[Mojo Video Capture] Simplify media::VideoCaptureDevice::Client:Buffer to a struct

content/browser/renderer_host/media/video_capture_controller.cc

 // Copyright (c) 2012 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 "content/browser/renderer_host/media/video_capture_controller.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <map>
 #include <set>
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/sparse_histogram.h"
 #include "build/build_config.h"
 #include "components/display_compositor/gl_helper.h"
 #include "content/browser/renderer_host/media/media_stream_manager.h"
 #include "content/browser/renderer_host/media/video_capture_manager.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/common/content_switches.h"
 #include "media/base/video_frame.h"
 #include "media/capture/video/video_capture_buffer_pool.h"
 #include "media/capture/video/video_capture_buffer_tracker_factory_impl.h"
 #include "media/capture/video/video_capture_device_client.h"
+#include "mojo/public/cpp/system/platform_handle.h"
 
 #if !defined(OS_ANDROID)
 #include "content/browser/compositor/image_transport_factory.h"
 #endif
 
 using media::VideoCaptureFormat;
 using media::VideoFrame;
 using media::VideoFrameMetadata;
 
 namespace content {
@@ skipping 50 matching lines @@
 
   // Indicates whether the client is paused, if true, VideoCaptureController
   // stops updating its buffer.
   bool paused;
 };
 
 VideoCaptureController::BufferState::BufferState(
     int buffer_id,
     int frame_feedback_id,
     media::VideoFrameConsumerFeedbackObserver* consumer_feedback_observer,
-    media::FrameBufferPool* frame_buffer_pool,
-    scoped_refptr<media::VideoFrame> frame)
+    media::FrameBufferPool* frame_buffer_pool)
     : buffer_id_(buffer_id),
       frame_feedback_id_(frame_feedback_id),
       consumer_feedback_observer_(consumer_feedback_observer),
       frame_buffer_pool_(frame_buffer_pool),
-      frame_(std::move(frame)),
       max_consumer_utilization_(
           media::VideoFrameConsumerFeedbackObserver::kNoUtilizationRecorded),
       consumer_hold_count_(0) {}
 
 VideoCaptureController::BufferState::~BufferState() = default;
 
 VideoCaptureController::BufferState::BufferState(
     const VideoCaptureController::BufferState& other) = default;
 
 void VideoCaptureController::BufferState::RecordConsumerUtilization(
@@ skipping 248 matching lines @@
   client->buffers_in_use.erase(buffers_in_use_entry_iter);
 }
 
 const media::VideoCaptureFormat&
 VideoCaptureController::GetVideoCaptureFormat() const {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   return video_capture_format_;
 }
 
 void VideoCaptureController::OnIncomingCapturedVideoFrame(
-    std::unique_ptr<media::VideoCaptureDevice::Client::Buffer> buffer,
+    media::VideoCaptureDevice::Client::Buffer buffer,
     scoped_refptr<VideoFrame> frame) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
-  DCHECK(frame_buffer_pool_);
-  const int buffer_id = buffer->id();
+  const int buffer_id = buffer.id;

[miu, 2016/12/20 22:25:37]

If |frame_buffer_pool_| is null, should we return early here?

[chfremer, 2016/12/22 19:01:20]

No. Before this CL |frame_buffer_pool_| == null was illegal, because it was
needed in DoNewBufferOnIOThread(). After this CL it is legal. We may add an
entry to |buffer_id_to_state_map_| with |frame_buffer_pool_| == null, and if
SetFrameBufferPool() is called after that, the entry will get updated.

[miu, 2016/12/27 23:38:48]

Acknowledged.

   DCHECK_NE(buffer_id, media::VideoCaptureBufferPool::kInvalidId);
 
   // Insert if not exists.
   const auto it =
       buffer_id_to_state_map_
           .insert(std::make_pair(
-              buffer_id, BufferState(buffer_id, buffer->frame_feedback_id(),
+              buffer_id, BufferState(buffer_id, buffer.frame_feedback_id,
                                      consumer_feedback_observer_.get(),
-                                     frame_buffer_pool_.get(), frame)))
+                                     frame_buffer_pool_.get())))
           .first;
   BufferState& buffer_state = it->second;
   DCHECK(buffer_state.HasZeroConsumerHoldCount());
 
   if (state_ == VIDEO_CAPTURE_STATE_STARTED) {
     if (!frame->metadata()->HasKey(VideoFrameMetadata::FRAME_RATE)) {
       frame->metadata()->SetDouble(VideoFrameMetadata::FRAME_RATE,
                                    video_capture_format_.frame_rate);
     }
     std::unique_ptr<base::DictionaryValue> metadata(
         new base::DictionaryValue());
     frame->metadata()->MergeInternalValuesInto(metadata.get());
 
     // Only I420 and Y16 pixel formats are currently supported.
     DCHECK(frame->format() == media::PIXEL_FORMAT_I420 ||
            frame->format() == media::PIXEL_FORMAT_Y16)
         << "Unsupported pixel format: "
         << media::VideoPixelFormatToString(frame->format());
 
     // Sanity-checks to confirm |frame| is actually being backed by |buffer|.
+    auto buffer_access = buffer.access_provider->GetReadWriteAccess();
     DCHECK(frame->storage_type() == media::VideoFrame::STORAGE_SHMEM);
-    DCHECK(frame->data(media::VideoFrame::kYPlane) >= buffer->data(0) &&
+    DCHECK(frame->data(media::VideoFrame::kYPlane) >= buffer_access->data() &&
            (frame->data(media::VideoFrame::kYPlane) <
-            (reinterpret_cast<const uint8_t*>(buffer->data(0)) +
-             buffer->mapped_size())))
+            (buffer_access->data() + buffer_access->mapped_size())))
         << "VideoFrame does not appear to be backed by Buffer";
 
     for (const auto& client : controller_clients_) {
       if (client->session_closed || client->paused)
         continue;
 
       // On the first use of a buffer on a client, share the memory handles.
       auto known_buffers_entry_iter =
           std::find(std::begin(client->known_buffers),
                     std::end(client->known_buffers), buffer_id);
       bool is_new_buffer = false;
       if (known_buffers_entry_iter == std::end(client->known_buffers)) {
         client->known_buffers.push_back(buffer_id);
         is_new_buffer = true;
       }
-      if (is_new_buffer)
-        DoNewBufferOnIOThread(client.get(), buffer.get(), frame);
-
+      if (is_new_buffer) {
+        mojo::ScopedSharedBufferHandle handle =
+            buffer.access_provider->GetHandleForTransit();
+        client->event_handler->OnBufferCreated(
+            client->controller_id, std::move(handle),
+            buffer_access->mapped_size(), buffer_id);
+      }
       client->event_handler->OnBufferReady(client->controller_id, buffer_id,
                                            frame);
 
       auto buffers_in_use_entry_iter =
           std::find(std::begin(client->buffers_in_use),
                     std::end(client->buffers_in_use), buffer_id);
       if (buffers_in_use_entry_iter == std::end(client->buffers_in_use))
         client->buffers_in_use.push_back(buffer_id);
       else
         DCHECK(false) << "Unexpected duplicate buffer: " << buffer_id;
@@ skipping 30 matching lines @@
   }
 }
 
 void VideoCaptureController::OnLog(const std::string& message) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   MediaStreamManager::SendMessageToNativeLog("Video capture: " + message);
 }
 
 void VideoCaptureController::OnBufferDestroyed(int buffer_id_to_drop) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
-  DCHECK(frame_buffer_pool_);
 
   for (const auto& client : controller_clients_) {
     if (client->session_closed)
       continue;
 
     auto known_buffers_entry_iter =
         std::find(std::begin(client->known_buffers),
                   std::end(client->known_buffers), buffer_id_to_drop);
     if (known_buffers_entry_iter != std::end(client->known_buffers)) {
       client->known_buffers.erase(known_buffers_entry_iter);
       client->event_handler->OnBufferDestroyed(client->controller_id,
                                                buffer_id_to_drop);
     }
   }
 
   buffer_id_to_state_map_.erase(buffer_id_to_drop);
 }
 
-void VideoCaptureController::DoNewBufferOnIOThread(
-    ControllerClient* client,
-    media::VideoCaptureDevice::Client::Buffer* buffer,
-    const scoped_refptr<media::VideoFrame>& frame) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-  DCHECK_EQ(media::VideoFrame::STORAGE_SHMEM, frame->storage_type());
-
-  const int buffer_id = buffer->id();
-  mojo::ScopedSharedBufferHandle handle =
-      frame_buffer_pool_->GetHandleForTransit(buffer_id);
-  client->event_handler->OnBufferCreated(client->controller_id,
-                                         std::move(handle),
-                                         buffer->mapped_size(), buffer_id);
-}
-
 VideoCaptureController::ControllerClient* VideoCaptureController::FindClient(
     VideoCaptureControllerID id,
     VideoCaptureControllerEventHandler* handler,
     const ControllerClients& clients) {
   for (const auto& client : clients) {
     if (client->controller_id == id && client->event_handler == handler)
       return client.get();
   }
   return nullptr;
 }
 
 VideoCaptureController::ControllerClient* VideoCaptureController::FindClient(
     int session_id,
     const ControllerClients& clients) {
   for (const auto& client : clients) {
     if (client->session_id == session_id)
       return client.get();
   }
   return nullptr;
 }
 
 }  // namespace content