SetSoundMediaBalance balance parameter clarification

Q: Q: I'm having problems with the QuickTime SetSoundMediaBalance (MediaSetSoundBalance) function. The ranges I'm using for the balance parameter are from -1.0 to 1.0, but no matter what value I pass I'm not hearing much of a difference in either the left or right channel output. What's going on?

A: The balance parameter value may range from -128 to 127. Negative values emphasize the left sound channel, while positive values emphasize the right sound channel. A value of -128 forces all output through the left channel. Similarly, a value of 127 forces all output through the right channel.

Passing a positive balance value causes the left channel to get quieter.

Passing a negative balance value causes the right channel to get quieter.

The amount it gets quieter can be seen in the following examples:

A balance value of 32 would lower the left volume by one quarter of its current value (since 32 is a quarter of 127, the full volume setting). A balance value of -96 would lower the right volume by 3/4 of its current value (since 96 is 3/4 of 128).

Document Revision History

DateNotes
2004-12-01Editorial
1998-10-19Describes correct parameter values for the SetSoundMediaBalance routine.

Posted: 2004-12-01

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