Exception in libmkv_trace

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JVoorhees13
Posts: 2
Joined: Wed Jun 30, 2021 11:04 am

Exception in libmkv_trace

Post by JVoorhees13 »

So I got an error while reading a disc, it's brand new out of the shrink wrap, and the drive has very little use on it.

I've narrowed it down to a combination of disc mastering errors and a possible bug in makemkv. The disc reads fine in ImgBurn in iso read mode with no errors.

The closest I got to a playable file is using the disc backup in makemkv with decryption turned on, but it's not ideal as there is no metadata or chapters in those output files.

One file has a few missing frames in the audio which goes out of sync in one spot, which I can live with since it has two audio tracks; but the other file causes an exception and the output is 0 bytes.

I've attached logs of three different attempts, each in a different mode. The disc backup with decryption turned on had no errors, so I didn't bother adding that log. Ignore the warnings about drive speed, I was using an external usb3 harddrive but the motherboard only has usb2 on it.
Attachments
MakeMKV_log-single_title_to_mkv.txt
(29.38 KiB) Downloaded 195 times
MakeMKV_log-encrypted_files_to_mkv.txt
(73.69 KiB) Downloaded 196 times
MakeMKV_log-decrypted_files_to_mkv.txt
(63.37 KiB) Downloaded 193 times
dcoke22
Posts: 2560
Joined: Wed Jul 22, 2020 11:25 pm

Re: Exception in libmkv_trace

Post by dcoke22 »

If MakeMKV made a decrypted disc backup cleanly without errors, then that would indicate that it could read the optical disc correctly.

The single title to mkv log indicates that it failed to save title 14, which according to the log is : 003307:0000 File 00017.m2ts was added as title #14

A player like MPV (https://mpv.io) or VLC should be able to play 00017.m2ts directly so can see if that file is indeed corrupt. Look in <backup_name>\BDMV\STREAM for all the .m2ts files.

The thing that is likely the one you want to rip is probably one of the titles from a .mpls, not from the .m2ts files. This is an oversimplification but .m2ts files are just video files. A .mpls file is a playlist of video files.
JVoorhees13
Posts: 2
Joined: Wed Jun 30, 2021 11:04 am

Re: Exception in libmkv_trace

Post by JVoorhees13 »

00017.m2ts plays from start to finish in VLC, and I did see one little hiccup. There is a narrow horizontal stripe near the top of the video which shifts left for about a quarter second.

00006.m2ts plays fine, but the DTS-HD track does skip a second later than the position makemkv reports, so this audio track can't be saved (unless I can convert it to FLAC and insert the missing bit from the Dolby track and volume normalize it, but we'll see. I might leave it as is). At least the Dolby Stereo track is intact and doesn't skip.

Makemkv just ticked all boxes by default, so that's what I ripped first. After the error showed up, I did the single title log.

Out of interest, I transcoded both files with ffmpeg, and 00006.m2ts showed no errors.

00017.m2ts showed this single error:
[h264 @ 000001d80e7dc880] concealing 2075 DC, 2075 AC, 2075 MV errors in B frames
00017.m2ts: corrupt decoded frame in stream 0

So yeah, I guess this is a mastering issue, and makemkv can't handle this particular case yet and throws an exception. I'm not too worried though, both titles are extras on the disc. The main titles are 100% fine, which is really what I wanted.

Nevermind, I'll just manually make an mkv for that title. I was considering converting these to AV1 to save space and utilize it's aggressive denoising filter as there is a fair amount of noise in all of them.
mike admin
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Re: Exception in libmkv_trace

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