v4.5.0 — Public video API (transport-only)

[4.5.0] - 2026-07-15

Added

• Public video API (transport-only): send and receive encoded video frames over the public
  facade. client.Media.CreateVideoReceiver() exposes inbound frames via
  IVideoReceiver.FrameReceived (a VideoFrame: encoded payload, RTP payload type, 90 kHz
  timestamp, key-frame flag); client.Media.CreateVideoSender().SendAsync(VideoFrame) injects
  outbound encoded frames. The SDK negotiates the video m-line, packetizes/depacketizes RTP
  (VP8, H.264) and moves the bytes — it never encodes or decodes. Bring your own codec.
• Recommended outbound video bitrate: IVideoSender.RecommendedBitrateBps and
  NetworkQuality (Good/Fair/Poor) are derived from transport-cc feedback, with a
  RecommendedBitrateChanged event so you can size your encoder to the network in one line
  (sender.RecommendedBitrateChanged += (_, e) => encoder.SetBitrate(e.RecommendedBitrateBps)).
• Keyframe handling: inbound frames carry VideoFrame.IsKeyFrame (VP8 P-bit, H.264 IDR);
  IVideoSender.KeyFrameRequested fires when the peer requests a fresh reference frame (RTCP
  PLI/FIR) so you can force an intra frame. On inbound loss the SDK reports it to the peer
  (Generic NACK + throttled PLI, RFC 4585) gated on the peer's advertised feedback. FIR is
  honoured on receive but not generated.
• Default-video convenience: client.AttachDefaultVideoAsync(call) /
  DetachDefaultVideoAsync(call) wire an application-supplied IVideoDevice (your codec
  package: capture + encode + decode + render) to the call, mirroring
  AttachDefaultAudioAsync. The device is resolved from dependency injection and receives the
  negotiated codec via VideoConnectionParameters; without a registered IVideoDevice the
  attach fails closed (the core ships no codec). Negotiated video parameters are readable on
  ICall.MediaParameters.Video (CallVideoParameters).
• Example: examples/CalloraVoipSdk.Sample.VideoCalling wires a video call over the public
  API only, including the bitrate hook against a marked StubVideoEncoder placeholder.