Tab Audio Capture: Browser-side connect/disconnect functionality.

content/browser/renderer_host/media/audio_renderer_host.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/audio_renderer_host.h"
 
 #include "base/bind.h"
 #include "base/metrics/histogram.h"
 #include "base/process.h"
 #include "base/shared_memory.h"
 #include "content/browser/browser_main_loop.h"
 #include "content/browser/renderer_host/media/audio_sync_reader.h"
+#include "content/browser/renderer_host/media/web_contents_audio_input_stream.h"
 #include "content/common/media/audio_messages.h"
 #include "content/public/browser/media_observer.h"
+#include "media/audio/audio_io.h"
 #include "media/audio/shared_memory_util.h"
 #include "media/base/audio_bus.h"
 #include "media/base/limits.h"
 
 using media::AudioBus;
 
 namespace content {
 
 struct AudioRendererHost::AudioEntry {
   AudioEntry();
   ~AudioEntry();
 
   // The AudioOutputController that manages the audio stream.
   scoped_refptr<media::AudioOutputController> controller;
 
   // The audio stream ID.
   int stream_id;
 
+  // The routing ID of the source render view.
+  int render_view_id;
+
   // Shared memory for transmission of the audio data.
   base::SharedMemory shared_memory;
 
   // The synchronous reader to be used by the controller. We have the
   // ownership of the reader.
   scoped_ptr<media::AudioOutputController::SyncReader> reader;
 
+  // When non-NULL, normal audio output is being diverted for audio mirroring.
+  media::AudioOutputStream::AudioSourceCallback* diverted_callback;
+
   // Set to true after we called Close() for the controller.
   bool pending_close;
 };
 
 AudioRendererHost::AudioEntry::AudioEntry()
     : stream_id(0),
+      render_view_id(MSG_ROUTING_NONE),
+      diverted_callback(NULL),
       pending_close(false) {
 }
 
-AudioRendererHost::AudioEntry::~AudioEntry() {}
+AudioRendererHost::AudioEntry::~AudioEntry() {
+  DCHECK(!diverted_callback);
+}
 
 ///////////////////////////////////////////////////////////////////////////////
 // AudioRendererHost implementations.
 AudioRendererHost::AudioRendererHost(
+    int render_process_id,
     media::AudioManager* audio_manager, MediaObserver* media_observer)
-    : audio_manager_(audio_manager),
+    : render_process_id_(render_process_id),
+      audio_manager_(audio_manager),
       media_observer_(media_observer) {
 }
 
 AudioRendererHost::~AudioRendererHost() {
   DCHECK(audio_entries_.empty());
+  DCHECK(mirror_sessions_.empty());
+}
+
+base::LazyInstance<AudioRendererHost::ActiveHostMap>::Leaky
+    AudioRendererHost::g_host_map_ = LAZY_INSTANCE_INITIALIZER;
+
+void AudioRendererHost::OnChannelConnected(int32 peer_pid) {
+  g_host_map_.Get().insert(std::make_pair(render_process_id_, this));
+
+  BrowserMessageFilter::OnChannelConnected(peer_pid);
 }
 
 void AudioRendererHost::OnChannelClosing() {
   BrowserMessageFilter::OnChannelClosing();
 
   // Since the IPC channel is gone, close all requested audio streams.
   DeleteEntries();
+
+  while (!mirror_sessions_.empty()) {
+    MirrorSessionMap::iterator it = mirror_sessions_.begin();
+    DoStopMirroring(render_process_id_, it->first, it->second);
+  }
+
+  g_host_map_.Get().erase(render_process_id_);
 }
 
 void AudioRendererHost::OnDestruct() const {
   BrowserThread::DeleteOnIOThread::Destruct(this);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // media::AudioOutputController::EventHandler implementations.
 void AudioRendererHost::OnCreated(media::AudioOutputController* controller) {
   BrowserThread::PostTask(
@@ skipping 129 matching lines @@
     IPC_MESSAGE_HANDLER(AudioHostMsg_PauseStream, OnPauseStream)
     IPC_MESSAGE_HANDLER(AudioHostMsg_FlushStream, OnFlushStream)
     IPC_MESSAGE_HANDLER(AudioHostMsg_CloseStream, OnCloseStream)
     IPC_MESSAGE_HANDLER(AudioHostMsg_SetVolume, OnSetVolume)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP_EX()
 
   return handled;
 }
 
+// static
+AudioRendererHost* AudioRendererHost::FromRenderProcessID(
+    int render_process_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  ActiveHostMap& host_map = g_host_map_.Get();
+  ActiveHostMap::const_iterator it = host_map.find(render_process_id);
+  return it == host_map.end() ? NULL : it->second;
+}
+
+// static
+void AudioRendererHost::StartMirroring(
+    int render_process_id, int render_view_id,

[Alpha Left Google, 2012/11/28 20:02:25]

This is called on the IO thread, why the extra thread jumping?

[miu, 2012/11/28 22:05:50]

It's called from the audio thread.  To make this clearer, I just changed code in
WCAIS to explicitly grab a ref to the audio thread's message loop from
AudioManager so that the DCHECKs are making it clear where code is running on
the audio thread.

+    const scoped_refptr<WebContentsAudioInputStream>& destination) {
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&AudioRendererHost::DoStartMirroring,
+                 render_process_id, render_view_id, destination));
+}
+
+// static
+void AudioRendererHost::DoStartMirroring(
+    int render_process_id, int render_view_id,
+    const scoped_refptr<WebContentsAudioInputStream>& destination) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  DCHECK(destination);
+
+  AudioRendererHost* const host = FromRenderProcessID(render_process_id);
+  if (!host) {
+    return;
+  }
+
+  // If a mirroring session is already active for |render_process_id| +
+  // |render_view_id|, force-stop it.
+  MirrorSessionMap::iterator session_it =
+      host->mirror_sessions_.find(render_view_id);
+  if (session_it != host->mirror_sessions_.end()) {
+    DVLOG(1) << "Forcing StopMirroring(" << render_view_id
+             << ") on existing mirroring session (@" << session_it->second
+             << ").";
+    DoStopMirroring(render_process_id, render_view_id, session_it->second);
+  }
+
+  DVLOG(1) << "Start mirroring RenderProcess:View="
+           << render_process_id << ':' << render_view_id
+           << " --> WebContentsAudioInputStream@" << destination;
+
+  // Insert an entry into the set of active mirroring sessions and divert any
+  // existing audio outputs to |destination|.
+  host->mirror_sessions_.insert(std::make_pair(render_view_id, destination));
+  for (AudioEntryMap::const_iterator it = host->audio_entries_.begin();
+       it != host->audio_entries_.end(); ++it) {
+    AudioEntry* const entry = it->second;
+    if (entry->render_view_id == render_view_id &&
+        !entry->pending_close) {
+      entry->diverted_callback = entry->controller->Divert();
+      destination->AddInput(entry->diverted_callback,
+                            entry->controller->params());
+    }
+  }
+}
+
+// static
+void AudioRendererHost::StopMirroring(
+    int render_process_id, int render_view_id,
+    const scoped_refptr<WebContentsAudioInputStream>& destination) {
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&AudioRendererHost::DoStopMirroring,
+                 render_process_id, render_view_id, destination));
+}
+
+// static
+void AudioRendererHost::DoStopMirroring(
+    int render_process_id, int render_view_id,
+    const scoped_refptr<WebContentsAudioInputStream>& destination) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  AudioRendererHost* const host = FromRenderProcessID(render_process_id);
+  if (!host) {
+    return;
+  }
+
+  MirrorSessionMap::iterator session_it =
+      host->mirror_sessions_.find(render_view_id);
+  if (session_it == host->mirror_sessions_.end() ||
+      destination != session_it->second) {
+    return;
+  }
+
+  DVLOG(1) << "Stop mirroring RenderProcess:View="
+           << render_process_id << ':' << render_view_id
+           << " --> WebContentsAudioInputStream@" << destination;
+
+  // Revert the "divert" for each audio stream currently active in the mirroring
+  // session being stopped.
+  for (AudioEntryMap::const_iterator it = host->audio_entries_.begin();
+       it != host->audio_entries_.end(); ++it) {
+    AudioEntry* const entry = it->second;
+    if (entry->render_view_id == render_view_id &&
+        entry->diverted_callback) {
+      destination->RemoveInput(entry->diverted_callback);
+      entry->controller->Revert(entry->diverted_callback);
+      entry->diverted_callback = NULL;
+    }
+  }
+
+  host->mirror_sessions_.erase(session_it);
+}
+
 void AudioRendererHost::OnCreateStream(
     int stream_id, const media::AudioParameters& params, int input_channels) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK(LookupById(stream_id) == NULL);
 
   media::AudioParameters audio_params(params);
   uint32 buffer_size = media::AudioBus::CalculateMemorySize(audio_params);
   DCHECK_GT(buffer_size, 0U);
   DCHECK_LE(buffer_size,
             static_cast<uint32>(media::limits::kMaxPacketSizeInBytes));
@@ skipping 47 matching lines @@
   }
 
   // If we have created the controller successfully, create an entry and add it
   // to the map.
   entry->stream_id = stream_id;
   audio_entries_.insert(std::make_pair(stream_id, entry.release()));
   if (media_observer_)
     media_observer_->OnSetAudioStreamStatus(this, stream_id, "created");
 }
 
+void AudioRendererHost::OnAssociateStreamWithProducer(int stream_id,
+                                                      int render_view_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  AudioEntry* const entry = LookupById(stream_id);
+  if (!entry) {
+    SendErrorMessage(stream_id);
+    return;
+  }
+
+  if (entry->render_view_id == render_view_id)
+    return;  // No change.
+
+  // If this stream is currently being mirrored, remove it from that mirroring
+  // session.
+  MirrorSessionMap::const_iterator prev_session_it =
+      mirror_sessions_.find(entry->render_view_id);
+  if (prev_session_it != mirror_sessions_.end()) {
+    if (entry->diverted_callback) {
+      prev_session_it->second->RemoveInput(entry->diverted_callback);
+    }
+  }
+
+  entry->render_view_id = render_view_id;
+
+  // If a mirroring session is already active for the RenderView, add this
+  // stream to that mirroring session.
+  MirrorSessionMap::const_iterator next_session_it =
+      mirror_sessions_.find(render_view_id);
+  if (next_session_it != mirror_sessions_.end()) {
+    if (!entry->pending_close) {
+      if (!entry->diverted_callback) {
+        entry->diverted_callback = entry->controller->Divert();
+      }
+      next_session_it->second->AddInput(entry->diverted_callback,
+                                        entry->controller->params());
+    }
+  } else if (entry->diverted_callback) {
+    // Clean-up: The audio stream was removed from the previous mirroring
+    // session, but there is no other mirroring session for it to be added to.
+    // So, "revert the divert."
+    entry->controller->Revert(entry->diverted_callback);
+    entry->diverted_callback = NULL;
+  }
+}
+
 void AudioRendererHost::OnPlayStream(int stream_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   AudioEntry* entry = LookupById(stream_id);
   if (!entry) {
     SendErrorMessage(stream_id);
     return;
   }
 
   entry->controller->Play();
@@ skipping 69 matching lines @@
   for (AudioEntryMap::iterator i = audio_entries_.begin();
        i != audio_entries_.end(); ++i) {
     CloseAndDeleteStream(i->second);
   }
 }
 
 void AudioRendererHost::CloseAndDeleteStream(AudioEntry* entry) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   if (!entry->pending_close) {
+    // If this stream is currently being mirrored, remove it from the mirroring
+    // session.
+    MirrorSessionMap::const_iterator session_it =
+        mirror_sessions_.find(entry->render_view_id);
+    if (session_it != mirror_sessions_.end() &&
+        entry->diverted_callback) {
+      session_it->second->RemoveInput(entry->diverted_callback);
+      // Note: We don't call AudioOutputController::Revert() since we're about
+      // to close the controller below.  If we did call Revert(), it would cause
+      // an unnecessary round of immediate starting and stopping.
+    }
+
     entry->controller->Close(
         base::Bind(&AudioRendererHost::DeleteEntry, this, entry));
+    entry->diverted_callback = NULL;
     entry->pending_close = true;
   }
 }
 
 void AudioRendererHost::DeleteEntry(AudioEntry* entry) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   // Delete the entry when this method goes out of scope.
   scoped_ptr<AudioEntry> entry_deleter(entry);
 
@@ skipping 40 matching lines @@
   return NULL;
 }
 
 media::AudioOutputController* AudioRendererHost::LookupControllerByIdForTesting(
     int stream_id) {
   AudioEntry* const entry = LookupById(stream_id);
   return entry ? entry->controller : NULL;
 }
 
 }  // namespace content