DTS Audio Forcing Full Transcode on VC-1 MKVs - Xbox One S

[Paul77nz 8]

I have ripped some of my Blu-ray discs using MakeMKV, the video codec is reported as VC1 and they have DTS 5.1 audio; but when I play them Emby Theatre it is doing a full transcode of both the video and audio. The stated reason for the transcoding is "Audio codec not supported".

 

However, if I switch to the commentary track on the same rip (which is in DD 2.0) the file direct plays with no transcoding.

 

Why is Emby transcoding the video stream instead of just the audio?

 

Also, I have several h264 MKVs with DTS 5.1 audio and they all direct stream in Emby Theater - so it seems to be a combination of VC1 with DTS.

Edited April 21, 2018 by Paul77nz

[Luke 37057]

Hi there @@Paul77nz, can you please attach the emby server and ffmpeg log? you can learn how to do that here:

https://emby.media/community/index.php?/topic/739-how-to-report-a-problem/

Thanks.

[Paul77nz 8]

Hi there @@Paul77nz, can you please attach the emby server and ffmpeg log? you can learn how to do that here:

https://emby.media/community/index.php?/topic/739-how-to-report-a-problem/

Thanks.

 

Hi @@Luke,

 

EDITED: to supply better info.

 

Attached are my server log and ffmpeg logs.

 

Tested on the following 4 videos:

 

Game of Thrones - s01e01 - Winter Is Coming.mkv

Video: h264

Audio: DTS

Result: Direct Stream (Remux)

 

Battlestar Galactica - s01e02 - Water.mkv

Video: VC1

Audio: DTS

Result: Transcodes

 

Battlestar Galactica - s01e03 - Bastille Day.mkv

Video: VC1

Audio: DTS-MA

Result: Transcodes

 

Battlestar Galactica - s01e04 - Act of Contrition.mkv

Video: VC1

Audio: DTS and Dolby Digital

Result: Transcodes when DTS audio selected, immediately changes to Direct Play when audio switched to Dolby Digital.

 

Thanks

server-63660003331.txt

ffmpeg-remux-9a615aa3-7b9b-452f-bf88-334f9e6fe7c1.txt

ffmpeg-transcode-96b47825-6118-49a3-8404-8025c9d66c91.txt

ffmpeg-transcode-70ea752f-ad31-4f56-a1cb-d7315876ee31.txt

ffmpeg-transcode-771cafae-f350-4ecb-a8e3-eb89384a0eb3.txt

Edited April 22, 2018 by Paul77nz

[Paul77nz 8]

FYI, same thing happens with Dolby TrueHD audio with VC1 video - forces full transcode.

[Luke 37057]

I will test to confirm but this is likely expected behavior.

 

Anytime a conversion is needed we use the hls streaming protocol. I'm pretty sure vc1 cannot be used with hls and that's why we're also transcoding the video.

[Paul77nz 8]

I will test to confirm but this is likely expected behavior.

 

Anytime a conversion is needed we use the hls streaming protocol. I'm pretty sure vc1 cannot be used with hls and that's why we're also transcoding the video.

 

Thanks @@Luke,

 

I'm not in a position to test at the moment, but will this also mean a full transcode for any VC1 videos with SRT subtitles?

[Luke 37057]

No because we can pull down srt subtitles separately.

[Paul77nz 8]

No because we can pull down srt subtitles separately.

 

Thanks @@Luke, that at least means I don't need to go through the long and painful process of re-encoding everything to h264.

 

I would have preferred if it transoded just the audio on-the-fly, but if that's not possible with VC1 I'll just have to convert all audio to Dolby Digital. However, I'll hold off on starting this until you can confirm that VC1 definitely doesn't support HLS - I don't want to do this and then discover it wasn't required after all!

 

Thanks again for your help.

 

Paul

Edited April 22, 2018 by Paul77nz

[Paul77nz 8]

I will test to confirm but this is likely expected behavior.

 

Anytime a conversion is needed we use the hls streaming protocol. I'm pretty sure vc1 cannot be used with hls and that's why we're also transcoding the video.

 

Hi @@Luke, just wondering if you've had a chance to test and confirm that this is expected behaviour?

 

Thanks

[Luke 37057]

Yes, I tried putting vc1 in the HLS streaming protocol and it would not play.

[Paul77nz 8]

Yes, I tried putting vc1 in the HLS streaming protocol and it would not play.

Thanks @@Luke for confirming. I'll get started converting all my audio to standard AC3!