Windows port Phase 1: real cpal/WASAPI audio backend

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Author	SHA1	Message	Date
molluskandClaude Opus 4.8	47c58047ce	Windows port Phase 1: real cpal/WASAPI audio backend windows-build / windows-build (push) Has been cancelled Details cargo-deny / cargo-deny (pull_request) Has been cancelled Details windows-build / windows-build (pull_request) Has been cancelled Details Replace the Phase 0 no-op CpalBackend stub with a working cpal backend (WASAPI on Windows), preserving the exact PipeWire AudioBackend contract so the mixer/encoder/jitter pipeline is unchanged. - Capture: input stream -> downmix to mono -> 960-sample (20ms) i16 frames -> tx, matching the encoder/jitter frame size. - Playback: 200ms stereo ring prefilled to PLAYBACK_TARGET_SAMPLES; the output callback drains it (silence on underrun) while the owning thread feeds it from rx. ring_fill is the exact delta-maintained occupancy counter (fetch_add on push, fetch_sub on pop), preserving the clock-paced production design (not ringbuf's stale occupied_len). - cpal::Stream is !Send, but AudioBackend is Send+Sync and shared via Arc, so each stream lives on its own owning thread (built/played/dropped there); the struct holds only the running flag + JoinHandle. stop() flips the flag and joins. - Generic over F32/I16/U16 sample formats; device selected by name else default; requires a native 48kHz config (clear error otherwise, no resampling yet). Mirrors the PipeWire drain_loop and playout-health line. - Cargo.toml: add cpal 0.15 under cfg(windows). Verified by temporarily compiling cpal_impl against real cpal on Linux/ALSA: build + clippy clean, 6/6 cpal_impl unit tests pass. Reverted to windows-only gating; shipped Linux state green (316/316). Runtime/WASAPI end-to-end is unverified and pending a Windows host (plan M2). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>	2026-06-18 17:15:56 -04:00

Author

SHA1

Message

Date

molluskandClaude Opus 4.8

47c58047ce

Windows port Phase 1: real cpal/WASAPI audio backend

windows-build / windows-build (push) Has been cancelled

Details

cargo-deny / cargo-deny (pull_request) Has been cancelled

Details

windows-build / windows-build (pull_request) Has been cancelled

Details

Replace the Phase 0 no-op CpalBackend stub with a working cpal backend
(WASAPI on Windows), preserving the exact PipeWire AudioBackend contract
so the mixer/encoder/jitter pipeline is unchanged.

- Capture: input stream -> downmix to mono -> 960-sample (20ms) i16 frames
  -> tx, matching the encoder/jitter frame size.
- Playback: 200ms stereo ring prefilled to PLAYBACK_TARGET_SAMPLES; the
  output callback drains it (silence on underrun) while the owning thread
  feeds it from rx. ring_fill is the exact delta-maintained occupancy
  counter (fetch_add on push, fetch_sub on pop), preserving the clock-paced
  production design (not ringbuf's stale occupied_len).
- cpal::Stream is !Send, but AudioBackend is Send+Sync and shared via Arc,
  so each stream lives on its own owning thread (built/played/dropped
  there); the struct holds only the running flag + JoinHandle. stop()
  flips the flag and joins.
- Generic over F32/I16/U16 sample formats; device selected by name else
  default; requires a native 48kHz config (clear error otherwise, no
  resampling yet). Mirrors the PipeWire drain_loop and playout-health line.
- Cargo.toml: add cpal 0.15 under cfg(windows).

Verified by temporarily compiling cpal_impl against real cpal on Linux/ALSA:
build + clippy clean, 6/6 cpal_impl unit tests pass. Reverted to windows-only
gating; shipped Linux state green (316/316). Runtime/WASAPI end-to-end is
unverified and pending a Windows host (plan M2).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

2026-06-18 17:15:56 -04:00

Windows port Phase 1: real cpal/WASAPI audio backend #3