nvaccess · seanbudd · Mar 6, 2024 · Jan 18, 2024 · Jan 22, 2024 · Jan 23, 2024
@@ -16,6 +16,9 @@ diff_match_patch_python==1.0.2
 # typing_extensions are required for specifying default value for `TypeVar`, which is not yet possible with any released version of Python (see PEP 696)
 typing-extensions==4.9.0 
 
+# pycaw is a Core Audio Windows Library used for sound split
+pycaw==20240210                                                                                   
+
 # Packaging NVDA
 git+https://github.com/py2exe/py2exe@4e7b2b2c60face592e67cb1bc935172a20fa371d#egg=py2exe
 

@@ -0,0 +1,16 @@
+# A part of NonVisual Desktop Access (NVDA)
+# Copyright (C) 2024 NV Access Limited
+# This file is covered by the GNU General Public License.
+# See the file COPYING for more details.
+
+from .soundSplit import (
+	SoundSplitState,
+	setSoundSplitState,
+	toggleSoundSplitState,
+)
+
+__all__ = [
+	"SoundSplitState",
+	"setSoundSplitState",
+	"toggleSoundSplitState",
+]
@@ -0,0 +1,189 @@
+# A part of NonVisual Desktop Access (NVDA)
+# Copyright (C) 2024 NV Access Limited
+# This file is covered by the GNU General Public License.
+# See the file COPYING for more details.
+
+import atexit
+import config
+from enum import IntEnum, unique
+import globalVars
+from logHandler import log
+import nvwave
+from pycaw.api.audiopolicy import IAudioSessionManager2
+from pycaw.callbacks import AudioSessionNotification
+from pycaw.utils import AudioSession, AudioUtilities
+import ui
+from utils.displayString import DisplayStringIntEnum
+from dataclasses import dataclass
+
+VolumeTupleT = tuple[float, float]
+
+
+@unique
+class SoundSplitState(DisplayStringIntEnum):
+	OFF = 0
+	NVDA_LEFT_APPS_RIGHT = 1
+	NVDA_LEFT_APPS_BOTH = 2
+	NVDA_RIGHT_APPS_LEFT = 3
+	NVDA_RIGHT_APPS_BOTH = 4
+	NVDA_BOTH_APPS_LEFT = 5
+	NVDA_BOTH_APPS_RIGHT = 6
+
+	@property
+	def _displayStringLabels(self) -> dict[IntEnum, str]:
+		return {
+			# Translators: Sound split state
+			SoundSplitState.OFF: pgettext("SoundSplit", "Disabled"),
+			# Translators: Sound split state
+			SoundSplitState.NVDA_LEFT_APPS_RIGHT: _("NVDA on the left and applications on the right"),
+			# Translators: Sound split state
+			SoundSplitState.NVDA_LEFT_APPS_BOTH: _("NVDA on the left and applications in both channels"),
+			# Translators: Sound split state
+			SoundSplitState.NVDA_RIGHT_APPS_LEFT: _("NVDA on the right and applications on the left"),
+			# Translators: Sound split state
+			SoundSplitState.NVDA_RIGHT_APPS_BOTH: _("NVDA on the right and applications in both channels"),
+			# Translators: Sound split state
+			SoundSplitState.NVDA_BOTH_APPS_LEFT: _("NVDA in both channels and applications on the left"),
+			# Translators: Sound split state
+			SoundSplitState.NVDA_BOTH_APPS_RIGHT: _("NVDA in both channels and applications on the right"),
+		}
+
+	def getAppVolume(self) -> VolumeTupleT:
+		match self:
+			case SoundSplitState.OFF | SoundSplitState.NVDA_LEFT_APPS_BOTH | SoundSplitState.NVDA_RIGHT_APPS_BOTH:
+				return (1.0, 1.0)
+			case SoundSplitState.NVDA_RIGHT_APPS_LEFT | SoundSplitState.NVDA_BOTH_APPS_LEFT:
+				return (1.0, 0.0)
+			case SoundSplitState.NVDA_LEFT_APPS_RIGHT | SoundSplitState.NVDA_BOTH_APPS_RIGHT:
+				return (0.0, 1.0)
+			case _:
+				raise RuntimeError(f"Unexpected or unknown state {self=}")
+
+	def getNVDAVolume(self) -> VolumeTupleT:
+		match self:
+			case SoundSplitState.OFF | SoundSplitState.NVDA_BOTH_APPS_LEFT | SoundSplitState.NVDA_BOTH_APPS_RIGHT:
+				return (1.0, 1.0)
+			case SoundSplitState.NVDA_LEFT_APPS_RIGHT | SoundSplitState.NVDA_LEFT_APPS_BOTH:
+				return (1.0, 0.0)
+			case SoundSplitState.NVDA_RIGHT_APPS_LEFT | SoundSplitState.NVDA_RIGHT_APPS_BOTH:
+				return (0.0, 1.0)
+			case _:
+				raise RuntimeError(f"Unexpected or unknown state {self=}")
+
+
+audioSessionManager: IAudioSessionManager2 | None = None
+activeCallback: AudioSessionNotification | None = None
+
+
+def initialize() -> None:
+	if nvwave.usingWasapiWavePlayer():
+		global audioSessionManager
+		audioSessionManager = AudioUtilities.GetAudioSessionManager()
+		state = SoundSplitState(config.conf["audio"]["soundSplitState"])
+		setSoundSplitState(state)
+	else:
+		log.debug("Cannot initialize sound split as WASAPI is disabled")
+
+
+@atexit.register
+def terminate():
+	if nvwave.usingWasapiWavePlayer():
+		setSoundSplitState(SoundSplitState.OFF)
+		unregisterCallback()
+	else:
+		log.debug("Skipping terminating sound split as WASAPI is disabled.")
+
+
+def applyToAllAudioSessions(
+		callback: AudioSessionNotification,
+		applyToFuture: bool = True,
+) -> None:
+	"""
+		Executes provided callback function on all active audio sessions.
+		Additionally, if applyToFuture is True, then it will register a notification with audio session manager,
+		which will execute the same callback for all future sessions as they are created.
+		That notification will be active until next invokation of this function,
+		or until unregisterCallback() is called.
+	"""
+	unregisterCallback()
+	if applyToFuture:
+		audioSessionManager.RegisterSessionNotification(callback)
+		# The following call is required to make callback to work:
+		audioSessionManager.GetSessionEnumerator()
+		global activeCallback
+		activeCallback = callback
+	sessions: list[AudioSession] = AudioUtilities.GetAllSessions()
+	for session in sessions:
+		callback.on_session_created(session)
+
+
+def unregisterCallback() -> None:
+	global activeCallback
+	if activeCallback is not None:
+		audioSessionManager.UnregisterSessionNotification(activeCallback)
+		activeCallback = None
+
+
+@dataclass(unsafe_hash=True)
+class VolumeSetter(AudioSessionNotification):
+	leftVolume: float
+	rightVolume: float
+	leftNVDAVolume: float
+	rightNVDAVolume: float
+	foundSessionWithNot2Channels: bool = False
+
+	def on_session_created(self, new_session: AudioSession):
+		pid = new_session.ProcessId
+		channelVolume = new_session.channelAudioVolume()
+		channelCount = channelVolume.GetChannelCount()
+		if channelCount != 2:
+			log.warning(f"Audio session for pid {pid} has {channelCount} channels instead of 2 - cannot set volume!")
+			self.foundSessionWithNot2Channels = True
+			return
+		if pid != globalVars.appPid:
+			channelVolume.SetChannelVolume(0, self.leftVolume, None)
+			channelVolume.SetChannelVolume(1, self.rightVolume, None)
+		else:
+			channelVolume.SetChannelVolume(0, self.leftNVDAVolume, None)
+			channelVolume.SetChannelVolume(1, self.rightNVDAVolume, None)
+
+
+def setSoundSplitState(state: SoundSplitState) -> dict:
+	leftVolume, rightVolume = state.getAppVolume()
+	leftNVDAVolume, rightNVDAVolume = state.getNVDAVolume()
+	volumeSetter = VolumeSetter(leftVolume, rightVolume, leftNVDAVolume, rightNVDAVolume)
+	applyToAllAudioSessions(volumeSetter)
+	return {
+		"foundSessionWithNot2Channels": volumeSetter.foundSessionWithNot2Channels,
+	}
+
+
+def toggleSoundSplitState() -> None:
+	if not nvwave.usingWasapiWavePlayer():
+		message = _(
+			# Translators: error message when wasapi is turned off.
+			"Sound split cannot be used. "
+			"Please enable WASAPI in the Advanced category in NVDA Settings to use it."
+		)
+		ui.message(message)
+		return
+	state = SoundSplitState(config.conf["audio"]["soundSplitState"])
+	allowedStates: list[int] = config.conf["audio"]["includedSoundSplitModes"]
+	try:
+		i = allowedStates.index(state)
+	except ValueError:
+		# State not found, resetting to default (OFF)
+		i = -1
+	i = (i + 1) % len(allowedStates)
+	newState = SoundSplitState(allowedStates[i])
+	result = setSoundSplitState(newState)
+	config.conf["audio"]["soundSplitState"] = newState.value
+	ui.message(newState.displayString)
+	if result["foundSessionWithNot2Channels"]:
+		msg = _(
+			# Translators: warning message when sound split trigger wasn't successful due to one of audio sessions
+			# had number of channels other than 2 .
+			"Warning: couldn't set volumes for sound split: "
+			"one of audio sessions is either mono, or has more than 2 audio channels."
+		)
+		ui.message(msg)
@@ -57,6 +57,8 @@
 	soundVolume = integer(default=100, min=0, max=100)
 	audioAwakeTime = integer(default=30, min=0, max=3600)
 	whiteNoiseVolume = integer(default=0, min=0, max=100)
+	soundSplitState = integer(default=0)
+	includedSoundSplitModes = int_list(default=list(0, 1, 2))
 
 # Braille settings
 [braille]

@@ -276,6 +276,7 @@ def resetConfiguration(factoryDefaults=False):
 	import bdDetect
 	import hwIo
 	import tones
+	import audio
 	log.debug("Terminating vision")
 	vision.terminate()
 	log.debug("Terminating braille")
@@ -286,6 +287,8 @@ def resetConfiguration(factoryDefaults=False):
 	speech.terminate()
 	log.debug("terminating tones")
 	tones.terminate()
+	log.debug("terminating sound split")
+	audio.soundSplit.terminate()
 	log.debug("Terminating background braille display detection")
 	bdDetect.terminate()
 	log.debug("Terminating background i/o")
@@ -315,6 +318,9 @@ def resetConfiguration(factoryDefaults=False):
 	bdDetect.initialize()
 	# Tones
 	tones.initialize()
+	# Sound split
+	log.debug("initializing sound split")
+	audio.soundSplit.initialize()
 	#Speech
 	log.debug("initializing speech")
 	speech.initialize()
@@ -663,6 +669,9 @@ def main():
 	log.debug("Initializing tones")
 	import tones
 	tones.initialize()
+	log.debug("Initializing sound split")
+	import audio
+	audio.soundSplit.initialize()
 	import speechDictHandler
 	log.debug("Speech Dictionary processing")
 	speechDictHandler.initialize()

@@ -66,6 +66,7 @@
 from base64 import b16encode
 import vision
 from utils.security import objectBelowLockScreenAndWindowsIsLocked
+import audio
 
 
 #: Script category for text review commands.
@@ -113,6 +114,9 @@
 #: Script category for document formatting commands.
 # Translators: The name of a category of NVDA commands.
 SCRCAT_DOCUMENTFORMATTING = _("Document formatting")
+#: Script category for audio streaming commands.
+# Translators: The name of a category of NVDA commands.
+SCRCAT_AUDIO = _("Audio")
 
 # Translators: Reported when there are no settings to configure in synth settings ring
 # (example: when there is no setting for language).
@@ -127,6 +131,7 @@ class GlobalCommands(ScriptableObject):
 			# Translators: Describes the Cycle audio ducking mode command.
 			"Cycles through audio ducking modes which determine when NVDA lowers the volume of other sounds"
 		),
+		category=SCRCAT_AUDIO,
 		gesture="kb:NVDA+shift+d"
 	)
 	def script_cycleAudioDuckingMode(self,gesture):
@@ -4461,6 +4466,17 @@ def script_cycleParagraphStyle(self, gesture: "inputCore.InputGesture") -> None:
 		config.conf["documentNavigation"]["paragraphStyle"] = newFlag.name
 		ui.message(newFlag.displayString)
 
+	@script(
+		description=_(
+			# Translators: Describes a command.
+			"Cycles through sound split modes",
+		),
+		category=SCRCAT_AUDIO,
+		gesture="kb:NVDA+alt+s",
+	)
+	def script_cycleSoundSplit(self, gesture: "inputCore.InputGesture") -> None:
+		audio.toggleSoundSplitState()
+
 
 #: The single global commands instance.
 #: @type: L{GlobalCommands}