1 

     2 :mod:`al` --- Audio functions on the SGI

     3 ========================================

     4 

     5 .. module:: al

     6    :platform: IRIX

     7    :synopsis: Audio functions on the SGI.

     8    :deprecated:

     9    

    10 .. deprecated:: 2.6

    11     The :mod:`al` module has been deprecated for removal in Python 3.0.

    12 

    13 

    14 This module provides access to the audio facilities of the SGI Indy and Indigo

    15 workstations.  See section 3A of the IRIX man pages for details.  You'll need to

    16 read those man pages to understand what these functions do!  Some of the

    17 functions are not available in IRIX releases before 4.0.5.  Again, see the

    18 manual to check whether a specific function is available on your platform.

    19 

    20 All functions and methods defined in this module are equivalent to the C

    21 functions with ``AL`` prefixed to their name.

    22 

    23 .. index:: module: AL

    24 

    25 Symbolic constants from the C header file ``<audio.h>`` are defined in the

    26 standard module :mod:`AL`, see below.

    27 

    28 .. warning::

    29 

    30    The current version of the audio library may dump core when bad argument values

    31    are passed rather than returning an error status.  Unfortunately, since the

    32    precise circumstances under which this may happen are undocumented and hard to

    33    check, the Python interface can provide no protection against this kind of

    34    problems. (One example is specifying an excessive queue size --- there is no

    35    documented upper limit.)

    36 

    37 The module defines the following functions:

    38 

    39 

    40 .. function:: openport(name, direction[, config])

    41 

    42    The name and direction arguments are strings.  The optional *config* argument is

    43    a configuration object as returned by :func:`newconfig`.  The return value is an

    44    :dfn:`audio port object`; methods of audio port objects are described below.

    45 

    46 

    47 .. function:: newconfig()

    48 

    49    The return value is a new :dfn:`audio configuration object`; methods of audio

    50    configuration objects are described below.

    51 

    52 

    53 .. function:: queryparams(device)

    54 

    55    The device argument is an integer.  The return value is a list of integers

    56    containing the data returned by :cfunc:`ALqueryparams`.

    57 

    58 

    59 .. function:: getparams(device, list)

    60 

    61    The *device* argument is an integer.  The list argument is a list such as

    62    returned by :func:`queryparams`; it is modified in place (!).

    63 

    64 

    65 .. function:: setparams(device, list)

    66 

    67    The *device* argument is an integer.  The *list* argument is a list such as

    68    returned by :func:`queryparams`.

    69 

    70 

    71 .. _al-config-objects:

    72 

    73 Configuration Objects

    74 ---------------------

    75 

    76 Configuration objects returned by :func:`newconfig` have the following methods:

    77 

    78 

    79 .. method:: audio configuration.getqueuesize()

    80 

    81    Return the queue size.

    82 

    83 

    84 .. method:: audio configuration.setqueuesize(size)

    85 

    86    Set the queue size.

    87 

    88 

    89 .. method:: audio configuration.getwidth()

    90 

    91    Get the sample width.

    92 

    93 

    94 .. method:: audio configuration.setwidth(width)

    95 

    96    Set the sample width.

    97 

    98 

    99 .. method:: audio configuration.getchannels()

   100 

   101    Get the channel count.

   102 

   103 

   104 .. method:: audio configuration.setchannels(nchannels)

   105 

   106    Set the channel count.

   107 

   108 

   109 .. method:: audio configuration.getsampfmt()

   110 

   111    Get the sample format.

   112 

   113 

   114 .. method:: audio configuration.setsampfmt(sampfmt)

   115 

   116    Set the sample format.

   117 

   118 

   119 .. method:: audio configuration.getfloatmax()

   120 

   121    Get the maximum value for floating sample formats.

   122 

   123 

   124 .. method:: audio configuration.setfloatmax(floatmax)

   125 

   126    Set the maximum value for floating sample formats.

   127 

   128 

   129 .. _al-port-objects:

   130 

   131 Port Objects

   132 ------------

   133 

   134 Port objects, as returned by :func:`openport`, have the following methods:

   135 

   136 

   137 .. method:: audio port.closeport()

   138 

   139    Close the port.

   140 

   141 

   142 .. method:: audio port.getfd()

   143 

   144    Return the file descriptor as an int.

   145 

   146 

   147 .. method:: audio port.getfilled()

   148 

   149    Return the number of filled samples.

   150 

   151 

   152 .. method:: audio port.getfillable()

   153 

   154    Return the number of fillable samples.

   155 

   156 

   157 .. method:: audio port.readsamps(nsamples)

   158 

   159    Read a number of samples from the queue, blocking if necessary. Return the data

   160    as a string containing the raw data, (e.g., 2 bytes per sample in big-endian

   161    byte order (high byte, low byte) if you have set the sample width to 2 bytes).

   162 

   163 

   164 .. method:: audio port.writesamps(samples)

   165 

   166    Write samples into the queue, blocking if necessary.  The samples are encoded as

   167    described for the :meth:`readsamps` return value.

   168 

   169 

   170 .. method:: audio port.getfillpoint()

   171 

   172    Return the 'fill point'.

   173 

   174 

   175 .. method:: audio port.setfillpoint(fillpoint)

   176 

   177    Set the 'fill point'.

   178 

   179 

   180 .. method:: audio port.getconfig()

   181 

   182    Return a configuration object containing the current configuration of the port.

   183 

   184 

   185 .. method:: audio port.setconfig(config)

   186 

   187    Set the configuration from the argument, a configuration object.

   188 

   189 

   190 .. method:: audio port.getstatus(list)

   191 

   192    Get status information on last error.

   193 

   194 

   195 :mod:`AL` --- Constants used with the :mod:`al` module

   196 ======================================================

   197 

   198 .. module:: AL

   199    :platform: IRIX

   200    :synopsis: Constants used with the al module.

   201    :deprecated:

   202 

   203 .. deprecated:: 2.6

   204    The :mod:`AL` module has been deprecated for removal in Python 3.0.

   205 

   206 

   207 This module defines symbolic constants needed to use the built-in module

   208 :mod:`al` (see above); they are equivalent to those defined in the C header file

   209 ``<audio.h>`` except that the name prefix ``AL_`` is omitted.  Read the module

   210 source for a complete list of the defined names.  Suggested use::

   211 

   212    import al

   213    from AL import *

   214