LinuxQuestions.org
Visit the LQ Articles and Editorials section
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Hardware
User Name
Password
Linux - Hardware This forum is for Hardware issues.
Having trouble installing a piece of hardware? Want to know if that peripheral is compatible with Linux?

Notices

Reply
 
Search this Thread
Old 01-06-2009, 03:17 PM   #1
drivesoslow
LQ Newbie
 
Registered: Jan 2009
Posts: 2

Rep: Reputation: 0
HDMI and onboard microphone


I'm trying to use by system for Karaoke and I have a issue with my sound setup. I'm using audio over HDMI through my ATI video card to my TV, and I am using the on board sound card for the microphone. When I do this there is a decent delay (1/4-1/2 a second) from what goes in the mic to what comes out over the TV. Does anyone know a way to remedy this?

Here is my .asoundrc
Code:
pcm.!default {
        type asym
        playback.pcm {
                type plug
                slave.pcm "hw:1,3"
        }

        capture.pcm {
                type plug
                slave.pcm "hw:0,0"
        }
}

Last edited by drivesoslow; 01-06-2009 at 03:26 PM.
 
Old 01-08-2009, 01:07 AM   #2
GlennsPref
Senior Member
 
Registered: Apr 2004
Location: Brisbane, Australia
Distribution: Mageia Studio-13.37 Kubuntu.
Posts: 3,325
Blog Entries: 33

Rep: Reputation: 199Reputation: 199
Hi, Welcome to LQ!

To get fast sound from a pc, you'll have to get a dedicated sound card.

There will be a latency with OnBoard sound chips, that will be hard to overcome.

A cheap pci card will reduce the delay significantly, but there will still be a small delay.

A more expensive but profoundly better option is to get a firewire or usb solution,

where you can get very fast (low times) latency, (the time it takes to get a signal from the input to the output)

And being outside the box (pc) there's all of that electronic noise (rfi) from the pc the sound circuit won't have to deal with

requiring less cmr (common mode rejection ratio, for amplifier circuits) and less distortions just from the extra shielding.

There may be other ways but I haven't found them easy.

A better option would be to use the pc as the jukebox and get a mic preamp (small mixer) and use that to get the mic into the TV.

You may even be able to make one that would plug into the tv rca connectors.

With a small mixer, Plug the pc and the mic into the mixer and that into the TV. Most small mixers have mic preamp/s

I have a Behringer xenyx 802 mixer. Under $100 (au). 2 mic's, 2 stero lines, tape and fx-send and str aux returns too.

You've picked one of my favourite topics, This post is getting long.....

I hope this gives you some indications.

Cheers, Glenn
 
Old 01-08-2009, 01:57 AM   #3
Electro
Guru
 
Registered: Jan 2002
Posts: 6,042

Rep: Reputation: Disabled
Capturing the audio from the microphone and then playing it back through another device is causing the delay. If the ALSA module for your sound card is written differently, it will minimize the delay. If your sound card can redirect the microphone to another digital output internally and with out letting the computer to record and play it back, it will then be near real time. You may then need a device to combine VGA or DVI with digital audio to HDMI converter if another digital output works. The following device should work.

DVI-I and Digital Audio to HDMI
http://www.gefen.com/kvm/dproduct.jsp?prod_id=3570

Buying a dedicated sound card will not fix your problem. The problem you have is AMD motherboard chipsets 780G or 790GX shows up as two sound cards to Linux.

GlennsPref, there is no such thing as fast sound. There is low latency for sound recording, but kernel developers does not care for low latency. At this time only jack can provide near low latency in Linux. The problem that drivesoslow has is AMD motherboard chipsets like the 780G and 790GX shows up as two sound cards. The sound is recording from one sound card and playing back on the other sound card. After fooling around with 780G chipset, HDMI is only good for playing back and not for real time duplexing. Not all external sound cards works reliable and stable in Linux.
 
Old 01-09-2009, 08:16 AM   #4
GlennsPref
Senior Member
 
Registered: Apr 2004
Location: Brisbane, Australia
Distribution: Mageia Studio-13.37 Kubuntu.
Posts: 3,325
Blog Entries: 33

Rep: Reputation: 199Reputation: 199
You're absolutely right Electro, I lept over the first hill.

alsa is the first place to start configuring.

I still feel it won't be fast enough.

"Fast sound" as in "getting it through your pc" to keep (my main objective).

I meant it metaphorically any way, we're often dealing with different languages, so I try to be descriptive, not miss leading.

I feel I could have dealt with any questions regarding My response.

I do have some experience, But do not compete. I have a lot to learn about GNU/Linux, but at the time I had lept to that mechanical conclusion.

Cheers, And thanks for the tip.

Regards Glenn
 
Old 01-10-2009, 01:27 AM   #5
drivesoslow
LQ Newbie
 
Registered: Jan 2009
Posts: 2

Original Poster
Rep: Reputation: 0
Quote:
Originally Posted by Electro View Post
Capturing the audio from the microphone and then playing it back through another device is causing the delay. If the ALSA module for your sound card is written differently, it will minimize the delay. If your sound card can redirect the microphone to another digital output internally and with out letting the computer to record and play it back, it will then be near real time. You may then need a device to combine VGA or DVI with digital audio to HDMI converter if another digital output works. The following device should work.

DVI-I and Digital Audio to HDMI
http://www.gefen.com/kvm/dproduct.jsp?prod_id=3570

Buying a dedicated sound card will not fix your problem. The problem you have is AMD motherboard chipsets 780G or 790GX shows up as two sound cards to Linux.

GlennsPref, there is no such thing as fast sound. There is low latency for sound recording, but kernel developers does not care for low latency. At this time only jack can provide near low latency in Linux. The problem that drivesoslow has is AMD motherboard chipsets like the 780G and 790GX shows up as two sound cards. The sound is recording from one sound card and playing back on the other sound card. After fooling around with 780G chipset, HDMI is only good for playing back and not for real time duplexing. Not all external sound cards works reliable and stable in Linux.
FYI I am not on a AMD motherboard. It is a Intel chip. I am using two seperate sound cards, one onboard and the other is the HDMI video card.
 
Old 01-10-2009, 07:56 PM   #6
Electro
Guru
 
Registered: Jan 2002
Posts: 6,042

Rep: Reputation: Disabled
You did not say it was an on-board sound from Intel. You just said it was an on-board sound. It does not make any difference because Linux sees both the on-board sound and the digital audio through HDMI as two sound cards.

Recording from one sound card and sending it to a different sound card will always have latency that you are experiencing. Again the only way to get around it is use your on-board sound and direct it to either its digital output or line-out. Though if you can hook up a loop cable from the digital audio from your on-board sound to the video card's digital input then you can experience near real time duplexing and with out the need for using the asym plug-in.

Use HDMI interface for media playback, but not for real time duplexing.
 
  


Reply

Tags
delay, hdmi, lag, microphone


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
are hdmi cables really necessary schneidz General 5 04-01-2008 06:01 PM
LXer: Using HDMI With ATI Linux Drivers LXer Syndicated Linux News 0 12-14-2007 12:30 PM
HDMI --> PCI Interface? Quantumstate Linux - Hardware 8 05-03-2006 07:12 PM
Poor sound from microphone with Asrock onboard sound Melon Mandriva 0 11-13-2004 04:19 AM
Microphone not working with A7V8X-X mobo w/ onboard sound n4zmz Linux - Hardware 0 04-23-2004 12:12 PM


All times are GMT -5. The time now is 02:18 PM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration