Sycning a split-title DVD

[Blue_MiSfit]

Hey guys,

I've got to rip Doctor Zhivagio today, and it's a real sucker of a DVD.

It's on a DVD9, but the movie is split into two parts (you tell me why :rolleyes:)

The big problem is that the audio delay is different for both parts -25ms for the first part, and -108ms for the second part.

Doing the video is easy enough, since I can either use AviSynth to link the two D2Vs, or encode separately and join elementary streams with copy /b.

I wasn't sure where to post this, since it's not exactly a decrypting problem, and not exactly an AviSynth problem.

What do you guys think?

~MiSfit

[setarip_old]

Hi!It's on a DVD9, but the movie is split into two parts (you tell me why)Theatre presentation included an intermission?...

Can't you just make two separate .AVIs - and then use VirtualDub to join them?

[Blue_MiSfit]

Indeed. The intermission is exactly the problem here :)

I'm not targeting AVI - I'm targeting x264+AC3 TS (for my employer's set-top box).

Would the same problems not apply in any case? How do you address the audio delay issue?

~MiSfit

[mikeytown2]

How do you address the audio delay issue?

This is my guess DelayAudio() (http://avisynth.org/mediawiki/DelayAudio)

Be sure to use ++ when adding the 2 clips together.

[Blue_MiSfit]

So, I'm going to have to re-encode the audio - huh?

[mikeytown2]

What's the container of the Transport Stream? You might be able to specify something in there???

AviDemux (http://avidemux.sourceforge.net/) might be your ticket out of jail since you don't want to use AVI

[setarip_old]

Would the same problems not apply in any case? How do you address the audio delay issue?Perhaps yes, perhaps not. My preferred tool for converting DVDs to .AVI is MPEGMediator (v.1.5), which seems to address audio delays automatically.

1) I'd suggest you try it, to create two .AVIs (Do NOT delete these initial .AVIs) "1.AVI" and "2.AVI" - and then join them with VirtualDub (Remember to set BOTH "Video" and "Audio" to "Direct Stream Copy") to create "Joined1and2.AVI".

2) If the combined .AVI goes out of synch at the juncture of the two files (and presumably, remains out of synch by the same amount to the end), delete this "Joined1and2.AVI" and then adjust the audio delay (Audio>>Interleaving>>Audio skew correction) of "2.avi" as needed and save as "Adjusted2.AVI"

3) Join "1.AVI" and "Adjusted2.AVI" with VirtualDub (Remember to set BOTH "Video" and "Audio" to "Direct Stream Copy") to create "Joined1and2.AVI".

[Blue_MiSfit]

What's the container of the Transport Stream?


Erm... Transport Stream :) (.TS)

Our proprietary muxer can handle audio delays...

Our encoding front-end produces elementary streams, which I could theoretically pack in AVI - but that sounds evil to me...

I like your idea setarip_old, but I'm not sure if its feasible. I will try it next week ;)

~MiSfit

[neuron2]

I assume the audio in the source is AC3. Demux the audio in two parts. Use DelayCut as needed on them. Then join them. Then mux with your AVC video.

[tebasuna51]

I assume the audio in the source is AC3. Demux the audio in two parts. Use DelayCut as needed on them. Then join them. Then mux with your AVC video.

This is the method. More detailed DelayCut steps:

1) Cut 32 ms (1 ac3 frame) at the begining of first ac3 audio to compensate for the -25 ms delay.

2) Check if the lenght of the new audio match the length of first video. If not, modify the second delay (-108 ms). For instance if first audio is 10 ms short than first video the delay in second part must be only -98 ms.

3) Cut/Add frames at the begining of second audio to compensate the modified delay.

This method guarantee a delay less than +/- 16 ms (half frame)

[Gavino]

I've got to rip Doctor Zhivagio today, and it's a real sucker of a DVD.
That will be the mafia version of Dr Zhivago, I assume? :D

Incidentally, The Godfather Part II also had an intermission when originally shown in cinemas - maybe it has the same problem.
(Sadly, I'm old enough to remember both movies in their original showings.)

[Blue_MiSfit]

Much appreciated, folks. I think the suggestions will result in a resolution!

@ Gavino:

You got me ;)

~MiSfit

[Blue_MiSfit]

Okay I finally got around to trying this out. I've applied the delays with DelayCut, and am encoding the video.

Now, what's the proper way to join AC3s? Can you safely just copy /b ?

~MiSfit

[tebasuna51]

Now, what's the proper way to join AC3s? Can you safely just copy /b ?

You can safely use the copy /b to join ac3 files if the basic parameters are the same:

- Acmod + LFE (num and channel structure)
- Bitrate
- Samplerate

[Blue_MiSfit]

Sweet, all of the above are true (3/2 384kbps 48KHz).

So, I'm encoding two elementary streams (which I will also copy /b), and will then mux with our perl (gasp) TS muxer.

~MiSfit