Java Development

[burakk]

Hello all,

I am going to work on application that will play mix two audio streams. I read in a few sources that the device capability of doing this can be queried with: System.getProperty("supports.mixing"). In all of the simulators I tried, as well as on my 9700 Bold, it always returns "false". I wonder which models support this? References state most of the GSM models support this feature, I am confused. Thanks in advance,

Best Regards

[PBernhardt]

Basically, GSM devices support multiple audio channels. CDMA do not.. The simulator may not be giving you accurate data, try it on an actual device.

[burakk]

Thanks, but my actual BB 9700 device also gives me "false". What do you suggest?

[BVP · Accepted solution]

All devices will return false for supports.mixing.  As Paul mentioned, you can mix sounds by using 2 players simultaneously on devices that support it.  Otherwise, you will have to mix the audio yourself before passing to a player.  It isn't difficult to do, a forum search should give you articles and sample code that explains how, and the DevConOnDemand portal has relevent content as well.



[burakk]

Thank you BVP. I had searched the forum about this, will do a more detailed search and will have a look at the DevConOnDemand portal.

I am wondering now, why will all devices return supports.mixing?

[BVP · Accepted solution]

Good question.  According to the MMAPI spec the requirements for supports.mixing is:

Query for whether audio mixing is supported. The string returned is either "true" or "false". If mixing is supported, the following conditions are true:

• At least two tones can be played with Manager.playTone simultaneously.
• Manager.playTone can be used at the same time when at least one Player is playing back audio.
• At least two Players can be used to play back audio simultaneously

Since I have just verified that the return value is hard-coded to false for all devices, it would appear you've found a bug

[burakk]

BVP, thanks for the explanation.

ff (System.getProperty("supports.mixing").equals("true"))

{

...

}

statement is a bad-practice then?

[BVP]

It would seem so, yes.  Sorry about that!