Voice to text from file

[Hiroller173]

Is anyone aware of an android app that will not only convert speech into a text file, but would also accept spoken words from a file (i.e. mp3)? An example would be to take a recording of a speech using voice recorder and generate a transcript. A second example (for illustration purposes only!) would be to take an mp3 version of a audio book and generate the text.

The parts would all seem to be there (speech to text via the phone and Google Voice's voicemail transcription) but I haven't seen it all brought together.