Struct AudioFrameGrid 

pub struct AudioFrameGrid {
    pub anchor: i64,
    pub period: i64,
    pub start_tolerance: i64,
    pub trimmed_tolerance: i64,
}

The source samples an audio stream’s frames start at, read from its first packets’ timestamps (audio_frame_grid): every period samples from anchor, at the stream’s rate.

A container that rounds timestamps (Matroska and WebM to the millisecond) stores a frame up to half its unit from where the frame starts, so the timestamp alone says where a frame starts only to that half unit, which is 24 samples at 48 kHz. A decode straight through places each frame where the one before it ended and is off by whatever the first timestamp was; a seek places the first frame after it by that frame’s own timestamp and is off by another amount. A codec whose frames are all one length (AAC’s 1024 samples, Opus’s 20 ms) puts every frame on one grid, and the first timestamps together say where it lies far more closely than any one of them: placing a first frame on it gives the samples a decode straight through gives, however it is reached.

Fields

anchor: i64

A source sample, at the stream’s rate, that a frame starts at.

period: i64

The samples in every frame.

start_tolerance: i64

The farthest a frame’s timestamp, as a sample, is from the start it stands for: half the rounding unit and the half sample of rounding it to a sample, rounded down to a whole sample after adding one.

trimmed_tolerance: i64

The farthest the end of a frame shorter than period is from the grid: a decoder that drops a codec’s delay from the first frame after a start or a seek (Opus’s pre-skip) moves its timestamp by the samples dropped, rounded to the unit again, so twice the half unit and a sample.

Implementations

impl AudioFrameGrid

pub fn place(&self, at: i64, frames: i64) -> i64

Where a frame of frames samples whose timestamp puts it at source sample at starts: on the grid when its timestamp is within the grid’s rounding of it, otherwise at at.

A frame shorter than Self::period is first taken as the end of a frame a decoder dropped the start of (Opus’s pre-skip, after a start or a seek): it ends on the grid. Otherwise a frame starts on it.

Trait Implementations

impl Clone for AudioFrameGrid

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for AudioFrameGrid

impl Debug for AudioFrameGrid

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

Formats the value using the given formatter.

impl Eq for AudioFrameGrid

impl PartialEq for AudioFrameGrid

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for AudioFrameGrid