I'm an IT student and got an assignment to do about Dynamic Time Warping(DTW) using the Speech Signal Processing Toolkit (SPTK) and comparing some words spoken by 2 speakers and finding the similarities. I managed to get the SPTK working, collected 8 people(4 females, 4 males) who recorded 8 words each for me(same words for every person) and saved them as files with a .wav extension.
My .wav files are in the following format:
- RIFF (little-endian) data ;
- WAVE audio ;
- mono ;
- sampled at $16\text{ kHz}$.
I transfered every .wav file into .raw data files with the SPTK conversion function :
wav2raw +f source_maleA.wav
The .raw file I get is:
- Unsigned 8 bit ;
- Sampled at $8 \text{ kHz}$ ;
- Mono.
I transfered every .raw file to a .mcep file with this line of code:
x2x +Sf < source_maleA.raw | frame -l 320 -p 160 -n | window -l 320 -L 512 -n 1 | mcep -l 512 -m 13 -a 0.42 > source_maleA.mcep
After that, I went to compare the .mcep files with this line of code:
dtw -m 13 -s Scorefile target_maleB.mcep < source_maleA.mcep > source_maleA_target_maleB.dtw
The output of that command line (the "Scorefile") is a binary file.
I programmed a code that decodes the binary sequence written inside of the Scorefile and the output is some kind of decimal number: $0.678382$, which could imply a percentage of something.
Since by the SPTK documentation they are using some .short files of their own, I tried to remove the header of the .wav files and use them as .raw format and then convert it to .mcep file for the further use.
Since my understanding of DTW is limited by itself, plus my understanding of the SPTK tool is also limited, could anyone tell me if what I did is good?
I divided the files into frames of $320$ samples and periods of 160 and I used $x[0]$ as the first point of the first frame. I applied a Blackman's window of 512 samples length with the normalization computed by this function:
$$\sum_{n=0}^{L-1} w^2 (n) = 1 $$
After that I used the mel cepstral analysis to get the coefficients with $alpha = 0.42$ and I set the mc order to $13$.
Since when changing the length of the window, frames, period etc. etc. I don't get any better result, could anyone explain me what would be a good setup for all those factors?