Auzentech HomeTheater HD Preview: Bitstreaming True HD/DTS-HD MA
by Anand Lal Shimpi on September 2, 2009 12:00 AM EST- Posted in
- GPUs
Last year ASUS released the Xonar HDAV; it’s a sound card. The Xonar HDAV’s claim to fame was its ability to bitstream Dolby TrueHD and DTS-HD MA over HDMI. Don’t have any idea what that means? I wrote a primer here last year, but I’ll give you the quick rundown.
Blu-ray discs are huge, you can store up to 50GB on a dual-layer disc. That’s not enough to store lossless video, but it’s enough to store lossless audio. In other words, you can have a bit-for-bit reproduction of the audio track that was mastered at a movie studio in your own home. For most consumers it’s cool as hell just for bragging rights, but for some super high end home theater enthusiasts it’s a perceived necessity.
These audio tracks are stored using one of two lossless compression algorithms: Dolby TrueHD or DTS-HD Master Audio. The content owners however were very nervous about putting these audio tracks on BDs, specifically allowing PC users access to them. After all, if you had unencrypted access to one of these tracks you could potentially...uh...idunno, turn them into MP3s? Stop going to the movies? I have no idea. Regardless, the studios were nervous and the result was a ridiculous requirement for security.
In order to play one of these tracks you have to properly implement what’s called a Protected Audio Path (PAP). I go into much greater detail about the encryption/decryption requirements for a PAP but you need OS, software, driver and hardware support for it. Windows Vista gave us OS support, ArcSoft and Cyberlink gave us software support and the GPU vendors gave us driver support - all we were lacking was the hardware.
The GPU vendors didn’t include support in their designs for a number of reasons, so no integrated or discrete graphics currently support sending these compressed audio streams over HDMI. Next year that will change, but for now it is what it is.
The only hope was for sound card makers to tackle the problem, but the sound card market isn’t what it was back in the 1990s. ASUS was the first to take it seriously, because, well, ASUS takes everything it does seriously.
The Xonar HDAV launched and as you’ll see, I haven’t reviewed it. When it first hit, driver support wasn’t there. Despite the hardware support, you couldn’t send TrueHD or DTS-HD MA over HDMI because the driver didn’t allow it. This part took months to fix, it took some more months to work out a number of other bugs and in that period I just gave up on it. I went back to it not too long ago and while it worked, I’d lost my interest.
Before I ever heard of the ASUS card I heard that Creative Labs and Auzentech were working on one. I even wrote about it. I actually expected it to be out first, but for whatever reason it got pushed back. The card finally launched this year and today it finally received support from Cyberlink to bitstream these codecs without any loss in quality. The PowerDVD 9 patch notes tell you right here:
You do need PowerDVD 9 for this to work, no it doesn’t come bundled with the card, yes the latest patch is needed for it to work.
Auzentech sent me a card and I went to testing it. Perhaps it would be my one last hurrah with high end HTPCs before I accept fate and build a modest XBMC box for my needs.
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hu24ebr - Wednesday, September 2, 2009 - link
I already have a slim ps3, and a home theater receiver that can bit stream, i tried to compare between the compressed and the pure audio, and I have failed to listen to any difference.cmdrdredd - Wednesday, September 2, 2009 - link
[quote]I already have a slim ps3, and a home theater receiver that can bit stream, i tried to compare between the compressed and the pure audio, and I have failed to listen to any difference.[/quote]That's because there is no difference.
Golgatha - Wednesday, September 2, 2009 - link
Yeah, I thought about getting all excited about HD audio, but my ears just can't tell the difference. I have a 5.1 Klipsch setup too, so my speakers aren't super high end, but they aren't crap either.I figured an upgrade to PowerDVD 9 was $50, a sound card that can pass the HDMI HD audio signals would be $200+, and then I get to pray to God it all works when I get it together...or, I could just keep what I have and live with HD audio sources downsampled to DD5.1 and live with it. This and the fact that later versions of the PowerDVD 8 software don't support playing HD audio/video back from a virtual drive pretty much killed any and all desire to upgrade my hardware.
Frankly, they have only succeeded making me not want to purchase hardware and software to playback Blu-ray discs with all this DRM in the mix. If things like AnyDVD HD weren't available, I wouldn't have purchased the BD reader and PowerDVD 8 software I currently use, so thank the "pirates" out there for your sales. Make the DRM any "better" at securing premium content and I'll make sure to give any new hardware supporting said DRM the middle finger.
CrimsonFury - Wednesday, September 2, 2009 - link
"For that price you’re $50 away from a PS3 Slim, which can bitstream Dolby TrueHD and DTS-HD MA in full 48kHz/24-bit fashion"The PS3 does NOT bitstream Dolby TrueHD or DTS-HD MA. It decodes them using the PS3's software and outputs them in 8 channel LPCM.
Anand Lal Shimpi - Wednesday, September 2, 2009 - link
While I haven't tested it myself, the word on the street is that the PS3 Slim can bitstream the hd audio codecs:http://www.engadget.com/2009/08/21/ps3-slim-bitsre...">http://www.engadget.com/2009/08/21/ps3-...by-trueh...
Take care,
Anand
Golgatha - Wednesday, September 2, 2009 - link
The PS3 can pass the audio stream to the receiver uncompressed, which makes the receiver pick it up as a LCPM stream. This is bit for bit equivalent to the HD audio formats, it's just that your little light indicating that's what your getting won't light up at the receiver.andy o - Wednesday, September 2, 2009 - link
Yeah, that's right, I just got my PS3 slim and many others also have confirmed. But the thing is that bitstreaming itself is not the big deal with this card, it's that software players have been screwing the audio in different ways with bugs (channel mapping, improper decoding, etc.). Bitstreaming is just a practical solution. The upcoming Slyplayer will NOT downsample audio so it'll be a good solution, it'll stream bit-perfect LPCM the same way as ReClock can do now with WASAPI exclusive-compatible HDMI devices like the ATI 4000 series with Realtek drivers.asdasd246246 - Wednesday, September 2, 2009 - link
The 48xx series already has HDMI output, with audio, so what's the point of this expensive and apparently, (as usual with Creative) unstable card?A Bluray disc contains digital data, that is generally just sent along it's way to the receiver? There's nothing that needs a codec.
George Powell - Wednesday, September 2, 2009 - link
The 48xx cards do not allow the raw bitstream data to be sent across HDMI. The data is first decoded and then sent as LPCM. There are advantages to both systems in my view.1. Bitstream allows for the highest quality possible. The decode is done by the amplifier which will use specialist hardware to perform the decode. Given high end enough equipment this will offer a better sound than LPCM.
2. LPCM can be fed into just about any amplifier with an HDMI in port. The amplifier doesn't need to do any decoding work. This is a good option for those who have older high end equipment, and I count myself as one of them.
archer75 - Friday, September 4, 2009 - link
It does'nt matter what does the decoding. Decoding is pretty much just like unzipping a file. You get the same thing if you do it on this computer or that one.LPCM works on receivers that support HDMI 1.3. and SOME older ones.
The problem with LPCM is your software player can mess with the audio. PowerDVD or TMT will downsample the audio when they decode it and then pass it out as LPCM.
The only way around that is to do your own Blu-Ray rips to your hard drive in a MKV container with lossless flac.