• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1Interface to CD-ROM player.
2
3This module implements an interface to the built-in cd module.  The
4intention is to provide a more user-friendly interface than the
5built-in module.
6
7The module defines a class Readcd with several methods.  The
8initialization of the class will try to open the CD player.  This
9means that initialization will fail if the CD player is already in
10use.  A RuntimeError will be raised by the cd module in that case.
11
12The way to work with this module is as follows.  The user specifies
13the parts of the CD that are to be read and he specifies callback
14functions which are to be called by the system.  At some point he can
15tell the system to play.  The specified parts of the CD will then be
16read and the callbacks will be called.
17
18Initialization.
19===============
20
21r = readcd.Readcd([cd-player [, mode]])
22
23The optional arguments are the name of the CD device and the mode.
24When "mode" is not specified, it defaults to 'r' (which is the only
25possible value); when "cd-player" also isn't specified, it defaults
26to "None" which indicates the default CD player.
27
28Methods.
29========
30
31eject() -- Eject the CD from the player.
32
33reset() -- Reset the list of data stretches to be played.
34
35appendtrack(track) -- Append the specified track to the list of music
36stretches.
37
38appendstretch(first, last) -- Append the stretch from "first" to "last"
39to the list of music stretches.  Both "first" and "last" can be in one
40of four forms.  "None": for "first", the beginning of the CD, for
41"last" the end of the CD; a single integer: a track number--playing
42starts at the beginning of the track or ends at the end of the
43specified track; a three-tuple: the absolute time from the start of
44the CD in minutes, seconds, frames; a four-tuple: track number and
45relative time within the track in minutes, seconds, frames.
46
47settracks(tracklist) -- The argument is a list of integers.  The list
48of stretches is set to argument list.  The old list is discarded.
49
50setcallback(type, func, arg) -- Set a callback function for "type".
51The function will be called as func(arg, type, data) where "arg" is
52the third argument of setcallback, "type" is the type of callback,
53"data" is type-dependent data.  See the CDsetcallback(3) manual page
54for more information.  The possible "type" arguments are defined in
55the CD module.
56
57removecallback(type) -- Remove the callback for "type".
58
59gettrackinfo([tracklist]) -- Return a list of tuples.  Each tuple
60consists of start and length information of a track.  The start and
61length information consist of three-tuples with minutes, seconds and
62frames.  The optional tracklist argument gives a list of interesting
63track numbers.  If no tracklist is specified, information about all
64tracks is returned.
65
66getstatus() -- Return the status information of the CD.
67
68play() -- Play the preprogrammed stretches of music from the CD.  When
69nothing was programmed, the whole CD is played.
70
71Specifying stretches.
72=====================
73
74There are three methods available to specify a stretch of music to be
75played.  The easiest way is to use "settracklist(tracklist)" with which
76a list of tracks can be specified.  "settracklist(tracklist)" is
77equivalent to the sequence
78	reset()
79	for track in tracklist:
80		appendtrack(track)
81
82The next method is "appendtrack(track)" with which a whole track can be
83added to the list of music to be played.  "appendtrack(track)" is
84equivalent to "appendstretch(track, track)".
85
86The most complete method is "appendstretch(first, last)".  Using this
87method, it is possible to specify any stretch of music.
88
89When two consecutive tracks are played, it is possible to choose
90whether the pause that may be between the tracks is played as well or
91whether the pause should be skipped.  When the end of a stretch is
92specified using a track number and the next stretch starts at the
93beginning of the following track and that was also specified using the
94track number (that is, both were specified as integers, not as tuples),
95the pause is played.  When either value was specified using absolute
96time or track-relative time (that is, as three-tuple or as
97four-tuple), the pause will not be played.
98
99Errors.
100=======
101
102When an error occurs, an exception will be raised.  Depending on where
103the error occurs, the exception may either be "readcd.Error" or
104"RuntimeError".
105