Pepper: PPB_VideoEncoder implementation

ppapi/proxy/video_encoder_resource.cc

 // Copyright 2015 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.
 
+#include "base/memory/shared_memory.h"
+#include "ppapi/c/pp_array_output.h"
+#include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/video_encoder_resource.h"
+#include "ppapi/proxy/video_frame_resource.h"
+#include "ppapi/shared_impl/media_stream_buffer.h"
+#include "ppapi/shared_impl/media_stream_buffer_manager.h"
+#include "ppapi/thunk/enter.h"
 
+using ppapi::proxy::SerializedHandle;
+using ppapi::thunk::EnterResourceNoLock;
 using ppapi::thunk::PPB_VideoEncoder_API;
 
 namespace ppapi {
 namespace proxy {
 
+namespace {
+
+class BufferManagerDelegate : public MediaStreamBufferManager::Delegate {
+ public:
+  BufferManagerDelegate() {}
+  ~BufferManagerDelegate() override {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(BufferManagerDelegate);
+};

[bbudge, 2015/02/10 01:31:08]

Same comment as on PepperVideoEncoderHost.

[llandwerlin-old, 2015/02/10 14:28:13]

Done.

+
+void RunCallback(scoped_refptr<TrackedCallback>* callback, int32_t error) {
+  if (!TrackedCallback::IsPending(*callback))
+    return;
+
+  scoped_refptr<TrackedCallback> temp;
+  callback->swap(temp);
+  temp->Run(error);
+}
+
+}  // namespace
+
+VideoEncoderResource::ShmBuffer::ShmBuffer(base::SharedMemoryHandle handle,
+                                           uint32_t id,
+                                           uint32_t size)
+    : shm(new base::SharedMemory(handle, true)), id(id), size(size) {
+  if (shm)

[bbudge, 2015/02/10 01:31:08]

You can assume shm is non-null here.

[llandwerlin-old, 2015/02/10 14:28:13]

Done.

+    shm->Map(size);
+}
+
+VideoEncoderResource::ShmBuffer::~ShmBuffer() {
+}
+
+VideoEncoderResource::BitstreamBuffer::BitstreamBuffer(uint32_t id,
+                                                       uint32_t size,
+                                                       bool key_frame)
+    : id(id), size(size), key_frame(key_frame) {
+}
+
+VideoEncoderResource::BitstreamBuffer::BitstreamBuffer(
+    const BitstreamBuffer& other)
+    : id(other.id), size(other.size), key_frame(other.key_frame) {
+}
+
+VideoEncoderResource::BitstreamBuffer::~BitstreamBuffer() {
+}
+
 VideoEncoderResource::VideoEncoderResource(Connection connection,
                                            PP_Instance instance)
-    : PluginResource(connection, instance) {
+    : PluginResource(connection, instance),
+      initialized_(false),
+      // Set |encoder_last_error_| to PP_OK after successful initialization.
+      // This makes error checking a little more concise, since we can check
+      // that the encoder has been initialized and hasn't returned an error by
+      // just testing |encoder_last_error_|.
+      encoder_last_error_(PP_ERROR_FAILED),
+      encoder_frame_count_(0),

[bbudge, 2015/02/10 01:31:08]

initialize encoder_coded_size_.

[llandwerlin-old, 2015/02/10 14:28:13]

Done.

+      waiting_for_video_frames_(false),
+      buffer_manager_delegate_(new BufferManagerDelegate()),
+      buffer_manager_(
+          new MediaStreamBufferManager(buffer_manager_delegate_.get())) {
+  SendCreate(RENDERER, PpapiHostMsg_VideoEncoder_Create());
 }
 
 VideoEncoderResource::~VideoEncoderResource() {
+  encoder_last_error_ = PP_ERROR_ABORTED;

[bbudge, 2015/02/10 01:31:08]

I think it's clearer if encoder_last_error_ represents the last error received
from the host side (in response to NotifyError from the VEA). This seems
contrary to that. Just pass PP_ERROR_ABORTED directly below.

[llandwerlin-old, 2015/02/10 14:28:12]

Done.

+  RunCallback(&initialize_callback_, encoder_last_error_);
+  RunCallback(&get_bitstreamer_buffer_callback_, encoder_last_error_);
+  NotifyGetVideoFrameCallbacksError(encoder_last_error_);
+  ReleaseFrames();

[bbudge, 2015/02/10 01:31:07]

I think Close() should be called somewhere in here.

[llandwerlin-old, 2015/02/10 14:28:12]

Done.

 }
 
 PPB_VideoEncoder_API* VideoEncoderResource::AsPPB_VideoEncoder_API() {
   return this;
 }
 
 int32_t VideoEncoderResource::GetSupportedProfiles(
     const PP_ArrayOutput& output,
     const scoped_refptr<TrackedCallback>& callback) {
-  return PP_ERROR_FAILED;
+  // TODO(llandwerlin): should we prevent concurrent calls?

[bbudge, 2015/02/10 01:31:08]

The IDL leaves it unspecified but I don't think concurrent calls are useful. We
will probably make another pass over the IDL file as the implementation raises
issues like this so I would hold off on updating it.

[llandwerlin-old, 2015/02/10 14:28:13]

Acknowledged.

+  Call<PpapiPluginMsg_VideoEncoder_GetSupportedProfilesReply>(
+      RENDERER, PpapiHostMsg_VideoEncoder_GetSupportedProfiles(),
+      base::Bind(&VideoEncoderResource::OnPluginMsgGetSupportedProfilesReply,
+                 this, output, callback));
+  return PP_OK_COMPLETIONPENDING;
+}
+
+int32_t VideoEncoderResource::GetFramesRequired() {
+  if (encoder_last_error_)
+    return encoder_last_error_;
+  return encoder_frame_count_;
+}
+
+int32_t VideoEncoderResource::GetFrameCodedSize(PP_Size* size) {
+  if (encoder_last_error_)
+    return encoder_last_error_;
+  *size = encoder_coded_size_;
+  return PP_OK;
 }
 
 int32_t VideoEncoderResource::Initialize(
     PP_VideoFrame_Format input_format,
     const PP_Size* input_visible_size,
     PP_VideoProfile output_profile,
     uint32_t initial_bitrate,
     PP_HardwareAcceleration acceleration,
     const scoped_refptr<TrackedCallback>& callback) {
-  return PP_ERROR_FAILED;
-}
-
-int32_t VideoEncoderResource::GetFramesRequired() {
-  return PP_ERROR_FAILED;
-}
-
-int32_t VideoEncoderResource::GetFrameCodedSize(PP_Size* size) {
-  return PP_ERROR_FAILED;
+  if (initialized_)
+    return PP_ERROR_FAILED;
+  if (TrackedCallback::IsPending(initialize_callback_))
+    return PP_ERROR_INPROGRESS;
+
+  initialize_callback_ = callback;
+  Call<PpapiPluginMsg_VideoEncoder_InitializeReply>(
+      RENDERER, PpapiHostMsg_VideoEncoder_Initialize(
+                    input_format, *input_visible_size, output_profile,
+                    initial_bitrate, acceleration),
+      base::Bind(&VideoEncoderResource::OnPluginMsgInitializeReply, this));
+  return PP_OK_COMPLETIONPENDING;
 }
 
 int32_t VideoEncoderResource::GetVideoFrame(
     PP_Resource* video_frame,
     const scoped_refptr<TrackedCallback>& callback) {
-  return PP_ERROR_FAILED;
+  if (encoder_last_error_)
+    return encoder_last_error_;
+
+  get_video_frame_cbs_.push_back(std::make_pair(video_frame, callback));
+
+  // Lazily ask for video frames buffers.

[bbudge, 2015/02/10 01:31:08]

The terminology here is a little confusing. You're really asking for a single
block of shared memory.

[llandwerlin-old, 2015/02/10 14:28:13]

Done.

+  if (buffer_manager_->number_of_buffers() < 1) {
+    // Check that we haven't ask for the buffers already.
+    if (!waiting_for_video_frames_) {
+      waiting_for_video_frames_ = true;
+      Call<PpapiPluginMsg_VideoEncoder_GetVideoFramesReply>(
+          RENDERER, PpapiHostMsg_VideoEncoder_GetVideoFrames(),
+          base::Bind(&VideoEncoderResource::OnPluginMsgGetVideoFramesReply,
+                     this));
+    }
+    return PP_OK_COMPLETIONPENDING;
+  }
+
+  NotifyGetVideoFrameCallbacks();
+
+  return PP_OK_COMPLETIONPENDING;
 }
 
 int32_t VideoEncoderResource::Encode(
     PP_Resource video_frame,
     PP_Bool force_keyframe,
     const scoped_refptr<TrackedCallback>& callback) {
-  return PP_ERROR_FAILED;
+  if (encoder_last_error_)
+    return encoder_last_error_;
+
+  VideoFrameMap::iterator it = video_frames_.find(video_frame);
+  if (it == video_frames_.end())
+    // TODO(llandwerlin): deal MediaStreamVideoTrack's video frames.
+    return PP_ERROR_BADRESOURCE;
+
+  scoped_refptr<VideoFrameResource> frame_resource = it->second;
+
+  Call<PpapiPluginMsg_VideoEncoder_EncodeReply>(
+      RENDERER,
+      PpapiHostMsg_VideoEncoder_Encode(frame_resource->GetBufferIndex(),
+                                       PP_ToBool(force_keyframe)),
+      base::Bind(&VideoEncoderResource::OnPluginMsgEncodeReply, this,
+                 callback));
+
+  return PP_OK_COMPLETIONPENDING;
 }
 
 int32_t VideoEncoderResource::GetBitstreamBuffer(
-    PP_BitstreamBuffer* picture,
-    const scoped_refptr<TrackedCallback>& callback) {
-  return PP_ERROR_FAILED;
+    PP_BitstreamBuffer* bitstream_buffer,
+    const scoped_refptr<TrackedCallback>& callback) {
+  if (encoder_last_error_)
+    return encoder_last_error_;
+  if (TrackedCallback::IsPending(get_bitstreamer_buffer_callback_))
+    return PP_ERROR_INPROGRESS;
+
+  if (available_bitstream_buffers_.empty()) {
+    get_bitstreamer_buffer_callback_ = callback;
+    get_bitstreamer_buffer_data_ = bitstream_buffer;
+    return PP_OK_COMPLETIONPENDING;
+  }
+
+  BitstreamBuffer buffer(available_bitstream_buffers_.front());
+
+  available_bitstream_buffers_.pop_front();
+  WriteBitstreamerBuffer(bitstream_buffer, buffer);
+
+  return PP_OK;
 }
 
 void VideoEncoderResource::RecycleBitstreamBuffer(
-    const PP_BitstreamBuffer* picture) {
+    const PP_BitstreamBuffer* bitstream_buffer) {
+  if (encoder_last_error_)
+    return;
+  BitstreamBufferMap::const_iterator iter =
+      bitstream_buffers_map_.find(bitstream_buffer->buffer);
+  if (iter != bitstream_buffers_map_.end())
+    Post(RENDERER,
+         PpapiHostMsg_VideoEncoder_RecycleBitstreamBuffer(iter->second));
 }
 
 void VideoEncoderResource::RequestEncodingParametersChange(uint32_t bitrate,
                                                            uint32_t framerate) {
+  if (encoder_last_error_)
+    return;
+  Post(RENDERER, PpapiHostMsg_VideoEncoder_RequestEncodingParametersChange(
+                     bitrate, framerate));
 }
 
 void VideoEncoderResource::Close() {
+  if (encoder_last_error_)
+    return;
+  // Synchronously call into the host to make sure all in flight
+  // Encode request are properly cancelled. This will also trigger the
+  // NotifyError callback before SyncCall() returns.
+  SyncCall<PpapiPluginMsg_VideoEncoder_CloseReply>(
+      RENDERER, PpapiHostMsg_VideoEncoder_Close());
+}
+
+void VideoEncoderResource::OnReplyReceived(
+    const ResourceMessageReplyParams& params,
+    const IPC::Message& msg) {
+  PPAPI_BEGIN_MESSAGE_MAP(VideoEncoderResource, msg)
+  PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL(
+      PpapiPluginMsg_VideoEncoder_BitstreamBufferReady,
+      OnPluginMsgBitstreamBufferReady)
+  PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL(PpapiPluginMsg_VideoEncoder_NotifyError,
+                                      OnPluginMsgNotifyError)
+  PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL_UNHANDLED(
+      PluginResource::OnReplyReceived(params, msg))
+  PPAPI_END_MESSAGE_MAP()
+}
+
+void VideoEncoderResource::OnPluginMsgGetSupportedProfilesReply(
+    const PP_ArrayOutput& output,
+    const scoped_refptr<TrackedCallback>& callback,
+    const ResourceMessageReplyParams& params,
+    const std::vector<PP_VideoProfileDescription>& profiles) {
+  void* ptr = output.GetDataBuffer(output.user_data, profiles.size(),
+                                   sizeof(PP_VideoProfileDescription));
+
+  if (!ptr) {
+    callback->Run(PP_ERROR_BADARGUMENT);

[bbudge, 2015/02/10 01:31:07]

The plugin is allowed to return null, so I think PP_ERROR_FAILED is a better
return value here.
See:
https://code.google.com/p/chromium/codesearch#chromium/src/ppapi/proxy/file_i...

[llandwerlin-old, 2015/02/10 14:28:13]

Done.

+    return;
+  }
+
+  memcpy(ptr, &profiles[0],

[bbudge, 2015/02/10 01:31:08]

profiles could be empty in theory, in which case &profiles[0] is undefined. You
should check for size.

[llandwerlin-old, 2015/02/10 14:28:12]

Thanks for spotting this. Done.

+         profiles.size() * sizeof(PP_VideoProfileDescription));
+  callback->Run(PP_OK);
+}
+
+void VideoEncoderResource::OnPluginMsgInitializeReply(
+    const ResourceMessageReplyParams& params,
+    uint32_t buffer_count,
+    uint32_t buffer_length,
+    uint32_t input_frame_count,
+    const PP_Size& input_coded_size) {
+  encoder_last_error_ = params.result();
+  if (encoder_last_error_) {
+    RunCallback(&initialize_callback_, encoder_last_error_);
+    return;
+  }
+
+  std::vector<base::SharedMemoryHandle> buffer_handles;

[bbudge, 2015/02/10 01:31:08]

shm_handles to match shm_buffers_?

[llandwerlin-old, 2015/02/10 14:28:12]

Done.

+  params.TakeAllSharedMemoryHandles(&buffer_handles);
+
+  CHECK(buffer_handles.size() >= buffer_count);

[bbudge, 2015/02/10 01:31:08]

This implies that buffer_handles is the source of truth for the buffer count.
Why not eliminate the 'buffer_count' parameter and use buffer_handles.size()?

[llandwerlin-old, 2015/02/10 14:28:12]

Make sense. Done.

+
+  bitstream_buffers_.clear();
+  bitstream_buffers_map_.clear();

[bbudge, 2015/02/10 01:31:08]

I don't see how these two collections could be non-empty at this point.

[llandwerlin-old, 2015/02/10 14:28:13]

I was thinking that maybe after the encoder is closed, it could be
reinitialized.

[bbudge, 2015/02/10 22:47:36]

In Pepper the convention is that calling Close is permanent, i.e. no other
methods can be called.

+  for (uint32_t i = 0; i < buffer_count; ++i) {
+    ShmBuffer* buffer = new ShmBuffer(buffer_handles[i], i, buffer_length);
+    bitstream_buffers_.push_back(buffer);
+    bitstream_buffers_map_.insert(
+        std::make_pair(buffer->shm->memory(), buffer->id));
+  }
+
+  encoder_frame_count_ = input_frame_count;
+  encoder_coded_size_ = input_coded_size;

[bbudge, 2015/02/10 01:31:08]

Looking at this, I think 'input_frame_count_' and 'input_coded_size_' would be
better names for these.

[llandwerlin-old, 2015/02/10 14:28:13]

Done.

+  initialized_ = true;
+  RunCallback(&initialize_callback_, encoder_last_error_);
+}
+
+void VideoEncoderResource::OnPluginMsgGetVideoFramesReply(
+    const ResourceMessageReplyParams& params,
+    uint32_t frame_count,
+    uint32_t frame_length,
+    const PP_Size& frame_size) {
+  int32_t error = params.result();
+  if (error) {
+    NotifyError(error);
+    return;
+  }
+
+  std::vector<base::SharedMemoryHandle> buffer_handles;
+  params.TakeAllSharedMemoryHandles(&buffer_handles);
+  CHECK(buffer_handles.size() == 1);
+
+  if (!buffer_manager_->SetBuffers(
+          frame_count, frame_length,
+          make_scoped_ptr(new base::SharedMemory(buffer_handles[0], false)),
+          true)) {
+    NotifyError(PP_ERROR_FAILED);
+    return;
+  }
+
+  waiting_for_video_frames_ = false;
+
+  NotifyGetVideoFrameCallbacks();
+}
+
+void VideoEncoderResource::OnPluginMsgEncodeReply(
+    const scoped_refptr<TrackedCallback>& callback,
+    const ResourceMessageReplyParams& params,
+    uint32_t frame_id) {
+  encoder_last_error_ = params.result();
+  callback->Run(encoder_last_error_);
+  buffer_manager_->EnqueueBuffer(frame_id);
+  NotifyGetVideoFrameCallbacks();
+}
+
+void VideoEncoderResource::OnPluginMsgBitstreamBufferReady(
+    const ResourceMessageReplyParams& params,
+    uint32_t buffer_id,
+    uint32_t buffer_size,
+    bool key_frame) {
+  available_bitstream_buffers_.push_back(
+      BitstreamBuffer(buffer_id, buffer_size, PP_FromBool(key_frame)));
+
+  if (TrackedCallback::IsPending(get_bitstreamer_buffer_callback_)) {
+    BitstreamBuffer buffer(available_bitstream_buffers_.front());
+    available_bitstream_buffers_.pop_front();
+    WriteBitstreamerBuffer(get_bitstreamer_buffer_data_, buffer);
+    get_bitstreamer_buffer_data_ = nullptr;
+
+    scoped_refptr<TrackedCallback> callback;
+    get_bitstreamer_buffer_callback_.swap(callback);
+    callback->Run(PP_OK);
+  }
+}
+
+void VideoEncoderResource::OnPluginMsgNotifyError(
+    const ResourceMessageReplyParams& params,
+    int32_t error) {
+  NotifyError(error);
+}
+
+void VideoEncoderResource::NotifyError(int32_t error) {
+  encoder_last_error_ = error;
+  RunCallback(&initialize_callback_, error);
+  RunCallback(&get_bitstreamer_buffer_callback_, error);
+  NotifyGetVideoFrameCallbacksError(error);
+}
+
+void VideoEncoderResource::NotifyGetVideoFrameCallbacks() {
+  int32_t frame_id;
+
+  while (!get_video_frame_cbs_.empty() &&
+         (frame_id = buffer_manager_->DequeueBuffer()) >= 0) {
+    std::pair<PP_Resource*, scoped_refptr<TrackedCallback> > cb =
+        get_video_frame_cbs_.front();
+    get_video_frame_cbs_.pop_front();
+
+    scoped_refptr<VideoFrameResource> resource = new VideoFrameResource(
+        pp_instance(), frame_id, buffer_manager_->GetBufferPointer(frame_id));
+    video_frames_.insert(
+        VideoFrameMap::value_type(resource->pp_resource(), resource));
+
+    *cb.first = resource->GetReference();
+    cb.second->Run(PP_OK);
+  }
+}
+
+void VideoEncoderResource::NotifyGetVideoFrameCallbacksError(int32_t error) {
+  while (!get_video_frame_cbs_.empty()) {
+    std::pair<PP_Resource*, scoped_refptr<TrackedCallback> > cb =
+        get_video_frame_cbs_.front();
+    get_video_frame_cbs_.pop_front();
+    cb.second->Run(error);
+  }
+}
+
+void VideoEncoderResource::WriteBitstreamerBuffer(
+    PP_BitstreamBuffer* bitstream_buffer,
+    const BitstreamBuffer& buffer) {
+  bitstream_buffer->size = buffer.size;
+  bitstream_buffer->buffer = bitstream_buffers_[buffer.id]->shm->memory();
+  bitstream_buffer->key_frame = PP_FromBool(buffer.key_frame);
+}
+
+void VideoEncoderResource::ReleaseFrames() {
+  for (VideoFrameMap::iterator it = video_frames_.begin();
+       it != video_frames_.end(); ++it) {
+    it->second->Invalidate();
+    it->second = nullptr;
+  }
 }
 
 }  // namespace proxy
 }  // namespace ppapi