fix(audio,ios): bypass VPIO voice processing for clean playback (rc.8+68)

User report at +67 (.voiceChat mode): playback still 'broken'.
Even with VPIO's Apple-documented session-mode pairing,
its output-side gating chain (echo subtraction + adaptive
noise suppression) chops quiet inter-phoneme content of human
voice. Musicbot signal (loud, ~continuous) survives because it
stays above the gating threshold; speech does not.

Fix: set kAUVoiceIOProperty_BypassVoiceProcessing = 1 on the
unit immediately after EnableIO (before stream format / callbacks
/ initialize). This disables ALL VPIO voice processing \u2014 the
unit becomes effectively a vanilla RemoteIO with mic + speaker
buses. Raw samples pass through both directions.

Trade-off:
* Lost: Apple's hardware AEC + AGC + NS on the mic path. User
  reports current capture is clean already, suggesting their
  test environment (headset? non-speakerphone?) doesn't need
  AEC. If echo loops back when speakerphone is engaged, we'll
  re-evaluate \u2014 either re-enable VPIO selectively for
  echo-prone routes or ship software AEC (DEC-007).
* Gained: playback is no longer gated. Quiet inter-phoneme
  speech content reaches the speaker.

Property setter:
* Constant: kAUVoiceIOProperty_BypassVoiceProcessing = 2100
* Scope: Global, Element: Input (1) per WebRTC's reference iOS
  ADM (voice_processing_audio_unit.mm).
* Value: u32 = 1 (= bypass).
* Soft-fail with warn log if the property is rejected on an
  exotic iOS version (the unit still works, just with VPIO
  defaults).

Build counter 67 -> 68.

This commit is contained in:

EdisonJwa

2026-05-17 01:54:07 +08:00

parent c89acacc74

commit c16318c86b

2 changed files with 60 additions and 1 deletions

									
										apps/chanora_flutter/pubspec.yaml
									
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				@@ -16,7 +16,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev

				# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html

				# In Windows, build-name is used as the major, minor, and patch parts

				# of the product and file versions while build-number is used as the build suffix.

				version: 1.0.0-rc.8+67

				version: 1.0.0-rc.8+68

				environment:

				  sdk: ^3.11.5