Buffering issue & transcoding a 1080p HEVC MKV container (shouldn't it direct play?)

Plex Players Gaming Consoles
1

Server: HP ProLiant MicroServer Gen8 running Windows Server 2012 R2 and PMS 1.10.1.4602
Client: Xbox One (original) ethernet connected to LAN
Movie File: MKV container with HEVC 1080p video and DTS-HD MA 5.1 audio.

I know the Xbox One doesn’t support DTS-HD and so the audio would need to be transcoded, but I thought (based on FAQ - What media formats are supported?) it did support MKV container with HEVC encoded video as so the video could direct play? Or does Audio also need to be in AAC, AC3, ALAC, FLAC, MP3 format to avoid the video being transcoded (i.e. all or nothing?)

I also get significant buffering making watching movie of this encoding unwatchable. Is this expected or does this fall under the umbrella of a lot of the other ‘buffering issues on Xbox One’ posts I’m seeing?

Logs attached for reference.

Content Video/Audio more detailed information:

Video
ID : 1
Format : HEVC
Format/Info : High Efficiency Video Coding
Format profile : Main@L4@Main
Codec ID : V_MPEGH/ISO/HEVC
Duration : 1h 53mn
Bit rate : 7 519 Kbps
Width : 1 920 pixels
Height : 816 pixels
Display aspect ratio : 2.35:1
Frame rate mode : Constant
Frame rate : 23.976 (24000/1001) fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Bits/(Pixel*Frame) : 0.200
Stream size : 5.95 GiB (65%)
Default : Yes
Forced : No
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709

Audio
ID : 2
Format : DTS
Format/Info : Digital Theater Systems
Format profile : MA / Core
Mode : 16
Format settings, Endianness : Big
Codec ID : A_DTS
Duration : 1h 53mn
Bit rate mode : Variable / Constant
Bit rate : 4 032 Kbps / 1 509 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Frame rate : 93.750 fps (512 spf)
Bit depth : 24 bits
Compression mode : Lossless / Lossy
Stream size : 3.19 GiB (35%)
Language : English
Default : No
Forced : No

As a way of comparison (whether valid or not), same file played back fine on my Android tablet (Samsung Galaxy Tab S2) over WiFi and the video stayed in Direct Play:

2

This new app seems to want everything transcoded. Before the October surprise virtually none of my media had to transcode, now it seems everything is being transcoded.

Makes no sense to me since I can go to Xbox Media Player and browse to the movies and play them directly. If Plex really is just piggy backing on the Xbox player why does it want to transcode?

It’s been 4 months and has only gotten worse…

3

Its the audio codec, the new app doesn’t support direct play of any of the HD audio formats.

4

@morpheus2n2 said:
Its the audio codec, the new app doesn’t support direct play of any of the HD audio formats.

I know. That’s why I said in my post “I know the Xbox One doesn’t support DTS-HD” :wink:

What I’m not clear on is whether:

  1. The Xbox One client has the ability to Direct Stream the video and transcode the audio (same as the Android client screenshot in my post) or,
  2. The Xbox One client can only Direct Stream if both audio and video are supported formats, otherwise, BOTH Audio and Video will be transcoded if EITHER is not supported, or
  3. The Xbox One client can Direct Stream either audio or video while the other is transcoded (again, like the Android client example) and the fact that it is not is a BUG.

Hoping a Plex staffer can confirm, and if it is a bug, confirm that and advise what additional data they might like to investigate further (and add to known issues post).

5

Hi there. The answer to your question depends on your Xbox One model. The original Xbox One model does not currently support direct streaming HEVC video, and so if the file cannot be direct played because of the audio track then the HEVC video stream will always be transcoded to H264 during playback. The Xbox One S and Xbox One X support direct streaming HEVC and so it does not matter what the audio track is.

6

@Moussa said:
Hi there. The answer to your question depends on your Xbox One model. The original Xbox One model does not currently support direct streaming HEVC video, and so if the file cannot be direct played because of the audio track then the HEVC video stream will always be transcoded to H264 during playback. The Xbox One S and Xbox One X support direct streaming HEVC and so it does not matter what the audio track is.

Thanks @Moussa, that answers my question.

I was clear to specify in my original post “Client: Xbox One (original)” and it seems that that is the key point.

It also highlights that Support article I referenced (https://support.plex.tv/articles/203824396-what-media-formats-are-supported) is inaccurate as it states that Xbox One does support HEVC direct streaming. It would appear that a caveat about the original Xbox One NOT supporting HEVC needs to be added to that document to make it accurate.

7

The support article lists what codecs are supported for direct play. It is a little misleading in the case of HEVC when it comes to direct streaming. I’ll get that updated with some notes.