Audio Issue with Harry Potter Order of the Phoenix "Extra"

[Ravik]

I'm having a bizarre issue ripping just the Deleted Scene extra from the Harry Potter Order of the Phoenix film disc (disc 1). I have not been able to replicate this issue on any other discs or content, but I wanted to report the issue nevertheless.

After opening the disc in MakeMKV (and I use the M2TS integrity verification method exclusively) the extra in question (title_03) appears to contain 12-14 English sound channels (which from what I can tell are all the same). After extraction and immediately upon playback in VLC 2.1.5 the audio stream becomes completely jarbled and incomprehensible. However...what's really weird is that if I switch from the current audio track to one of the alternate audio tracks the sound corrects itself. Furthermore, when I switch back to the previously jarbled audio track it's working again!

So I'm not sure if the issue is related to my disc (which I checked, and it doesn't have a visible scratch on it) or if it's due to a decryption method of MakeMKV 1.8.13 (x64) or if it's a VLC weird-ism or what. Nevertheless, I thought I'd report it here.

Let me know if you'd like me to run any additional tests on it.

Ravik

[Woodstock]

Not sure what you're doing - are you opening the disk and creating MKV files, backing up the disk and playing the m2ts files that result, or are you using MakeMKV as a "Bluray playback library" to decode the disk on the fly for VLC?

If you are converting to MKV, which audio tracks did you select? What did MakeMKV record in the debugging log? MakeMKV will try to make sure the audio tracks are synchronized with the video track, which USUALLY isn't a problem, but can be.

When backing up to m2ts files, what you get is what was in the m2ts files, just without the encryption. The playback issue would be with VLC, and it is possible they have an error in their decoder for the default audio track on the extras. I'd have to dig my copy out of storage to see what is being used.

[Ravik]

My extraction method was to backup the entire disc to my hard-drive so that MakeMKV would cross-check the data against the M2TS hash tables. Once I'd done this, I would load the index.bdmv, select the files I wanted, and save as MKV. This way I knew that the files were being double-checked against the hast tables, since I've had issues in the past with the burst method messing up the beginning of a video.

That said, I failed to capture the log data from earlier, but I'll try it again shortly and hopefully post it here in a few hours.

-Ravik-

[Woodstock]

That is one way to do things, but usually not necessary... Especially if you are not taking all audio/subtitle tracks in the final product. I have tried that a few times, but it always wasted time (compared to my normal work flow), and often gave bad results if ONE file (not necessarily one of the ones I wanted) has a problem, and fails the hash check. That would could cause the whole backup to be flagged as "failed", even though 99% of it was good.

You also have the option of feeding the m2ts files directly to Handbrake, although you did not mention whether you were worried about minimizing the disk space used.

During the backup phase, MakeMKV is not going to do anything to resync video/audio, nor will it convert any audio tracks to other formats. When you play the m2ts files in VLC, do the audio problems exist?

[ndjamena]

I can't reproduce this one.

[Ravik]

@ndjamera: That's at least some confirmation. Thanks for checking.

@woodstock: Yeah, my method is to dump the disc fully (decryption enabled) to disc using the M2TS integrity checks. If I get any errors I simply retry the disc with my secondary drive. I didn't receive any hash check errors, and like I said--the disc has no visible scratches whatsoever. I will try a direct dump later this afternoon to see if that changes anything.

And thus far I've just been keeping all the relevant English tracks only. I don't modify anything in Handbrake, though that method you referred is useful to know about. :)

-Ravik-

[ndjamena]

The only things of note I can see in my MKV of that clip is the NTSC frame-rate on a Blu Ray intended for PAL territory and the presence of my current arch nemesis, the dreaded twin B-frames before the first I-frame. I've tried both bit-streaming to my receiver and native VLC decoding of the AC3 and everything seems fine, but I only have the one disc in my case so maybe yours is a different version.