SndNewChannel

Alocate a sound-channel record

#include <Sound.h> Sound Manager

OSErr SndNewChannel(chan, synth, init, userRoutine );

SndChannelPtr *chan; a pointer to a sound channel

short synth specifies which playback synthesizer is to be used

long init; specifies an initialization option

ProcPtr userRoutine ; a pointer to a callback procedure

returns Error Code; 0=no error

You use the SndNewChannel to allocate a sound-channel record in your

application's heap and return a pointer to that record

chan a pointer to a sound channel

synth specifies which playback synthesizer is to be used. You specify a

synthesizer by its resource ID, and this 'snth' resource is loaded into

memory and linked to the channel. To create a channel without linking

it to a synthesizer, pass 0 as the synth parameter. In general,

however, you should specify a nonzero value in the synth parameter

to ensure that CPU load tests are performed and hence that you can

actually produce sound in the new channel.

init specifies an initialization option that should be sent to the

synthesizer when you open the channel. For example, to open the

third wave-table channel, use initChan2 as the init parameter. Only

the wave-table synthesizer and sampled sound synthesizer currently

use the init options. To determine if a particular option is understood

by the synthesizer, use the availableCmd command with the

SndControl function.

userRoutine a pointer to a callback procedure. If your application produces

sounds asynchronously or needs to be alerted when a command has

completed, define a callback procedure and pass a pointer to that

procedure in the userRoutine parameter. This routine is called once

the synthesizer has received the callBackCmd command. If you pass

NULL as the userRoutine parameter, then any callBackCmd commands

are ignored.

Returns: an operating system Error Code.

noErr (0) No error

resProblem (-204) Problem loading the resource

badChannel (-205) Channel is corrupt or unusable

Notes: To release the memory previously allocated to a sound channel that is no

longer needed, call SndDisposeChannel.

Referenced by (28):