Quote:
Originally Posted by
hlkc 
How to do that today?
There are a few ways, easiest would be to run say a 48xx and a Panasonic BD50 into an AVR, volume match the two inputs, start the same movie on each (sync'd) and have someone else switch back and forth without telling you which is which.
Other would be to rip the movie, decode it with a decoder known not to degrade the audio (eg ffmpeg perhaps) and then either purposefully downconvert to 16/48kHz or capture the output from a known down-converting decoder and compare them with something like WinABX.
Point is, everyone knows there's downconverting going on, but it seems the only reason we know
for certain is because Cyberlink et al have confirmed it. I don't recall ever reading that someone did a blind test and confirmed it empirically.
Quote:
Originally Posted by
odditory
Perhaps they think people will use AnyDVDHD to remove AACS flag and be able to bitstream without PAP. If that's the case I don't see how what people do after the fact is Cyberlink's problem. If they've fulfilled AACS requirements to downsample protected HD audio then why take it one step further and play cat and mouse with end users and HD audio? Paranoia they'll find the AACS's foot implanted in their a$$ when word gets out AnyDVDHD gets around encrypted audio path the way it does for video path?
It's probably nothing more complicated than this:
99.9% of HD DVDs are AACS protected and 100% of pre-recorded BDs are, so it's far easier to just downconvert everything (since there's no protected path) than to have two code paths and risk having a bug cost them (another) $8 million.
Quote:
Originally Posted by
redtyler1
There was a recent article in Home Theater Mag or Sound and Vision or one of those that did a comparison between the new HD Audio codecs and the previous generation of Dolby and DTS. Some ridiculously high percentage of listeners (whom were not all just average folks off the street, but self-described audiophiles) couldn't tell the difference between those two formats.
That doesn't surprise me at all.
Quote:
I would wager that downsampled LPCM would be really difficult to differentiate from PAP non-downsampled LPCM. Furthermore, isn't it relatively understood that unless you have high end receivers and speakers then you are unlikely to be able to detect the difference because your hardware can't make the difference clear enough? Some folks on here may be able to hear the difference, but I bet in a comparison, a lot of us wouldn't be able to detect a distinction.
People get all bent out of shape about the downconverting thing but it really seems to be in the noise if you dig into it:
99%+ of movie soundtracks are sampled at 48kHz, so the 16bit/48kHz limitation has no impact on sample rate and thus frequency range. ie you can't argue that this is causing the loss of "ultrasonics"
As far as bit depth goes, movies generally have a 24bit master, but what bit depth really buys you is signal to noise ratio between your signal and the quantization noise caused by the discrete sampling. 16bit sampling has the well known quantization noise floor of -96dB. However most people's listenning environments are lucky to have a room with NC40 (40dB background noise, or -65dB from peak reference level), THX only requires NC22 (IIRC) equating to about -83dB from reference level, so even in a THX approved HT, quantization noise is below the rooms noise floor at a "mere" 16 bits.
Quote:
Originally Posted by
odditory
...and
I would wager that if your city government decided to begin injecting fractional percentage levels of chlorine chemical into the city's drinking water, for the purpose of dealing with bacterial growth in water pipes, that you wouldn't be too pleased with it, especially when the city said "our research suggests it won't be harmful to you, and besides you won't notice the difference in taste anyway".
I don't think I've been to a city that doesn't do that, and if I did go to one, I probably wouldn't want to drink the water.
Quote:
Sure drinking water and HD audio are apples and oranges, but the point is the same that many of us don't trust some bungling idiots to handle something properly (ie Cyberlink, especially when they've demonstrated their ineptness with the borderline-intentional bug that downsamples all audio, even unencrypted/unprotected HD audio) and we also don't appreciate being forced to deal with something a certain way "just because" the AACS says so.
Re trust: Where do you draw the line? Cyberlink and Arcosft both have been approved by Dolby and DTS for decoding their respective formats, how is that any different than Panasonic, Pioneer, Anthem, etc? If you don't trust one company, who do you trust?
Re ineptness: I've already said my best guess, I'm sure it was a well known, and probably thoroughly discussed design decision to always downsample audio until PAP comes down the pipe. We may not like the decision but they're not building the app for those who use AnyDVD, they're building the app for the likes of Dell, Sony, HP, who need it to work right with protected discs and
100% of Blu-ray Discs are AACS protected and thus require downsampling without PAP.
Finally, no one here likes AACS and no one here likes downsampling. I'd much prefer it if the programs left audio untouched for unprotected content. But given that we don't have a solution that does that, I think far too much is made of the whole issue.
So just sit back and enjoy the best movie audio we've ever had on the PC and stop worrying about the minutia.
