Bug 1343140 - Output a black frame if Widevine CDM refuses to decode …

…due to losing a key. r=gerald

MozReview-Commit-ID: JQon5f87FSF

dom/media/gmp/widevine-adapter/WidevineVideoDecoder.cpp

@@ -78,7 +78,7 @@ WidevineVideoDecoder::InitDecode(const GMPVideoCodec& aCodecSettings,
     return;
   }
   config.format = kYv12;
-  config.coded_size = Size(aCodecSettings.mWidth, aCodecSettings.mHeight);
+  config.coded_size = mCodedSize = Size(aCodecSettings.mWidth, aCodecSettings.mHeight);
   nsTArray<uint8_t> extraData;
   if (aCodecSpecificLength > 0) {
     // The first byte is the WebRTC packetization mode, which can be ignored.
@@ -128,7 +128,18 @@ WidevineVideoDecoder::Decode(GMPVideoEncodedFrame* aInputFrame,
   aInputFrame->Destroy();
   aInputFrame = nullptr;
 
-  if (rv == kSuccess) {
+  if (rv == kSuccess || rv == kNoKey) {
+    if (rv == kNoKey) {
+      CDM_LOG("NoKey for sample at time=%" PRId64 "!", sample.timestamp);
+      // Somehow our key became unusable. Typically this would happen when
+      // a stream requires output protection, and the configuration changed
+      // such that output protection is no longer available. For example, a
+      // non-compliant monitor was attached. The JS player should notice the
+      // key status changing to "output-restricted", and is supposed to switch
+      // to a stream that doesn't require OP. In order to keep the playback
+      // pipeline rolling, just output a black frame. See bug 1343140.
+      frame.InitToBlack(mCodedSize.width, mCodedSize.height, sample.timestamp);
+    }
     if (!ReturnOutput(frame)) {
       CDM_LOG("WidevineVideoDecoder::Decode() Failed in ReturnOutput()");
       mCallback->Error(GMPDecodeErr);

dom/media/gmp/widevine-adapter/WidevineVideoDecoder.h

@@ -73,6 +73,7 @@ class WidevineVideoDecoder : public GMPVideoDecoder
   // If a reset is being performed. Used to track if ReturnOutput should
   // dump current frame.
   bool mResetInProgress;
+  cdm::Size mCodedSize;
 };
 
 } // namespace mozilla

dom/media/gmp/widevine-adapter/WidevineVideoFrame.cpp

@@ -124,4 +124,31 @@ WidevineVideoFrame::Timestamp() const
   return mTimestamp;
 }
 
+void
+WidevineVideoFrame::InitToBlack(uint32_t aWidth, uint32_t aHeight, int64_t aTimeStamp)
+{
+  SetFormat(VideoFormat::kI420);
+  SetSize(cdm::Size(aWidth, aHeight));
+  size_t ySize = aWidth * aHeight;
+  size_t uSize = ((aWidth + 1) / 2) * ((aHeight + 1) / 2);
+  WidevineBuffer* buffer = new WidevineBuffer(ySize + uSize);
+  // Black in YCbCr is (0,128,128).
+  memset(buffer->Data(), 0, ySize);
+  memset(buffer->Data() + ySize, 128, uSize);
+  if (mBuffer) {
+    mBuffer->Destroy();
+    mBuffer = nullptr;
+  }
+  SetFrameBuffer(buffer);
+  SetPlaneOffset(VideoFrame::kYPlane, 0);
+  SetStride(VideoFrame::kYPlane, aWidth);
+  // Note: U and V planes are stored at the same place in order to
+  // save memory since their contents are the same.
+  SetPlaneOffset(VideoFrame::kUPlane, ySize);
+  SetStride(VideoFrame::kUPlane, (aWidth + 1) / 2);
+  SetPlaneOffset(VideoFrame::kVPlane, ySize);
+  SetStride(VideoFrame::kVPlane, (aWidth + 1) / 2);
+  SetTimestamp(aTimeStamp);
+}
+
 } // namespace mozilla

dom/media/gmp/widevine-adapter/WidevineVideoFrame.h

@@ -36,6 +36,8 @@ class WidevineVideoFrame : public cdm::VideoFrame {
   void SetTimestamp(int64_t aTimestamp) override;
   int64_t Timestamp() const override;
 
+  void InitToBlack(uint32_t aWidth, uint32_t aHeight, int64_t aTimeStamp);
+
 protected:
   cdm::VideoFormat mFormat;
   cdm::Size mSize;