Login

2017-12-09, 12:25 AM

I got a few Cinema DTS discs and on one of them, in each file after precisely 2 minutes a locomotive-like noise comes in, garbling the audio and making it unusable.

Any idea what this might be?

It does not occur in the trailers-file, only in the main files.

Update: Here's a short example of what I mean: https://www.sendspace.com/file/qzmk1y

~~Jetrell Fo~~ · (This post was last modified: 2017-12-10, 04:28 PM by Jetrell Fo.)

That is not a locomotive noise, it is a fast forward/skipping audio noise. Are the audio files .aue as I suspect they are? If so, they aren't decoding due to the protection on those discs.

2017-12-11, 02:25 AM

The files were .apx files. I renamed them to .aud. The first 2 minutes always decode fine, afterwards it's all full of this. You think anything can be done about it? I googled and the movie is from 2011, so you may just be right about the encryption.

~~Jetrell Fo~~ · (This post was last modified: 2017-12-11, 02:39 AM by Jetrell Fo.)

Tom, what film is it? We may have to find a way to do this.

Smile

From the Film-Tech Forums:

I think APX was the file format for a disc watermarking system that was being tested back then. The discs were individually watermarked, so that if there was a pirated copy of a movie that surfaced on the internet, and the audio was captured from a DTS disc (either by recording in the auditorium or tapping the analog output), a forensics team would be able to identify which disc was used on that playback.

It was pretty cool technology, but in the end cost prohibitive and never saw a rollout.

2017-12-11, 02:52 AM

It should be Kung Fu Panda 2. It's definitely some Kung Fu Panda going by the first 2 minutes of the reels, but I don't know the movies enough to verify whether it's part 2.

Interesting. Though I doubt this noise is purely watermarking, as it is .... fairly audible. Big Grin

Fairly strongly audible.

~~Jetrell Fo~~ · 2017-12-11, 09:53 PM

(2017-12-11, 02:52 AM)TomArrow Wrote: It should be Kung Fu Panda 2. It's definitely some Kung Fu Panda going by the first 2 minutes of the reels, but I don't know the movies enough to verify whether it's part 2.

Interesting. Though I doubt this noise is purely watermarking, as it is .... fairly audible. Fairly strongly audible.

If you want to send me the audio via WeTransfer I can check it out.

2017-12-12, 02:30 AM

Okay, I'll do that when I feel a bit less lazy!

Login
Username:
Password:	Lost Password?
	Remember me

Possibly Related Threads…
Thread		Author	Replies	Views	Last Post
	Cinema DTS - main thread	spoRv	43	42,400	2023-03-08, 11:05 AM Last Post: 2001CluelessDianogas
	CDS (Cinema Digital Sound) system overview	spoRv	21	10,930	2022-12-20, 02:10 PM Last Post: dvdmike
	Why are cinema surround speakers set to -3Db?	Turisu	6	3,054	2021-10-04, 12:26 AM Last Post: zoidberg
	What is Cinema DTS?	Hitcher	7	5,091	2020-05-28, 09:30 PM Last Post: allldu
	The Past, Present & Future of Home Cinema.	CSchmidlapp	26	24,506	2017-08-27, 03:46 AM Last Post: captainsolo
	composite rainbow noise	deblock	2	3,672	2017-03-24, 02:19 AM Last Post: zoidberg