Determining the format of audio file (MP3) using SAPI

Question

Hi
I'm trying to create a "Speech to text" app that can transcribe any audio/video file. I've created an app based on this post and it works great for WAV files. But if I use an MP3 file, the line hr = cpInputStream->BindToFile(wInputFileName.c_str(), SPFM_OPEN_READONLY, &sInputFormat.FormatId(), sInputFormat.WaveFormatExPtr(), SPFEI_ALL_EVENTS); returns

The Parameter is incorrect

The question is, can I use MP3 files as input for SAPI? and if yes, how do I determine the correct format for the call to hr = sInputFormat.AssignFormat(SPSF_16kHz16BitStereo) because SPSF_16kHz16BitStereo will certainly not be correct and I don't think we should hardcode it.