Support for Chrome OS natural voices

[HadrienGardeur]

In the latest Chrome OS update, Google added support for natural voices on some languages.

Based on the few tests that I've made so far, these natural voices seem to be similar to the Android voices available in Chrome OS that we already document in this repo.
The main difference being that you can use these natural voices offline as well.

We could use a similar approach to what we already document with Apple voices where:

• the primary name would become these new natural voices
• but we would keep on documenting the Android voices in altNames

[HadrienGardeur]

Now that I've tested support for Dutch natural voices, I can confirm that these are equivalent to the (badly named) Android ones.

[HadrienGardeur]

Natural voices in Chrome OS only support 6 languages through vs 70+ through the embedded Android voices.

[HadrienGardeur]

Update: after further testing, I've updated this message. It's not as bad as I thought but remains less than ideal.

It seems that in its latest Chrome OS updates, Google has made some major changes which I need to fully evaluate.

Good news

• Google has extended its support for natural voices to more languages, most of the languages covered in the project now offer high quality voices that work offline
• These natural voices seem to be an embedded version of the Android voices that previously required to be online

Not so good news

• Unlike the preloaded Android voices, these natural voices require the user to install them before they can be used
• When installing a language pack, Android also installs "Chrome OS" voices: lower quality variants of these Natural voices, which doesn't make much sense
• When these voice packs are installed, the Android voices tend to fallback to them instead, which means that there's even more redundancy.

Bad news

• All of the Android voices are currently broken in the Chrome OS build that I have, which means that without a major update to this project, many voices will show up in a list but won't work at all
• For some languages (I've identified the following ones so far: Bulgarian, Catalan, Croatian, Romanian and Russian), there are no Chrome OS and natural voices alternatives, which means that users are left with zero ability to use TTS if we don't remove eSpeak voices from the list of very low quality voices
• The required voice/language packs for higher quality offline voices have a tendency to disappear whenever Chrome OS is updated, which happens very often (once a week?)
• For some languages, Android voices can take dozens of second before the first utterance is spoken (up to a minute in some of my tests). From a user perspective, they'll feel that TTS is just broken.
• Android voices can also get completely stuck until the user goes to the system settings and tries out a number of other voices

It's a shame because this could have been a major step forward for Chrome OS which could become the best platform for TTS support if it fixed these issues.