Struct CMBufferCallbacks 

#[repr(C, packed(4))]
pub struct CMBufferCallbacks {
    pub version: u32,
    pub refcon: *mut c_void,
    pub getDecodeTimeStamp: CMBufferGetTimeCallback,
    pub getPresentationTimeStamp: CMBufferGetTimeCallback,
    pub getDuration: CMBufferGetTimeCallback,
    pub isDataReady: CMBufferGetBooleanCallback,
    pub compare: CMBufferCompareCallback,
    pub dataBecameReadyNotification: *const CFString,
    pub getSize: CMBufferGetSizeCallback,
}

Available on crate features CMBufferQueue and CMTime only.

Callbacks provided to CMBufferQueueCreate, for use by the queue in interrogating the buffers that it will see.

With the exception of isDataReady, all these callbacks must always return the same result for the same arguments. A buffer’s duration, timestamps, or position relative to other buffers must not appear to change while it is in the queue. Once isDataReady has returned true for a given CMBuffer, it must always return true for that CMBuffer. Durations must always be positive.

See also Apple’s documentation

Fields

version: u32

Must be 0 or 1.

refcon: *mut c_void

Client refcon to be passed to all callbacks (can be NULL, if the callbacks don’t require it).

getDecodeTimeStamp: CMBufferGetTimeCallback

This callback is called from CMBufferQueueGetFirstDecodeTimeStamp (once), and from CMBufferQueueGetMinDecodeTimeStamp (multiple times). It should return the decode timestamp of the buffer. If there are multiple samples in the buffer, this callback should return the minimum decode timestamp in the buffer. Can be NULL (CMBufferQueueGetFirstDecodeTimeStamp and CMBufferQueueGetMinDecodeTimeStamp will return kCMTimeInvalid).

getPresentationTimeStamp: CMBufferGetTimeCallback

This callback is called from CMBufferQueueGetFirstPresentationTimeStamp (once) and from CMBufferQueueGetMinPresentationTimeStamp (multiple times). It should return the presentation timestamp of the buffer. If there are multiple samples in the buffer, this callback should return the minimum presentation timestamp in the buffer. Can be NULL (CMBufferQueueGetFirstPresentationTimeStamp and CMBufferQueueGetMinPresentationTimeStamp will return kCMTimeInvalid).

getDuration: CMBufferGetTimeCallback

This callback is called (once) during enqueue and dequeue operations to update the total duration of the queue. Must not be NULL.

isDataReady: CMBufferGetBooleanCallback

This callback is called from CMBufferQueueDequeueIfDataReadyAndRetain, to ask if the buffer that is about to be dequeued is ready. Can be NULL (data will be assumed to be ready).

compare: CMBufferCompareCallback

This callback is called (multiple times) from CMBufferQueueEnqueue, to perform an insertion sort. Can be NULL (queue will be FIFO).

dataBecameReadyNotification: *const CFString

If triggers of type kCMBufferQueueTrigger_WhenDataBecomesReady are installed, the queue will listen for this notification on the head buffer. Can be NULL (then the queue won’t listen for it).

getSize: CMBufferGetSizeCallback

This callback is called (once) during enqueue and dequeue operation to update the total size of the queue. Can be NULL. Ignored if version < 1.

Trait Implementations

impl Clone for CMBufferCallbacks

fn clone(&self) -> CMBufferCallbacks

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CMBufferCallbacks

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

Formats the value using the given formatter.

impl Encode for CMBufferCallbacks

Available on crate feature objc2 only.

const ENCODING: Encoding

The Objective-C type-encoding for this type.

impl PartialEq for CMBufferCallbacks

fn eq(&self, other: &CMBufferCallbacks) -> 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 CMBufferCallbacks

Available on crate feature objc2 only.

const ENCODING_REF: Encoding

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

impl Copy for CMBufferCallbacks

impl StructuralPartialEq for CMBufferCallbacks