Quicktime Surround sound?

**NeonDev** · 04-04-2008, 10:38 AM

so I know the Quicktime application can play surround sound audio from movies and I can only assume the same is true of properly crafted audio files. My question is: if I am using the quicktime frame work in an application do I need to do anything special to take advantage of 5.1 audio? Does the QTMovie object handle this setup on its own? I cannot find anything using google, and I know mac FEs other than my own use quicktime for audio playback; I am hoping one of the other devs knows.

I don't have either the hardware or a test file, but if nobody knows the answer would somebody be willing to test my software with a a 5.1 audio file that works as 5.1 in quicktime player? I would be very grateful. I am ever so curious if 5.1 audio is functional or can be functional in NBB.

It may influence my decisions when i finally get around to buying my hardware for my car.

**Jirka Jirout** · 04-04-2008, 05:30 PM

Full surround is a pain in the neck. Long story short - yes, you can just use QTMovie to play multi-channel tracks, that's not a problem. The problem is that you cannot easily use the built-in optical audio out port and external sound adapters usually do not allow you to control the volume, so you need a suitable (pre-)amplifier to do this.

**NeonDev** · 04-04-2008, 06:02 PM

wow thats nice to know thank you.

Do I have to do anything special (call a certain function/ use a certain initializer) to playback 5.1? or is initializing a QTMovie object using a 5.1 file enough? is it safe to list 5.1 audio support as an application feature?

do you have any hardware suggestions for playing 5.1?

**maded** · 04-06-2008, 11:17 PM

Hi NeonDev, it seems to me that its fairly "auto". As in when i plug a regular 3.5 stereo jack into my Mini, it'll play in stereo but when the TOSLink goes in (and as long as your amps are capable of TOSLink input), it plays/splits into the 5.1 channels just fine.

And yes, no volume control except on the amp.

I've tried this with Quicktime and am currently using CFE as a frontend, but would really like to give yours a testdrive.

**NeonDev** · 04-07-2008, 10:24 AM

I would appreciate that. ;-)

I'm definitely curious if it'll do it. kinda sucks that you can't control the volume... why is that exactly?

**maded** · 04-08-2008, 12:04 AM

The 3.5mm stereo plug uses relative voltage as a volume (i think) so if you lower the volume, while the waveform (of the music) remains the same, the amplitude comes down.

The Toslink's signal is digital - 1's and 0's, so no volume embedded in the signal. In your digital home theather system, you can't tweak the volume from the DVD player, but from your amp - so same case here.

Having said this, you can tweak the volume on Quicktime (not system volume) and the volume actually changes. I don't know how this works....