Don't let make write the filename into the output
[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 section "Options for stream mode"
66 #================================
67
68
69 option "begin_chunk" b
70 #~~~~~~~~~~~~~~~~~~~~~
71 "skip a number of chunks"
72 int typestr="chunk_num"
73 default="0"
74 dependon="stream"
75 optional
76 details="
77 The chunk_num argument must be between -num_chunks and
78 num_chunks - 1 inclusively where num_chunks is the total number
79 of chunks which is printed when using the --info option. If
80 chunk_num is negative, the given number of chunks are counted
81 backwards from the end of the file. For example --begin_chunk
82 -100 instructs para_afh to start output at chunk num_chunks
83 - 100. This is mainly useful for cutting off the end of an
84 audio file.
85 "
86
87 option "end_chunk" e
88 #~~~~~~~~~~~~~~~~~~~
89 "only write up to chunk chunk_num"
90 int typestr="chunk_num"
91 dependon="stream"
92 optional
93 details="
94 For the chunk_num argument the same rules as for --begin_chunk
95 apply. The default is to write up to the last chunk.
96 "
97
98 option "just_in_time" j
99 #~~~~~~~~~~~~~~~~~~~~~~
100 "use timed writes"
101 flag off
102 dependon="stream"
103 details="
104 Write the specified chunks of data 'just in time', i.e. the
105 write of each chunk is delayed until the time it is needed
106 by the decoder/player in order to guarantee an uninterupted
107 audio stream.
108 "
109
110 option "no_header" H
111 #~~~~~~~~~~~~~~~~~~~
112 "do not write an audio file header"
113 flag off
114 dependon="stream"
115 details="
116 If an audio format needs information about the audio file
117 in a format-specific header in order to be understood by
118 the decoding software, a suitable header is automatically
119 send. This option changes the default behaviour, i.e. no
120 header is written.
121 "
122 </qu>