MediaEncodingProfile.CreateHevc(VideoEncodingQuality.Auto)

Hong 1,211

I followed the official instructions to transcode media files, so let me avoid copying all the code here. If I use the following:

MediaEncodingProfile profile = MediaEncodingProfile.CreateMp4(VideoEncodingQuality.Auto);

Everything works flawlessly - the app can transcode both any H.264 and H.265 file to an MP4 file with H.264 encoding.

However, if I use the following:

MediaEncodingProfile profile = MediaEncodingProfile.CreateHevc(VideoEncodingQuality.Auto);  
...  
PrepareTranscodeResult prepareOp = await  
                                            transcoder.PrepareFileTranscodeAsync(sourcefile, destinationfile, profile);

prepareOp.CanTranscode is false and prepareOp. FailureReason is "Unknown".

Could anyone offer a tip on how to diagnose this?

Roy Li - MSFT 32,921 Reputation points Microsoft Vendor

2022-09-19T03:05:38.017+00:00

Are you using the same code from the document and is the destinationfile a .HEVC file? I made a simple test following the document. The prepareOp.CanTranscode shows true. I'm testing on a Windows 11 device. Are you testing on Windows 11?
Hong 1,211 Reputation points

2022-09-20T02:34:24.537+00:00

Thank you very much for your help. I should have stated that I was transcoding fragmented MP4. If you do not mind, could you try this sample fragmented MP4?
Yes, I am testing on a Windows 11 PC.
Roy Li - MSFT 32,921 Reputation points Microsoft Vendor

2022-09-20T06:38:45.91+00:00

I could reproduce the behavior when using that fragmented MP4 file. I'll consult other engineers to check if this kind of files are supported for transcoding.
Hong 1,211 Reputation points

2022-09-20T10:24:10.563+00:00

Thanks a lot for the test. I assume CreateMp4 works fine with this fragmented MP4 on your side too.
Roy Li - MSFT 32,921 Reputation points Microsoft Vendor

2022-09-21T05:56:46.81+00:00

No, actually when using the fragmented MP4 file, no matter the profile is CreateHevc or CreateMp4, the CanTranscode is always false. I've told the team about this and now trying to find other media engineers to take a look at this.

Hong 1,211

Thank you for the test. CreateMp4 works here.

    MediaEncodingProfile profile = MediaEncodingProfile.CreateMp4(VideoEncodingQuality.Auto);  
    MediaTranscoder transcoder = new MediaTranscoder();  
    PrepareTranscodeResult prepareOp = await  
        transcoder.PrepareFileTranscodeAsync(_sfRecordingFile, sfMP4Regular, profile);  
    if (prepareOp.CanTranscode)  
    {  
        var transcodeOp = prepareOp.TranscodeAsync();  
        ...

However, it generates IDR frame only MP4 file, so the final MP4 is extraordinarily large. For example, a 4MB H.265 MP4 file would be transcoded to a 400MB H.264 MP4 file.

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MediaEncodingProfile.CreateHevc(VideoEncodingQuality.Auto)

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