Refactor VideoTrackRecorder into smaller classes

content/renderer/media_recorder/vea_encoder.cc

+// Copyright 2017 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/renderer/media_recorder/vea_encoder.h"
+
+#include <string>
+
+#include "content/renderer/media/renderer_gpu_video_accelerator_factories.h"
+#include "content/renderer/render_thread_impl.h"
+#include "media/base/bind_to_current_loop.h"
+#include "media/base/video_frame.h"
+#include "third_party/libyuv/include/libyuv.h"
+#include "ui/gfx/geometry/size.h"
+
+using media::VideoFrame;
+using video_track_recorder::kVEAEncoderMinResolutionWidth;
+using video_track_recorder::kVEAEncoderMinResolutionHeight;
+
+namespace content {
+
+namespace {
+
+// HW encoders expect a nonzero bitrate, so |kVEADefaultBitratePerPixel| is used
+// to estimate bits per second for ~30 fps with ~1/16 compression rate.
+const int kVEADefaultBitratePerPixel = 2;
+// Number of output buffers used to copy the encoded data coming from HW
+// encoders.
+const int kVEAEncoderOutputBufferCount = 4;
+
+}  // anonymous namespace
+
+VEAEncoder::VEAEncoder(
+    const VideoTrackRecorder::OnEncodedVideoCB& on_encoded_video_callback,
+    int32_t bits_per_second,
+    media::VideoCodecProfile codec,
+    const gfx::Size& size)
+    : Encoder(on_encoded_video_callback,
+              bits_per_second > 0 ? bits_per_second
+                                  : size.GetArea() * kVEADefaultBitratePerPixel,
+              RenderThreadImpl::current()->GetGpuFactories()->GetTaskRunner()),
+      gpu_factories_(RenderThreadImpl::current()->GetGpuFactories()),
+      codec_(codec),
+      error_notified_(false) {
+  DCHECK(gpu_factories_);
+  DCHECK_GE(size.width(), kVEAEncoderMinResolutionWidth);
+  DCHECK_GE(size.height(), kVEAEncoderMinResolutionHeight);
+
+  encoding_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&VEAEncoder::ConfigureEncoderOnEncodingTaskRunner,
+                            this, size));
+}
+
+VEAEncoder::~VEAEncoder() {
+  base::WaitableEvent release_waiter(
+      base::WaitableEvent::ResetPolicy::MANUAL,
+      base::WaitableEvent::InitialState::NOT_SIGNALED);
+  // base::Unretained is safe because the class will be alive until
+  // |release_waiter| is signaled.
+  // TODO(emircan): Consider refactoring media::VideoEncodeAccelerator to avoid
+  // using naked pointers and using DeleteSoon() here, see
+  // http://crbug.com/701627.
+  // It is currently unsafe because |video_encoder_| might be in use on another
+  // function on |encoding_task_runner_|, see http://crbug.com/701030.
+  encoding_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&VEAEncoder::DestroyOnEncodingTaskRunner,
+                            base::Unretained(this), &release_waiter));
+  release_waiter.Wait();
+}
+
+void VEAEncoder::RequireBitstreamBuffers(unsigned int /*input_count*/,
+                                         const gfx::Size& input_coded_size,
+                                         size_t output_buffer_size) {
+  DVLOG(3) << __func__;
+  DCHECK(encoding_task_runner_->BelongsToCurrentThread());
+
+  vea_requested_input_coded_size_ = input_coded_size;
+  output_buffers_.clear();
+  std::queue<std::unique_ptr<base::SharedMemory>>().swap(input_buffers_);
+
+  for (int i = 0; i < kVEAEncoderOutputBufferCount; ++i) {
+    std::unique_ptr<base::SharedMemory> shm =
+        gpu_factories_->CreateSharedMemory(output_buffer_size);
+    if (shm)
+      output_buffers_.push_back(base::WrapUnique(shm.release()));
+  }
+
+  for (size_t i = 0; i < output_buffers_.size(); ++i)
+    UseOutputBitstreamBufferId(i);
+}
+
+void VEAEncoder::BitstreamBufferReady(int32_t bitstream_buffer_id,
+                                      size_t payload_size,
+                                      bool keyframe,
+                                      base::TimeDelta timestamp) {
+  DVLOG(3) << __func__;
+  DCHECK(encoding_task_runner_->BelongsToCurrentThread());
+
+  base::SharedMemory* output_buffer =
+      output_buffers_[bitstream_buffer_id].get();
+
+  std::unique_ptr<std::string> data(new std::string);
+  data->append(reinterpret_cast<char*>(output_buffer->memory()), payload_size);
+
+  const auto front_frame = frames_in_encode_.front();
+  frames_in_encode_.pop();
+  origin_task_runner_->PostTask(
+      FROM_HERE, base::Bind(OnFrameEncodeCompleted, on_encoded_video_callback_,
+                            front_frame.first, base::Passed(&data), nullptr,
+                            front_frame.second, keyframe));
+  UseOutputBitstreamBufferId(bitstream_buffer_id);
+}
+
+void VEAEncoder::NotifyError(media::VideoEncodeAccelerator::Error error) {
+  DVLOG(3) << __func__;
+  DCHECK(encoding_task_runner_->BelongsToCurrentThread());
+
+  // TODO(emircan): Notify the owner via a callback.
+  error_notified_ = true;
+}
+
+void VEAEncoder::UseOutputBitstreamBufferId(int32_t bitstream_buffer_id) {
+  DVLOG(3) << __func__;
+  DCHECK(encoding_task_runner_->BelongsToCurrentThread());
+
+  video_encoder_->UseOutputBitstreamBuffer(media::BitstreamBuffer(
+      bitstream_buffer_id, output_buffers_[bitstream_buffer_id]->handle(),
+      output_buffers_[bitstream_buffer_id]->mapped_size()));
+}
+
+void VEAEncoder::FrameFinished(std::unique_ptr<base::SharedMemory> shm) {
+  DVLOG(3) << __func__;
+  DCHECK(encoding_task_runner_->BelongsToCurrentThread());
+  input_buffers_.push(std::move(shm));
+}
+
+void VEAEncoder::EncodeOnEncodingTaskRunner(scoped_refptr<VideoFrame> frame,
+                                            base::TimeTicks capture_timestamp) {
+  DVLOG(3) << __func__;
+  DCHECK(encoding_task_runner_->BelongsToCurrentThread());
+
+  if (input_visible_size_ != frame->visible_rect().size() && video_encoder_)
+    video_encoder_.reset();
+
+  if (!video_encoder_)
+    ConfigureEncoderOnEncodingTaskRunner(frame->visible_rect().size());
+
+  if (error_notified_) {
+    DVLOG(3) << "An error occurred in VEA encoder";
+    return;
+  }
+
+  // Drop frames if there is no output buffers available.
+  if (output_buffers_.empty()) {
+    // TODO(emircan): Investigate if resetting encoder would help.
+    DVLOG(3) << "Might drop frame.";
+    last_frame_.reset(new std::pair<scoped_refptr<VideoFrame>, base::TimeTicks>(
+        frame, capture_timestamp));
+    return;
+  }
+
+  // If first frame hasn't been encoded, do it first.
+  if (last_frame_) {
+    std::unique_ptr<VideoFrameAndTimestamp> last_frame(last_frame_.release());
+    EncodeOnEncodingTaskRunner(last_frame->first, last_frame->second);
+  }
+
+  // Lower resolutions may fall back to SW encoder in some platforms, i.e. Mac.
+  // In that case, the encoder expects more frames before returning result.
+  // Therefore, a copy is necessary to release the current frame.
+  // Only STORAGE_SHMEM backed frames can be shared with GPU process, therefore
+  // a copy is required for other storage types.
+  scoped_refptr<media::VideoFrame> video_frame = frame;
+  if (video_frame->storage_type() != VideoFrame::STORAGE_SHMEM ||
+      vea_requested_input_coded_size_ != frame->coded_size() ||
+      input_visible_size_.width() < kVEAEncoderMinResolutionWidth ||
+      input_visible_size_.height() < kVEAEncoderMinResolutionHeight) {
+    // Create SharedMemory backed input buffers as necessary. These SharedMemory
+    // instances will be shared with GPU process.
+    std::unique_ptr<base::SharedMemory> input_buffer;
+    const size_t desired_mapped_size = media::VideoFrame::AllocationSize(
+        media::PIXEL_FORMAT_I420, vea_requested_input_coded_size_);
+    if (input_buffers_.empty()) {
+      input_buffer = gpu_factories_->CreateSharedMemory(desired_mapped_size);
+    } else {
+      do {
+        input_buffer = std::move(input_buffers_.front());
+        input_buffers_.pop();
+      } while (!input_buffers_.empty() &&
+               input_buffer->mapped_size() < desired_mapped_size);
+      if (!input_buffer || input_buffer->mapped_size() < desired_mapped_size)
+        return;
+    }
+
+    video_frame = media::VideoFrame::WrapExternalSharedMemory(
+        media::PIXEL_FORMAT_I420, vea_requested_input_coded_size_,
+        gfx::Rect(input_visible_size_), input_visible_size_,
+        reinterpret_cast<uint8_t*>(input_buffer->memory()),
+        input_buffer->mapped_size(), input_buffer->handle(), 0,
+        frame->timestamp());
+    video_frame->AddDestructionObserver(media::BindToCurrentLoop(
+        base::Bind(&VEAEncoder::FrameFinished, this,
+                   base::Passed(std::move(input_buffer)))));
+    libyuv::I420Copy(frame->visible_data(media::VideoFrame::kYPlane),
+                     frame->stride(media::VideoFrame::kYPlane),
+                     frame->visible_data(media::VideoFrame::kUPlane),
+                     frame->stride(media::VideoFrame::kUPlane),
+                     frame->visible_data(media::VideoFrame::kVPlane),
+                     frame->stride(media::VideoFrame::kVPlane),
+                     video_frame->visible_data(media::VideoFrame::kYPlane),
+                     video_frame->stride(media::VideoFrame::kYPlane),
+                     video_frame->visible_data(media::VideoFrame::kUPlane),
+                     video_frame->stride(media::VideoFrame::kUPlane),
+                     video_frame->visible_data(media::VideoFrame::kVPlane),
+                     video_frame->stride(media::VideoFrame::kVPlane),
+                     input_visible_size_.width(), input_visible_size_.height());
+  }
+  frames_in_encode_.push(std::make_pair(
+      media::WebmMuxer::VideoParameters(frame), capture_timestamp));
+
+  video_encoder_->Encode(video_frame, false);
+}
+
+void VEAEncoder::ConfigureEncoderOnEncodingTaskRunner(const gfx::Size& size) {
+  DVLOG(3) << __func__;
+  DCHECK(encoding_task_runner_->BelongsToCurrentThread());
+  DCHECK(gpu_factories_->GetTaskRunner()->BelongsToCurrentThread());
+  DCHECK_GT(bits_per_second_, 0);
+
+  input_visible_size_ = size;
+  video_encoder_ = gpu_factories_->CreateVideoEncodeAccelerator();
+  if (!video_encoder_ ||
+      !video_encoder_->Initialize(media::PIXEL_FORMAT_I420, input_visible_size_,
+                                  codec_, bits_per_second_, this)) {
+    NotifyError(media::VideoEncodeAccelerator::kPlatformFailureError);
+  }
+}
+
+void VEAEncoder::DestroyOnEncodingTaskRunner(
+    base::WaitableEvent* async_waiter) {
+  DCHECK(encoding_task_runner_->BelongsToCurrentThread());
+  video_encoder_.reset();
+  async_waiter->Signal();
+}
+
+}  // namespace content