CODEWITHSUNDEEP
c++matlabarmadillolibsndfile
ductran
ductran

Reputation: 10203

Armadillo load wav file to mat

I want to read wav file into mat using Armadillo. It looks like wavread function in matlab:

[sample_data,sample_rate] = wavread('test.wav');
sample_data = sample_data(1 : sample_rate * 1.5);

Seems Armadillo doesn't support this, so I tried to use libsndfile lib:

SNDFILE     *infile = NULL ;
SF_INFO     sfinfo ;
infile = sf_open(filename, SFM_READ, &sfinfo);

int N = 1024;
double samples[N];
double sample_rate = sfinfo.samplerate;
sf_read_double(infile, samples, N);

My questions:

  1. Is this way correct? Seem I can only read fixed amount samples.
  2. How can I convert sample data to mat or vec?
  3. Is there any way to access matrix by colon range index like this matlab code: sample_data = sample_data(1 : sample_rate * 1.5); ?

Upvotes: 1

Views: 319

Answers (1)

user4651282
user4651282

Reputation:

  1. Yes, this way correct. If you need get all samples you can do so:

    auto sample_chanels = sfinfo.channels;

std::vector<std::vector<double>> vec;

std::vector<double> temp(sample_chanels);

while(sf_read_double(infile, temp.data(), sample_chanels))
vec.push_back(temp);

  2. For example so:

    mat m1(vec.size(),sample_chanels);

for( size_t i=0;i<vec.size();i++)
   m1.row(i) = mat(vec[i]).t();

  3. Complete analogy was not available, but you can use std::copy (), because the mat have member functions begin()

      arma::vec D(shift);

  if(shift < m1.size())
    std::copy(m1.begin(),m1.begin()+shift,D.begin());

Link to the complete example: http://pastebin.com/X4fgzBrR

Upvotes: 4

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