From 4c1d0136c904413d0709dc6b481fc8b88f645a0e Mon Sep 17 00:00:00 2001
From: Alex Chronopoulos <achronop@gmail.com>
Date: Thu, 18 Jun 2020 15:50:03 +0000
Subject: [PATCH] Bug 1584959 - Avoid calling the converter if the conversion
 is not possible. r=bryce

Differential Revision: https://phabricator.services.mozilla.com/D56736
---
 dom/media/AudioConverter.cpp      | 29 +++++++++++++++++++++--------
 dom/media/AudioConverter.h        |  1 +
 dom/media/mediasink/AudioSink.cpp | 12 +++++++++---
 3 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/dom/media/AudioConverter.cpp b/dom/media/AudioConverter.cpp
index bf03d8c79a00..d2eb7335a997 100644
--- a/dom/media/AudioConverter.cpp
+++ b/dom/media/AudioConverter.cpp
@@ -21,14 +21,8 @@ namespace mozilla {
 
 AudioConverter::AudioConverter(const AudioConfig& aIn, const AudioConfig& aOut)
     : mIn(aIn), mOut(aOut), mResampler(nullptr) {
-  MOZ_DIAGNOSTIC_ASSERT(
-      aIn.Format() == aOut.Format() && aIn.Interleaved() == aOut.Interleaved(),
-      "No format or rate conversion is supported at this stage");
-  MOZ_DIAGNOSTIC_ASSERT(
-      aOut.Channels() <= 2 || aIn.Channels() == aOut.Channels(),
-      "Only down/upmixing to mono or stereo is supported at this stage");
-  MOZ_DIAGNOSTIC_ASSERT(aOut.Interleaved(),
-                        "planar audio format not supported");
+  MOZ_DIAGNOSTIC_ASSERT(CanConvert(aIn, aOut),
+                        "The conversion is not supported");
   mIn.Layout().MappingTable(mOut.Layout(), &mChannelOrderMap);
   if (aIn.Rate() != aOut.Rate()) {
     RecreateResampler();
@@ -42,6 +36,25 @@ AudioConverter::~AudioConverter() {
   }
 }
 
+bool AudioConverter::CanConvert(const AudioConfig& aIn,
+                                const AudioConfig& aOut) {
+  if (aIn.Format() != aOut.Format() ||
+      aIn.Interleaved() != aOut.Interleaved()) {
+    NS_WARNING("No format conversion is supported at this stage");
+    return false;
+  }
+  if (aIn.Channels() != aOut.Channels() && aOut.Channels() > 2) {
+    NS_WARNING(
+        "Only down/upmixing to mono or stereo is supported at this stage");
+    return false;
+  }
+  if (!aOut.Interleaved()) {
+    NS_WARNING("planar audio format not supported");
+    return false;
+  }
+  return true;
+}
+
 bool AudioConverter::CanWorkInPlace() const {
   bool needDownmix = mIn.Channels() > mOut.Channels();
   bool needUpmix = mIn.Channels() < mOut.Channels();
diff --git a/dom/media/AudioConverter.h b/dom/media/AudioConverter.h
index 40e88b664b01..0ace580b26e9 100644
--- a/dom/media/AudioConverter.h
+++ b/dom/media/AudioConverter.h
@@ -233,6 +233,7 @@ class AudioConverter {
   bool CanReorderAudio() const {
     return mIn.Layout().MappingTable(mOut.Layout());
   }
+  static bool CanConvert(const AudioConfig& aIn, const AudioConfig& aOut);
 
   const AudioConfig& InputConfig() const { return mIn; }
   const AudioConfig& OutputConfig() const { return mOut; }
diff --git a/dom/media/mediasink/AudioSink.cpp b/dom/media/mediasink/AudioSink.cpp
index 9097d7b485af..45ee052c3b09 100644
--- a/dom/media/mediasink/AudioSink.cpp
+++ b/dom/media/mediasink/AudioSink.cpp
@@ -398,9 +398,15 @@ void AudioSink::NotifyAudioNeeded() {
           mOutputChannels == data->mChannels
               ? inputLayout
               : AudioConfig::ChannelLayout(mOutputChannels);
-      mConverter = MakeUnique<AudioConverter>(
-          AudioConfig(inputLayout, data->mChannels, data->mRate),
-          AudioConfig(outputLayout, mOutputChannels, mOutputRate));
+      AudioConfig inConfig =
+          AudioConfig(inputLayout, data->mChannels, data->mRate);
+      AudioConfig outConfig =
+          AudioConfig(outputLayout, mOutputChannels, mOutputRate);
+      if (!AudioConverter::CanConvert(inConfig, outConfig)) {
+        mErrored = true;
+        return;
+      }
+      mConverter = MakeUnique<AudioConverter>(inConfig, outConfig);
     }
 
     // See if there's a gap in the audio. If there is, push silence into the