Struct SvcConfig 

pub struct SvcConfig {
    pub num_temporal_layers: u8,
    pub num_spatial_layers: u8,
    pub temporal_layers: Vec<TemporalLayerConfig>,
    pub spatial_layers: Vec<SpatialLayerConfig>,
    pub operating_points: Vec<OperatingPoint>,
    pub inter_layer_prediction: bool,
}

SVC (Scalable Video Coding) configuration for AV1.

AV1 supports temporal scalability through operating points defined in the sequence header. Each operating point specifies which temporal and spatial layers are included, enabling adaptive streaming where decoders can drop higher layers for lower latency or bandwidth.

Temporal Layer Structure

T0: I----P---------P---------P    (base layer, always decodable)
T1:      |    P         P         (enhancement, depends on T0)
T2:      |  P   P     P   P      (highest, depends on T0+T1)

Example

use oximedia_codec::av1::sequence::{SvcConfig, TemporalLayerConfig};

let mut svc = SvcConfig::new(3, 1); // 3 temporal, 1 spatial
svc.set_temporal_layer(0, TemporalLayerConfig {
    layer_id: 0,
    framerate_fraction: 0.25,
    bitrate_fraction: 0.5,
    qp_offset: 0,
    reference_mode: SvcReferenceMode::KeyOnly,
});

Fields

num_temporal_layers: u8

Number of temporal layers (1-8).

num_spatial_layers: u8

Number of spatial layers (1-4).

temporal_layers: Vec<TemporalLayerConfig>

Per-layer temporal configuration.

spatial_layers: Vec<SpatialLayerConfig>

Per-layer spatial configuration.

operating_points: Vec<OperatingPoint>

Operating points derived from layer configuration.

inter_layer_prediction: bool

Enable inter-layer prediction.

Implementations

impl SvcConfig

pub fn new(temporal_layers: u8, spatial_layers: u8) -> Self

Create a new SVC configuration.

Arguments

• temporal_layers - Number of temporal layers (clamped to 1-8)
• spatial_layers - Number of spatial layers (clamped to 1-4)

pub fn set_temporal_layer(&mut self, layer_id: u8, config: TemporalLayerConfig)

Set configuration for a specific temporal layer.

Arguments

• layer_id - Temporal layer index (0-based)
• config - Layer configuration

pub fn set_spatial_layer(&mut self, layer_id: u8, config: SpatialLayerConfig)

Set configuration for a specific spatial layer.

pub fn get_operating_point( &self, temporal_id: u8, spatial_id: u8, ) -> Option<&OperatingPoint>

Get operating point for given temporal and spatial IDs.

pub fn num_operating_points(&self) -> usize

Get total number of operating points.

pub fn frame_temporal_layer(&self, frame_index: u64) -> u8

Determine which temporal layer a frame belongs to based on its index.

Uses a dyadic temporal structure:

• Layer 0 (base): frames 0, 4, 8, … (for 3 layers)
• Layer 1: frames 2, 6, 10, …
• Layer 2: frames 1, 3, 5, 7, …

pub fn frame_qp_offset(&self, frame_index: u64) -> i8

Get QP offset for a frame based on its temporal layer.

pub fn is_droppable(&self, frame_index: u64) -> bool

Check if a frame at given index can be dropped without affecting lower temporal layers.

pub fn frame_reference_mode(&self, frame_index: u64) -> SvcReferenceMode

Get the reference mode for a frame based on its temporal layer.

pub fn validate(&self) -> CodecResult<()>

Validate the SVC configuration.

Errors

Returns error if the configuration is inconsistent.

Trait Implementations

impl Clone for SvcConfig

fn clone(&self) -> SvcConfig

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SvcConfig

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

Formats the value using the given formatter.