Struct AVAudioConverter

#[repr(C)]
pub struct AVAudioConverter { /* private fields */ }

Available on crate feature AVAudioConverter only.

Converts streams of audio between various formats.

See also Apple’s documentation

Implementations

impl AVAudioConverter

pub unsafe fn initFromFormat_toFormat( this: Allocated<Self>, from_format: &AVAudioFormat, to_format: &AVAudioFormat, ) -> Option<Retained<Self>>

Available on crate feature AVAudioFormat only.

Initialize from input and output formats.

Parameter fromFormat: The input format.

Parameter toFormat: The output format.

Returns nil if the format conversion is not possible.

pub unsafe fn reset(&self)

Resets the converter so that a new stream may be converted.

pub unsafe fn inputFormat(&self) -> Retained<AVAudioFormat>

Available on crate feature AVAudioFormat only.

The format of the input audio stream. (NB. AVAudioFormat includes the channel layout)

pub unsafe fn outputFormat(&self) -> Retained<AVAudioFormat>

Available on crate feature AVAudioFormat only.

The format of the output audio stream. (NB. AVAudioFormat includes the channel layout)

pub unsafe fn channelMap(&self) -> Retained<NSArray<NSNumber>>

An array of integers indicating from which input to derive each output.

The array has size equal to the number of output channels. Each element’s value is the input channel number, starting with zero, that is to be copied to that output. A negative value means that the output channel will have no source and will be silent. Setting a channel map overrides channel mapping due to any channel layouts in the input and output formats that may have been supplied.

pub unsafe fn setChannelMap(&self, channel_map: &NSArray<NSNumber>)

Setter for channelMap.

pub unsafe fn magicCookie(&self) -> Option<Retained<NSData>>

Decoders require some data in the form of a magicCookie in order to decode properly. Encoders will produce a magicCookie.

pub unsafe fn setMagicCookie(&self, magic_cookie: Option<&NSData>)

Setter for magicCookie.

pub unsafe fn downmix(&self) -> bool

If YES and channel remapping is necessary, then channels will be mixed as appropriate instead of remapped. Default value is NO.

pub unsafe fn setDownmix(&self, downmix: bool)

Setter for downmix.

pub unsafe fn dither(&self) -> bool

Setting YES will turn on dither, if dither makes sense in given the current formats and settings. Default value is NO.

pub unsafe fn setDither(&self, dither: bool)

Setter for dither.

pub unsafe fn sampleRateConverterQuality(&self) -> NSInteger

An AVAudioQuality value as defined in AVAudioSettings.h.

pub unsafe fn setSampleRateConverterQuality( &self, sample_rate_converter_quality: NSInteger, )

Setter for sampleRateConverterQuality.

pub unsafe fn sampleRateConverterAlgorithm(&self) -> Option<Retained<NSString>>

An AVSampleRateConverterAlgorithmKey value as defined in AVAudioSettings.h.

pub unsafe fn setSampleRateConverterAlgorithm( &self, sample_rate_converter_algorithm: Option<&NSString>, )

Setter for sampleRateConverterAlgorithm.

pub unsafe fn primeMethod(&self) -> AVAudioConverterPrimeMethod

Indicates the priming method to be used by the sample rate converter or decoder.

pub unsafe fn setPrimeMethod(&self, prime_method: AVAudioConverterPrimeMethod)

Setter for primeMethod.

pub unsafe fn primeInfo(&self) -> AVAudioConverterPrimeInfo

Available on crate feature AVAudioTypes only.

Indicates the the number of priming frames.

pub unsafe fn setPrimeInfo(&self, prime_info: AVAudioConverterPrimeInfo)

Available on crate feature AVAudioTypes only.

Setter for primeInfo.

pub unsafe fn convertToBuffer_fromBuffer_error( &self, output_buffer: &AVAudioPCMBuffer, input_buffer: &AVAudioPCMBuffer, ) -> Result<(), Retained<NSError>>

Available on crate feature AVAudioBuffer only.

Perform a simple conversion. That is, a conversion which does not involve codecs or sample rate conversion.

Parameter inputBuffer: The input buffer.

Parameter outputBuffer: The output buffer.

Parameter outError: An error if the conversion fails.

Returns: YES is returned on success, NO when an error has occurred.

The output buffer’s frameCapacity should be at least at large as the inputBuffer’s frameLength. If the conversion involves a codec or sample rate conversion, you instead must use convertToBuffer:error:withInputFromBlock:.

pub unsafe fn convertToBuffer_error_withInputFromBlock( &self, output_buffer: &AVAudioBuffer, out_error: Option<&mut Option<Retained<NSError>>>, input_block: AVAudioConverterInputBlock, ) -> AVAudioConverterOutputStatus

Available on crate features AVAudioBuffer and AVAudioTypes and block2 only.

Perform any supported conversion.

Parameter inputBlock: A block which will be called to get input data as needed. See description for AVAudioConverterInputBlock.

Parameter outputBuffer: The output buffer.

Parameter outError: An error if the conversion fails.

Returns: An AVAudioConverterOutputStatus is returned.

It attempts to fill the buffer to its capacity. On return, the buffer’s length indicates the number of sample frames successfully converted.

impl AVAudioConverter

Methods declared on superclass NSObject.

pub unsafe fn init(this: Allocated<Self>) -> Retained<Self>

pub unsafe fn new() -> Retained<Self>

impl AVAudioConverter

Encoding.

pub unsafe fn bitRate(&self) -> NSInteger

bitRate in bits per second. Only applies when encoding.

pub unsafe fn setBitRate(&self, bit_rate: NSInteger)

Setter for bitRate.

pub unsafe fn bitRateStrategy(&self) -> Option<Retained<NSString>>

When encoding, an AVEncoderBitRateStrategyKey value constant as defined in AVAudioSettings.h. Returns nil if not encoding.

pub unsafe fn setBitRateStrategy(&self, bit_rate_strategy: Option<&NSString>)

Setter for bitRateStrategy.

pub unsafe fn maximumOutputPacketSize(&self) -> NSInteger

The maximum size of an output packet, in bytes.

When encoding it is useful to know how large a packet can be in order to allocate a buffer to receive the output.

pub unsafe fn availableEncodeBitRates( &self, ) -> Option<Retained<NSArray<NSNumber>>>

When encoding, an NSArray of NSNumber of all bit rates provided by the codec. Returns nil if not encoding.

pub unsafe fn applicableEncodeBitRates( &self, ) -> Option<Retained<NSArray<NSNumber>>>

When encoding, an NSArray of NSNumber of bit rates that can be applied based on the current formats and settings. Returns nil if not encoding.

pub unsafe fn availableEncodeSampleRates( &self, ) -> Option<Retained<NSArray<NSNumber>>>

When encoding, an NSArray of NSNumber of all output sample rates provided by the codec. Returns nil if not encoding.

pub unsafe fn applicableEncodeSampleRates( &self, ) -> Option<Retained<NSArray<NSNumber>>>

When encoding, an NSArray of NSNumber of output sample rates that can be applied based on the current formats and settings. Returns nil if not encoding.

pub unsafe fn availableEncodeChannelLayoutTags( &self, ) -> Option<Retained<NSArray<NSNumber>>>

When encoding, an NSArray of NSNumber of all output channel layout tags provided by the codec. Returns nil if not encoding.

Methods from Deref<Target = NSObject>

pub fn doesNotRecognizeSelector(&self, sel: Sel) -> !

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>

pub fn class(&self) -> &'static AnyClass

Dynamically find the class of this object.

Example

Check that an instance of NSObject has the precise class NSObject.

use objc2::ClassType;
use objc2::runtime::NSObject;

let obj = NSObject::new();
assert_eq!(obj.class(), NSObject::class());

pub unsafe fn get_ivar<T>(&self, name: &str) -> &T

where T: Encode,

👎Deprecated: this is difficult to use correctly, use Ivar::load instead.

Use Ivar::load instead.

Safety

The object must have an instance variable with the given name, and it must be of type T.

See Ivar::load_ptr for details surrounding this.

pub fn downcast_ref<T>(&self) -> Option<&T>

where T: DowncastTarget,

Attempt to downcast the object to a class of type T.

This is the reference-variant. Use Retained::downcast if you want to convert a retained object to another type.

Mutable classes

Some classes have immutable and mutable variants, such as NSString and NSMutableString.

When some Objective-C API signature says it gives you an immutable class, it generally expects you to not mutate that, even though it may technically be mutable “under the hood”.

So using this method to convert a NSString to a NSMutableString, while not unsound, is generally frowned upon unless you created the string yourself, or the API explicitly documents the string to be mutable.

See Apple’s documentation on mutability and on isKindOfClass: for more details.

Generic classes

Objective-C generics are called “lightweight generics”, and that’s because they aren’t exposed in the runtime. This makes it impossible to safely downcast to generic collections, so this is disallowed by this method.

You can, however, safely downcast to generic collections where all the type-parameters are AnyObject.

Panics

This works internally by calling isKindOfClass:. That means that the object must have the instance method of that name, and an exception will be thrown (if CoreFoundation is linked) or the process will abort if that is not the case. In the vast majority of cases, you don’t need to worry about this, since both root objects NSObject and NSProxy implement this method.

Examples

Cast an NSString back and forth from NSObject.

use objc2::rc::Retained;
use objc2_foundation::{NSObject, NSString};

let obj: Retained<NSObject> = NSString::new().into_super();
let string = obj.downcast_ref::<NSString>().unwrap();
// Or with `downcast`, if we do not need the object afterwards
let string = obj.downcast::<NSString>().unwrap();

Try (and fail) to cast an NSObject to an NSString.

use objc2_foundation::{NSObject, NSString};

let obj = NSObject::new();
assert!(obj.downcast_ref::<NSString>().is_none());

Try to cast to an array of strings.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);
// This is invalid and doesn't type check.
let arr = arr.downcast_ref::<NSArray<NSString>>();

This fails to compile, since it would require enumerating over the array to ensure that each element is of the desired type, which is a performance pitfall.

Downcast when processing each element instead.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);

for elem in arr {
    if let Some(data) = elem.downcast_ref::<NSString>() {
        // handle `data`
    }
}

Trait Implementations

impl AsRef<AVAudioConverter> for AVAudioConverter

fn as_ref(&self) -> &Self

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<AnyObject> for AVAudioConverter

fn as_ref(&self) -> &AnyObject

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<NSObject> for AVAudioConverter

fn as_ref(&self) -> &NSObject

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<AnyObject> for AVAudioConverter

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for AVAudioConverter

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for AVAudioConverter

const NAME: &'static str = "AVAudioConverter"

The name of the Objective-C class that this type represents.

type Super = NSObject

The superclass of this class.

type ThreadKind = <<AVAudioConverter as ClassType>::Super as ClassType>::ThreadKind

Whether the type can be used from any thread, or from only the main thread.

fn class() -> &'static AnyClass

Get a reference to the Objective-C class that this type represents.

fn as_super(&self) -> &Self::Super

Get an immutable reference to the superclass.

impl Debug for AVAudioConverter

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for AVAudioConverter

type Target = NSObject

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl Hash for AVAudioConverter

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Message for AVAudioConverter

fn retain(&self) -> Retained<Self>

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for AVAudioConverter

fn isEqual(&self, other: Option<&AnyObject>) -> bool

where Self: Sized + Message,

Check whether the object is equal to an arbitrary other object.

fn hash(&self) -> usize

where Self: Sized + Message,

An integer that can be used as a table address in a hash table structure.

fn isKindOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of the class, or one of its subclasses.

fn is_kind_of<T>(&self) -> bool

where T: ClassType, Self: Sized + Message,

👎Deprecated: use isKindOfClass directly, or cast your objects with AnyObject::downcast_ref

Check if the object is an instance of the class type, or one of its subclasses.

fn isMemberOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of a specific class, without checking subclasses.

fn respondsToSelector(&self, aSelector: Sel) -> bool

where Self: Sized + Message,

Check whether the object implements or inherits a method with the given selector.

fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> bool

where Self: Sized + Message,

Check whether the object conforms to a given protocol.

fn description(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object.

fn debugDescription(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object to use when debugging.

fn isProxy(&self) -> bool

where Self: Sized + Message,

Check whether the receiver is a subclass of the NSProxy root class instead of the usual NSObject.

fn retainCount(&self) -> usize

where Self: Sized + Message,

The reference count of the object.

impl PartialEq for AVAudioConverter

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl RefEncode for AVAudioConverter

const ENCODING_REF: Encoding = <NSObject as ::objc2::RefEncode>::ENCODING_REF

The Objective-C type-encoding for a reference of this type.

impl DowncastTarget for AVAudioConverter

impl Eq for AVAudioConverter