从字符串到numpy.int16数组的快速转换

Question

I read (int)32 bit audio data (given as string by previous commands) into a numpy.int32 array with :

myarray = numpy.fromstring(data, dtype=numpy.int32)

But then I want to store it in memory as int16 (I know this will decrease the bit depth / resolution / sound quality) :

myarray = myarray >> 16
my_16bit_array = myarray.astype('int16')

It works very well, but : is there a faster solution? (here I use : a string buffer, 1 array in int32, 1 array in int16 ; I wanted to know if it's possible to save one step)

Answer 1

How about this?

np.fromstring(data, dtype=np.uint16)[0::2]

Note however, that overhead of the kind you describe here is common when working with numpy, and cannot always be avoided. If this kind of overhead isn't acceptable for your application, make sure that you plan ahead to write extension modules for the performance critical parts.

Note: it should be 0::2 or 1::2 depending on the endianness of your platform