Blu-ray audio specifications

[gentlevoice]

Hi Audiofolks,

Anybody here who knows what the specifications for audio are on Blu-ray? I have read that linear PCM 5.1 192 kHz/24bits is available, but do any of you know what the bits/second rate for the .1 channel is?

Also if there is any limit on how much of the available disc storage capacity can be used for audio (the full 25 GB or 50 GB)?

If one of you have the file format specification for blu-ray I'd be very pleased to see it ....

I'm considering storing a stereo 11,289 MHz 1-bit signal on blu-ray discs multiplexing 3 channels of 192 kHz/24 bits for each channel. However, one of the stereo channels might be using the .1 channel's storage capacity, so if you know what it is I'd appreciate this information.

Thanks!

Jesper

[gentlevoice]

Anybody has suggestions/knowledge of this?

Also, if you know if the full 5.1 192kHz/24 bits signal is available through a blu-ray player's digital output?

Or where I can search for this information ...

Regards,

Jesper

[jonsmirl]

I believe all of the Blue-ray channels are encoded at 192/24 and then AC3 compressed. A few disks have uncompressed audio on them.

The decoded hi-res audio is not available the the S/PDIF output. For copy protection (barf) reason they output a 44.1/16 (or worse) audio track on S/PDIF. This track is separately encoded onto the disk. The track can either be uncompressed stereo or it will be 5.1 mpeg on the S/PDIF cable.

The full audio is only available on the encrypted HDMI link. That's why you have to buy new audio receivers that can decode the encrypted HDMI. Just a HDMI switching receiver is not enough, the receiver needs to be able to pick off the encrypted HDMI audio and decode it.

If this sounds like an unnecessary conspiracy to make you buy all new audio and video hardware, you're right. Probability of a DIY'er getting a HDMI decryption license = zero.

To get around this major inconvenience people will "illegally" rip their Blue-disks to a media server. They can then be played back on your existing unencrypted audio hardware.

[gentlevoice]

Thanks for your reply - can you say a bit more about which hardware could play back the "ripped" disks? What do you consider the playback chain to consist of?

Not that I would be doing this, but it may be a way of publicizing new records ...

Best regards,

Jesper

[jonsmirl]

Ripped Blue-ray contains up to eight channels of 192Khz sampled, 24bit audio. This is the same resolution of SACD audio CDs. The Intel HD Audio compatible hardware in current PCs is capable of playing this. There are probably other high-end sound cards that can play 192/24 too. Common PC hardware is 44.1/16, the CD standard.

[Daveis]

Does anyone know how I could burn my own 24-bit/96khz blu ray discs?

I'm looking for software that can master a blu ray disc with lossless high definition audio. This would substitute for SACD and DVD Audio, both of which are pretty much dead formats.

I have some vinyl albums I'd like archive and enjoy with 24/96 blu ray.

[planet10]

Originally posted by jonsmirl
The full audio is only available on the encrypted HDMI link. That's why you have to buy new audio receivers that can decode the encrypted HDMI. Just a HDMI switching receiver is not enough, the receiver needs to be able to pick off the encrypted HDMI audio and decode it.

What about the idea of using one of the avaiable real cheap HT receivers as a source for the decryption/decodong, and largely replacing the rest of the insides?

dave

[Daveis]

Originally posted by planet10


What about the idea of using one of the avaiable real cheap HT receivers as a source for the decryption/decodong, and largely replacing the rest of the insides?

dave

I never understood the big interest in HDMI as a consumer. RCA cables are cheap and I personally don't mind having 6-8 short cables from preamp or DVD/BD player to amplifiers.

There's also some BD players with 6.1/7.1 analog outputs built into the player.

I like your idea provided someone finds a readily available unit that's easy to mod. Always been interested in tapping the digital signal being fed into DAC's on various cheap devices so I could choose what I wanted to do with it. In my case run through DRC/crossover.

Getting back to the topic. A friend was a little peeved at the blu ray spec for not mandating a single audio lossless codec.

Dolby True HD and DTS Master Audio. Why two formats? And why would anyone master discs with old Dolby Digital anymore? True HD and DTS Master Audio sound so nice.

The new lossless format probably meant that you went out and bought a new pre/processor or receiver to support DTS Master Audio. And the format was new so why not just a single lossless format?