--- a/dom/media/platforms/apple/AppleVTDecoder.cpp
+++ b/dom/media/platforms/apple/AppleVTDecoder.cpp
@@ -356,17 +356,17 @@ AppleVTDecoder::OutputFrame(CVPixelBuffe
   if (useNullSample) {
     data = new NullData(aFrameRef.byte_offset,
                         aFrameRef.composition_timestamp,
                         aFrameRef.duration);
   } else if (mUseSoftwareImages) {
     size_t width = CVPixelBufferGetWidth(aImage);
     size_t height = CVPixelBufferGetHeight(aImage);
     DebugOnly<size_t> planes = CVPixelBufferGetPlaneCount(aImage);
-    MOZ_ASSERT(planes == 2, "Likely not NV12 format and it must be.");
+    MOZ_ASSERT(planes == 3, "Likely not YUV420 format and it must be.");
 
     VideoData::YCbCrBuffer buffer;
 
     // Lock the returned image data.
     CVReturn rv = CVPixelBufferLockBaseAddress(aImage, kCVPixelBufferLock_ReadOnly);
     if (rv != kCVReturnSuccess) {
       NS_ERROR("error locking pixel data");
       MonitorAutoLock mon(mMonitor);
@@ -386,25 +386,25 @@ AppleVTDecoder::OutputFrame(CVPixelBuffe
     buffer.mPlanes[0].mSkip = 0;
     // Cb plane.
     buffer.mPlanes[1].mData =
       static_cast<uint8_t*>(CVPixelBufferGetBaseAddressOfPlane(aImage, 1));
     buffer.mPlanes[1].mStride = CVPixelBufferGetBytesPerRowOfPlane(aImage, 1);
     buffer.mPlanes[1].mWidth = (width+1) / 2;
     buffer.mPlanes[1].mHeight = (height+1) / 2;
     buffer.mPlanes[1].mOffset = 0;
-    buffer.mPlanes[1].mSkip = 1;
+    buffer.mPlanes[1].mSkip = 0;
     // Cr plane.
     buffer.mPlanes[2].mData =
-      static_cast<uint8_t*>(CVPixelBufferGetBaseAddressOfPlane(aImage, 1));
-    buffer.mPlanes[2].mStride = CVPixelBufferGetBytesPerRowOfPlane(aImage, 1);
+      static_cast<uint8_t*>(CVPixelBufferGetBaseAddressOfPlane(aImage, 2));
+    buffer.mPlanes[2].mStride = CVPixelBufferGetBytesPerRowOfPlane(aImage, 2);
     buffer.mPlanes[2].mWidth = (width+1) / 2;
     buffer.mPlanes[2].mHeight = (height+1) / 2;
-    buffer.mPlanes[2].mOffset = 1;
-    buffer.mPlanes[2].mSkip = 1;
+    buffer.mPlanes[2].mOffset = 0;
+    buffer.mPlanes[2].mSkip = 0;
 
     gfx::IntRect visible = gfx::IntRect(0,
                                         0,
                                         mPictureWidth,
                                         mPictureHeight);
 
     // Copy the image data into our own format.
     data =
@@ -597,17 +597,17 @@ AppleVTDecoder::CreateDecoderSpecificati
 }
 
 CFDictionaryRef
 AppleVTDecoder::CreateOutputConfiguration()
 {
   if (mUseSoftwareImages) {
     // Output format type:
     SInt32 PixelFormatTypeValue =
-      kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange;
+      kCVPixelFormatType_420YpCbCr8Planar;
     AutoCFRelease<CFNumberRef> PixelFormatTypeNumber =
       CFNumberCreate(kCFAllocatorDefault,
                      kCFNumberSInt32Type,
                      &PixelFormatTypeValue);
     const void* outputKeys[] = { kCVPixelBufferPixelFormatTypeKey };
     const void* outputValues[] = { PixelFormatTypeNumber };
     static_assert(ArrayLength(outputKeys) == ArrayLength(outputValues),
                   "Non matching keys/values array size");