Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > rec.video.desktop > #13926

Re: how to extact audio from "display port"

Show all headers | View raw

On 6/28/2022 5:51 PM, Computer Nerd Kev wrote:
> hput <hputn3@zohomail.com> wrote:
>> There must be some way to separate the audio and video on a
>> "display port" output?  I know they have adapters from "Display port"
>> to hdmi.
>>
>> But having no luck googling up a tool that splits the audio signal out
>> of display port..
> 
> HDMI and DisplayPort are both entirely digital standards, so in
> neither case is there a conventional audio signal at the port. It's
> just digital signals basically like those feeding into the sound
> card/onboard-chip in the computer, so you effectively need another
> sound card like device to plug in to the DisplayPort and supply
> an analogue audio output.
> 
>> Can anyone suggest something that might help?
> 
> I haven't seen such a device myself, but they probably exist. Maybe
> adapters to VGA etc. with audio output built-in will be cheaper,
> though they'll likely be poor quality.
> 
>> Also, am I wrong in thinking that the sound quality at the sound card
>> (a Quadro M4000 8GB) "Display port" will be superior to the sound at
>> the rca mini port in back?
> 
> Seeing as the former is digital, they're not comparable. In
> practice it would depend on the quality of the sound
> card/onboard-chip in your computer compared to whatever device you
> plug into the DisplayPort which does the same job.
> 

The DisplayPort 8ch LPCM and the HDMI 8ch LPCM, are digital
from end to end and no degradation is present. You stuff the
digital samples into the interleaved stream in the DP output.

The sound is only as good as the source.

It is when the 8ch LPCM is converted to analog with a DAC,
that the degradation occurs.

This assumes nothing is going on, such as a previous scam
where a 24 bit digital audio standard, some of the manufacturers
were setting the 8 least significant bits to 0 permanently,
causing the audio actually sent to be 16 bit audio. So stupid
stuff has happened in the past, but I haven't heard of this
happening with the present day stuff.

There was at least one adapter or dock, that had SPDIF
as an output. Which would give you stereo with 24 bit accuracy.
The SPDIF is converted back to analog, inside the AV Receiver/Amp.

"HDMI to VGA + Optical Toslink SPDIF + 3.5mm Stereo Audio Converter Support 1080P"
https://www.amazon.ca/Security-01-Optical-Toslink-Converter-Support/dp/B01FVFWMAY

You can also convert VGA back into HDMI, but this is a bad idea.
Only mentioned for completeness. There should be HDMI to HDMI+Audio,
as that's the sort of thing soundbars use.

    Paul

Back to rec.video.desktop | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

how to extact audio from "display port" hput <hputn3@zohomail.com> - 2022-06-28 16:17 -0400
  Re: how to extact audio from "display port" Paul <nospam@needed.invalid> - 2022-06-28 17:45 -0400
  Re: how to extact audio from "display port" not@telling.you.invalid (Computer Nerd Kev) - 2022-06-29 07:51 +1000
    Re: how to extact audio from "display port" Paul <nospam@needed.invalid> - 2022-06-28 20:34 -0400
      Re: how to extact audio from "display port" Computer Nerd Kev <not@telling.you.invalid> - 2022-06-29 11:12 +1000

csiph-web