Z9X Won't Play this file

I have a number of mkv files that won't play on the Z9X with the latest firmware. The files don't play on my OPPO-203 either but they play on a PC with VLC.. They are h265 10 bit encoded. I think I need to convert them to h264 and I have worked out some scripts for ffmpeg, but I would like to know why they don't play.
Here's a Mediainfo report:

General
Unique ID : 209013840476657221744116299077992212977 (0x9D3E99F66F26216FBD70AEA26B2E69F1)
Complete name : C:\Users\ (deleted) ----.mkv
Format : Matroska
Format version : Version 4
File size : 225 MiB
Duration : 1 h 15 min
Overall bit rate : 413 kb/s
Encoded date : UTC 2017-03-07 20:21:57
Writing application : mkvmerge v9.2.0 ('Photograph') 64bit
Writing library : libebml v1.3.3 + libmatroska v1.4.4
Encoder application : Internet Friendly Media Encoder
library : Nemu 7

Video
ID : 1
Format : HEVC
Format/Info : High Efficiency Video Coding
Format profile : Format Range@L3.1@Main
Codec ID : V_MPEGH/ISO/HEVC
Duration : 1 h 15 min
Width : 960 pixels
Height : 720 pixels
Display aspect ratio : 4:3
Frame rate mode : Constant
Frame rate : 23.976 (23976/1000) FPS
Chroma subsampling : 4:4:4
Bit depth : 10 bits
Writing library : x265 1.9+3-548a45bbf223:[Windows][GCC 5.2.0][64 bit] 10bit
Encoding settings : wpp / ctu=64 / min-cu-size=8 / max-tu-size=32 / tu-intra-depth=1 / tu-inter-depth=1 / me=1 / subme=2 / merange=57 / no-rect / no-amp / max-merge=2 / temporal-mvp / no-early-skip / rdpenalty=0 / no-tskip / no-tskip-fast / strong-intra-smoothing / no-lossless / no-cu-lossless / no-constrained-intra / no-fast-intra / open-gop / no-temporal-layers / interlace=0 / keyint=250 / min-keyint=23 / scenecut=40 / rc-lookahead=20 / lookahead-slices=4 / bframes=4 / bframe-bias=0 / b-adapt=2 / ref=3 / limit-refs=0 / no-limit-modes / weightp / no-weightb / aq-mode=1 / qg-size=32 / aq-strength=0.00 / cbqpoffs=0 / crqpoffs=0 / rd=3 / psy-rd=0.00 / rdoq-level=0 / psy-rdoq=0.00 / no-rd-refine / signhide / deblock / sao / no-sao-non-deblock / b-pyramid / cutree / no-intra-refresh / rc=crf / crf=26.0 / qcomp=0.60 / qpmin=0 / qpmax=51 / qpstep=4 / ipratio=1.40 / pbratio=1.30
Language : English
Default : Yes
Forced : No
Duration_Source : General_Duration

Audio
ID : 2
Format : AAC LC SBR
Format/Info : Advanced Audio Codec Low Complexity with Spectral Band Replication
Commercial name : HE-AAC
Format settings : Explicit
Codec ID : A_AAC-2
Duration : 1 h 15 min
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 44.1 kHz
Frame rate : 21.533 FPS (2048 SPF)
Compression mode : Lossy
Delay relative to video : 33 ms
Language : English
Default : Yes
Forced : No
Duration_Source : General_Duration

Thanks for any insight. Not looking forward to converting 20 GB of these files.

 

The frame rate is oddly defined.

Frame rate : 23.976 (23976/1000) FPS

Since it's not an integer it should read:

Frame rate : 23.976 (24000/1001) FPS

What does it say for "Default Duration" in the video section of the Header? (use Header editor in MKVToolnix)

 

There is no "Default Duration" item listed. Now I'm using V 43.0.0 if that makes any difference.
I tried remuxing by setting the Default Duration/fps to Frame rate : 23.976 (24000/1001) FPS, resulting file does not play.
Now, I'm still an amateur with these files but I'm learning as I go.

 

Can't see anything else odd in there - the encoding level (3.1) fits with the resolution and framerate so it's not that.

 

If there's nothing obvious then I'll plan on converting the files to h264.

 

I’ve found, on a different media box, simply remuxing with mkvtoolnix will fix the problem. Doesn’t reveal why but it has worked for me consistently over the years.

 

I will do some more experimentation before I do total recodes.

 

MKVToolNix can do bulk mode remuxes and I would try one file to see if it works. The process takes about 3 to 10 minutes depending on the speed of your PC or MAC.

 

There might be a time code discontinuity on the file caused by either a download glitch or if from a UHD or Blu ray source the playback device.

 

There are a few dozen files in that group, all of them seem to have the same problem. I will try some remux on my sample file.

 

Do the same, but also with "Fix bitstream timing info" checked. If the timecodes in the elementary videostream are flawed, they will be repaired. See if it helps.

 

Tried that, didn't help. Haven't had time to try anything else with it. Thanks.

 

Maybe the Zidoo can't demux/decode video with no chroma subsampling (4:4:4) ?
I never tried, actually.

 

Well spotted! Didn't see that.

 

Thanks Mark.

If the non chroma subsampling is the culprit indeed, I see no reason to recode with another codec.

 

What would be a ffmpeg command line to fix this without recoding?

 

No it definitely needs re-encoding - colour subsampling is a pretty fundamental change.

I've never tried it, but I'd expect Staxrip and the like would downsample to 4:2:0 if you re-encode. If you want to upload say a 5 minute sample somewhere I'd be interested to see.

 

I'm not sure if I could make a five minute sample without re-encoding.
I never tried Staxrip but Vidcoder re-encodes it and the resultant file plays. I could also use ffmpeg in a batch file but I'm not quite sure of the proper parameters although the result will play. I've tried:

for %%f in (*.mkv) do ffmpeg -i "%%f" -map 0 -c copy -c:v libx264 -vf format=yuv420p -profile:v high -level:v 4.0 -crf 18 -preset medium h264vids\%%f.mkv

but I'm not sure the profile and level are appropriate. Any advice on that?

 

MKVToolnix allows you to split by size or time etc - I'd set it to split by a duration of 600s say.

I'd use High Profile and the original file is Level 3.1 although specifying a higher level is fine since it's a ceiling not an absolute value.

So the resultant files that play - can you give us a MediaInfo output?

Staxrip is great and I use it with hardware (Nvidia) encoding so it'll do a 4K encode in about an hour or less and a 2K encode in minutes to a very high standard. I use it with remux stuff I've watched and am not particularly precious about to save disc space.

 

I could have been more clear, my apologies. I indeed meant that using another codec for the recoding process wasn't necessary. I would not know the ffmpeg script for converting to 4:2:0 subsampling.