sip_helper 0.3.0

A lightweight SIP/VoIP library for Dart. SIP protocol (UDP), RTP audio transport, G.711 A-law codec, and platform-native audio I/O.

0.3.0

• Breaking: cross-platform audio abstraction — WinAudioPlayer, WinAudioRecorder, WinAudioDevices are no longer exported from the barrel file. Use AudioPlatform.instance.createPlayer(), AudioPlatform.instance.createRecorder(), and AudioPlatform.instance.devices instead.
• New abstract interfaces: AudioPlayer, AudioRecorder, AudioDevices for platform-agnostic audio.
• AudioPlatform singleton auto-detects the platform at runtime (Windows → WinMM, others → stub).
• Custom audio backends can be registered via AudioPlatform.override().
• Removed platforms: windows: restriction — SIP/RTP/codec now works on all Dart platforms.
• Stub backend allows graceful degradation on unsupported platforms (audio returns false from open()).

0.2.3

• Fix: local IP detection — TCP connect to server is now the primary method (OS picks correct route). Falls back to subnet matching, then interface name heuristic. Fixes wrong IP on machines with Hyper-V/WSL virtual adapters.

0.2.2

• Fix: local IP detection now picks the interface that can route to the SIP server instead of grabbing the first 192.168.* address. Uses UDP probe with TCP and NetworkInterface fallbacks.

0.2.1

• Fix: add rport to all SIP Via headers for NAT traversal — fixes incoming calls failing with "unavailable".
• Fix: send 100 Trying immediately on incoming INVITE before 180 Ringing to prevent server timeout.

0.2.0

• Feature: call hold and resume via SIP re-INVITE (holdCall, unholdCall).
• Feature: remote hold detection (HELD/RESUMED/REMOTE_HELD/REMOTE_RESUMED states).
• Feature: activeCalls getter to query all current calls.
• Feature: proper incoming re-INVITE handling with SDP direction negotiation.
• Fix: hanging up an outgoing call while ringing now sends SIP CANCEL instead of BYE.
• Fix: late 200 OK received after CANCEL is properly ACKed and followed by BYE.
• Fix: 487/486/603 final responses are now ACKed correctly.
• Fix: ACK direction-aware for incoming call dialogs.

0.1.2

• Updated dependencies: ffi ^2.2.0, crypto ^3.0.7, lints ^6.1.0, test ^1.30.0.

0.1.1

• Fix: AudioPlayerService was not initialized by SipHelper, causing no voice playback during calls.

0.1.0

• Initial release.
• SIP protocol support over UDP (REGISTER, INVITE, BYE, ACK, CANCEL).
• RTP audio transport with sequence numbering and timestamping.
• G.711 A-law (PCMA) encoder and decoder.
• Windows audio capture and playback via WinMM FFI.
• Audio level metering (RMS-based, normalized 0.0-1.0).
• Pure Dart SIP configuration and call info models.
• Pluggable logging abstraction.