Enum ConstantRate 

enum ConstantRate {
    Buffer,
    Unbounded,
    Seconds(f64),
}

What bounds the frames of a constant-rate session, by what the driver’s rate control does with each bound.

A buffer of vbv_bits (a frame and a half) with every frame capped at it is the tightest, and the default. Intel’s iHD stops coding under it: measured on Intel Arc at 1080p and 60 fps, its H.264 and HEVC rate controls skip every block and pad the frame with zeros up to the target once the buffer or the cap binds, and its AV1 one spends a third of the target, so a scroll sat at 19 to 20 dB at 2, 8, and 30 Mbit/s alike and a still screen was never refined. So on that driver H.264 and HEVC run with no bound of their own, where a still screen of text at 2 Mbit/s reaches 46 to 51 dB, and AV1, which takes no cap, in a buffer of IHD_AV1_BUFFER_S, which halved its largest frame. The driver’s low-delay frame tolerance holds an H.264 frame to three budgets, but leaves a still screen of dense text at 27 dB, every block skipped; a cap of six budgets cost HEVC 3 dB. Its VP9 refines in the default buffer and keeps it.

Variants

Buffer

The session’s buffer, and the frame cap where the driver takes one.

Unbounded

No buffer and no cap.

Seconds(f64)

A buffer of this many seconds of the target and no cap.

Trait Implementations

impl Clone for ConstantRate

fn clone(&self) -> ConstantRate

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ConstantRate

impl Debug for ConstantRate

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

Formats the value using the given formatter.

impl PartialEq for ConstantRate

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ConstantRate