Define EncodedVideoSource and RtcCapturedEncodingVideoCapturer.

content/renderer/media/video_capture_impl.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/renderer/media/video_capture_impl.h"
 
 #include "base/bind.h"
+#include "base/callback_helpers.h"
 #include "base/stl_util.h"
 #include "content/child/child_process.h"
+#include "content/common/media/encoded_video_capture_messages.h"
 #include "content/common/media/video_capture_messages.h"
 #include "media/base/limits.h"
 
 namespace content {
 
 struct VideoCaptureImpl::DIBBuffer {
  public:
   DIBBuffer(
       base::SharedMemory* d,
       media::VideoCapture::VideoFrameBuffer* ptr)
@@ skipping 74 matching lines @@
       base::Bind(&VideoCaptureImpl::DoStartCaptureOnCaptureThread,
                  base::Unretained(this), handler, capability));
 }
 
 void VideoCaptureImpl::StopCapture(media::VideoCapture::EventHandler* handler) {
   capture_message_loop_proxy_->PostTask(FROM_HERE,
       base::Bind(&VideoCaptureImpl::DoStopCaptureOnCaptureThread,
                  base::Unretained(this), handler));
 }
 
+void VideoCaptureImpl::RequestCapabilities(
+    const media::EncodedVideoSource::RequestCapabilitiesCallback& callback) {
+  capture_message_loop_proxy_->PostTask(FROM_HERE,
+      base::Bind(&VideoCaptureImpl::DoRequestCapabilitiesOnCaptureThread,
+                 base::Unretained(this), callback));

[Ami GONE FROM CHROMIUM, 2013/06/13 22:56:58]

Yowza.  So, Unretained(this) is safe (even though the I/O thread is scoped to
the renderer process and the capture_message_loop_proxy_ thread is scoped to the
VideoCaptureImplManager) because VideoCaptureImplManager only triggers deletion
of its VideoCaptureImpl's by calling DeInit which detours through the capture &
I/O threads, so as long as nobody posts tasks after the DeInit() call is made,
it is guaranteed none of these Unretained posted tasks will dangle after the
delete goes through.

[hshi1, 2013/06/13 23:33:40]

Ok so I assume there's no action item for me then.

[Ami GONE FROM CHROMIUM, 2013/06/18 20:56:27]

If you felt like adding this comment to the class header comments that talk
about threading I think that would be an improvement.  Otherwise I'll do it.

[hshi1, 2013/06/18 23:01:19]

I'd feel more comfortable if you add the appropriate comments. I'm not confident
that I'll be able to phrase it correctly and concisely. Thanks! 

+}
+
+void VideoCaptureImpl::StartFetchCapabilities() {
+  Send(new EncodedVideoCaptureHostMsg_GetCapabilities(
+      device_id_, current_params_.session_id));
+}
+
+void VideoCaptureImpl::OpenBitstream(
+    media::EncodedVideoSource::Client* client,
+    const media::VideoEncodingParameters& params) {
+  capture_message_loop_proxy_->PostTask(FROM_HERE,
+      base::Bind(&VideoCaptureImpl::DoOpenBitstreamOnCaptureThread,
+                 base::Unretained(this), client, params));
+}
+
+void VideoCaptureImpl::CloseBitstream() {
+  capture_message_loop_proxy_->PostTask(FROM_HERE,
+      base::Bind(&VideoCaptureImpl::DoCloseBitstreamOnCaptureThread,
+                 base::Unretained(this)));
+}
+
+void VideoCaptureImpl::ReturnBitstreamBuffer(
+    scoped_refptr<const media::EncodedBitstreamBuffer> buffer) {
+  Send(new EncodedVideoCaptureHostMsg_BitstreamBufferConsumed(
+      device_id_, buffer->buffer_id()));
+}
+
+void VideoCaptureImpl::TrySetBitstreamConfig(
+    const media::RuntimeVideoEncodingParameters& params) {
+  Send(new EncodedVideoCaptureHostMsg_TryConfigureBitstream(
+      device_id_, params));
+}
+
+void VideoCaptureImpl::OnEncodingCapabilitiesAvailable(
+    const media::VideoEncodingCapabilities& capabilities) {
+  capture_message_loop_proxy_->PostTask(FROM_HERE, base::Bind(
+      &VideoCaptureImpl::DoNotifyCapabilitiesAvailableOnCaptureThread,
+      base::Unretained(this), capabilities));
+}
+
+void VideoCaptureImpl::OnEncodedBitstreamOpened(
+    const media::VideoEncodingParameters& params,
+    const std::vector<base::SharedMemoryHandle>& buffers,
+    uint32 buffer_size) {
+  capture_message_loop_proxy_->PostTask(FROM_HERE,
+      base::Bind(&VideoCaptureImpl::DoNotifyBitstreamOpenedOnCaptureThread,
+                 base::Unretained(this), params, buffers, buffer_size));
+}
+
+void VideoCaptureImpl::OnEncodedBitstreamClosed() {
+  capture_message_loop_proxy_->PostTask(FROM_HERE,
+      base::Bind(&VideoCaptureImpl::DoNotifyBitstreamClosedOnCaptureThread,
+                 base::Unretained(this)));
+}
+
+void VideoCaptureImpl::OnEncodingConfigChanged(
+      const media::RuntimeVideoEncodingParameters& params) {
+  capture_message_loop_proxy_->PostTask(FROM_HERE,
+      base::Bind(
+          &VideoCaptureImpl::DoNotifyBitstreamConfigChangedOnCaptureThread,
+          base::Unretained(this), params));
+}
+
+void VideoCaptureImpl::OnEncodedBufferReady(
+    int buffer_id,
+    uint32 size,
+    const media::BufferEncodingMetadata& metadata) {
+  capture_message_loop_proxy_->PostTask(FROM_HERE,
+      base::Bind(&VideoCaptureImpl::DoNotifyBitstreamBufferReadyOnCaptureThread,
+                 base::Unretained(this), buffer_id, size, metadata));
+}
+
 void VideoCaptureImpl::FeedBuffer(scoped_refptr<VideoFrameBuffer> buffer) {
   capture_message_loop_proxy_->PostTask(FROM_HERE,
       base::Bind(&VideoCaptureImpl::DoFeedBufferOnCaptureThread,
                  base::Unretained(this), buffer));
 }
 
 void VideoCaptureImpl::OnBufferCreated(
     base::SharedMemoryHandle handle,
     int length, int buffer_id) {
   capture_message_loop_proxy_->PostTask(FROM_HERE,
@@ skipping 185 matching lines @@
     it->first->OnBufferReady(this, buffer);
   }
   cached_dibs_[buffer_id]->references = clients_.size();
 }
 
 void VideoCaptureImpl::DoStateChangedOnCaptureThread(VideoCaptureState state) {
   DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
 
   switch (state) {
     case VIDEO_CAPTURE_STATE_STARTED:
+      StartFetchCapabilities();
       break;
     case VIDEO_CAPTURE_STATE_STOPPED:
       state_ = VIDEO_CAPTURE_STATE_STOPPED;
       DVLOG(1) << "OnStateChanged: stopped!, device_id = " << device_id_;
       STLDeleteValues(&cached_dibs_);
       if (!clients_.empty() || !clients_pending_on_restart_.empty())
         RestartCapture();
       break;
     case VIDEO_CAPTURE_STATE_PAUSED:
       for (ClientInfo::iterator it = clients_.begin();
@@ skipping 54 matching lines @@
   }
 }
 
 void VideoCaptureImpl::DoSuspendCaptureOnCaptureThread(bool suspend) {
   DVLOG(1) << "DoSuspendCapture: suspend " << (suspend ? "yes" : "no");
   DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
 
   suspended_ = suspend;
 }
 
+void VideoCaptureImpl::DoRequestCapabilitiesOnCaptureThread(
+    const RequestCapabilitiesCallback& callback) {
+  DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
+  DCHECK(callback_.is_null());
+  callback_ = callback;
+
+  // Invoke callback immediately if capabilities are already available.
+  if (!capabilities_.empty())
+    base::ResetAndReturn(&callback_).Run(capabilities_);
+}
+
+void VideoCaptureImpl::DoOpenBitstreamOnCaptureThread(
+    media::EncodedVideoSource::Client* client,
+    const media::VideoEncodingParameters& params) {
+  DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
+  DCHECK(!client_);
+  client_ = client;
+  Send(new EncodedVideoCaptureHostMsg_OpenBitstream(
+      device_id_, current_params_.session_id, params));
+}
+
+void VideoCaptureImpl::DoCloseBitstreamOnCaptureThread() {
+  DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
+  Send(new EncodedVideoCaptureHostMsg_CloseBitstream(device_id_));
+  client_ = NULL;
+}
+
+void VideoCaptureImpl::DoNotifyBitstreamOpenedOnCaptureThread(
+    const media::VideoEncodingParameters& params,
+    const std::vector<base::SharedMemoryHandle>& buffers,
+    uint32 buffer_size) {
+  DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
+  DCHECK(bitstream_buffers_.empty());
+  for (size_t i = 0; i < buffers.size(); ++i) {
+    base::SharedMemory* shm = new base::SharedMemory(buffers[i], true);
+    bitstream_buffers_.push_back(shm);
+  }
+  client_->OnOpened(params);
+}
+
+void VideoCaptureImpl::DoNotifyBitstreamClosedOnCaptureThread() {
+  DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
+  for (size_t i = 0; i < bitstream_buffers_.size(); ++i) {
+    bitstream_buffers_[i]->Close();
+    delete bitstream_buffers_[i];
+  }
+  bitstream_buffers_.clear();
+  if (client_) {
+    client_->OnClosed();
+    client_ = NULL;
+  }
+}
+
+void VideoCaptureImpl::DoNotifyBitstreamConfigChangedOnCaptureThread(
+    const media::RuntimeVideoEncodingParameters& params) {
+  DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
+  client_->OnConfigChanged(params);
+}
+
+void VideoCaptureImpl::DoNotifyBitstreamBufferReadyOnCaptureThread(
+    int buffer_id,
+    uint32 size,
+    const media::BufferEncodingMetadata& metadata) {
+  DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
+  if (buffer_id >= 0 && buffer_id < (int)bitstream_buffers_.size()) {

[Ami GONE FROM CHROMIUM, 2013/06/13 22:56:58]

s/(int)/static_cast<int>/ but that risks overflow; better to go the other way
once you assure non-negativity:
buffer_id >= 0 && static_cast<size_t>(buffer_id) < bitstream_buffers_.size()

[hshi1, 2013/06/13 23:33:40]

Done.

+    base::SharedMemory* shm = bitstream_buffers_[buffer_id];
+    if (shm && shm->Map(size)) {

[Ami GONE FROM CHROMIUM, 2013/06/13 22:56:58]

shm can't be NULL here.

[Ami GONE FROM CHROMIUM, 2013/06/13 22:56:58]

You test shm->Map() for failing but you don't do anything with that fact.  I
think CHECK-failing would be a fine thing to do here.

[hshi1, 2013/06/13 23:33:40]

Done.

[hshi1, 2013/06/13 23:33:40]

Done.

+      scoped_refptr<media::EncodedBitstreamBuffer> buffer =
+          new media::EncodedBitstreamBuffer(
+              buffer_id, (uint8*)shm->memory(), size, metadata);
+      client_->OnBufferReady(buffer);
+      shm->Unmap();

[Ami GONE FROM CHROMIUM, 2013/06/13 22:56:58]

Is it clear why you want to Map & Unmap on every bitstreambuffer delivery?
ISTM much better to Map each SHM once in DoNotifyBitstreamOpenedOnCaptureThread
and then Unmap each of them once in DoNotifyBitstreamClosedOnCaptureThread.

[hshi1, 2013/06/13 23:33:40]

Done. (Notice: no need to Unmap on close - bitstream_buffers[i]->Close()
automatically does Unmap).

+    }
+  }
+}
+
+void VideoCaptureImpl::DoNotifyCapabilitiesAvailableOnCaptureThread(
+    const media::VideoEncodingCapabilities& capabilities) {
+  DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
+  capabilities_ = capabilities;
+  if (!callback_.is_null())
+    base::ResetAndReturn(&callback_).Run(capabilities_);
+}
+
 void VideoCaptureImpl::StopDevice() {
   DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
 
   device_info_available_ = false;
   if (state_ == VIDEO_CAPTURE_STATE_STARTED) {
     state_ = VIDEO_CAPTURE_STATE_STOPPING;
     Send(new VideoCaptureHostMsg_Stop(device_id_));
     current_params_.width = current_params_.height = 0;
   }
 }
@@ skipping 68 matching lines @@
   if (it != clients->end()) {
     handler->OnStopped(this);
     handler->OnRemoved(this);
     clients->erase(it);
     found = true;
   }
   return found;
 }
 
 }  // namespace content