Struct PcrTracker 

pub struct PcrTracker {
    pub max_jitter_27mhz: u32,
    /* private fields */
}

Per-PCR-PID PCR recovery + discontinuity detector.

Construct one per PCR_PID and call [observe] for every TS packet on that PID. Packets without a PCR are silently ignored (the tracker still reads them for the discontinuity_indicator flag, since §2.4.3.5 allows the indicator to be set in packets prior to the one carrying the new PCR).

The tracker keeps the last PCR + byte-offset to compute the instantaneous bitrate, and the previous pair so a fresh sample can have its jitter computed without a second sample arriving.

Fields

max_jitter_27mhz: u32

Threshold (in 27 MHz ticks) beyond which an unsignalled jump is reported as a discontinuity. Defaults to 100 ms × 27000 = 2 700 000 ticks. The spec says ±500 ns is the spec tolerance; real-world re-mux jitter is far higher (tens of milliseconds) so we use a window large enough to ignore schedule wobble but small enough to catch a clean time-base reset.

Implementations

impl PcrTracker

pub const DEFAULT_MAX_JITTER_27MHZ: u32 = 2_700_000

Default jitter window: 100 ms.

At 27 MHz that’s 2 700 000 ticks. Comfortably above the ±500 ns spec PCR tolerance but tight enough that a clean re-mux time-base reset (which jumps by seconds or hours) fires the discontinuity path.

pub fn new() -> Self

Build a tracker with the default jitter window.

pub fn with_jitter_window(max_jitter_27mhz: u32) -> Self

Build a tracker with a custom jitter window (27 MHz ticks).

pub fn observe( &mut self, af: &AdaptationField<'_>, byte_offset: u64, ) -> Option<PcrEvent>

Observe one packet’s adaptation field.

byte_offset is the position of this packet’s first byte in the contiguous TS stream. It only needs to be monotonic; the tracker uses differences, not absolute values. Typical callers pass bytes_read - 188.

Returns None when the packet had no PCR and no pending discontinuity to commit.

pub fn last_pcr(&self) -> Option<Pcr>

Most recent PCR sample, if any.

pub fn reset(&mut self)

Discard accumulated state — useful after the demuxer independently detects an EOF + restart (e.g. an HLS discontinuity boundary between two segments).

Trait Implementations

impl Clone for PcrTracker

fn clone(&self) -> PcrTracker

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PcrTracker

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

Formats the value using the given formatter.

impl Default for PcrTracker

fn default() -> Self

Returns the “default value” for a type.