From bf28a582ea5e7ad3a9aa12abe68f25ee6e80e0c8 Mon Sep 17 00:00:00 2001
From: Jean-Yves Avenard <jyavenard@mozilla.com>
Date: Thu, 29 Oct 2015 00:46:31 +1100
Subject: [PATCH] Bug 1195094: P2. Ensure TrackInfo object passed to
 constructor is never modified. r=cpearce

The PDM documentation states that it is safe to keep a reference to the TrackInfo object provided to the constructor.

However, this wasn't enforced by the H264Converter which would modify the object and worse, did in a non thread-safe fashion
---
 dom/media/platforms/PlatformDecoderModule.h    | 2 ++
 dom/media/platforms/wrappers/H264Converter.cpp | 3 ++-
 dom/media/platforms/wrappers/H264Converter.h   | 1 +
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/dom/media/platforms/PlatformDecoderModule.h b/dom/media/platforms/PlatformDecoderModule.h
index 46d3ecde8ed..9ce212a4f4a 100644
--- a/dom/media/platforms/PlatformDecoderModule.h
+++ b/dom/media/platforms/PlatformDecoderModule.h
@@ -214,6 +214,8 @@ public:
   // that the format of the next input sample is about to change.
   // If video decoder, aConfig will be a VideoInfo object.
   // If audio decoder, aConfig will be a AudioInfo object.
+  // It is not safe to store a reference to this object and the decoder must
+  // make a copy.
   virtual nsresult ConfigurationChanged(const TrackInfo& aConfig)
   {
     return NS_OK;
diff --git a/dom/media/platforms/wrappers/H264Converter.cpp b/dom/media/platforms/wrappers/H264Converter.cpp
index 4afdd44f851..104c3c92fc8 100644
--- a/dom/media/platforms/wrappers/H264Converter.cpp
+++ b/dom/media/platforms/wrappers/H264Converter.cpp
@@ -22,6 +22,7 @@ H264Converter::H264Converter(PlatformDecoderModule* aPDM,
                              FlushableTaskQueue* aVideoTaskQueue,
                              MediaDataDecoderCallback* aCallback)
   : mPDM(aPDM)
+  , mOriginalConfig(aConfig)
   , mCurrentConfig(aConfig)
   , mLayersBackend(aLayersBackend)
   , mImageContainer(aImageContainer)
@@ -139,7 +140,7 @@ H264Converter::CreateDecoder()
   }
   UpdateConfigFromExtraData(mCurrentConfig.mExtraData);
 
-  mDecoder = mPDM->CreateVideoDecoder(mCurrentConfig,
+  mDecoder = mPDM->CreateVideoDecoder(mNeedAVCC ? mCurrentConfig : mOriginalConfig,
                                       mLayersBackend,
                                       mImageContainer,
                                       mVideoTaskQueue,
diff --git a/dom/media/platforms/wrappers/H264Converter.h b/dom/media/platforms/wrappers/H264Converter.h
index 132a3f8e9dc..bba2ac6349f 100644
--- a/dom/media/platforms/wrappers/H264Converter.h
+++ b/dom/media/platforms/wrappers/H264Converter.h
@@ -53,6 +53,7 @@ private:
   void OnDecoderInitFailed(MediaDataDecoder::DecoderFailureReason aReason);
 
   RefPtr<PlatformDecoderModule> mPDM;
+  const VideoInfo& mOriginalConfig;
   VideoInfo mCurrentConfig;
   layers::LayersBackend mLayersBackend;
   RefPtr<layers::ImageContainer> mImageContainer;