alsa: Kill unnecessary -B option.
[paraslash.git] / ggo / afh.m4
1 include(header.m4)
2 <qu>
3 text "
4 para_afh, the audio format handler tool, is a stand-alone program
5 contained in the paraslash package for analyzing and streaming audio
6 files. It can be used to
7
8 - print tech info about the given audio file to stdout.
9 In particular, the 'chunk table' of the audio file, an array
10 of offsets within the audio file, may be printed. This table
11 can be used by other programs unaware of the particular audio
12 format to stream the audio file.
13
14 - write selected parts of the given audio file in complete
15 chunks without decoding. Thus para_afh can be used to 'cut'
16 an audio file.
17
18 - write selected parts of the given audio files 'just in time'
19 to sdout. This may be useful for third-party software that
20 is capable of reading from stdin.
21 "
22 </qu>
23
24 include(loglevel.m4)
25
26 <qu>
27 defgroup "mode"
28 #--------------
29 groupdesc="
30 There are two modes of operation: Info mode and stream mode,
31 one of which must be selected by the corresponding option.
32 See below.
33 "
34 required
35
36 groupoption "info" i
37 #~~~~~~~~~~~~~~~~~~~
38 "select info mode"
39 group="mode"
40 details="
41 In this mode, the program prints technical information about
42 the given audio file to stdout.
43 "
44
45 groupoption "stream" s
46 #~~~~~~~~~~~~~~~~~~~~~
47 "select stream mode"
48 group="mode"
49 details="
50 If this mode is selected, the selected parts of the content
51 of the audio file are written to stdout. Only complete chunks
52 with respect of the underlying audio format are written.
53 For example, only complete frames in case of mp3 files.
54 "
55
56 section "Options for info mode"
57 #==============================
58
59 option "chunk_table" c
60 #~~~~~~~~~~~~~~~~~~~~~
61 "print also the chunk table"
62 flag off
63 dependon="info"
64
65 option "human" u
66 #~~~~~~~~~~~~~~~
67 "use human-readable output format"
68 flag off
69 dependon = "info"
70 details = "
71 Currently this option only affects the format of the chunk table,
72 so it has no effect if --chunk_table is not given.
73
74 The human-readable output consists of one output line per
75 chunk and the output contains also the chunk number, the
76 duration and the size of each chunk.
77 "
78
79 section "Options for stream mode"
80 #================================
81
82
83 option "begin_chunk" b
84 #~~~~~~~~~~~~~~~~~~~~~
85 "skip a number of chunks"
86 int typestr="chunk_num"
87 default="0"
88 dependon="stream"
89 optional
90 details="
91 The chunk_num argument must be between -num_chunks and
92 num_chunks - 1 inclusively where num_chunks is the total number
93 of chunks which is printed when using the --info option. If
94 chunk_num is negative, the given number of chunks are counted
95 backwards from the end of the file. For example --begin_chunk
96 -100 instructs para_afh to start output at chunk num_chunks
97 - 100. This is mainly useful for cutting off the end of an
98 audio file.
99 "
100
101 option "end_chunk" e
102 #~~~~~~~~~~~~~~~~~~~
103 "only write up to chunk chunk_num"
104 int typestr="chunk_num"
105 dependon="stream"
106 optional
107 details="
108 For the chunk_num argument the same rules as for --begin_chunk
109 apply. The default is to write up to the last chunk.
110 "
111
112 option "just_in_time" j
113 #~~~~~~~~~~~~~~~~~~~~~~
114 "use timed writes"
115 flag off
116 dependon="stream"
117 details="
118 Write the specified chunks of data 'just in time', i.e. the
119 write of each chunk is delayed until the time it is needed
120 by the decoder/player in order to guarantee an uninterupted
121 audio stream.
122 "
123
124 option "no_header" H
125 #~~~~~~~~~~~~~~~~~~~
126 "do not write an audio file header"
127 flag off
128 dependon="stream"
129 details="
130 If an audio format needs information about the audio file
131 in a format-specific header in order to be understood by
132 the decoding software, a suitable header is automatically
133 send. This option changes the default behaviour, i.e. no
134 header is written.
135 "
136 </qu>