Languages detected in input document should be mentioned in scripts that use TTS

[prashantverma2014]

In scripts such as DTBook to DAISY 3, after the DTBook browse field, there can be a read only text box that displays languages/dialects detected in the input file selected by the user.
Some text like "Make sure you select TTS voices for these languages" can be added over there.

[bertfrees]

While I agree it could be useful information for the user to have, I'm not sure that the warning would not confuse people, at least the way it is worded right now, because Pipeline is capable of selecting the right voice for the right languages (if the TTS engines have been set up correctly). What of course is left up to the user is to set voice preferences. But that is not required to get a "correct" output.

Perhaps the user should only get a warning when the app detects a potential issue in the settings, e.g. if there are multiple alternatives for a language that occurs in the document, and the user hasn't set up any preferences in the GUI or CSS, so that the output would be undetermined.

[prashantverma2014]

WordToEPUB in its Settings window displays the detected language codes separated by commas. It is then upon the user to ignore it or take any action. When users will want to troubleshoot the use of unwanted TTS voices, this display of languages in the input document in Pipeline window will be very useful. The text around this this proposed new field can be mutually decided, may be it will just say “languages detected in input document” Many a times documents in regional languages have wrong language codes. In such cases the user will get alerted by the detected languages field and may take corrective action.

[bertfrees]

I'm in favor of the extra information. We can think about whether
warnings could also be useful, and how to word them.

[bertfrees]

I have an idea for a new API call for providing this kind of information. It will be something for a future version.

[bertfrees]

See daisy/pipeline-modules#96

[marisademeglio]

Re stylesheet-parameters and voices endpoints
https://daisy-dev.slack.com/archives/C064GB8U9/p1724083351219419