Spotty support for UHD/4K 2160p60 video in MediaTranscoder?

Adam Zofware 76

I'm trying to use MediaTranscoder to transcode UHD 2160p60 (aka 4K at 60 frames per second) video files. I've had good success transcoding from 2160p60 to 2160p30 (30 frames per second) on two devices I have: a Surface Pro LTE with a Core i5 CPU from 2018 and a desktop gaming machine with an Intel i7-5960X processor and an Nvidia GTX 980 Ti GPU.

Unfortunately, I've had less success transcoding from 2160p60 to lower bitrate 2160p60. It works fine on the Surface Pro but fails on the desktop machine. In that case MediaTranscoder.PrepareFileTranscodeAsync returns CanTranscode==false and FailureReason==Unknown. Based on the modules being loaded as shown in the debugger, I think MediaTranscoder is trying to use Nvidia's NVENC to transcode the file. NVENC for my GPU is supposed to support 2160p60 so I don't know why this fails.

Is 2160p60 output officially supported by MediaTranscoder? It seems to work on devices with Intel integrated GPUs with Quick Sync Video but not on devices with Nvidia discrete GPUs.

Thanks!

Roy Li - MSFT 32,231 Reputation points Microsoft Vendor

2020-05-01T02:28:57.717+00:00

Interesting question.

Could you please tell me the format that you are trying to convert?
Adam Zofware 76 Reputation points

2020-05-01T02:53:48.03+00:00

Additional detail: Transcoding to MP4/h.264 at 2160p60 is what fails. Interestingly, transcoding to MP4/h.265 at 2160p60 succeeds.
Roy Li - MSFT 32,231 Reputation points Microsoft Vendor

2020-05-04T08:10:13.437+00:00

One thing that I want to know is which method you chose when you are creating MediaEncodingProfile? CreateMp4 or CreateHevc? And the same process works in Surface Pro but failed on desktop machine?

Adam Zofware 76

I have used both CreateMp4 and CreateHevc.

For example, this profile results in a failed transcode on my desktop machine but succeeds on my Surface Pro:

 // create UHD 2160p profile at 59.94 frames per second using H.264
 var profile = MediaEncodingProfile.CreateMp4(VideoEncodingQuality.Uhd2160p);
 profile.Video.FrameRate.Numerator = 60000;
 profile.Video.FrameRate.Denominator = 1001;

On the other hand, this profile results in a successful transcode on both machines:

 // create UHD 2160p profile at 59.94 frames per second using H.265/HEVC
 var profile = MediaEncodingProfile.CreateHevc(VideoEncodingQuality.Uhd2160p);
 profile.Video.FrameRate.Numerator = 60000;
 profile.Video.FrameRate.Denominator = 1001;

A fairly easy way to test these is by hacking the MediaTranscoding sample from Microsoft on GitHub.

Adam Zofware 76 Reputation points

2020-05-18T23:56:26.453+00:00
I captured a trace with WPR and it showed one thing that might be a clue:

EventName: Microsoft-Windows-Runtime-Media/WinRTTranscode_PrepareTranscode_Task/Stop Payload: ErrorCode="-1,072,861,856" FormattedMessage="PrepareTranscode operation 0x29ed6283fe0{Object} ended. -1,072,861,856{ErrorCode} "

That error code happens to be MF_E_TRANSFORM_TYPE_NOT_SET. The Media Foundation doc page for the H.264 encoder says this:

The output type must be set before the input type. Until the output type is set, the encoder's IMFTransform::SetInputType method returns MF_E_TRANSFORM_TYPE_NOT_SET.

So maybe there's a bug in how the OS sets up the graph when transcoding to 59.94 fps.