CurtPalme.com Home Theater Forum

[Elaine Benes]

[VideoGrabber]

That's interesting, Elaine. Thanks for the information. You're certainly correct about what the file size would have been.

> You're a newsgroup user, no? <

Well, I was a heavy newsgroup user, back in the 70's, 80's, and 90's, and participated in a lot of discussions over the years. But not at all in the last 5-8 years, though I am aware that large files get segmented and streamed in various alt.bin groups.

> 5c is circumventable in the digital domain too, as Japanese WoWo movies are posted regularly too now <

I have to say I'm more than a little surprised (I would have expected to have caught a hint of it through tech channels), but it sounds like you know more about it than I do, so it would be silly for me to argue the point. Thanks for educating me.

[AnalogRocks]

[AnalogRocks]

[Elaine Benes]

[kschmit2]

[VideoGrabber]

Kai,

thanks for the details on the transport streams. I knew the TS achieved the constant (CBR) 28 MBit/sec with NULL packets. I didn't know the bitrate breakdowns though. The audio from D-Theater was always exceptional, and that explains why.

It also explains how it was accomplished, which was as I expected... a hardware hook that simply bypassed the encryption technique. So, in a sense, Dave is still correct that 5C and D-Theater protections have not been cracked, but simply circumvented. A moot point, in a sense.

[kschmit2]

there is no "D-Theater" protection. That was all marketing hype.
The tapes only use 5C protection.

And any encryption system is broken once you can access the data w/o a key. Only the licensor of a circumvented/broken encryption system will claim otherwise. Their robustness requirements simply weren't adequate.

[VideoGrabber]

Kai wrote:
> there is no "D-Theater" protection. That was all marketing hype. <

So why won't my D-Theater tapes play on my Mitsu 2000 D-VHS deck, only my JVC-30K, 40K, or 5U? Is it just a codec thing, and not an encryption thing?

[Elaine Benes]

[VideoGrabber]

Thanks for the followup, Elaine.

> Regular 5c encrypted tapes won't play in those either, will they ? <

Yes, they play (and record) 5C just fine. It would be kind of silly if they didn't.

> Your Mits decks don't have built in MPEG decoders(unlike the JVC's), <

That is correct. No analog encoders OR decoders, and thus only digital bitstreams in and out.

> so you have to transfer the bitstream to an outboard decoder for an image, right? <

Yes. I can play them through my Samsung SIR-T165 tuner/switcher, or my LG LST-3410A HD-DVR. They can also be played on a FW-equipped TV (which I don't have), or through any of my JVC D-VHS decks (as long as Record isn't engaged). There are folks with Mitsu decks (rock-solid transports) playing their 5C tapes back through JVC deck (decoders), with totally non-functional transports.

> Wasn't 5c encryption designed to prevent exactly that? Supposedly no digital transfer whatsoever depending on the flag? <

No digital transfer to an untrusted recipient. All of the above devices I mentioned above can handle the 5C handshaking requirements. That capability is not limited to JVC decks.

It's always possible I was doing something wrong, the one time I tried playing one of my D-Theater tapes on my Mitsu, which is why I was inquiring. But since I "knew" (had read) that it wasn't possible for it to work, I didn't spend any time trying to finagle it.

[Elaine Benes]

But I thought the whole point of 5c was there were varying degrees of protection easily set via a flag ? What if the D-Theater tapes simply have a copy never flag set ?

[VideoGrabber]

> the whole point of 5c was there were varying degrees of protection easily set via a flag ? <

Yes, that's correct.

> What if the D-Theater tapes simply have a copy never flag set ? <

Then they can never be copied. That doesn't mean they can't ever be played.

[KoBE]