On what platform to make software (win / mac) for detecting audio tags on video?

Question

.NET

Good afternoon! We need to write software for computers with Windows and MacOS.
The software must analyze the video and look for DTMF (or equivalent) audio tags in user-provided video files. On the entire video file, show video fragments where there is an audio tag. Save video clips with these tags, timing (IN-OUT) is defined by the user.
Tell me on which cross-platform system is it better to look for a programmer for this software? unity3d, xamarin, .NET?
I would like to find one programmer to do it for Win/Mac at a time.
Thank you!

Answer 1

In my opinion the best would be Qt C++