Fix SAPI4 failing to load some voices

[gexgd0419]

Link to issue number:

None

Summary of the issue:

The SAPI4 synth driver fails to load some voices, because the voices do not support certain parameters, or because the voices do not expect the client to create multiple instances of ITTSCentral objects (with feature flag TTSFEATURE_SINGLEINSTANCE).

The synth driver tries to detect whether a parameter is supported or not when loading the voice. However, removeSetting is checking against the name attribute of each setting, which should now be called id. This can cause errors when loading a voice that does not support all the parameters.

Description of user facing changes

Some of the SAPI4 voices will no longer fail to load.

Description of development approach

In removeSetting, if s.name == name is changed to if s.id == name.

Before creating a new ITTSCentral object, and when terminate is called, set both _ttsCentral and _ttsAttrs to None to release the previous ITTSCentral object.

Ignore the exception thrown from _ttsCentral.UnRegister. Some voices do not handle this well, and the whole ITTSCentral will be released anyway.

Some voices keep the pausing state even after resetting, meaning that they will still pause the audio after _ttsCentral.AudioReset and silence the output. A variable _paused is used to track the pausing state, and if it's paused, unpause it before resetting.

Testing strategy:

Manually tested with some voices.

Known issues with pull request:

None yet

Code Review Checklist:

• Documentation:
  • Change log entry
  • User Documentation
  • Developer / Technical Documentation
  • Context sensitive help for GUI changes
• Testing:
  • Unit tests
  • System (end to end) tests
  • Manual testing
• UX of all users considered:
  • Speech
  • Braille
  • Low Vision
  • Different web browsers
  • Localization in other languages / culture than English
• API is compatible with existing add-ons.
• Security precautions taken.

@coderabbitai summary

[AppVeyorBot]

• PASS: Translation comments check.
• PASS: License check.
• PASS: Unit tests.
• PASS: Lint check.
• FAIL: System tests (tags: installer NVDA). See test results for more information.
• Build (for testing PR): https://ci.appveyor.com/api/buildjobs/2olgw0t45t7eycf9/artifacts/output/nvda_snapshot_pr17726-35374,fe03cedc.exe
• CI timing (mins):
  INIT 0.0,
  INSTALL_START 1.2,
  INSTALL_END 1.1,
  BUILD_START 0.0,
  BUILD_END 35.2,
  TESTSETUP_START 0.0,
  TESTSETUP_END 0.4,
  TEST_START 0.0,
  TEST_END 18.5,
  FINISH_END 0.1

See test results for failed build of commit fe03cedc25

[seanbudd]

Given there's no related issue filed, can you please provide more information?
What voices fail to load - can you provide examples?

[seanbudd]

Code changes look good

[cary-rowen]

Given there's no related issue filed, can you please provide more information? What voices fail to load - can you provide examples?

I'd love to file an Issue later today to provide more background about this fix.
Many thanks, @gexgd0419

[wmhn1872265132]

There is a very old Chinese speech engine called IBM Chinese TTS Runtime that had been unusable for many years, even causing the Microsoft Speech API version 4 driver to fail to load for users who installed it. This pull request fixes the issue and makes the speech engine work properly again.

[cary-rowen]

Ahh, sorry I didn't say it earlier, PitchCommand doesn't work in the current implementation.