Cast: Basic cast_receiver API for chrome.

content/public/renderer/media_stream_source_api.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 "content/public/renderer/media_stream_source_api.h"
+
+#include "base/callback.h"
+#include "base/strings/utf_string_conversions.h"
+#include "content/renderer/media/media_stream_audio_source.h"
+#include "content/renderer/media/media_stream_video_capturer_source.h"
+#include "media/base/audio_capturer_source.h"
+#include "media/base/video_capturer_source.h"
+#include "third_party/WebKit/public/platform/WebMediaDeviceInfo.h"
+#include "third_party/WebKit/public/platform/WebMediaStreamSource.h"
+
+namespace content {
+
+void InitializeWebMediaStreamSourceForVideo(
+    scoped_ptr<media::VideoCapturerSource> source,
+    blink::WebMediaStreamSource* webkit_source,
+    bool is_remote,
+    bool is_readonly) {
+  webkit_source->initialize(base::UTF8ToUTF16(""),
+                            blink::WebMediaStreamSource::TypeVideo,
+                            base::UTF8ToUTF16(""),
+                            is_remote,
+                            is_readonly);
+  webkit_source->setExtraData(
+      new content::MediaStreamVideoCapturerSource(
+          content::MediaStreamSource::SourceStoppedCallback(),
+          source.Pass()));
+}
+
+void InitializeSourceForAudioWebMediaStream(
+    scoped_refptr<media::AudioCapturerSource> source,
+    blink::WebMediaStreamSource* webkit_source,
+    bool is_remote,
+    bool is_readonly) {
+  webkit_source->initialize(base::UTF8ToUTF16(""),
+                            blink::WebMediaStreamSource::TypeAudio,
+                            base::UTF8ToUTF16(""),
+                            is_remote,
+                            is_readonly);
+  MediaStreamAudioSource* audio_source(

[perkj_chrome, 2015/02/10 15:29:51]

This seems to require dark art in order to get right. It should be up to the
webrtc team to clean up the audio source code so only arguments that make sense
are needed and the dependencies understandable. Unfortunately, that will not
happen for quite some time.

[hubbe, 2015/02/11 22:38:17]

Acknowledged.

+        new MediaStreamAudioSource(
+            -1,
+            StreamDeviceInfo(),
+            content::MediaStreamSource::SourceStoppedCallback(),
+            RenderThreadImpl::current()->GetPeerConnectionDependencyFactory()));
+  scoped_refptr<WebRtcAudioCapturer> capturer(
+      WebRtcAudioCapturer::CreateCapturer(
+          -1,
+          StreamDeviceInfo(),
+          blink::WebMediaConstraints(),
+          NULL,

[miu, 2015/02/11 02:52:50]

nit: nullptr

[hubbe, 2015/02/11 22:38:17]

Done.

+          audio_source));
+  media::AudioParameters params;
+  capturer->SetCapturerSource(source, params);

[miu, 2015/02/11 02:52:50]

It works with invalid AudioParameters?  Is that because there's a later
SetFormat() call before the audio comes pouring in?

[hubbe, 2015/02/11 22:38:17]

Unfortunately I have not been able to properly test this code yet, so I don't
know if it really works or not.
I'm not going to check it in until I've managed to actually make it work at
least.

However, the right thing to do is probably to have media::AudioParameters to be
an argument to this function and let the caller figure it out.

+  audio_source->SetAudioCapturer(capturer);
+  webkit_source->setExtraData(audio_source);
+}
+
+}  // namespace content