# Extract feature from audio file using DWT

I have an assignment of extracting features from audio file using Discrete Wavelet transform and C++. I believe the purpose of the homeworks were just for demo, so here is my plan for it:

1. Audio file is .wav file. I will read .wav file as an array of signals.
2. After getting signals array, i apply Discrete Wavelet transform using Haar
wavelet to get the coefficients array. Then i use this array to calculate
features.

Since my knowledge is limited, i have some questions:

1. How to read .wav file by C++ properly?
2. I know if Haar wavelet decomposition level is $$k$$ then signal’s length
should be divided by $$2^k$$. So what should we do if signal’s length is
not divided by $$2^k$$?.
3. Which features can we get from the coefficients array of DWT method
above (if the method were right)?
4. I read some documents which said if length of signals array was loo
long then we should apply DWT on overlapping segments. Does it
change how we calculate the features?

I know that i should search for the anwser first. But since i don’t have much time for researching, i really need your help.