VoiceOver for App Preview
Use macOS terminal to create a voiceover
With macOS you can create voiceovers directly from the command line. Create a text file and use comma’s, full stops and delays. It requires a bit of experimenting with words, structure and grammar to get the best result. It could be something like this:
Hello [[slnc 300]] and welcome to [[slnc 300]] VPN Monitor. [[slnc 400]]] This utility, will keep an eye, on your VPN connection. [[slnc 300]] As soon as the connection drops, it will reconnect. [[slnc 400]] In standby mode, it will connect the VPN, when it detects an insecure network. [[slnc 300]] To start, click the icon on the status bar. [[slnc 300]] When you already have VPN services configured, simply click: connect. [[slnc 300]] Once connected, VPN Monitor ensures you stay connected.
To create the voiceover use the ‘say’ command in terminal. There are multiple voices & accents available, under system configuration -> accessibility -> voiceover -> voiceover utility, you can find and download all voices. You need to try a few voices to see which one best matches your text. To convert your text to a voiceover audio file use:
say -v Karen -f speak.txt -o voiceover.aiff
To play the audio file from the command line use:
afplay voiceover.aiff
The output file in aiff (a high quality audio file) is directly usable in iMovie.
To get the exact length of the audiofile use:
afinfo voiceover.aiff
To end result would be something like this: