Broken libmmbd with libbdplus

[Hen23776]

Hi there,

There is a bug with libmmbd and some disks using bdplus encoding.

First of all, using MakeMkv directly works without issues.

However, any player (VLC, HandBrake...) using libmmbd (or libbdplus emulation) will start receiving garbage after about 20 minutes. It looks like only the first part of the FUT is being applied even though libmmbd thinks it is using the whole table (nothing on the log)

I have only seen this with James Bond movies (1080 BDs), but it looks like all of them do the same, regardless of the version of BD+ encoding.

I reported the issue earlier this year but I guess it was the wrong forum. Also, it looks like I'm not the only one seeing the issue.

I hope this time Mike sees the post

[pikmin_tom]

Hi,

I've only just started to try using libmmbd for direct disc playback in VLC and I've seen exactly the same behaviour with the video starting to be corrupted after 15 or 20 minutes. I don't think I have many BD+ discs but it happens with both of the discs I've tried: Skyfall and Avatar. I have three BD drives, all different models, and it happens with all of them.

I'm running Linux and I've tried with both the most recent v1.18.3 and older v1.17.7 versions of MakeMKV and it happens with both. If I rip the discs directly with MakeMKV then they rip perfectly.

[MrPenguin]

I've only just started to try using libmmbd for direct disc playback in VLC and I've seen exactly the same behaviour with the video starting to be corrupted after 15 or 20 minutes. I don't think I have many BD+ discs but it happens with both of the discs I've tried: Skyfall and Avatar. I have three BD drives, all different models, and it happens with all of them.

Personally, I don't recommend "direct disc playback" because it puts unnecessary wear-and-tear on your drive. And such drives are no longer being manufactured, so are becoming increasingly difficult to replace.

Suppose you create an encrypted back-up of one of these disks, i.e. replicating the contents of the BD on your hard drive: Can VLC play the back-up cleanly? Because if so, maybe there's an occasional glitch in the data stream from the drive over the data bus (USB?), and VLC isn't coping with it successfully? However, a data stream read from a hard drive should be smoother...

[Sayaka]

Personally, I don't recommend "direct disc playback" because it puts unnecessary wear-and-tear on your drive.

Is this true even if you plan on watching a Blu-ray movie only once ? Could anyone please clarify this ? It would take forever to make a backup copy of each disc from my Walking Dead collection (not to mention I believe it would use up a lot of storage space), and once I'm done watching the seasons I missed I am unlikely to have the time needed to go through the whole series again, so I just had to ask - making a backup of each disc just doesn't seem worth it right now.

[Billycar11]

Personally, I don't recommend "direct disc playback" because it puts unnecessary wear-and-tear on your drive.

Is this true even if you plan on watching a Blu-ray movie only once ? Could anyone please clarify this ? It would take forever to make a backup copy of each disc from my Walking Dead collection (not to mention I believe it would use up a lot of storage space), and once I'm done watching the seasons I missed I am unlikely to have the time needed to go through the whole series again, so I just had to ask - making a backup of each disc just doesn't seem worth it right now.

i backed up the whole walking dead its like 2tb
but i used 6 drives at a time to do it