Ednunp
6d6d6897e4
Single biggest change: added the Concentus.Native NuGet package. Concentus 2.0+ auto-detects native libopus at runtime and routes encode calls through it; encoder state lives on the C side and is reused across calls rather than `new`ing ~15 working buffers per call (Concentus issue #22, open since 2018). Measured on the desktop test at 15:36:55 — Opus 10 ms allocation rate dropped from 4,625 KB/s to 108 KB/s, a 97.7% reduction. Process CPU dropped from 4.7% to 1.6% in the same config. Audio is bit- for-bit identical (it's literally the same encoder, just better packaged). `OpusEncoderState.cs` itself unchanged on the call site. Diagnostic / measurement layer (gated on Enable-logs, zero cost when off): * ProcessSelfMeter: CPU%, managed heap MB, working set MB, allocation rate per second, GC counts per generation * Per-thread work-time counters: captureMs / sendMs / recvMs / renderMs expressed as milliseconds of CPU consumed by each audio thread per second * Inter-packet arrival gap measured at the user-space UDP socket (rxNetGapMs) — pinpoints whether arrival jitter is in the network or our own dispatch path Small efficiency wins (each one was small but cumulative): * deviceRefreshTimer interval 1s -> 3s (item 4) * WaitHandle array allocations eliminated in MixingEngine.MixLoop and MultiOutputPlayout.ProduceLoop (item 6) * MultiOutputPlayout caches its output-buffer snapshot and only rebuilds on SetOutputDevices, instead of rebuilding every 10 ms (item 7) * HeartbeatService reuses an outbound ping byte[] instead of allocating per send (item 14) * PeerDiscoveryService caches broadcast addresses and invalidates on Windows' NetworkChange event instead of walking all NICs every 1.5 s (item 16) Legacy / dead-code removal: * KeepAlive packet's implementation (struct, enums, writer, reader, size constant) — all dead since HeartbeatService landed 2026-05-06. Kept the RemPacketType.KeepAlive enum value and silent-drop dispatch for wire compat with any pre-2026-05-06 build still in the wild (item 30) * driftDropFramesTotal / driftRepeatFramesTotal fields and accessors — Phase-2 splice corrector relics, never incremented since Phase-4 resampler design landed; backed five always-zero diag log columns (items 34 + 35) * DriftAccumulator (always returned 0) — same shape, removed alongside the driftAcc= column (item 35) * TakeMaxFanOutCacheBytes / Ms + fanCacheMs column — FanOutSource was retired in May (item 36) Project documentation: * RemSoundefficiency.md added as the canonical record of the efficiency analysis, every item's status, and the measured wins from this round * Honest item-by-item review of the original 50-item list — several items I had sized optimistically in the original analysis turned out to be already-done (item 20), already-optimal (item 22), or below the meter floor (items 9, 15, 17, 25). Recorded so future passes don't re-investigate. Wire format and audio pipeline unchanged from v1.5 onward — v1.5 through v2.2 peers interoperate.
RemSound
Low-latency peer-to-peer audio between two or more Windows PCs over UDP. Pick what each machine captures and what it plays back; audio flows directly between them, no central server.
Built for music collaboration over the internet, live monitoring across rooms in a house, podcast co-hosting, NVDA-Remote audio workflows, and anything else that wants "send the sound from this PC to that PC, fast".
Highlights
- WASAPI and ASIO side by side. Run them as two independent UDP streams at their own native latencies, or use WASAPI alone. ASIO drivers get hardware-clocked timing; WASAPI gets push-mode timing on single-source captures.
- Profiles. Save your full setup (device ticks, peers, codec, latency targets, hotkeys, ASIO driver) into one JSON file. Pick which profile to load at launch.
- Continuous auto-tune. Watches receive jitter and nudges the latency target to stay click-free without forcing you to overshoot. Independent per-lane in WASAPI+ASIO mode.
- Opus with inband FEC. Single-packet losses recover transparently — no click. PCM 24-bit 48 kHz is also available for clean LAN.
- Remote control hotkeys. Configurable global hotkeys can nudge a peer's RemSound volume or their Windows system master volume, opt-in on the receiver.
- Built-in self-updater. Optional GitHub-driven update check on a schedule you set.
- Designed for screen readers. Each control has a paired Alt+letter mnemonic. State changes raise the right UIA notifications. F1 anywhere opens the user manual.
Install
- Download the latest
RemSound-vX.Y.zipfrom Releases. - Extract somewhere it can write — e.g.
C:\RemSound\, yourDocuments, or a folder in your user profile. AvoidProgram Filesunless you grant write permission to the install folder (the self-updater needs to overwrite files in place). - Run
RemSound.exe. On first launch Windows Firewall will prompt — allow on private networks. - Open the user manual from the Help menu (or press F1) for the full walkthrough.
RemSound requires the .NET 10 Desktop Runtime. If it's not installed, Windows offers to fetch it on first launch. You can also install it from https://dotnet.microsoft.com/download/dotnet/10.0 (pick the "Windows x64 Desktop Runtime").
Updates
RemSound can check this repository's Releases page on a schedule (never, hourly, every 6 hours, every 24 hours) and either prompt you to install or do it silently. Configure via File → Preferences. You can also trigger a manual check from the Help menu or the same Preferences dialog.
Build from source
You need the .NET 10 SDK. The solution lives at RemSound.slnx.
cd D:\proj\RemSound
dotnet build -c Release
dotnet publish src\RemSound.App\RemSound.App.csproj -c Release
The publish output lands at src\RemSound.App\bin\Release\net10.0-windows\publish\. Copy its contents into a folder of your choice — or zip it for distribution. Don't enable PublishSingleFile or SelfContained=true; RemSound ships framework-dependent on purpose so the publish folder stays under 2 MB.
Project layout
src/RemSound.Core packet protocol, peer discovery, hotkeys, MMCSS, heartbeat, settings, AppConfig
src/RemSound.Sender capture → mix → encode → UDP send
src/RemSound.Receiver UDP receive → ring buffer → drift-corrected playout → render
src/RemSound.Harness console test program (1 sender → 1 receiver, no UI)
src/RemSound.App WinForms UI (sender + receiver + heartbeat + discovery + updater)
server/ optional Raspberry Pi / systemd-Linux relay bundle (see below)
Optional: running your own relay server
Two RemSound peers normally reach each other directly over your LAN, or via Tailscale across the internet. If neither of those work for your situation — for example one peer is behind a router that won't forward inbound UDP and you'd prefer not to use Tailscale — you can run a small Python relay on a publicly-reachable host (a Raspberry Pi at home with one UDP port forwarded works fine) and have both peers dial that.
The server/ folder in this repo is a self-contained bundle: relay script, systemd unit, install / uninstall / smoke-test scripts, and a step-by-step README. See server/README.md for the setup walkthrough.
Issues and feedback
Open an issue on the GitHub issues page. If reporting an audio problem, please tick File → Preferences → Enable logs, reproduce the issue, then attach the latest log file from logs\ next to RemSound.exe.
Licence
MIT. See LICENSE.