From 097de34e5b7e56970eddaa0a9f84dcfe6aa8549d Mon Sep 17 00:00:00 2001
From: Paul Adenot <paul@paul.cx>
Date: Thu, 31 Aug 2017 17:14:34 +0200
Subject: [PATCH] Bug 1395593 - Don't query the maximum channel count in
 ::PlayAudio using cubeb. r=achronop

MozReview-Commit-ID: 97ri5vhzsRF

--HG--
extra : rebase_source : 56bc0f44566dfc3e271444f8dfc9f89e12a1a0a1
---
 dom/media/GraphDriver.h        | 6 ++++++
 dom/media/MediaStreamGraph.cpp | 3 ++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/dom/media/GraphDriver.h b/dom/media/GraphDriver.h
index 2f26e08acaba..67d2f9453ba9 100644
--- a/dom/media/GraphDriver.h
+++ b/dom/media/GraphDriver.h
@@ -445,6 +445,12 @@ public:
     return this;
   }
 
+  uint32_t OutputChannelCount()
+  {
+    MOZ_ASSERT(mOuputChannels != 0 && mOuputChannels <= 8);
+    return mOuputChannels;
+  }
+
   /* Enqueue a promise that is going to be resolved when a specific operation
    * occurs on the cubeb stream. */
   void EnqueueStreamAndPromiseForOperation(MediaStream* aStream,
diff --git a/dom/media/MediaStreamGraph.cpp b/dom/media/MediaStreamGraph.cpp
index 23944d56a768..b916f3089a54 100644
--- a/dom/media/MediaStreamGraph.cpp
+++ b/dom/media/MediaStreamGraph.cpp
@@ -948,7 +948,8 @@ MediaStreamGraphImpl::PlayAudio(MediaStream* aStream)
 
     // Need unique id for stream & track - and we want it to match the inserter
     output.WriteTo(LATENCY_STREAM_ID(aStream, track->GetID()),
-                                     mMixer, AudioChannelCount(),
+                                     mMixer,
+                                     CurrentDriver()->AsAudioCallbackDriver()->OutputChannelCount(),
                                      mSampleRate);
   }
   return ticksWritten;