LWN: Comments on "TDC: Audio routing for vehicles"

TDC: Audio routing for vehicles

Quazatron — Thu, 06 Jun 2013 16:26:54 +0000

This is a perfect example of why open source matters: the needs of a specific sector ends up benefiting the whole system.

Now I hope the automotive industry would require built-in equalizer/compressor/spatializers so that the desktop could also have it.

I find it lacking that every media player brings its own equalizer implementation, but if you use other audio sources (flash, games) you don't have that control over the sound quality.

I know, I know... "patches welcome". :-)

TDC: Audio routing for vehicles

micka — Tue, 04 Jun 2013 14:51:27 +0000

One again, true, I only paid attention to the numeric value. those are explicitely percentage of population values.

The territory coverage is "only" 97,8 %. The difference is probably in the mountain areas.

TDC: Audio routing for vehicles

anselm — Tue, 04 Jun 2013 14:36:12 +0000

The caveat here is that mobile communications providers like to measure their coverage area in »percent of population reached«. This means that even with near-100% coverage on paper, there may be huge swathes of countryside out in the boonies, where hardly anyone lives, with poor to no actual coverage. (This may not be a big issue in places like France or Germany; more so with, say, Canada or Sweden.)

TDC: Audio routing for vehicles

micka — Tue, 04 Jun 2013 11:17:19 +0000

> my car has a built-in high-powered (3W!) cell phone which can be used far outside of normal reception areas

You know what, that made me realize something completely out of topic : I havent actually thought about reception area for a very long time and I wasn't even aware of it.

That drove me to check the GSM service in my country (France), which appeared to be between 99 % and 99,9 % (depending on provider) on 2012-01, and 3G was 93-98 (modulo roaming agreements).

Completely out of topic, but I wouldn't have even checked without this comment.

TDC: Audio routing for vehicles

Cyberax — Tue, 04 Jun 2013 11:13:50 +0000

Sure, it's an OnStar phone. My vehicle is Chevy Volt, but you can install OnStar on any vehicle (they sell special kits).

TDC: Audio routing for vehicles

hummassa — Tue, 04 Jun 2013 11:09:00 +0000

> Yes. For example, my car has a built-in high-powered (3W!) cell phone which can be used far outside of normal reception areas. It would be nice to make it available to passengers.

Do you mind if I ask which car and/or which high-powered cell phone unit, for reference? This would be immensely useful to me, too...

TDC: Audio routing for vehicles

Cyberax — Tue, 04 Jun 2013 10:41:33 +0000

Yes. For example, my car has a built-in high-powered (3W!) cell phone which can be used far outside of normal reception areas. It would be nice to make it available to passengers.

Then there are RVs and mini-vans where the passengers can realistically talk over the phone without the driver even hearing them.

TDC: Audio routing for vehicles

micka — Tue, 04 Jun 2013 09:18:37 +0000

Well that's true.

Not flooding the car with the call might not change anything.
I suppose that means the driver (or the person on the phone in the car) is supposed to have a headset so the other persons don't hear what is received.
But they'll have to bear at least what's told by the person in the car. So maybe half the communication can't be hidden.

And if the caller already has a headset, is all of this really useful ?

TDC: Audio routing for vehicles

dlang — Tue, 04 Jun 2013 09:05:54 +0000

well, wouldn't that depend on if the call is incoming or outgoing?

for an outgoing call initiated by the driver, I think it would be a great idea not to flood the entire car with the call.

TDC: Audio routing for vehicles

micka — Tue, 04 Jun 2013 08:53:54 +0000

> For example, an incoming hands-free phone call may need to target the driver alone

I think that's a bad example, the driver is in any case the last resort when choosing who to deliver a phone call to, even hand-free.

TDC: Audio routing for vehicles

pr1268 — Mon, 03 Jun 2013 01:50:06 +0000

When an application creates a new audio stream, the system automatically creates a default route for it based on its class (which might specify that "music" streams are routed to the whole-car speaker system, but "navigation" streams are routed to the front-seat speakers only). Users can request an explicit route to override the default if desired, assuming there is application support, that is.

Wow... When reading this article, my head was spinning by then.

I'm not that old, but I can remember riding in cars which had an AM radio, only one speaker, two knobs (volume and tuning), and five mechanical preset buttons. How times have changed!

TDC: Audio routing for vehicles

dlang — Fri, 31 May 2013 04:16:34 +0000

I've been wanting something along these lines for a number of years for use in emergency services communications. typically there are radios and speakers stuffed wherever they can fit.

It would be much nicer to feed each radio into a common system and have the result able to be mixed to multiple sets of outputs.

It sounds as if this comes extremely close to what I was thinking of. The only additional feature I would want is the ability to 'position' an audio source. If you have multiple radios you need to listen to, you could position them at different 'positions' in your audio space. This could be done as the audio is fed into the system, but it's much better if you can do it as you feed the audio out to the zones, that way you can have things positioned differently for a person using headphones than you do for speakers in an operations center (where you can actually position the audio 360 degrees around the room)

This sort of capability has a lot of other uses. Think of people who may be on troubleshooting calls where they want to have one phone line open to sysadmins fixing the problem and another open to managers talking about the impact of the problem. Today this is almost impossible to do, but with VoIP and proper positioning of the sources, you could potentially not only differentiate the different calls by position, but also the individual speakers, allowing for much better identification of who is saying what.