User reported persistent crackling/popping from peer audio on Linux even
after fixing the 48k->device-rate resampler boundary discontinuities,
clamping pre-Opus-encode peaks, and pre-allocating the playback scratch
buffer. Logs confirmed cpal opened raw ALSA at 44.1k native, no callback
budget violations, no underrun warnings -- yet the audio was still poor.
Root cause: cpal on Linux opens raw ALSA's 'default' PCM. On modern
PipeWire / pipewire-alsa boxes that virtual device routes through ALSA's
dmix + plug layers, whose default resampler is nearest-neighbour. cpal
also picks a small default period size (~256 frames / 5.8 ms) leaving no
headroom for kernel scheduler jitter. Both effects compound into the
crackling the user heard.
Upstream tsclientlib's own audio example
(tsclientlib/examples/audio_utils/ts_to_audio.rs) and the official Qint
client both use SDL2 with AudioSpecDesired { freq: 48000, channels: 2,
samples: 960 }. SDL2 on the same systems routes through PipeWire's PA
bridge (or PulseAudio directly), both carrying high-quality resamplers.
Fix:
* Add sdl2 = '0.37' as a target_os=linux dependency. Links libSDL2-2.0
.so (Arch sdl2-compat over SDL3, Debian libsdl2-2.0-0, Fedora SDL2).
* New module crates/chanora_audio/src/sdl_output.rs implementing
SdlOutput: opens a 48 kHz stereo 960-frame callback that zeroes the
buffer and calls AudioHandler::fill_buffer directly (no user-side
resampler). Master gain + hard-mute atomics wired in identically to
the cpal callback so set_output_gain / set_output_muted keep working.
* engine.rs cfg-gated: target_os='linux' builds SdlOutput; everywhere
else continues with the cpal output path (including the device-native-
rate negotiation and resampler-continuity fixes shipped earlier --
those remain correct on Windows/macOS where cpal targets WASAPI /
CoreAudio cleanly).
* The cpal output helpers (build_output_stream, PlaybackResampleState,
FromF32) are now cfg(not(target_os='linux'))-gated so the Linux
build doesn't emit dead-code warnings.
Capture path still cpal on every platform -- outbound audio was not
reported as bad. Resampler-continuity fix on the capture side stays:
microphone -> Opus encoder still goes through the linear interpolator
with the last-sample anchor.
Tests: 32 / 0 / 0 (chanora_audio), workspace 78 / 0 / 1 unchanged.
Chanora
Chanora is a cross-platform voice communication client for TeamSpeak-compatible servers.
It is built with a shared Flutter UI and a Rust core, with TeamSpeak-compatible protocol integration isolated behind tsclientlib.
Flutter UI + Rust Core + tsclientlib
Chanora is an independent project and is not affiliated with, endorsed by, sponsored by, or officially associated with TeamSpeak.
Status
Chanora is currently in early planning and baseline-candidate design.
Current documentation baseline: v0.9.2
Current status: Baseline Candidate
Implementation status: Not production-ready
The current engineering focus is:
- defining the system and software architecture;
- preparing the Flutter + Rust application structure;
- validating TeamSpeak-compatible protocol integration through
tsclientlib; - defining cross-platform audio behavior;
- preparing release, verification, security, privacy, and legal gates.
Target Platforms
Chanora is intended to support:
- Windows
- macOS
- Linux
- Android
- iOS / iPadOS
Current platform policy:
| Platform | Baseline |
|---|---|
| iOS / iPadOS runtime target | iOS 13+ unless Flutter, plugin, audio, or product constraints require raising it |
| App Store Connect upload gate | Xcode 26+ with iOS 26 / iPadOS 26 SDK+ for upload on or after 2026-04-28 |
| Android runtime target | Android API 24+ unless Flutter, plugin, audio, or product constraints require raising it |
| Google Play target API | Target the Google Play-required API level on upload date |
The App Store / Play Store upload gates are release requirements. They are separate from local development and internal testing requirements.
Architecture Overview
Chanora separates UI, protocol logic, state synchronization, audio processing, diagnostics, and platform services.
Flutter Application
├─ App Shell
├─ Material 3 / Chanora Design System
├─ Feature Modules
├─ View Models / State
└─ Typed Flutter/Rust Bridge
Rust Core
├─ Connection Manager
├─ State Synchronization
├─ Protocol Adapter
├─ Audio Subsystem
├─ Storage Services
└─ Diagnostics
Protocol Layer
└─ tsclientlib
└─ TeamSpeak-compatible server
Key architecture rules:
- Flutter does not call
tsclientlibdirectly. - Protocol-specific types do not leak into the Flutter UI layer.
- Rust Core owns protocol coordination, state synchronization, audio logic, storage services, diagnostics, and bridge-facing DTOs.
- Flutter owns presentation, navigation, Material 3 theming, accessibility, localization presentation, and platform UI behavior.
- Product localization and server-provided content are separated.
- UTF-8 is the internal cross-layer text representation.
- Non-UTF-8 conversion, if needed, occurs only at explicit protocol or platform boundaries.
MVP Direction
The current recommended MVP scope is:
| Area | MVP decision |
|---|---|
| Active server connections | One active server connection per client instance |
| UI baseline | Material 3 + Chanora Design System |
| Product language | English UI first, i18n-ready architecture |
| Server content | Preserve Unicode and do not translate server-provided content |
| Audio processing defaults | Echo Canceller, Automatic Gain Control, Noise Suppression, and High-Pass Filter enabled where supported and stable |
| Audio implementation path | Platform-native first; fallback isolated behind the audio subsystem |
| Local non-secret storage | SQLite or equivalent embedded database |
| Secret storage | Platform secure storage |
| Flutter/Rust bridge | Stable typed bridge with generated or schema-controlled DTOs |
| Diagnostics | Local, user-initiated export only |
| Telemetry | None in MVP |
| Crash reporting | Disabled unless explicitly approved later |
Desktop Push-to-Talk
Chanora's desktop Push-to-Talk (PTT) follows a capability-based design (see
docs/architecture/desktop-ptt-architecture.md).
Focused PTT — the user holds a bound key or mouse button inside the
focused Chanora window — is mandatory on Windows, macOS, and Linux.
Global PTT (recognised while the application is not focused) is
capability-dependent: it requires the operating system, the
user-granted permission set, the display server, and the available
input backend to all permit it.
The application reports a PttCapabilityLevel (L0Focused,
L1GlobalShortcut, L2GlobalHoldToTalk, L3GlobalWithMouseButtons)
that matches actual runtime behaviour, not the platform's theoretical
maximum. The UI capability badge shows the live value.
Per-platform strategy (resolved by owner rulings 2026-05-15, see
docs/governance/product-decision-register.md DEC-023 through
DEC-028):
- Windows — Raw Input first, low-level keyboard hook fallback, Focused PTT terminal fallback. Mouse side buttons supported. P0 / MVP.
- macOS — permission-aware Event Tap with Focused PTT fallback; Global PTT upgrades asynchronously when the user grants Input Monitoring / Accessibility. P0 / MVP.
- Linux — officially tested on GNOME on Wayland using the
org.freedesktop.portal.GlobalShortcutsinterface; every other Linux environment falls back to Focused PTT. Release notes do not claim Global PTT support outside the tested compositor. - Raw key codes, scan codes, virtual-key values, keysyms, and key-press timing sequences are never logged or included in the user-initiated diagnostic export. The diagnostic export carries only capability level, backend identifier, and bound input class.
A missed-key-up watchdog (default 30 s) clears transmit_active
when the OS suppresses a key-up event so a stuck-PTT bug class is
ruled out by construction.
Repository Layout
The repository documentation is expected to live under docs/.
docs/
requirements/
sysrs.md
srs.md
architecture/
sysdes.md
sad.md
sdd.md
verification/
verification-master-plan.md
swe4-unit-verification-plan.md
swe5-software-integration-verification-plan.md
swe6-software-verification-plan.md
sys4-system-integration-verification-plan.md
release/
release-readiness-go-nogo-record.md
platform-release-policy.md
security/
security-privacy-legal-guideline.md
threat-model.md
secure-storage-audit-report.md
diagnostic-redaction-audit-report.md
dependency-and-supply-chain-report.md
privacy/
privacy-policy.md
legal/
trademark-and-attribution-review.md
ui-ux/
material3-guideline.md
material3-design-tokens.md
material3-component-catalog.md
adaptive-layout-platform-guide.md
i18n/
localization-architecture.md
governance/
document-index.md
document-naming-convention.md
traceability-matrix.md
baseline-approval-record.md
baseline-candidate-validation-report.md
document-review-report.md
product-decision-register.md
decision-impact-assessment.md
git-commit-message-convention.md
repo-format-validation-report.md
path-migration-map.md
references/
external-references.md
aspice-swe2-swe3-integration-note.md
Implementation source folders may be added later. A likely structure is:
apps/
chanora_flutter/
core/
chanora_core/
crates/
chanora_protocol/
chanora_audio/
chanora_state/
chanora_storage/
chanora_diagnostics/
chanora_bridge/
The exact implementation layout should be finalized when the repository scaffold is created.
Documentation Entry Points
Start here:
| Topic | Document |
|---|---|
| System requirements | docs/requirements/sysrs.md |
| Software requirements | docs/requirements/srs.md |
| System architecture | docs/architecture/sysdes.md |
| Software architecture | docs/architecture/sad.md |
| Software detailed design | docs/architecture/sdd.md |
| Verification strategy | docs/verification/verification-master-plan.md |
| Release readiness | docs/release/release-readiness-go-nogo-record.md |
| Platform release policy | docs/release/platform-release-policy.md |
| Product decisions | docs/governance/product-decision-register.md |
| Traceability | docs/governance/traceability-matrix.md |
| Security/privacy/legal gates | docs/security/security-privacy-legal-guideline.md |
Engineering Process
Chanora follows this documentation hierarchy:
SysRS -> SysDes -> SRS -> SAD -> SDD
Direct traceability rules:
| Document | Direct upstream source |
|---|---|
| SysDes | SysRS |
| SRS | SysDes only |
| SAD | SRS only |
| SDD | SAD only |
Verification mapping:
SDD -> SWE.4 Unit Verification
SAD + SDD -> SWE.5 Software Integration Verification
SRS -> SWE.6 Software Verification
SysDes -> SYS.4 System Integration Verification
Release readiness is tracked separately through the Go/No-Go record.
Release Readiness
A release is not approved by design documents alone.
Before an external or public release, the project must complete:
docs/release/release-readiness-go-nogo-record.md
The release decision must explicitly state:
Go
Conditional Go
No-Go
Release readiness must include:
- release scope;
- build number;
- commit SHA;
- Git tag;
- artifact hashes;
- satisfied P0/MVP requirements;
- deferred requirements;
- verification results;
- waivers;
- security review status;
- platform readiness;
- legal and OSS review status;
- privacy policy status;
- approval decision and approvers.
Security, Privacy, and Legal Gates
Security, privacy, and legal evidence are required before public or store release.
Required documents include:
docs/security/threat-model.md
docs/security/secure-storage-audit-report.md
docs/security/diagnostic-redaction-audit-report.md
docs/security/dependency-and-supply-chain-report.md
docs/privacy/privacy-policy.md
docs/legal/trademark-and-attribution-review.md
Important gates:
- identity secrets and server passwords must use platform secure storage;
- logs and diagnostic exports must redact secrets;
- diagnostic export must be user-initiated unless a later approved policy changes this;
- dependency licenses and vulnerabilities must be reviewed;
- OSS notices must be prepared where required;
- public wording must not imply official TeamSpeak affiliation;
- privacy policy must describe local storage, diagnostics, permissions, and data handling.
Git Commit Convention
Chanora uses a Conventional Commits style format:
<type>(<scope>): <summary>
Examples:
feat(voice): add push-to-talk state handling
fix(protocol): recover channel tree after reconnect snapshot
docs(sad): add interface catalog and performance view
i18n(ui): add fallback behavior for missing localization keys
sec(diagnostics): redact server password from export bundle
release(android): prepare internal alpha build metadata
See:
docs/governance/git-commit-message-convention.md
Development
Implementation commands will be added after the repository scaffold is finalized.
Expected future commands may include:
flutter pub get
flutter test
cargo test
cargo clippy
cargo fmt
Do not treat these as authoritative until the actual Flutter/Rust workspace has been created.
Contributing
Before making a change:
- Check the affected requirement/design document.
- Confirm the correct traceability layer.
- Use the Git commit convention.
- Update docs and verification plans when the change affects requirements, architecture, detailed design, release behavior, security, privacy, or legal gates.
License
Chanora is dual-licensed under either of:
- Apache License, Version 2.0 (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)
at your option. This dual-license model was Accepted on 2026-05-14
as decision DEC-020 in
docs/governance/product-decision-register.md.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in Chanora by you, as defined in the Apache-2.0 license, shall be dual-licensed as above, without any additional terms or conditions.
Third-party software bundled or linked by Chanora is listed in
NOTICE with its own licenses. The complete legal review of
the dependency tree (DEC-012) must complete before any public/store
release. See:
docs/governance/product-decision-register.md
docs/security/dependency-and-supply-chain-report.md
docs/legal/trademark-and-attribution-review.md