Monitoring 6 ch's @96Khz Encode/Decode

[DarthFader777]

Why aren't there any solutions for surround mixing and encoding at 96Khz in realtime for HD-DVD or Blu-Ray production. I like to mix while hearing the effects of the Encode/Decode process but it seems nobody is going to offer a realtime solution for 6 or more channels at 96Khz. Anybody else
have these same concerns? Or any inside info of plugins or hardware to be released soon?
It seems in audio both our info-structure and hardware need to offer inputs and outputs that support 96Khz. Open for discussion? Let's chat.

[KK Proffitt]

Why aren't there any solutions for surround mixing and encoding at 96Khz in realtime for HD-DVD or Blu-Ray production. I like to mix while hearing the effects of the Encode/Decode process but it seems nobody is going to offer a realtime solution for 6 or more channels at 96Khz. Anybody else
have these same concerns? Or any inside info of plugins or hardware to be released soon?
It seems in audio both our info-structure and hardware need to offer inputs and outputs that support 96Khz. Open for discussion? Let's chat.

Since both Dolby and DTS offer lossless encoding/decoding, theoretically, it should be exactly the same as the discretes. If you're going for hi-def video, I think the audio should match. A lot of people will just do 48kHz uncompressed which will still be better than lossy DD.

[DarthFader777]

Thanks for your reply KK Proffitt. I know you perform work in this area.
I have been mixing surround sessions using Dolby 569 and 564. You can hear the effects of the
encoding and compensate for it as I'm sure you understand. I quess as mixers we would rather hear those effects while we are mixing. How can we be confident without losing time during mixing.
Anyway I have been fortunate to have these tools available rather than pass .wav files off to an authoring department.
Thanks,
Skipp

[audiogeek1]

We had these guys come by the other day to sell us some stuff. Most of what they do seems to be aimed at a TV station. But this product hit my eye especially since it will do 96k.

http://www.linearacoustic.com/streamstackerhd.htm

Not sure if that is what you are looking for. Also have no idea how much it costs. We did not discuss price. All I know is the guy that started this company worked at Dolby for like 8 years and then made this stuff. Who knows.

Mike

[KK Proffitt]

Thanks for your reply KK Proffitt. I know you perform work in this area.
I have been mixing surround sessions using Dolby 569 and 564. You can hear the effects of the
encoding and compensate for it as I'm sure you understand. I quess as mixers we would rather hear those effects while we are mixing. How can we be confident without losing time during mixing.
Anyway I have been fortunate to have these tools available rather than pass .wav files off to an authoring department.
Thanks,
Skipp

These are for AC3 and thus you are hearing the effects of *lossy* encoding. With lossless, you won't hear any difference because it's lossless. If there were any difference, bit for bit, it would not be lossless. All I can suggest is that you buy the sw audio tools from Dolby that do lossless file encoding and see if you hear a difference. Lossless encode/decode path yields the same bit-for-bit audio. To do this realtime would take quite a bit of processing, so the delay in the encode/decode loop would longer than you are hearing with your AC3 hw.

Let's make the distinction between audio for disc and audio for broadcast. HDTV broadcast incorporates AC3 from the satellite to your monitor and decoder. For broadcast you already have the equipment.

For Blu-ray lossless, there's DTS and Dolby TruHD, but these are file based as far as I know, because they are intended for disc, not broadcast. I haven't seen hardware for lossless encode/decode. There may be some out there and I would like to hear about it. I've been busy dealing with learning about P2, 2K and 4K video, so my audio chops are on hold at the moment!

[KK Proffitt]

We had these guys come by the other day to sell us some stuff. Most of what they do seems to be aimed at a TV station. But this product hit my eye especially since it will do 96k.

http://www.linearacoustic.com/streamstackerhd.htm

Not sure if that is what you are looking for. Also have no idea how much it costs. We did not discuss price. All I know is the guy that started this company worked at Dolby for like 8 years and then made this stuff. Who knows.

Mike

These apparently are for lossy encode/decode, not lossless.

[audiogeek1]

These apparently are for lossy encode/decode, not lossless.

that is what I thought he wanted. To hear the effects of the encode/decode process but at 96k.

Mike

[KK Proffitt]

that is what I thought he wanted. To hear the effects of the encode/decode process but at 96k.

Mike

AC3 is by definition limited to 48kHz.

The device you mentioned is really a multiplexer for carrying multiple streams of PCM, AC3, and other types of audio streams combined as one stream that is decoded into the originals at the other end. It's not an encoder in the sense that it makes a file structure suitable for putting on a disc or for broadcast as is. It's just a convenient way to route heterogeneous signals around a facility.

I was wrong about the lossy encode/decode because I just glanced at it and saw "AC3" and assumed it was another AC3 encoder. Sorry, my bad.

To my knowledge, encoding for 96kHz that produces DD+ (a lossy stream that is better than AC3 but still not lossless) is file based, not real-time hw based. Same for DTS and its various flavors at this point. (I could be wrong though, and if I am, I'd love to know which hw is available now.)

In other words there's not just one "encode/decode process at 96kHz". There are several.

Here from blu-ray.com are the audio codecs that Blu-ray supports:

Linear PCM (LPCM) - up to 8 channels of uncompressed audio. (mandatory)
Dolby Digital (DD) - format used for DVDs, 5.1-channel surround sound. (mandatory)
Dolby Digital Plus (DD+) - extension of Dolby Digital, 7.1-channel surround sound. (optional)
Dolby TrueHD - lossless encoding of up to 8 channels of audio. (optional)
DTS Digital Surround - format used for DVDs, 5.1-channel surround sound. (mandatory)
DTS-HD High Resolution Audio - extension of DTS, 7.1-channel surround sound. (optional)
DTS-HD Master Audio - lossless encoding of up to 8 channels of audio. (optional)

HD DVD is dead in the water. Sonic announced today they are discontinuing their authoring system for it.