[Numpy-discussion] 24bit arrays

[Maxim K. <max...@gm...>]

Hi all.

I'm writing a tool to access uncompressed audio files (currently in
wave, aiff and wave64 formats) using numarray.memmap module -- it maps
the whole file to memory, then finds the waveform data region and casts
it to and array of appropriate type and shape.

This works pretty well for both 16-bit integer and 32-bit float data,
but not for 24-bit files, since there is no Int24 data type in numarray.

Is there some clever way to achieve the same goal for 24bit data without
copying  everything into a new 32-bit array?

The typical 24bit audio file contains two interleaved channels, i.e.
frames of 3bytes+3bytes, so it can be cast to (nframes,3) Int32, or
(nframes,2,3) Int8 array, but this is hardly a useful representation for
audio data.

--Maxim