Add VideoFrameRecorder for use recording test frame sequences.

remoting/host/video_frame_recorder.cc

Index: remoting/host/video_frame_recorder.cc
diff --git a/remoting/host/video_frame_recorder.cc b/remoting/host/video_frame_recorder.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ee71d4706e7a9d39dca8af6e13181a494512b470
--- /dev/null
+++ b/remoting/host/video_frame_recorder.cc
@@ -0,0 +1,201 @@
+// Copyright 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.
+
+#include "remoting/host/video_frame_recorder.h"
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/single_thread_task_runner.h"
+#include "base/stl_util.h"
+#include "base/thread_task_runner_handle.h"
+#include "remoting/codec/video_encoder.h"
+#include "remoting/proto/video.pb.h"
+#include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
+#include "third_party/webrtc/modules/desktop_capture/desktop_geometry.h"
+#include "third_party/webrtc/modules/desktop_capture/desktop_region.h"
+
+namespace remoting {
+
+const int64 kDefaultMaxContentBytes = 10 * 1024 * 1024;

[Sergey Ulanov, 2014/06/20 22:32:13]

int64_t here and everywhere else in this file.

[Sergey Ulanov, 2014/06/20 22:32:13]

10MB fits about 2 frames - is that enough?

[Wez, 2014/06/24 01:02:14]

Done.

[Wez, 2014/06/24 01:02:15]

The intention is really for the caller to choose a suitable size; I'm going to
take this default out and require that callers specify the size explicitly.

+
+static int64 FrameContentBytes(const webrtc::DesktopFrame* frame) {

[Sergey Ulanov, 2014/06/20 22:32:12]

nit: Maybe GetFrameContentSize()? or just FrameContentSize()

[Wez, 2014/06/24 01:02:14]

<foo>Size() is too easy to confuse as being DesktopSize related; FrameDataSize()
might make sense, or how about FrameDataBytes()?

Have gone with FrameContentSize() for now.

+  return frame->stride() * frame->size().height();

[Sergey Ulanov, 2014/06/20 22:32:13]

that will be broken when stride is negative for flipped frames. Add DCHECK?

[Wez, 2014/06/24 01:02:14]

FrameContentSize() is only ever called for BasicDesktopFrame()s in this
implementation, FWIW.

+}
+
+class VideoFrameRecorder::RecordingVideoEncoder : public VideoEncoder {

[Sergey Ulanov, 2014/06/20 22:32:13]

add short comment to describe what this class is used for.

[Wez, 2014/06/24 01:02:14]

Done.

+ public:
+  RecordingVideoEncoder(scoped_ptr<VideoEncoder> encoder,
+                        scoped_refptr<base::TaskRunner> recorder_task_runner,
+                        base::WeakPtr<VideoFrameRecorder> recorder)
+    : encoder_(encoder.Pass()),

[Sergey Ulanov, 2014/06/20 22:32:13]

: needs to be indented 4 spaces,
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Constr...

[Wez, 2014/06/24 01:02:15]

Done.

+      recorder_task_runner_(recorder_task_runner),
+      recorder_(recorder),
+      enable_recording_(false),
+      weak_factory_(this) {
+    DCHECK(encoder_);
+    DCHECK(recorder_task_runner_);
+  }
+
+  base::WeakPtr<RecordingVideoEncoder> AsWeakPtr() {
+    return weak_factory_.GetWeakPtr();
+  }
+
+  void SetEnableRecording(bool enable_recording) {
+    enable_recording_ = enable_recording;

[Sergey Ulanov, 2014/06/20 22:32:12]

DCHECK we are on |encoder_taks_runner_|?

[Wez, 2014/06/24 01:02:14]

Since SetEnableRecording() is a simple setter and part of the internal
implementation of the class, I don't think that's really necessary, but sure,
why not. :P

+  }
+
+  // remoting::VideoEncoder interface.
+  virtual void SetLosslessEncode(bool want_lossless) OVERRIDE {
+    encoder_->SetLosslessEncode(want_lossless);
+  }
+  virtual void SetLosslessColor(bool want_lossless) OVERRIDE {
+    encoder_->SetLosslessColor(want_lossless);
+  }
+  virtual scoped_ptr<VideoPacket> Encode(
+      const webrtc::DesktopFrame& frame) OVERRIDE {
+    // If this is the first Encode() then store the TaskRunner and inform the
+    // VideoFrameRecorder so it can post SetEnableRecording() on it.
+    if (!encoder_task_runner_) {
+      encoder_task_runner_ = base::ThreadTaskRunnerHandle::Get();
+      recorder_task_runner_->PostTask(FROM_HERE,
+          base::Bind(&VideoFrameRecorder::SetEncoderTaskRunner,
+                     recorder_,
+                     encoder_task_runner_));
+    }
+
+    DCHECK(encoder_task_runner_->BelongsToCurrentThread());
+
+    if (enable_recording_) {
+      // Copy the frame and post it to the VideoFrameRecorder to store.
+      scoped_ptr<webrtc::DesktopFrame> frame_copy(
+          new webrtc::BasicDesktopFrame(frame.size()));
+      *frame_copy->mutable_updated_region() = frame.updated_region();
+      frame_copy->set_dpi(frame.dpi());
+      frame_copy->CopyPixelsFrom(frame.data(),
+                                 frame.stride(),
+                                 webrtc::DesktopRect::MakeSize(frame.size()));
+      recorder_task_runner_->PostTask(FROM_HERE,
+          base::Bind(&VideoFrameRecorder::RecordFrame,
+                     recorder_,
+                     base::Passed(&frame_copy)));
+    }
+
+    return encoder_->Encode(frame);
+  }
+
+ private:
+  scoped_ptr<VideoEncoder> encoder_;
+  scoped_refptr<base::TaskRunner> recorder_task_runner_;
+  base::WeakPtr<VideoFrameRecorder> recorder_;
+
+  bool enable_recording_;
+  scoped_refptr<base::SingleThreadTaskRunner> encoder_task_runner_;
+
+  base::WeakPtrFactory<RecordingVideoEncoder> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(RecordingVideoEncoder);
+};
+
+VideoFrameRecorder::VideoFrameRecorder()
+  : content_bytes_(0),

[Sergey Ulanov, 2014/06/20 22:32:12]

indentation

[Wez, 2014/06/24 01:02:14]

Done.

+    max_content_bytes_(kDefaultMaxContentBytes),
+    enable_recording_(false),
+    weak_factory_(this) {
+}
+
+VideoFrameRecorder::~VideoFrameRecorder() {
+  SetEnableRecording(false);
+  STLDeleteElements(&recorded_frames_);
+}
+
+scoped_ptr<VideoEncoder> VideoFrameRecorder::WrapVideoEncoder(
+    scoped_ptr<VideoEncoder> encoder) {
+  DCHECK(!caller_task_runner_);
+  caller_task_runner_ = base::ThreadTaskRunnerHandle::Get();
+
+  scoped_ptr<RecordingVideoEncoder> recording_encoder(
+      new RecordingVideoEncoder(encoder.Pass(),
+                                caller_task_runner_,
+                                weak_factory_.GetWeakPtr()));
+  recording_encoder_ = recording_encoder->AsWeakPtr();
+
+  return recording_encoder.PassAs<VideoEncoder>();
+}
+
+void VideoFrameRecorder::SetEnableRecording(bool enable_recording) {
+  DCHECK(!caller_task_runner_ || caller_task_runner_->BelongsToCurrentThread());
+
+  if (enable_recording_ == enable_recording) {
+    return;
+  }
+  enable_recording_ = enable_recording;
+
+  if (encoder_task_runner_) {
+    encoder_task_runner_->PostTask(FROM_HERE,
+        base::Bind(&RecordingVideoEncoder::SetEnableRecording,
+                   recording_encoder_,
+                   enable_recording_));
+  }
+}
+
+void VideoFrameRecorder::SetMaxContentBytes(int64 max_content_bytes) {
+  DCHECK(!caller_task_runner_ || caller_task_runner_->BelongsToCurrentThread());
+  DCHECK_GE(max_content_bytes, 0);
+
+  max_content_bytes_ = max_content_bytes;
+}
+
+scoped_ptr<webrtc::DesktopFrame> VideoFrameRecorder::NextFrame() {
+  DCHECK(caller_task_runner_->BelongsToCurrentThread());
+
+  scoped_ptr<webrtc::DesktopFrame> frame;
+  if (!recorded_frames_.empty()) {
+    frame.reset(recorded_frames_.front());
+    recorded_frames_.pop_front();

[Sergey Ulanov, 2014/06/20 22:32:13]

update content_bytes_?

[Wez, 2014/06/24 01:02:14]

Done + added a test case.

+  }
+
+  return frame.Pass();
+}
+
+void VideoFrameRecorder::SetEncoderTaskRunner(
+    scoped_refptr<base::TaskRunner> task_runner) {
+  DCHECK(caller_task_runner_->BelongsToCurrentThread());
+  DCHECK(!encoder_task_runner_);
+  DCHECK(task_runner);
+
+  encoder_task_runner_ = task_runner;
+
+  // If the caller already enabled recording, inform the recording encoder.
+  if (enable_recording_) {
+    enable_recording_ = false;
+    SetEnableRecording(true);

[Sergey Ulanov, 2014/06/20 22:32:13]

It looks wrong to reset enable_recording to false, just to set it to true again.
Either post task for SetEnableRecording() here or move PostTask() from
SetEnableRecording() to a separate method and call that method from here.

[Wez, 2014/06/24 01:02:15]

Done.

+  }
+}
+
+void VideoFrameRecorder::RecordFrame(scoped_ptr<webrtc::DesktopFrame> frame) {
+  DCHECK(caller_task_runner_->BelongsToCurrentThread());
+
+  int64 frame_bytes = FrameContentBytes(frame.get());
+  DCHECK_GE(frame_bytes, 0);
+
+  // Purge existing frames until there is space for the new one.
+  while (content_bytes_ + frame_bytes > max_content_bytes_ &&
+         !recorded_frames_.empty()) {
+    scoped_ptr<webrtc::DesktopFrame> drop_frame(recorded_frames_.front());
+    recorded_frames_.pop_front();
+    content_bytes_ -= FrameContentBytes(drop_frame.get());
+    DCHECK_GE(content_bytes_, 0);
+  }
+
+  // If the frame is still too big, ignore it.
+  if (content_bytes_ + frame_bytes > max_content_bytes_) {
+    return;
+  }
+
+  // Store the frame and update the content byte count.
+  recorded_frames_.push_back(frame.release());
+  content_bytes_ += frame_bytes;
+}
+
+}  // namespace remoting