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payload_starts_keyframe

o_sfu_rfc::rtp::vp8

Function payload_starts_keyframe 

Source 
pub fn payload_starts_keyframe(payload: &[u8]) -> bool
Expand description

Detects a complete VP8 keyframe prefix in the first RTP packet.

RFC 7741 section 4.2 defines the VP8 payload descriptor. A decodable keyframe starts at partition 0 (S=1, PartID=0) and the VP8 payload header starts with P=0. RFC 6386 section 9.1 defines the keyframe sync code and dimensions. The input must be the RTP codec payload.

Truncated descriptors, missing payload headers and non-start partitions return false. The helper performs only the cheap keyframe probe needed by packet gates and decoder-refresh detection.