OALAudioFile Class Reference

Inherits from	NSObject
Declared in	OALAudioFile.h

Overview

Maintains an open audio file and allows loading data from that file into new ALBuffer objects.

Tasks

url
The URL of the audio file
property
streamDescription
A description of the audio data in this file.
property
totalFrames
The total number of audio frames in this file
property
reduceToMono
If YES, reduce any stereo data to mono (stereo samples don’t support panning or positional audio).
property
+ fileWithUrl:reduceToMono:
Open the audio file at the specified URL. * * @param url The URL to open the audio file from. * @param reduceToMono If YES, reduce any stereo track to mono
```
                   (stereo samples don't support panning or positional audio).
```
- @return a new audio file object.
– initWithUrl:reduceToMono:
Initialize this object with the audio file at the specified URL. * * @param url The URL to open the audio file from. * @param reduceToMono If YES, reduce any stereo track to mono
```
                   (stereo samples don't support panning or positional audio).
```
- @return the initialized audio file object.
– audioDataWithStartFrame:numFrames:bufferSize:
Read audio data from this file into a new buffer.
– bufferNamed:startFrame:numFrames:
Create a new ALBuffer with the contents of this file.
+ bufferFromUrl:reduceToMono:
Convenience method to load the entire contents of a URL into a new ALBuffer. * * @param url The URL to open the audio file from. * @param reduceToMono If YES, reduce any stereo track to mono
```
                   (stereo samples don't support panning or positional audio).
```
- @return an ALBuffer object.

Properties

reduceToMono

If YES, reduce any stereo data to mono (stereo samples don’t support panning or positional audio).

@property (nonatomic, readwrite, assign) bool reduceToMono

Declared In

OALAudioFile.h

streamDescription

A description of the audio data in this file.

@property (nonatomic, readonly) AudioStreamBasicDescription *streamDescription

Declared In

OALAudioFile.h

totalFrames

The total number of audio frames in this file

@property (nonatomic, readonly) SInt64 totalFrames

Declared In

OALAudioFile.h

url

The URL of the audio file

@property (nonatomic, readonly) NSURL *url

Declared In

OALAudioFile.h

Class Methods

bufferFromUrl:reduceToMono:

Convenience method to load the entire contents of a URL into a new ALBuffer. * * @param url The URL to open the audio file from. * @param reduceToMono If YES, reduce any stereo track to mono

                   (stereo samples don't support panning or positional audio).

@return an ALBuffer object.

+ (ALBuffer *)bufferFromUrl:(NSURL *)url reduceToMono:(bool)reduceToMono

Declared In

OALAudioFile.h

fileWithUrl:reduceToMono:

Open the audio file at the specified URL. * * @param url The URL to open the audio file from. * @param reduceToMono If YES, reduce any stereo track to mono

                   (stereo samples don't support panning or positional audio).

@return a new audio file object.

+ (OALAudioFile *)fileWithUrl:(NSURL *)url reduceToMono:(bool)reduceToMono

Declared In

OALAudioFile.h

Instance Methods

audioDataWithStartFrame:numFrames:bufferSize:

Read audio data from this file into a new buffer.

- (void *)audioDataWithStartFrame:(SInt64)startFrame numFrames:(SInt64)numFrames bufferSize:(UInt32 *)bufferSize

Parameters

startFrame: The starting audio frame to read data from.

numFrames: The number of frames to read.

bufferSize: On successful return, contains the size of the returned buffer, in bytes.

Return Value

The audio data or nil on error. You are responsible for calling free() on the data.

Declared In

OALAudioFile.h

bufferNamed:startFrame:numFrames:

Create a new ALBuffer with the contents of this file.

- (ALBuffer *)bufferNamed:(NSString *)name startFrame:(SInt64)startFrame numFrames:(SInt64)numFrames

Parameters

name: The name to be given to this ALBuffer.

startFrame: The starting audio frame to read data from.

numFrames: The number of frames to read.

Return Value

a new ALBuffer containing the audio data.

Declared In

OALAudioFile.h

initWithUrl:reduceToMono:

Initialize this object with the audio file at the specified URL. * * @param url The URL to open the audio file from. * @param reduceToMono If YES, reduce any stereo track to mono

                   (stereo samples don't support panning or positional audio).

@return the initialized audio file object.

- (id)initWithUrl:(NSURL *)url reduceToMono:(bool)reduceToMono

Declared In

OALAudioFile.h