Changed default file type to MP3 (#35)

[Aga-C]

What is it?

• Bugfix
• Feature
• Codebase improvement

Description of the changes in your PR

Changed default file type to MP3, and also switched order in the dialog, so the default option is the first one.

Fixes the following issue(s)

• Fixes mp3 should be the automatic file extension type #35

Acknowledgement

• I read the contribution guidelines.

[David-Else]

While DEFAULT_BITRATE = 128000 is fine for Opus, it is not good for AAC and terrible for MP3. Please consider at least 192, ideally 320. If there is going to be a default for all codecs then maybe DEFAULT_BITRATE = 192000 would be better, but separate defaults would be ideal.

128k MP3 is widely regarded as terrible sounding, it was only a thing 20 odd years ago when people were putting ripped albums on a 256meg USB stick, there is absolutely no need for it in this day and age. This is still true for voice recordings on mobile phones, which I am sure this app is widely used for. I read in another issue that Opus was not being used yet due to Android compatibility, MP3 can sound decent, but just not at 128k.

Thanks for all the work on this great app, cheers!

[Aga-C]

@David-Else You're right, 128 kbps as the default for MP3 doesn't make sense. I've changed it to 192 kbps. However, I don't think separate default values are needed - when someone changes file type, the bitrate setting is right below, so it shouldn't be the problem to change it.