Struct CVTimeStamp 

#[repr(C)]
pub struct CVTimeStamp {
    pub version: u32,
    pub videoTimeScale: i32,
    pub videoTime: i64,
    pub hostTime: u64,
    pub rateScalar: c_double,
    pub videoRefreshPeriod: i64,
    pub smpteTime: CVSMPTETime,
    pub flags: u64,
    pub reserved: u64,
}

Available on crate feature CVBase only.

CoreVideo uses a CVTimeStamp structure to store video display time stamps.

This structure is purposely very similar to AudioTimeStamp defined in the CoreAudio framework. Most of the CVTimeStamp struct should be fairly self-explanatory. However, it is probably worth pointing out that unlike the audio time stamps, floats are not used to represent the video equivalent of sample times. This was done partly to avoid precision issues, and partly because QuickTime still uses integers for time values and time scales. In the actual implementation it has turned out to be very convenient to use integers, and we can represent framerates like NTSC (30000/1001 fps) exactly. The mHostTime structure field uses the same Mach absolute time base that is used in CoreAudio, so that clients of the CoreVideo API can synchronize between the two subsystems. Field: version The current CVTimeStamp is version 0. Field: videoTimeScale The scale (in units per second) of the videoTime and videoPeriod values Field: videoTime This represents the start of a frame (or field for interlaced) Field: hostTime Host root timebase time Field: rateScalar This is the current rate of the device as measured by the timestamps, divided by the nominal rate Field: videoRefreshPeriod This is the nominal update period of the current output device Field: smpteTime SMPTE time representation of the time stamp. Field: flags Possible values are: kCVTimeStampVideoTimeValid kCVTimeStampHostTimeValid kCVTimeStampSMPTETimeValid kCVTimeStampVideoPeriodValid kCVTimeStampRateScalarValid There are flags for each field to make it easier to detect interlaced vs progressive output kCVTimeStampTopField kCVTimeStampBottomField Some commonly used combinations of timestamp flags kCVTimeStampVideoHostTimeValid kCVTimeStampIsInterlaced Field: reserved Reserved. Do not use.

See also Apple’s documentation

Fields

version: u32

videoTimeScale: i32

videoTime: i64

hostTime: u64

rateScalar: c_double

videoRefreshPeriod: i64

smpteTime: CVSMPTETime

flags: u64

reserved: u64

Trait Implementations

impl Clone for CVTimeStamp

fn clone(&self) -> CVTimeStamp

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CVTimeStamp

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

Formats the value using the given formatter.

impl Encode for CVTimeStamp

Available on crate feature objc2 only.

const ENCODING: Encoding

The Objective-C type-encoding for this type.

impl PartialEq for CVTimeStamp

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

Available on crate feature objc2 only.

const ENCODING_REF: Encoding

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

impl Copy for CVTimeStamp

impl StructuralPartialEq for CVTimeStamp