Inside Macintosh: Sound /

Chapter 2 - Sound Manager / Sound Manager Reference

Sound Manager Routines / Obtaining Information

GetSoundHeaderOffset

You can use the GetSoundHeaderOffset function to get the offset from the beginning of a sound resource to the embedded sound header.

FUNCTION GetSoundHeaderOffset (sndHdl: Handle; 
                                 VAR offset: LongInt): OSErr;

sndHdl

A handle to a sound resource.

offset

On exit, the offset from the beginning of the sound resource specified by the sndHdl parameter to the beginning of the sound header within that sound resource.

DESCRIPTION

The GetSoundHeaderOffset function returns, in the offset parameter, the number of bytes from the beginning of the sound resource specified by the sndHdl parameter to the sound header that is contained within that resource. You might need this information if you want to use the address of that sound header in a sound command (such as the soundCmd or bufferCmd sound command).

The handle passed to GetSoundHeaderOffset does not have to be locked.

SPECIAL CONSIDERATIONS

The GetSoundHeaderOffset function is available only in version 3.0 and later of the Sound Manager. See "Obtaining a Pointer to a Sound Header" beginning on page 2-57 for a function you can call in earlier versions of the Sound Manager to obtain the same information.

You can call the GetSoundHeaderOffset function at interrupt time.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the GetSoundHeaderOffset function are

Trap macro	Selector
_SoundDispatch	$04040024

RESULT CODES

noErr	0	No error
badFormat	-206	Resource is corrupt or unusable

SEE ALSO

See Listing 2-27 on page 2-57 for an example of calling GetSoundHeaderOffset.