource resource);
   virtual ~PepperVideoDecoderHost();
 
  private:
   struct PendingDecode {
     PendingDecode(uint32_t shm_id,
                   const ppapi::host::ReplyMessageContext& reply_context);
     ~PendingDecode();
 
     const uint32_t shm_id;
     const ppapi::host::ReplyMessageContext reply_context;
   };
 
+  friend class VideoDecoderShim;
+
   // ResourceHost implementation.
   virtual int32_t OnResourceMessageReceived(
       const IPC::Message& msg,
       ppapi::host::HostMessageContext* context) OVERRIDE;
 
   // media::VideoDecodeAccelerator::Client implementation.
   virtual void ProvidePictureBuffers(uint32 requested_num_of_buffers,
                                      const gfx::Size& dimensions,
                                      uint32 texture_target) OVERRIDE;
   virtual void DismissPictureBuffer(int32 picture_buffer_id) OVERRIDE;
   virtual void PictureReady(const media::Picture& picture) OVERRIDE;
+  virtual void NotifyEndOfBitstreamBuffer(int32 bitstream_buffer_id) OVERRIDE;
+  virtual void NotifyFlushDone() OVERRIDE;
+  virtual void NotifyResetDone() OVERRIDE;
   virtual void NotifyError(media::VideoDecodeAccelerator::Error error) OVERRIDE;
-  virtual void NotifyFlushDone() OVERRIDE;
-  virtual void NotifyEndOfBitstreamBuffer(int32 bitstream_buffer_id) OVERRIDE;
-  virtual void NotifyResetDone() OVERRIDE;
 
   int32_t OnHostMsgInitialize(ppapi::host::HostMessageContext* context,
                               const ppapi::HostResource& graphics_context,
                               PP_VideoProfile profile,
                               bool allow_software_fallback);
   int32_t OnHostMsgGetShm(ppapi::host::HostMessageContext* context,
                           uint32_t shm_id,
                           uint32_t shm_size);
   int32_t OnHostMsgDecode(ppapi::host::HostMessageContext* context,
                           uint32_t shm_id,
                           uint32_t size,
                           int32_t decode_id);
   int32_t OnHostMsgAssignTextures(ppapi::host::HostMessageContext* context,
                                   const PP_Size& size,
                                   const std::vector<uint32_t>& texture_ids);
   int32_t OnHostMsgRecyclePicture(ppapi::host::HostMessageContext* context,
                                   uint32_t picture_id);
   int32_t OnHostMsgFlush(ppapi::host::HostMessageContext* context);
   int32_t OnHostMsgReset(ppapi::host::HostMessageContext* context);
 
+  // These methods are needed by VideoDecodeAdapter, to look like a

[Ami GONE FROM CHROMIUM, 2014/06/07 18:26:39]

s/Adapter/Shim/
(please make a pass)

[bbudge, 2014/06/07 21:28:33]

Done.

+  // VideoDecodeAccelerator.
+  void OnInitializeComplete(int32_t result);
+  intptr_t ShmIdToKey(uint32_t shm_id);
+  intptr_t ShmHandleToKey(const base::SharedMemoryHandle& handle);
+  const uint8_t* ShmHandleToAddress(const base::SharedMemoryHandle& handle);
+  void RequestTextures(uint32 requested_num_of_buffers,
+                       const gfx::Size& dimensions,
+                       uint32 texture_target,
+                       const std::vector<gpu::Mailbox>& mailboxes);
+
   // Non-owning pointer.
   RendererPpapiHost* renderer_ppapi_host_;
 
   scoped_ptr<media::VideoDecodeAccelerator> decoder_;
-  scoped_refptr<PPB_Graphics3D_Impl> graphics3d_;
 
   // A vector holding our shm buffers, in sync with a similar vector in the
   // resource. We use a buffer's index in these vectors as its id on both sides
   // of the proxy. Only add buffers or update them in place so as not to
   // invalidate these ids.
   ScopedVector<base::SharedMemory> shm_buffers_;
   // A vector of true/false indicating if a shm buffer is in use by the decoder.
   // This is parallel to |shm_buffers_|.
   std::vector<uint8_t> shm_buffer_busy_;
+  // A map of shm handles to memory addresses, to assist VideoDecoderShim.

[Ami GONE FROM CHROMIUM, 2014/06/07 18:26:39]

If you didn't need to go from Handle to addr (only from shm_id to addr) then it
would be simpler to just have a parallel vector shm_addrs_ to shm_buffers_
indexed by shm_id, right?
And AFAICT you only use ShmHandleTo* from outside this class while holding a
BitstreamBuffer, which has the id, too, so I think this should be doable (and
result in simpler/safer code).

[bbudge, 2014/06/07 21:28:33]

So much better.
Done.

+  // base::SharedMemoryHandle isn't suitable as a key on POSIX.
+  typedef base::hash_map<intptr_t, void*> SharedMemoryAddrMap;
+  SharedMemoryAddrMap shm_handle_to_memory_map_;
 
   // Maps decode uid to PendingDecode info.
   typedef base::hash_map<int32_t, PendingDecode> PendingDecodeMap;
   PendingDecodeMap pending_decodes_;
 
   ppapi::host::ReplyMessageContext flush_reply_context_;
   ppapi::host::ReplyMessageContext reset_reply_context_;
+  // Only used when in software fallback mode.
+  ppapi::host::ReplyMessageContext initialize_reply_context_;
 
   bool initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(PepperVideoDecoderHost);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_PEPPER_PEPPER_VIDEO_DECODER_HOST_H_