Terminator: The Sarah Connor Chronicles S1 - very long AV sync issue on special feature

[chrominance]

Went back to rip an old copy of Terminator: The Sarah Connor Chronicles Season 1 on Blu-Ray. Disc 3 contains a special extended version of the episode "The Demon Hand." For some reason, attempting to rip this episode using either of my Blu-Ray drives (a Pioneer BDR-212U and an LG BP60NB10) throws an AV sync error. Normally this wouldn't be a big deal, AV sync errors happen all the time, but in this particular case the audio skew is extremely large:

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AV sync issue in stream 1 at 0:05:00.992 with duration of 290.976s : 9093 frame(s) dropped to reduce audio skew to +6ms

Furthermore, the resulting video file is missing audio from almost the beginning of the video until 5:01, which just so happens to be about 291 seconds. (I'm guessing the beginning few seconds of the video is naturally silent, as the video shows a text message explaining the nature of the extended cut.) This AV sync issue happens using both the Default and FLAC profiles on the English stereo track, which is the only audio track for that video. It also happens regardless of whether I try to open the disc as video tracks directly in MakeMKV or make a backup of the entire disc and then open the backup files using MakeMKV.

If I try to play the same episode using the Pioneer drive inside Cyberlink PowerDVD 18, the episode audio plays normally as I'd expect. So it seems like the audio data is on the disc, though I can't say for sure if it's maybe damaged in a way I can't detect with just my ears.

Am I out of luck here or is there a way to recover the missing audio somehow?

[Radiocomms237]

I have TSCC on Blu-ray but it's one of the many (many) titles I haven't gotten around to yet.

If nobody else has any ideas in the next few days, I'll dig it out and see what I can see (assuming it's even the same pressing)?

Only I'm halfway through the Tales From The Crypt franchise at the moment (a dozen-odd movies and two TV series) and I kinda want to finish that before I start any new projects.

[chrominance]

If it helps, I have the US/Canada release (or at least I think so, Blu-Ray.com lists separate releases for US and Canada so they might be different in some meaningful way), UPC 883929025176. It's hard to make out any codes on the disc itself but the ones I was able to pick up are a mould code (engraved on the disc, M2S6) and some kind of disc ID, 2000003929 (printed on the label and faintly visible in both rings on the back). Given the popularity of the show (or lack thereof, sadly) I can't imagine there was a lot of pressings of this, so hopefully that helps us here.

Thanks! No rush, I've only had these sets for a decade so I'm sure a few days won't hurt them. (As an aside, in case it matters, the rest of the disc seems to rip totally fine, though I haven't watched every episode to confirm; at the very least there were no other errors in the log, aside from the usual "forced subtitles track #X turned out to be empty" ones.)

[Radiocomms237]

Just briefly, it appears I have the "Warner Bros." UK release: "The Complete First & Second Season" "All 31 Episodes On 8 Discs".

Mine has "1000103293" above the barcode and "5000072899" below, not sure how that relates to yours.

However, being Warner, they *may* still be the same disc pressings? I'll finish my current project and then I'll get back to you.

[Radiocomms237]

Okay, I just finished ripping season 1 and, although I haven't looked at season 2 yet, the discs I have done are an absolute mess, I've never seen MakeMKV split so many titles on one disc before!

Anyhow, the good news for you (bad news for me) is that my UK release does exactly the same thing on the extended version of S01E07 "The Demon Hand" as does yours...

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AV sync issue in stream 1 at 0:00:10.010 with duration of 290.982s : encountered overlapping frame, audio skew is +290.982s
AV sync issue in stream 1 at 0:05:00.992 with duration of 290.976s : 9093 frame(s) dropped to reduce audio skew to +6ms

If you look at the playlist for that title (00015.mpls assuming yours is the same) you'll see it has two segments of "2,10", which leads us to the problem.

00002.m2ts is the title card displayed at the beginning...



..but this file is all screwed up. Its duration is actually 00:00:10.010000000 but it's indexed at 00:05:00.992000000, so MakeMKV is trying to fit 5 minutes worth of silence into a 10 second slot!

The simple solution (assuming you're working from a decrypted backup) is to navigate to the "STREAMS" folder and rename 00002.m2ts temporarily...



..then fire-up MakeMKV and re-rip 00015.mpls, which will now contain only one segment of "10"

MakeMKV will adjust all the chapters for you (I've confirmed they're still correct) and (fingers crossed) should now rip the title without any audio sync issues whatsoever!

You should then have a working copy of The Demon Hand (Extended), just without the title card at the start.

I will probably add that back in eventually, I think it just needs to be re-encoded to repair the index, then appended (or should that be "prepended") back into the episode... But I don't have time to mess around with that at the moment so I'll just throw all the files together and worry about it later!

[Radiocomms237]

I just had a brainwave... Dropped 00002.m2ts into MKVToolNix and told it to split the output by timecode at 00:00:09.888000000 (which seems to be the next keyframe backwards) and a mux seems to have fixed the index!

Then prepended it to the extended episode, adjusted the chapters by hand (only needed to reset the starting time of "Chapter 00" to zero) and I'm done.

All appears to work and now I'm back where I should've been three hours ago (thanks to Warner Bros and their sloppy workmanship)!

[chrominance]

Oooh, very interesting! I'll give all this a shot and report back, thanks for looking into this!

[chrominance]

Yup, it all works. I used a slightly different method, as I still had the original flawed rip for that particular title so I cut that at the specified timecode instead and spliced that together with the new rip of just segment 10 from my backup, and everything's great! (The audio itself is weird, like it's been panned off to the left in the intro before the episode starts, but I'm chalking that up to the original recording being that way as opposed to a ripping error.)

Thanks again for figuring this out, this is a neat trick and I feel like I've learned a tiny bit more about the structure of Blu-Ray discs now.

[Radiocomms237]

No problemo.

As I said, I had this series in my (seemingly endless) 'to-do' list anyway so I would've had to deal with this screw-up sooner or later.

Yes, as the title card says: "a work in progress with unfinished sound"

I noticed that the audio is terrible in places when I watched random parts of the extended episode checking for sync issues, sometimes it's almost completely inaudible!

Anyhow, hasta la vista, baby!

[organicguy]

@Radiocomms237: This was super helpful, thank you!

For anyone else who comes across this thread (and for myself should I forget this in the future), here are the steps I took to correct this issue:

1. Create an unencrypted backup of the disc using MakeMKV.
2. From your backup root folder, open /BDMV/STREAM/00002.m2ts in the MKVToolNix GUI Multiplexer.
3. In the Output tab, check the "Stop after video track ends" option. This will force the newly muxed 00002.mkv file to have the correct length, bypassing the audio track indexing issue.
4. Click Start Multiplexing to create the new mkv file, and close your current tab in the MKVToolNix GUI Multiplexer. You'll use this file again later.
5. Under your backup root folder, temporarily rename /BDMV/STREAM/00002.m2ts as 00002.m2ts.hidden.
6. In MakeMKV, select File | Open Files..., and select the /BDMV/BACKUP/index.bdmv file under your backup root folder.
7. Unselect all tracks except for the track for the extended Episode 7 (hint: it's the track with the largest file size).
8. Rip the selected track to disc as you normally would with an appropriate name/filename. This will rip the episode without the intro track that you hid in step 5.
9. Now go back to MKVToolNix GUI, in the Multiplexer, and open or drag and drop the file you created in step 4.
10. Once your shortened 00002.mkv file is visible in the multiplexer, right-click it and select "Append files". Browse to the file you created in step 8, and select it.
11. You'll likely need to tweak which tracks are going to be default tracks, and remove the default flag from some tracks that are present in the second file (the one you appended) but not in the first. You can also uncheck some tracks if you don't want them in the final mkv file.
12. Click Start Multiplexing to merge the two files back together into one, leaving you with the rip you wanted in the first place.
13. (Optional) Go back and remove the ".hidden" suffix that you added to the file name in your backup root folder, or just drop the backup if you only wanted it to fix the indexing problem that brought you here in the first place.

Thanks again to @Radiocomms237 who gave enough details above for me to figure this out, learning a lot about features that help deal with such problems should I need to in the future.