Unmute Tab Audio For Desktop Share

content/browser/media/capture/audio_mirroring_manager.cc

 // Copyright (c) 2013 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/media/capture/audio_mirroring_manager.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 44 matching lines @@
   InitiateQueriesToFindNewDestination(NULL, candidates);
 }
 
 void AudioMirroringManager::RemoveDiverter(Diverter* diverter) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   // Find and remove the entry from the routing table.  If the stream is being
   // diverted, it is stopped.
   for (StreamRoutes::iterator it = routes_.begin(); it != routes_.end(); ++it) {
     if (it->diverter == diverter) {
       ChangeRoute(&(*it), NULL);

[miu, 2016/05/06 22:29:49]

Also need to call it->diverter->StopDuplicating() on all it->duplications here.
Since this code will be identical to what you wrote in the StopMirroring()
method, consider writing a StopAllDuplications(Diverter*) helper static method
(like how ChangeRoute() is a helper used in many places).

[qiangchen, 2016/05/10 22:36:52]

Done.

       routes_.erase(it);
       return;
     }
   }
   NOTREACHED();
 }
 
 void AudioMirroringManager::StartMirroring(MirroringDestination* destination) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(destination);
 
   // Insert an entry into the set of active mirroring sessions, if this is a
   // previously-unknown destination.
   if (std::find(sessions_.begin(), sessions_.end(), destination) ==
           sessions_.end()) {
     sessions_.push_back(destination);
   }
 
+  std::set<SourceFrameRef> candidates;
+
   // Query the MirroringDestination to see which of the audio streams should be
   // diverted.
-  std::set<SourceFrameRef> candidates;
   for (StreamRoutes::const_iterator it = routes_.begin(); it != routes_.end();
        ++it) {
-    if (!it->destination || it->destination == destination)
       candidates.insert(it->source_render_frame);
   }
   if (!candidates.empty()) {
     destination->QueryForMatches(
         candidates,
         base::Bind(&AudioMirroringManager::UpdateRoutesToDestination,
                    base::Unretained(this),
                    destination,
                    false));
   }
 }
 
 void AudioMirroringManager::StopMirroring(MirroringDestination* destination) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   // Stop diverting each audio stream in the mirroring session being stopped.
   // Each stopped stream becomes a candidate to be diverted to another
   // destination.
   std::set<SourceFrameRef> redivert_candidates;
   for (StreamRoutes::iterator it = routes_.begin(); it != routes_.end(); ++it) {
     if (it->destination == destination) {
       ChangeRoute(&(*it), NULL);
       redivert_candidates.insert(it->source_render_frame);
     }
+    auto dup_it = it->duplications.find(destination);
+    if (dup_it != it->duplications.end()) {
+      it->diverter->StopDuplicating(dup_it->second);
+      it->duplications.erase(dup_it);
+    }
   }
   if (!redivert_candidates.empty())
     InitiateQueriesToFindNewDestination(destination, redivert_candidates);
 
   // Remove the entry from the set of active mirroring sessions.
   const Destinations::iterator dest_it =
       std::find(sessions_.begin(), sessions_.end(), destination);
   if (dest_it == sessions_.end()) {
     NOTREACHED();
     return;
   }
   sessions_.erase(dest_it);
 }
 
 void AudioMirroringManager::InitiateQueriesToFindNewDestination(
     MirroringDestination* old_destination,
     const std::set<SourceFrameRef>& candidates) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   for (Destinations::const_iterator it = sessions_.begin();
        it != sessions_.end(); ++it) {
-    if (*it != old_destination) {
-      (*it)->QueryForMatches(
-          candidates,
-          base::Bind(&AudioMirroringManager::UpdateRoutesToDestination,
-                     base::Unretained(this),
-                     *it,
-                     true));
-    }
+    if (*it == old_destination)
+      continue;
+
+    (*it)->QueryForMatches(
+        candidates,
+        base::Bind(&AudioMirroringManager::UpdateRoutesToDestination,
+                   base::Unretained(this), *it, true));
   }
 }
 
 void AudioMirroringManager::UpdateRoutesToDestination(
     MirroringDestination* destination,
     bool add_only,
+    const std::set<SourceFrameRef>& matches,
+    bool is_duplicate) {
+  if (is_duplicate)
+    UpdateRoutesToDuplicateDestination(destination, add_only, matches);
+  else
+    UpdateRoutesToDivertDestination(destination, add_only, matches);
+}
+
+void AudioMirroringManager::UpdateRoutesToDivertDestination(
+    MirroringDestination* destination,
+    bool add_only,
     const std::set<SourceFrameRef>& matches) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   if (std::find(sessions_.begin(), sessions_.end(), destination) ==
           sessions_.end()) {
     return;  // Query result callback invoked after StopMirroring().
   }
 
   DVLOG(1) << (add_only ? "Add " : "Replace with ") << matches.size()
            << " routes to MirroringDestination@" << destination;
@@ skipping 11 matching lines @@
       if (it->destination == destination) {
         ChangeRoute(&(*it), NULL);
         redivert_candidates.insert(it->source_render_frame);
       }
     }
   }
   if (!redivert_candidates.empty())
     InitiateQueriesToFindNewDestination(destination, redivert_candidates);
 }
 
+void AudioMirroringManager::UpdateRoutesToDuplicateDestination(
+    MirroringDestination* destination,
+    bool add_only,
+    const std::set<SourceFrameRef>& matches) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (std::find(sessions_.begin(), sessions_.end(), destination) ==
+      sessions_.end()) {
+    return;  // Query result callback invoked after StopMirroring().
+  }
+
+  for (StreamRoutes::iterator it = routes_.begin(); it != routes_.end(); ++it) {
+    if (matches.find(it->source_render_frame) != matches.end()) {
+      media::AudioPushSink*& pusher = it->duplications[destination];

[miu, 2016/05/06 22:29:49]

Just before this line, please add a consistency check:

  // The same destination cannot have both a diverted audio flow and a
duplicated flow from the same source.
  DCHECK_NE(it->destination, destination);

[qiangchen, 2016/05/10 22:36:52]

Done.

+      if (!pusher) {
+        pusher = destination->AddPushInput(it->diverter->GetAudioParameters());
+        DCHECK(pusher);
+        it->diverter->StartDuplicating(pusher);
+      }
+    } else if (!add_only) {
+      auto dup_it = it->duplications.find(destination);
+      if (dup_it != it->duplications.end()) {
+        it->diverter->StopDuplicating(dup_it->second);
+        it->duplications.erase(dup_it);
+      }
+    }
+  }
+}
+
 // static
 void AudioMirroringManager::ChangeRoute(

[miu, 2016/05/06 22:29:49]

To aid readability, could you change the name of this method to
RouteDivertedFlow()? (to make it clear this is about diverted flows and not
duplicated ones)

[qiangchen, 2016/05/10 22:36:52]

Done.

     StreamRoutingState* route, MirroringDestination* new_destination) {
   if (route->destination == new_destination)

[miu, 2016/05/06 22:29:49]

At the top of this method, let's make sure there isn't an inconsistency where a
source is both diverted and duplicated at the same time. Something like:

  // The same destination cannot have both a diverted audio flow and a
duplicated flow from the same source.
  DCHECK(route->duplications.find(new_destination) ==
route->duplications.end());

[qiangchen, 2016/05/10 22:36:52]

Done.

     return;  // No change.
 
   if (route->destination) {
     DVLOG(1) << "Stop diverting render_process_id:render_frame_id="
              << route->source_render_frame.first << ':'
              << route->source_render_frame.second
              << " --> MirroringDestination@" << route->destination;
     route->diverter->StopDiverting();
     route->destination = NULL;
   }
@@ skipping 14 matching lines @@
   : source_render_frame(source_frame),
     diverter(stream_diverter),
     destination(NULL) {}
 
 AudioMirroringManager::StreamRoutingState::StreamRoutingState(
     const StreamRoutingState& other) = default;
 
 AudioMirroringManager::StreamRoutingState::~StreamRoutingState() {}
 
 }  // namespace content