Some MKVs won't playback, but others will - same settings

[alpa010]

Firstly, I'm new here, apologies if this has been asked a thousand times before. I didn't find the answer with a search, but I'm always happy to be pointed the right way

Anyhow. Happy registered user of Makemkv, great piece of software. I have a weird issue that I can reproduce but not account for, so I am turning to this group for help...

• I have a Windows fileserver which houses my MKV files.
• I stream the files over my wireless LAN (Netgear ORBI) to my laptop or Android TV.
• On my laptop, all the files play fine.
• On my Android TV, most play fine, including all DVDs, but some Blu Rays don't. The audio is fine, but the video plays perhaps one frame every few seconds, with grey blocks appearing from time to time.
• Not all Blu Rays are affected. And some higher bitrate files seem fine, while others don't.
• I converted several MKVs today. One of the Blu Rays worked fine, one did not. Exactly the same settings and LAN setup, etc.
• I have tried two players on the TV: VLC and Kodi. The same files have the same problems in either player (exactly how the issues manifest is a bit different, though).
• My current guess is that the Android TV's network connection is insufficient to handle the streaming. I've tried increasing the buffer in the players; this has no effect.
• I guess I could put the affected files on a USB flash drive, plug into the TV, and see if that works OK... that will be my next step.
• Meanwhile I am really happy to hear from anyone who might have a clue as to what is going on? What metadata should I be looking at with regards to the MKV files themselves?

I bow to your masterful knowledge of all things MKV

[preserve]

Since all play fine on your laptop - same experience on my side, I’ve never had a playback issue - it sounds as if your Android TV and the players there (VLC for one) are your problem, even if some MKVs do play correctly. I’m guessing the artifacts you’re seeing may look something like the screenshots here and here... or perhaps on a smaller scale, with parts of the image temporarily becoming “corrupted” and then clearing up - this in particular can be a VLC issue.

Not very helpful as to the exact issue I know, but hopefully some others can chime in on that. Just wanted to assure you that the MKVs themselves shouldn’t be at fault.

[dcoke22]

I think you guessed correctly that the network connection is probably the issue. Can you (temporarily at least) connect it via ethernet? I know that having it wired might not be a suitable long term solution, but in the short term, it can help prove the theory that the network is the limiting factor.

Is your fileserver connected to your network via ethernet?

Have you considered transcoding your blu-ray .mkv files to something smaller? If you prove that the network is the limiting factor and are unable to make network improvements, then reducing the size of your files might be the next best option.

[alpa010]

Thanks, both! Really appreciate the input.

So I checked, and the TV is wired (Ethernet), and so is the fileserver. For what it's worth I also tried the TV WiFi connection... no change / same issue.

I captured an example of what I am seeing in terms of artifacts - in the attachment posted here.

I am now wondering if the TV CPU can't cope with the decoding load, or something like that? Since the issue happens with two different players. But again, I'm really just guessing.

I will try putting the file on a USB stick next, to completely rule out network issues.

[alpa010]

I did the USB test. With the same movie that gives the grey blocks over the network, loaded onto a high-speed USB stick plugged into the TV, I get a very jerky 1-2fps playback with Kodi reading from the local USB filesystem. Not watchable.

So... is my conclusion that the TV (a Sony Bravia) isn't up to the task?

In which case, I have to transcode to some lesser resolution or higher compression rate or something?

Thanks once again for the advice.

[dcoke22]

I don't have any experience with Sony Bravia TVs, but it is possible that the TV's CPU is having trouble decoding a blu-ray rip I suppose. Do you have any streaming boxes you could try? An Apple TV, a Roku, a Fire stick, Chromecast, etc.?

Handbrake is a good place to start for the transcoding route: https://handbrake.fr Making a h.264 file from a ripped blu-ray can take a little while depending on the hardware you have. For testing, if you have something with hardware encoding (like a modern Nvidia GPU, an Intel CPU with Quick Sync Video, or a Mac that isn't too old), you can dramatically speed up the process.

[alpa010]

That's a good idea to try on Apple TV... that's going to be my next move. Thanks!

[alpa010]

OK, that was a great suggestion. The affected MKVs play just fine on VLC on my ATV4. I don't even need to convert them to any other format, or re-encode. THANKS for the idea!

Conclusion (such as it is) - the Sony Bravia lacks the capabilities to play high-bitrate MKV files. Is that an issue with the video player implementations on that Android platform, or a limitation of the TV's processing capabilities? Who knows.

The MKV files themselves are fine, though.

Appreciate the input and support, thank you!