Struct Timebase 

pub struct Timebase { /* private fields */ }

A media timebase represented as a rational number: numerator over non-zero denominator.

Typical values: 1/1000 for millisecond PTS, 1/90000 for MPEG-TS, 1/48000 for audio samples, 30000/1001 for NTSC video (when used as a frame rate).

Equality and ordering

Comparison is value-based: 1/2 equals 2/4, and 1/3 < 2/3 < 1/1. Hash hashes the reduced (lowest-terms) form, so equal rationals hash the same. Cross-multiplication uses u64 intermediates — exact for any u32 numerator / denominator.

Implementations

impl Timebase

pub const fn new(num: u32, den: NonZeroU32) -> Self

Creates a new Timebase with the given numerator and non-zero denominator.

pub const fn num(&self) -> u32

Returns the numerator.

pub const fn den(&self) -> NonZeroU32

Returns the denominator.

pub const fn with_num(self, num: u32) -> Self

Set the value of the numerator.

pub const fn with_den(self, den: NonZeroU32) -> Self

Set the value of the denominator.

pub const fn set_num(&mut self, num: u32) -> &mut Self

Set the value of the numerator in place.

pub const fn set_den(&mut self, den: NonZeroU32) -> &mut Self

Set the value of the denominator in place.

pub const fn rescale_pts(pts: i64, from: Self, to: Self) -> i64

Rescales pts from timebase from to timebase to, rounding toward zero.

Equivalent to FFmpeg’s av_rescale_q. Uses a 128-bit intermediate to avoid overflow for typical video PTS ranges. If the rescaled value exceeds i64’s range (pathological for real video), the result is saturated to i64::MIN or i64::MAX — this matches the behavior promised by duration_to_pts and avoids silent wraparound.

Panics

Panics if to.num() == 0 (division by zero).

pub const fn rescale(&self, pts: i64, to: Self) -> i64

Rescales pts from this timebase to to, rounding toward zero.

Method form of Self::rescale_pts: self is the source timebase.

Panics

Panics if to.num() == 0 (division by zero).

pub const fn frames_to_duration(&self, frames: u32) -> Duration

Treats self as a frame rate (frames per second) and returns the Duration corresponding to frames frames.

Examples:

• 30 fps: Timebase::new(30, nz(1)).frames_to_duration(15) → 500 ms
• NTSC: Timebase::new(30000, nz(1001)).frames_to_duration(30000) → 1001 ms

Note that “frame rate” and “PTS timebase” are conceptually different rationals even though both are represented as Timebase. A 30 fps stream typically has PTS timebase 1/30 (seconds per unit) and frame rate 30/1 (frames per second) — they are reciprocals.

Panics

Panics if self.num() == 0 (division by zero).

pub const fn duration_to_pts(&self, d: Duration) -> i64

Converts a Duration into the number of PTS units this timebase represents, rounding toward zero.

Inverse of “multiplying a PTS value by this timebase to get seconds”. Saturates at i64::MAX if the duration is absurdly large for this timebase. Returns 0 if self.num() == 0 (a degenerate timebase).

Trait Implementations

impl Arbitrary for Timebase

fn arbitrary(__quickcheck_g: &mut Gen) -> Self

Return an arbitrary value.

fn shrink(&self) -> Box<dyn Iterator<Item = Self>>

Return an iterator of values that are smaller than itself.

impl<'a> Arbitrary<'a> for Timebase

Available on crate feature arbitrary only.

fn arbitrary(u: &mut Unstructured<'a>) -> Result<Self>

Generate an arbitrary value of Self from the given unstructured data.

fn arbitrary_take_rest(u: Unstructured<'a>) -> Result<Self, Error>

Generate an arbitrary value of Self from the entirety of the given unstructured data.

fn size_hint(depth: usize) -> (usize, Option<usize>)

Get a size hint for how many bytes out of an Unstructured this type needs to construct itself.

fn try_size_hint( depth: usize, ) -> Result<(usize, Option<usize>), MaxRecursionReached>

Get a size hint for how many bytes out of an Unstructured this type needs to construct itself.

impl Clone for Timebase

fn clone(&self) -> Timebase

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Timebase

impl Debug for Timebase

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

Formats the value using the given formatter.

impl Default for Timebase

fn default() -> Self

Returns the “default value” for a type.

impl DefaultInstance for Timebase

Available on crate feature buffa only.

fn default_instance() -> &'static Self

Return a reference to the single default instance of this type.

impl<'de> Deserialize<'de> for Timebase

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for Timebase

impl Hash for Timebase

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 Timebase

Available on crate feature buffa only.

fn compute_size(&self, _cache: &mut SizeCache) -> u32

Compute the encoded byte size of this message, recording nested sub-message sizes in cache for write_to to consume.

fn write_to(&self, _cache: &mut SizeCache, buf: &mut impl BufMut)

Write this message’s encoded bytes to a buffer, consuming nested-message sizes from cache (populated by a prior compute_size call on the same cache).

fn merge_field( &mut self, tag: Tag, buf: &mut impl Buf, ctx: DecodeContext<'_>, ) -> Result<(), DecodeError>

Processes a single already-decoded tag and its associated field data from buf.

fn clear(&mut self)

Clear all fields to their default values.

fn encode(&self, buf: &mut impl BufMut)

Compute size, then write. This is the primary encoding API.

fn encode_with_cache(&self, cache: &mut SizeCache, buf: &mut impl BufMut)

Encode using a caller-supplied SizeCache, for reuse across many encodes in a hot loop. Clears the cache first.

fn encoded_len(&self) -> u32

Compute the encoded byte size of this message.

fn encode_length_delimited(&self, buf: &mut impl BufMut)

Encode this message as a length-delimited byte sequence.

fn encode_to_vec(&self) -> Vec<u8>

Encode this message to a new Vec<u8>.

fn encode_to_bytes(&self) -> Bytes

Encode this message to a new bytes::Bytes.

fn decode(buf: &mut impl Buf) -> Result<Self, DecodeError>

where Self: Sized,

Decode a message from a buffer.

fn decode_from_slice(data: &[u8]) -> Result<Self, DecodeError>

where Self: Sized,

Decode a message from a byte slice.

fn decode_length_delimited(buf: &mut impl Buf) -> Result<Self, DecodeError>

where Self: Sized,

Decode a length-delimited message from a buffer.

fn merge_to_limit( &mut self, buf: &mut impl Buf, ctx: DecodeContext<'_>, limit: usize, ) -> Result<(), DecodeError>

Merge fields from a buffer until buf.remaining() reaches limit.

fn merge_group( &mut self, buf: &mut impl Buf, ctx: DecodeContext<'_>, field_number: u32, ) -> Result<(), DecodeError>

Merges a group-encoded message from buf, reading fields until an EndGroup tag with the given field_number is encountered.

fn merge( &mut self, buf: &mut impl Buf, ctx: DecodeContext<'_>, ) -> Result<(), DecodeError>

Merge fields from a buffer into this message.

fn merge_from_slice(&mut self, data: &[u8]) -> Result<(), DecodeError>

Merge fields from a byte slice into this message.

fn merge_length_delimited( &mut self, buf: &mut impl Buf, ctx: DecodeContext<'_>, ) -> Result<(), DecodeError>

Merge fields from a length-delimited sub-message payload into this message.

impl Ord for Timebase

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Timebase

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 PartialOrd for Timebase

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for Timebase

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.