wavfile 0.1.1

Read/write wave audio files to/from lists of native Python types.

wavfile

A lightweight library to read/write wave audio files to/from lists of native Python types.

The library is currently limited to PCM (integer) formats but supports arbitrary precision, including 16-, 24-, 32-, and 64- bit samples.

Usage: reading wave files

f = wavfile.open(file, 'r')

where file is either a path to a wave file or a pointer to an open file. This returns a wavfile.wavread.WavRead object with the following properties:

• num_channels The number of audio channels in the stream.
• sample_rate The sampling rate/frequency of the audio stream.
• bits_per_sample The number of bits per audio sample.
• num_frames The total number of audio frames in the audio stream. A frame is a block of samples, one for each channel, corresponding to a single sampling point.

The object also has the following methods:

• read_int(N) Read, at most, N frames from the audio stream in their unmodified integer format. The method returns a list of lists with size (N,C), where C is the number of audio channels. Choosing N = None or N < 0 will read all remaining samples.
• read_float(N) This method is identical to read_int() except that it returns the samples as floats in the range [-1, 1).
• seek(N) Move to the Nth frame in the audio stream.
• tell() Return the current frame in the audio stream.
• close() Close the instance.

Usage: writing wave files

f = wavfile.open(file, 'w',
                 sample_rate=44100,
                 num_channels=None,
                 bits_per_sample=16)

where sample_rate is the sampling rate for the new file, num_channels is the number of audio channels, and bits_per_sample is the number of bits used to encode each sample. If num_channels is unspecified it will be determined automatically from the first block of samples that are written (see below). This returns a wavfile.wavread.WavWrite object. The object shares its properties with the wavfile.wavread.WavRead class. The object also offers the same seek(), tell(), and close() methods. In addition, the following methods are provided for writing audio data:

• write(N) Write N frames of data to the audio file. The data should be contained in a list of lists with size (N,C), where C is the number of audio channels. If the data are floats then they should be in the range [-1, 1). They will be converted automatically. Integers will be written directly.