Struct TwoPassStateTracker 

pub struct TwoPassStateTracker { /* private fields */ }

Lightweight two-pass VBR state tracker.

Provides a simplified API for recording per-frame complexity values during the first pass and computing per-frame bitrate targets during the second pass.

Usage

use oximedia_codec::vbr_twopass::TwoPassStateTracker;

let mut state = TwoPassStateTracker::new();
state.record_first_pass(1.5); // frame 0
state.record_first_pass(0.8); // frame 1
state.record_first_pass(2.3); // frame 2

let bits_frame0 = state.compute_bitrate(1.5, 4_000_000);
assert!(bits_frame0 > 0);

Implementations

impl TwoPassStateTracker

pub fn new() -> Self

Create a new, empty state tracker.

pub fn record_first_pass(&mut self, complexity: f32)

Record a complexity value for one frame during the first pass.

complexity must be a non-negative floating-point value. Typical values are SAD-normalised intra/inter costs in the range 0.1 – 20.0.

pub fn compute_bitrate(&self, complexity: f32, budget: u32) -> u32

Compute the per-frame bitrate target for a frame with the given complexity.

Uses complexity-proportional allocation:

target_bits = budget * complexity / sum(all_complexities)

If the accumulated first-pass data is empty the entire budget is returned (no-op case).

Parameters

• complexity – complexity value of the current frame (should have been recorded via Self::record_first_pass).
• budget – total bit budget for the session (bits).

Returns

Target number of bits for this frame, as a u32. Clamped to at least 1 and at most budget.

pub fn frame_count(&self) -> usize

Returns the number of frames recorded in the first pass.

pub fn total_complexity(&self) -> f32

Returns the total accumulated complexity.

pub fn mean_complexity(&self) -> f32

Returns the average complexity per frame.

Trait Implementations

impl Clone for TwoPassStateTracker

fn clone(&self) -> TwoPassStateTracker

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TwoPassStateTracker

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

Formats the value using the given formatter.

impl Default for TwoPassStateTracker

fn default() -> TwoPassStateTracker

Returns the “default value” for a type.