19.4 sunau -- Read and write Sun AU files
The sunau module provides a convenient interface to the Sun AU sound format. Note that this module is interface-compatible with the modules aifc and wave.
An audio file consists of a header followed by the data. The fields of the header are:
Field | Contents |
---|---|
magic word | The four bytes ".snd". |
header size | Size of the header, including info, in bytes. |
data size | Physical size of the data, in bytes. |
encoding | Indicates how the audio samples are encoded. |
sample rate | The sampling rate. |
# of channels | The number of channels in the samples. |
info | ASCII string giving a description of the audio file (padded with null bytes). |
Apart from the info field, all header fields are 4 bytes in size. They are all 32-bit unsigned integers encoded in big-endian byte order.
The sunau module defines the following functions:
-
If file is a string, open the file by that name, otherwise treat it
as a seekable file-like object. mode can be any of
- Read only mode.
- Write only mode.
A mode of
'r'
returns a AU_read object, while a mode of'w'
or'wb'
returns a AU_write object.
- A synonym for open, maintained for backwards compatibility.
The sunau module defines the following exception:
- An error raised when something is impossible because of Sun AU specs or implementation deficiency.
The sunau module defines the following data items:
- An integer every valid Sun AU file begins with, stored in big-endian form. This is the string ".snd" interpreted as an integer.
- Values of the encoding field from the AU header which are supported by this module.
- Additional known values of the encoding field from the AU header, but which are not supported by this module.
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