Ask for the headset profile at capture start; relaunch the daemon on update

The daemon now requests the Bluetooth headset profile itself (pactl
set-card-profile) the moment a take starts, instead of waiting for
WirePlumber to notice the stream and run its switch timer. The microphone
link comes up 0.15-0.18 s after the key instead of 0.21-0.27 s; WirePlumber
still restores A2DP when the stream goes away. First real audio is now at
0.82-0.86 s, which is the headset's own floor.

When the plugin is updated while the daemon runs, the daemon sees its source
change, exits with code 4 once idle, and the shell service relaunches it
without counting that as a crash.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Xoc9DJCViR7dg9eKzzAcfQ
This commit is contained in:
2026-09-09 12:17:06 +01:00
parent 6f7f7ddd6c
commit b93327dc26
3 changed files with 69 additions and 21 deletions
+19 -20
View File
@@ -5,49 +5,48 @@ Measured on a Sony WH-1000XM5 over an Intel AX210, PipeWire 1.6.8, WirePlumber
| | before | after |
|---|---|---|
| mic link (eSCO) up | 0.71.0 s, sometimes never | 0.260.49 s |
| first real audio at the daemon | 1.51.7 s, or never | 1.061.43 s |
| "Listening" in the bar | 2.1 s on a timer, even with no audio | 1.191.43 s, only on real audio |
| mic link (eSCO) up | 0.71.0 s, sometimes never | 0.150.18 s |
| first real audio at the daemon | 1.51.7 s, or never | 0.820.86 s |
| "Listening" in the bar | 2.1 s on a timer, even with no audio | 0.860.94 s, only on real audio |
"After" is with the daemon recording straight from `bluez_input.<addr>`; via
`camera-effects-mic` add ~0.25 s (its 250 ms poll and processing).
## What changed
| Change | Where it lives | Gain |
|---|---|---|
| Daemon indicator: green on real audio only (RMS > 0.0005 or three consecutive non-silent chunks), no timer | `daemon/sttd.py` | the bar cannot claim to listen to a dead mic |
| Daemon asks for the headset profile itself at capture start (`pactl set-card-profile`), before WirePlumber notices the stream | `daemon/sttd.py` | link up ~0.1 s sooner (0.210.27 s → 0.150.18 s); WirePlumber still restores A2DP |
| Record from `bluez_input.<addr>` instead of `camera-effects-mic` | `~/.config/speech-to-text/config.json` | ~0.25 s sooner, no noise suppression on dictation |
| WirePlumber profile-switch timeout 500 ms → 50 ms | `~/.local/share/wireplumber/scripts/device/autoswitch-bluetooth-profile.lua` | link up ~0.45 s sooner |
| A2DP auto-connect rule narrowed to the XM5 | `~/.config/wireplumber/wireplumber.conf.d/bluetooth-a2dp-autoconnect.conf` | no 5 s pages of absent devices at login |
| btusb driver patch `0002` | `/usr/lib/modules/<kernel>/updates/btusb.ko` | mic link no longer comes up silent when a page overlaps it |
| PipeWire bluez5 patches `0001` + `0003` | `~/.local/lib/spa-0.2/bluez5/` via `SPA_PLUGIN_DIR` drop-ins | no stale-error dead takes; back-to-back takes work |
Only the first row is part of this repo. The rest are machine-level and are
Only the first two rows are part of this repo. The rest are machine-level and are
described, with patches and measurements, in [HANDOFF.md](HANDOFF.md).
## Why ~0.9 s is the floor
## Why ~0.85 s is the floor
```
key press
0.00 s ─┬─ daemon starts pw-record on camera-effects-mic
0.00 s ─┬─ daemon asks for the headset profile, starts pw-record
│ Camera Effects notices the client (250 ms poll),
opens its helper stream, WirePlumber waits 50 ms,
│ then asks BlueZ for the headset profile
0.30 s ─┼─ eSCO link up (the headset must leave sniff mode,
│ then the radio sets up the synchronous link: ~0.1 s)
0.07 s ─┼─ eSCO connect() reaches the kernel
headset leaves sniff mode, radio sets up the link
0.16 s ─┼─ eSCO link up
│ headset sends encoded digital silence while its own
│ mic path starts and mSBC syncs: ~0.50.6 s
│ mic path starts and mSBC syncs: ~0.6 s
│ (measured at the decoder; Linux cannot shorten it)
0.85 s ─┼─ first non-zero samples leave the headset
Camera Effects processing + 50 ms chunking
0.90 s ─┴─ first real audio reaches the daemon
0.80 s ─┼─ first non-zero samples leave the headset
decode + 50 ms chunking
0.85 s ─┴─ first real audio reaches the daemon
```
What is left on the Linux side is the ~0.25 s before the profile switch is
even requested. The daemon could ask for the headset profile itself when
capture starts, but the WirePlumber autoswitch script only restores a profile
it switched, so the daemon would have to restore A2DP too. Not done.
Nothing measurable is left on the Linux side.
The headset's silence after link-up and the eSCO setup are hardware. Words
spoken in the first ~0.9 s are lost unless the microphone is already in