SPDIF - Sony/Philips Digital Interface

[emanresu]

Any chance we could pursue 64bit virtual audio cables and such? Would 64bit work on SPDiF / HDMi ? I have found only one Windows software supporting it live, but I need virtual audio cables, 64bit enabled.

Good job, thinking about the future

 

[Ferather]

You mean supporting a 64 bit OS or 64 bit audio out? If 64 bit audio out, does that actually exist in mainstream?
No HDMI or SPDIF don't currently have 32 bit capability, although both can if updated.

SPDIF and HDMI both run on HDA, so if HDA cannot do 64 bit, then nor can anything attached to it.

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TOSLink certainly has the bandwidth to do 64bit, @ 125mb max, but no supporting hardware.

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You would need a replacement to HDA, that is also HDA compatible, maybe UDA, or parallel HDA.

Here you can see Realtek (Optical) and AMD (GPU, Monitor) are HDAUDIO (HDA).




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[emanresu]

Woopwoop! There's one software..
Must be Windows XP times (best Kernel sound / tob)
PM!

 

[Ferather]

I updated my post a bit, the last image you can see the minimal circuiting (which is why SPDIF produces better sound) and the digital converters for SPDIF over TOSLink.
If you managed to get HDA to output 64bit audio, the DAC's (and other) on analogue need to support it, and the digital converters on digital.

The reason we use Dolby-DTS on SPDIF is because of the converters (and maybe other bits), else you get only 2 channel.
6 channel PCM is compressed (FX system) and the converter set to bitstream mode.

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Please note, many drivers have software (APO's) on analogue, but not digital, comparisons will be far from fair.

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[emanresu]

Is there a way to get HDMI to support 88.2 and 176.4?

And which DTS Sound Unbound versions do you have stocked?

If I have a particular version installed already, is there a way to .appx it "back" to being an installer?

 

[Ferather]

Wrong thread for DTS talk, but for HDMI 88.2 - 176.4 needs to be supported by the receiver, monitor.

In some cases drivers can knock off support for some samples even though the hardware does it.

 

[Ferather]

Digital audio sample rate converter: S/PDIF for N64, MV1C << "For optical output to work reliably at 192 kHz a 25 Mbps optical transmitter should be used"

DTS-HD MA, max bitrate: 24.5 Mbit/s

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Z-Systems OptiPatch+ | Pro Audio Solutions << "...for a total of 120 input channels and 120 output channels."

Z-Sys Optipatch+ 15 Channel Digital Audio ADAT/TOSlink/SPDIF Detangler Router | PicClick
Z-Sys Optipatch+ 15 Channel Digital Audio ADAT/TOSlink/SPDIF Detangler Router | eBay

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WM8805 | Cirrus Logic | CS8416 | Cirrus Logic

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The newest consumer standard, capped by HDA:

15 x 96k = 1,440k total aggregates, achievable.
8 x 192k = 1,536k total aggregates, normal.

 

[emanresu]

See ZonePlate (download works).
Can this aid you/us/light?

Tobybear Productions

and

VSTHost

VST Host Description

www.hermannseib.com

 

[Ferather]

Consumer level programmable 15 channel SPDIF [2.0] transmitter, S/PDIF Transmitter (SPDIF_Tx) (infineon.com):




Now for OEM's to catch up. 15 x 96k @ 24b on any HDA device.

 

[emanresu]

Yup

 

[Ferather]

Anyone with a Wiki account please update, both officially out of date, do not reference consumer standard then not update to the current:

S/PDIF - Wikipedia | and | TOSLINK - Wikipedia

It's like referencing HDMI 1.0 standard limits for HDMI 2.0.

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3.1 mbps (1983) || 9.2mbps (~2008) 'based on transmitter, 2x 192k @ 24b' || 125mbps (2008+) '~37mbps based on HDA limits, 15 x 96k @ 24b'

HDA and transmitter limits and are NOT SPDIF or TOSlink limits. Below we can see that parallel HDA still does hit the maximum.



Current consumer standard allows for 15 x 192k @ 24b, which is too much for HDA:

 

[emanresu]

*Church bells ringing in the distance...*

 

[Ferather]

Image updates (note, the digital converter in the first image is the transmitter-receiver, a chip):

 

[Ferather]

SABRE Audiophile DACs (8 channels), example: ESS SABRE ES 9028C2M, PDF link, see page 30-31 for SPDIF.
The standard is there though for 15 channel SPDIF, not sure about other DAC's at this time.

 

[The Von Matrices]

I still can't get over why SPDIF is designed not to be volume controllable by the source device.

The SPDIF standard is very basic; it's original design was to just send the output of a CD player to an amplifier. Even just for audio, HDMI is a much better digital transport - you have higher bitrates, metadata to support multiple formats, and CEC to transmit commands such as volume control. If you have the choice you should always use HDMI for audio rather than SPDIF.

If you wanted to control the volume of a digital output at the source, you would have to decode the signal, reduce the amplitude, then re-encode it. That doesn't make sense when the DAC has control out the output amplitude anyway.

 

[Ferather]

Its possible to overcome some of that issue, SPDIF can transmit data with audio, at least the current consumer standard, so its very possible to send volume and even channel controls in upload only.

When it comes to encoded audio, it does not count as PCM (instead imagine PCM inside a 7zip file), its passes thorough (hence passthrough aka bitstreaming).
The end receiver (lets say soundbar) is what decodes the audio as the end result, into essentially PCM, although it's possible before to LPCM.

If you imagine A PC connected to a TV, and also a soundbar to the TV, its possible for the TV to decode to PCM, change some things, and then continue as PCM (LPCM) to the soundbar.

If we used the data feature of SPDIF, it would be possible to tell the TV to tell the soundbar (HDMI-SPDIF) to change the volume | SPDIF > TV > SPDIF/HDMI > Soundbar.

Windows/apo's/drivers can control SPDIF PCM-LPCM volume, prior to output (pre DAC), I can change the volume of SPDIF which changes the volume with speakers (and watts used).


Note that essentially SPDIF-TOSLink can transmit (in upload) a variety of things, audio, data, video, to some extend internet, for bi-directional there is SMI.

Toshiba TODX2402 (rs-online.com) | Molex SMI Optical Interconnects

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15 x 192k @ 24b = ~70mbps, well below TOSLink @ 125mbps (working to consumer standard), however too high for HDA @ ~37mbps, for HDMI-SPDIF to get that spec HDA needs updates.
However, 15 x 96k @ 24b is a doable 34.56mbps (consumer standard), its also below the 6 x 192k @ 32b bitrate @ ~37mbps which we see on HDA.




Even GPU's use HDA to output to HDMI. It's not SPDIF's fault.

 

[Ferather]