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Extracting surround channels from HDMI LPCM digitally?

hoverdonkey

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Hi

Is there a product out there that can take 5.1 LPCM over HDMI and output the channels to 3 x SPDIF (i.e. front pair, rear pair & Centre+Sub) or 3 x USB?

I have seen a few boxes around that can take 7.1 LPCM over HDMI and output 7.1 analogue out, but not digital out. I would prefer to use my own nice DACs.


Thanks
 

staticV3

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If your DACs have AES3 in, then you could use this:

That sounds like an expensive and convoluted setup though.

Instead, consider the miniDSP Flex HT or Flex HTx. They have HDMI in, transparent outputs, versatile DSP, all in one box.
 
OP
H

hoverdonkey

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If your DACs have AES3 in, then you could use this:

That sounds like an expensive and convoluted setup though.

Instead, consider the miniDSP Flex HT or Flex HTx. They have HDMI in, transparent outputs, versatile DSP, all in one box.

Thanks for suggestions. I only have coax/optical/USB digital input on my DACs.

One reason I want/need digital out for surrounds is that I need to send 2 channels via through existing hidden cabling - and I only have optical and ethernet available. I have balun pair to send single ended audio over ethernet, but it is not great.

I have now found Meridian gear that can do it. Their HDMI switch (HD621) can send 8 channel LPCM over their proprietary MHL smart link to one of their MHL equipped surround processors (e.g. 568.2MM). The568 also solves another problem I have, which is that I do not have a centre speaker - it can mix 5.1 to 4.0.

Time to start saving...


Thanks again
 

Kal Rubinson

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I have now found Meridian gear that can do it. Their HDMI switch (HD621) can send 8 channel LPCM over their proprietary MHL smart link to one of their MHL equipped surround processors (e.g. 568.2MM).
You can extract the 8channel PCM output of the MHL SmartLink cable to 8 x AES/EBU.
 

JFMV

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You can extract the 8channel PCM output of the MHL SmartLink cable to 8 x AES/EBU.
Hello,
Please can you explain how you get the 8 digital audio streams in AES/EBU format in L-PCM (I guess…)with a MHL Smartlink cable ?
 

Kal Rubinson

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Hello,
Please can you explain how you get the 8 digital audio streams in AES/EBU format in L-PCM (I guess…)with a MHL Smartlink cable ?
Not any more. It is among the many things that I have long forgotten. However, I, and others, did post that information here and on https://www.meridianunplugged.com/ in regard to the using the HD621. You will have to search for it, I am afraid.
 

JFMV

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Not any more. It is among the many things that I have long forgotten. However, I, and others, did post that information here and on https://www.meridianunplugged.com/ in regard to the using the HD621. You will have to search for it, I am afraid.
OK Thank you very much...
It's a pity that such a simple device to extract L-PCM from HDMI data isn't currently available. There are several ways to do that, but it seems that isn't of interest for most people...
 

JFMV

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I've been considering rolling the dice on one of these -> https://www.diyaudio.com/community/threads/hdmi-to-aes-ebu.373383/post-7544159. The price is right, no idea on how well it works.

Michael
This decoder is based on an ADI processor. It focuses on audio, although video is also considered...
Compared with the FPGA version of the Vanity Pro, the jitter seems to be less of an issue with the ADI chip, since the I2S in and out streams are synchronized together...
 

yulun

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Hi

Is there a product out there that can take 5.1 LPCM over HDMI and output the channels to 3 x SPDIF (i.e. front pair, rear pair & Centre+Sub) or 3 x USB?

I have seen a few boxes around that can take 7.1 LPCM over HDMI and output 7.1 analogue out, but not digital out. I would prefer to use my own nice DACs.


Thanks
I DIYed a red box like this, with one HDMI input, one HDMI output, and 4 sets of AES/EBU outputs. It can be converted into 4-channel SPDIF output through the interface card. And the DSP card can be expanded internally.

586782c303303c0c2bed685a1f2ee81.jpg
c95171f645f602f10dd36c56fcd41ea.jpg
 

PGAMiami

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Not any more. It is among the many things that I have long forgotten. However, I, and others, did post that information here and on https://www.meridianunplugged.com/ in regard to the using the HD621. You will have to search for it, I am afraid.
Kal, is there a cost effective way to get the 5.1 LPCM audio coming out of an Apple TV into a Mac so it may be processed by a convolver? The VanityPro and Arvus should work, but they are rather expensive. From what I’ve read it seems the Apple TV decodes everything to LPCM if you turn off the Dolby Atmos output. My system is 5.0 so I would not benefit much if at all from Atmos.
 

PGAMiami

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I DIYed a red box like this, with one HDMI input, one HDMI output, and 4 sets of AES/EBU outputs. It can be converted into 4-channel SPDIF output through the interface card. And the DSP card can be expanded internally.

View attachment 340311View attachment 340313
Yulun, is there an hdmi to USB or AOIP AES 67 box? Trying to get the 5.0 LPCM coming out of Apple TV into Mac running a convolver.
 
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