symbian-qemu-0.9.1-12/python-2.6.1/Doc/library/sndhdr.rst
author Mike Kinghan <mikek@symbian.org>
Thu, 25 Nov 2010 14:28:39 +0000
branchGCC_SURGE
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:mod:`sndhdr` --- Determine type of sound file
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==============================================
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.. module:: sndhdr
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   :synopsis: Determine type of a sound file.
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.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
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.. Based on comments in the module source file.
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.. index::
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   single: A-LAW
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   single: u-LAW
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The :mod:`sndhdr` provides utility functions which attempt to determine the type
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of sound data which is in a file.  When these functions are able to determine
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what type of sound data is stored in a file, they return a tuple ``(type,
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sampling_rate, channels, frames, bits_per_sample)``.  The value for *type*
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indicates the data type and will be one of the strings ``'aifc'``, ``'aiff'``,
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``'au'``, ``'hcom'``, ``'sndr'``, ``'sndt'``, ``'voc'``, ``'wav'``, ``'8svx'``,
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``'sb'``, ``'ub'``, or ``'ul'``.  The *sampling_rate* will be either the actual
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value or ``0`` if unknown or difficult to decode.  Similarly, *channels* will be
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either the number of channels or ``0`` if it cannot be determined or if the
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value is difficult to decode.  The value for *frames* will be either the number
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of frames or ``-1``.  The last item in the tuple, *bits_per_sample*, will either
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be the sample size in bits or ``'A'`` for A-LAW or ``'U'`` for u-LAW.
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.. function:: what(filename)
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   Determines the type of sound data stored in the file *filename* using
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   :func:`whathdr`.  If it succeeds, returns a tuple as described above, otherwise
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   ``None`` is returned.
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.. function:: whathdr(filename)
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   Determines the type of sound data stored in a file based on the file  header.
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   The name of the file is given by *filename*.  This function returns a tuple as
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   described above on success, or ``None``.
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