Convert the wave file to a 16 bit signed binary format

Hi, I am working with the audio codecs and I need to give an input to the encoder which mentions that the input should be 16 bit signed binary files. I have the wave files with me and am using wavread function to read it into an array. Once I read it into the array I am not sure how to convert it into signed 16 bit binary file.

Answer 1

[dpb]

Would seem simplest to just use the optional FMT input argument to wavread and set the format of the returned values...

[Y,...]=wavread(...,FMT) specifies the data type format of Y used
      to represent samples read from the file.
      If FMT='double', Y contains double-precision normalized samples.
      If FMT='native', Y contains samples in the native data type
      found in the file.  Interpretation of FMT is case-insensitive,
      and partial matching is supported.  If omitted, FMT='double'.

...

Output Scaling
  The range of values in Y depends on the data format FMT specified.
  Some examples of output scaling based on typical bit-widths found
  in a WAV file are given below for both 'double' and 'native' formats.
  FMT='native'
     #Bits   MATLAB data type          Data range
     -----   ------------------------- -------------------
       8     uint8  (unsigned integer)      0 <= Y <= 255
      16     int16  (signed integer)   -32768 <= Y <= +32767

Presumes, of course, your .wav file is 16-bit.

Otherwise,

doc int16

which also presumes the data will fit into a 16-bit integer.

[Nishant Prakash]

Just a quick question: You are correct and I have tried it too and my wave file is 16 bit so if I use 'native' argument in the wavread then it will automatically store it as 16 bit signed integer or do I need to scale it in that range.

[dpb]

Then should be 16-bit automagically. You can check by the result of

whos

at the command line on the variable when you read a file just to be certain -- or programmatically by

isa('int16',varname)