concerned about file integrity

[grandpixel]

So I've been busy ripping my collection. I have about 700 discs on my NAS now. I haven't watched too many of them yet. I watched one the other day and noticed there is some glitches in the video. I thought maybe it's just my monitor, or hdcp issues, or hdmi issues, or something like that, so I didn't think much of it. I watched another movie the other day. There was some more glitching. There is one spot where it was very obvious. I rewind and it glitches in the same spot every time, which tells me it's more likely a Plex issue or a file issue. When I play it with VLC it glitches in the same spot, which tells me it's most likely an issue with the file, or if not that, it would be the same glitch on the disc as well. I haven't tried playing back from the disc yet, but this gives me cause for concern that I can't trust the mkv file integrity of my entire collection. I guess I need to figure out what's going on but not sure where to start. Any ideas?

[Billycar11]

More likely a decoder issue or a bandwidth limitation

[Woodstock]

Bitrot is possible, but rarely problematic. Bandwidth issues are more likely to cause glitches, and they'll appear at spots that have a lot of change. It's not just the bandwidth of the network connection, but the bandwidth of the decoder.

Is Plex re-encoding the file for playback? That can be a factor, too.

Test of file integrity is to copy the file to a local drive, then play it in VLC with nothing else running. If it still glitches in the same spot, it makes it more likely to be a file problem. No glitches, you have something in the pathway causing the video decoding to fall behind.

[grandpixel]

Well, it's streaming the file from the NAS with a 2.5Gb lan connection, so I don't think it's bandwidth. But I can copy to local to be sure. It is the same glitch in the same spot every time regardless if I play with Plex or VLC.

[grandpixel]

It does the same thing playing from a local drive, playing the file with VLC. So what does that mean? I guess I check the disc next and if the problem is on the disc then my collection is safe. If the problem isn't on the disc then I may have errors in all my mkv's?

[grandpixel]

By the way this is happening with Aladdin (2019) at 29:35 right as she says "cat" and Jasmine turns her head, her face shows significant glitching. Does this happen for anyone else?

[Billycar11]

What device or devices is this happening on try another?

[grandpixel]

Streaming via Plex on my iPhone 13, the first time it got to the spot, the screen flashed white. After that, it would show a similar glitch but it was different than what happens on my PC. Still glitches near her face, but just a different pattern. Pretty sure it's transcoding on the server when streaming to my phone.