--- a/dom/media/platforms/wrappers/H264Converter.cpp
+++ b/dom/media/platforms/wrappers/H264Converter.cpp
@@ -50,17 +50,18 @@ H264Converter::Init()
 }
 
 void
 H264Converter::Input(MediaRawData* aSample)
 {
   if (!mp4_demuxer::AnnexB::ConvertSampleToAVCC(aSample)) {
     // We need AVCC content to be able to later parse the SPS.
     // This is a no-op if the data is already AVCC.
-    mCallback->Error(MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR, __func__));
+    mCallback->Error(MediaResult(NS_ERROR_OUT_OF_MEMORY,
+                                 RESULT_DETAIL("ConvertSampleToAVCC")));
     return;
   }
 
   if (mInitPromiseRequest.Exists()) {
     if (mNeedKeyframe) {
       if (!aSample->mKeyframe) {
         // Frames dropped, we need a new one.
         mCallback->InputExhausted();
@@ -83,28 +84,31 @@ H264Converter::Input(MediaRawData* aSamp
       // Ignore for the time being, the MediaRawData will be dropped.
       mCallback->InputExhausted();
       return;
     }
   } else {
     rv = CheckForSPSChange(aSample);
   }
   if (NS_FAILED(rv)) {
-    mCallback->Error(MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR, __func__));
+    mCallback->Error(
+      MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR,
+                  RESULT_DETAIL("Unable to create H264 decoder")));
     return;
   }
 
   if (mNeedKeyframe && !aSample->mKeyframe) {
     mCallback->InputExhausted();
     return;
   }
 
   if (!mNeedAVCC &&
       !mp4_demuxer::AnnexB::ConvertSampleToAnnexB(aSample)) {
-    mCallback->Error(MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR, __func__));
+    mCallback->Error(MediaResult(NS_ERROR_OUT_OF_MEMORY,
+                                 RESULT_DETAIL("ConvertSampleToAnnexB")));
     return;
   }
 
   mNeedKeyframe = false;
 
   aSample->mExtraData = mCurrentConfig.mExtraData;
 
   mDecoder->Input(aSample);
@@ -257,18 +261,19 @@ H264Converter::OnDecoderInitDone(const T
   }
   mMediaRawSamples.Clear();
 }
 
 void
 H264Converter::OnDecoderInitFailed(MediaResult aError)
 {
   mInitPromiseRequest.Complete();
-  mCallback->Error(MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR,
-                                    __func__));
+  mCallback->Error(
+    MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR,
+                RESULT_DETAIL("Unable to initialize H264 decoder")));
 }
 
 nsresult
 H264Converter::CheckForSPSChange(MediaRawData* aSample)
 {
   RefPtr<MediaByteBuffer> extra_data =
     mp4_demuxer::AnnexB::ExtractExtraData(aSample);
   if (!mp4_demuxer::AnnexB::HasSPS(extra_data) ||