All Databases Inside Mac - Sound Mgr

SndRecord

Record a sound into memory

#include <SoundInput.h> Sound Manager

OSErr SndRecord( filterProc, corner, quality, sndHandle );

ProcPtr filterProc; a pointer to a procedure

Point corner; coordinates of the upper-left corner of the dialog

box

OSType quality; the desired quality of the recorded sound

Handle * sndHandle; a handle to some storage space

returns Error Code; 0=no error

The SndRecord function records sound into memory. The recorded data has

the structure of a format 1 'snd ' resource and can later be played using

SndPlay or can be stored as a resource. By using this high-level routine,

you can be assured that your application will present a user interface that is

consistent with that displayed by other applications doing sound input. Both

SndRecord and SndRecordToFile attempt to record sound data from the

sound input hardware currently selected in the Sound control panel.

filterProc determines how user actions in the dialog box are filtered (and

hence is similar to the filterProc parameter specified in a call to

ModalDialog). By specifying your own filter procedure, you can

override or add to the default actions of the items in the dialog box. If

filterProc is not NULL, SndRecord filters events by calling the

procedure that filterProc points to

corner gives the horizontal and vertical coordinates of the upper-left

corner of the dialog box (in global coordinates).

quality the desired quality of the recorded sound. Currently, three values

are recognized for the quality parameter: 'good', 'betr', and 'best'. The

precise meanings of these parameters are dependent on the sound

input driver. For Apple-supplied drivers, this parameter

determines whether the recorded sound is to be compressed, and if so,

whether at a 6:1 or a 3:1 ratio. A quality of 'best' does not compress

the sound and provides the best quality output, but at the expense of

memory. The quality 'betr' is suitable for most nonvoice recording,

and 'good' is suitable for voice recording.

sndHandle is a handle to some storage space. You must pass in either a valid

handle or NULL. If sndHandle is NULL, the Sound Manager allocates

the largest amount of space in the application's heap that it can and

then resizes the handle when the user clicks the Save button in the

sound input dialog box. If the sndHandle parameter passed to

SndRecord is not NULL, the recording time is derived from the

amount of memory reserved by the handle.

Returns: an operating system Error Code.

noErr (0) No error

userCanceledErr (-128) User canceled the ope ration

siBadSoundInDevice (-221) Invalid sound input device

siUnknownQuality (-232) Unknown quality

Notes: SndRecord displays a sound input dialog box and is always called

synchronously. Controls in the dialog box allow the user to start, stop,

pause, and resume sound recording, as well as to play back the recorded

sound. The dialog box also lists the amount of time remaining to record and

the current microphone sound level.

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