Module frame_marking 

Video Frame Marking RTP header-extension payload values.

Frame marking is carried as one negotiated RTP header extension

These helpers retain temporal-layer fields for future negotiated SVC selection while current packet gates match simulcast RIDs

Short form, non-scalable stream

+---+---+---+---+---------------+
| S | E | I | D | reserved      |
+---+---+---+---+---------------+

Long form, scalable stream

+---+---+---+---+---+-----------+---------------+---------------+
| S | E | I | D | B | TID       | LID           | TL0PICIDX     |
+---+---+---+---+---+-----------+---------------+---------------+
| first octet                    | optional      | optional      |
+---+---+---+---+---+-----------+---------------+---------------+

Reference: RFC 9626 section 3.

Constants

BASE_LAYER_ID

Base layer identifier used for TID and LID.

BASE_LAYER_SYNC_MASK

Base-layer-sync flag in the long-form first octet.

DISCARDABLE_FRAME_MASK

Discardable-frame flag in the first frame-marking octet.

END_OF_FRAME_MASK

End-of-frame flag in the first frame-marking octet.

INDEPENDENT_FRAME_MASK

Independent-frame flag in the first frame-marking octet.

LONG_DATA_LEN_FLAGS_ONLY

Long-form payload length when both LID and TL0PICIDX are omitted.

LONG_DATA_LEN_WITHOUT_TL0PICIDX

Long-form payload length when TL0PICIDX is omitted.

LONG_DATA_LEN_WITH_TL0PICIDX

Full long-form frame-marking payload length.

SHORT_DATA_LEN

Short-form non-scalable frame-marking payload length.

START_OF_FRAME_MASK

Start-of-frame flag in the first frame-marking octet.

TEMPORAL_LAYER_ID_MASK

Temporal-layer identifier bits in the long-form first octet.

TEMPORAL_LAYER_ID_MAX

Maximum temporal-layer identifier representable by the 3-bit TID field.

Functions

is_valid_temporal_layer_id

Returns whether value fits in the RFC 9626 three-bit temporal-layer field.

temporal_layer_id

Extracts the temporal-layer ID from the first long-form frame-marking octet.