Struct TranscodeEstimator 

pub struct TranscodeEstimator;

Analytical estimator for transcoding resource and quality metrics.

All methods are pure functions — they perform no I/O and no actual encoding. Results are approximations useful for pre-flight planning (UI display, job scheduling, storage budgeting) rather than precise measurements.

Implementations

impl TranscodeEstimator

pub fn estimate_size_bytes( duration_secs: f64, video_bitrate_kbps: Option<u32>, audio_bitrate_kbps: Option<u32>, ) -> u64

Estimates the output file size in bytes.

Uses the combined bitrate of video and audio streams to compute the expected byte count for a given duration.

Arguments

• duration_secs — Content duration in seconds.
• video_bitrate_kbps — Video bitrate in kilobits per second (or None for audio-only output).
• audio_bitrate_kbps — Audio bitrate in kilobits per second (or None for video-only output).

pub fn estimate_speed_factor( codec: &str, preset: &str, resolution_pixels: u64, ) -> f32

Estimates the encoding speed factor relative to real-time.

A factor of 1.0 means encoding takes as long as the source duration. A factor of 0.5 means encoding takes half the source duration (2× faster than real-time), while 4.0 means encoding takes four times longer than the source (0.25× real-time).

Arguments

• codec — Codec name (e.g. "av1", "vp9", "h264", "flac", "opus").
• preset — Encoder preset string (e.g. "slow", "fast", "ultrafast").
• resolution_pixels — Total pixel count (width × height; use 0 for audio-only streams).

pub fn estimate_vmaf(bitrate_kbps: u32, resolution_pixels: u64) -> f32

Estimates perceptual video quality as an approximate VMAF score (0–100).

The estimate is derived from the bits-per-pixel metric and a logarithmic saturation curve that reflects empirically observed VMAF behaviour. It is not a substitute for actual VMAF measurement.

Arguments

• bitrate_kbps — Video bitrate in kilobits per second.
• resolution_pixels — Total pixel count (width × height).

Returns

An estimated VMAF score in the range [0.0, 100.0].

Trait Implementations

impl Clone for TranscodeEstimator

fn clone(&self) -> TranscodeEstimator

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TranscodeEstimator

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

Formats the value using the given formatter.