AEUtilities.h File Reference

#import <Foundation/Foundation.h>
#import <AudioToolbox/AudioToolbox.h>
#import "AETypes.h"

Go to the source code of this file.

Macros
#define	AECheckOSStatus(result, operation)   (_AECheckOSStatus((result),(operation),strrchr(__FILE__, '/')+1,__LINE__))
	Check an OSStatus condition.

Functions
AudioComponentDescription	AEAudioComponentDescriptionMake (OSType manufacturer, OSType type, OSType subtype)
	Create an AudioComponentDescription structure.
BOOL	AERateLimit (void)
	Rate limit an operation.
void	AEError (OSStatus result, const char *_Nonnull operation, const char *_Nonnull file, int line)
	An error occurred within AECheckOSStatus.
ExtAudioFileRef _Nullable	AEExtAudioFileCreate (NSURL *_Nonnull url, AEAudioFileType fileType, double sampleRate, int channelCount, NSError *_Nullable *_Nullable error)
	Initialize an ExtAudioFileRef for writing to a file.
ExtAudioFileRef _Nullable	AEExtAudioFileOpen (NSURL *_Nonnull url, AudioStreamBasicDescription *_Nullable outAudioDescription, UInt64 *_Nullable outLengthInFrames, NSError *_Nullable *_Nullable error)
	Open an audio file for reading.

Macro Definition Documentation

#define AECheckOSStatus	(		result,
			operation
	)		(_AECheckOSStatus((result),(operation),strrchr(__FILE__, '/')+1,__LINE__))

Check an OSStatus condition.

Parameters

result	The result
operation	A description of the operation, for logging purposes

Function Documentation

AudioComponentDescription AEAudioComponentDescriptionMake	(	OSType	manufacturer,
		OSType	type,
		OSType	subtype
	)

Create an AudioComponentDescription structure.

Parameters

manufacturer	The audio component manufacturer (e.g. kAudioUnitManufacturer_Apple)
type	The type (e.g. kAudioUnitType_Generator)
subtype	The subtype (e.g. kAudioUnitSubType_AudioFilePlayer)

Returns

An AudioComponentDescription structure with the given attributes

BOOL AERateLimit

(

void

)

Rate limit an operation.

This can be used to prevent spamming error messages to the console when something goes wrong.

void AEError	(	OSStatus	result,
		const char *_Nonnull	operation,
		const char *_Nonnull	file,
		int	line
	)

An error occurred within AECheckOSStatus.

Create a symbolic breakpoint with this function name to break on errors.

ExtAudioFileRef _Nullable AEExtAudioFileCreate	(	NSURL *_Nonnull	url,
		AEAudioFileType	fileType,
		double	sampleRate,
		int	channelCount,
		NSError *_Nullable *_Nullable	error
	)

Initialize an ExtAudioFileRef for writing to a file.

This provides a simple way to create an audio file writer, initialised appropriately for the given file type. To begin recording asynchronously, you should use ExtAudioFileWriteAsync(audioFile, 0, NULL); to prime asynchronous recording. For writing on the main thread, use ExtAudioFileWrite.

Finish writing and close the file by using ExtAudioFileDispose once you are done.

Use this function only on the main thread.

Parameters

url	URL to the file to write to
fileType	The type of the file to write
sampleRate	Sample rate to use for input & output
channelCount	Number of channels for input & output
error	If not NULL, the error on output

Returns

The initialized ExtAudioFileRef, or NULL on error

ExtAudioFileRef _Nullable AEExtAudioFileOpen	(	NSURL *_Nonnull	url,
		AudioStreamBasicDescription *_Nullable	outAudioDescription,
		UInt64 *_Nullable	outLengthInFrames,
		NSError *_Nullable *_Nullable	error
	)

Open an audio file for reading.

This utility creates a new reader instance, and returns the reader, the client format AudioStreamBasicDescription used for reading, and the total length in frames, both usually useful for operating on files.

It will be configured to use the standard AEAudioDescription format, with the channel count and sample rate determined by the file format - this configured format is returned via the outAudioDescription parameter. Use kExtAudioFileProperty_ClientDataFormat to change this if required.

Parameters

url	URL to the file to read from
outAudioDescription	On output, the AEAudioDescription-derived stream format for reading (the client format)
outLengthInFrames	On output, the total length in frames
error	If not NULL, the error on output

Returns

The initialized ExtAudioFileRef, or NULL on error