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comparison main/audio/sound.m @ 0:6b33357c7561 octave-forge

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Initial revision
author pkienzle
date Wed, 10 Oct 2001 19:54:49 +0000
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1 ## Copyright (C) 1999-2000 Paul Kienzle
2 ##
3 ## This program is free software; you can redistribute it and/or modify
4 ## it under the terms of the GNU General Public License as published by
5 ## the Free Software Foundation; either version 2 of the License, or
6 ## (at your option) any later version.
7 ##
8 ## This program is distributed in the hope that it will be useful,
9 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
10 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 ## GNU General Public License for more details.
12 ##
13 ## You should have received a copy of the GNU General Public License
14 ## along with this program; if not, write to the Free Software
15 ## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
16
17 ## usage: sound(x [, fs])
18 ##
19 ## Play the signal through the speakers. Data is a matrix with
20 ## one column per channel. Rate fs defaults to 8000 Hz. The signal
21 ## is clipped to [-1, 1].
22 ##
23 ## Note that if $DISPLAY != $HOSTNAME:n then a remote shell is opened
24 ## to the host specified in $HOSTNAME to play the audio. See manual
25 ## pages for rsh and .rhosts for your system to learn how to set it up.
26 ##
27 ## This function writes the audio data through a pipe to the program
28 ## "play" from the sox distribution. sox runs pretty much anywhere,
29 ## but it only has audio drivers for OSS (primarily linux and freebsd)
30 ## and SunOS. In case your local machine is not one of these, write
31 ## a shell script such as ~/bin/octaveplay, substituting AUDIO_UTILITY
32 ## with whatever audio utility you happen to have on your system:
33 ## #!/bin/sh
34 ## cat > ~/.octave_play.au
35 ## SYSTEM_AUDIO_UTILITY ~/.octave_play.au
36 ## rm -f ~/.octave_play.au
37 ## and set the global variable (e.g., in .octaverc)
38 ## global sound_play_utility="~/bin/octaveplay";
39 ##
40 ## If your audio utility can accept an AU file via a pipe, then you
41 ## can use it directly:
42 ## global sound_play_utility="SYSTEM_AUDIO_UTILITY flags"
43 ## where flags are whatever you need to tell it that it is receiving
44 ## an AU file.
45 ##
46 ## With clever use of the command dd, you can chop out the header and
47 ## dump the data directly to the audio device in big-endian format:
48 ## global sound_play_utility="dd of=/dev/audio ibs=2 skip=12"
49 ## or little-endian format:
50 ## global sound_play_utility="dd of=/dev/dsp ibs=2 skip=12 conv=swab"
51 ## but you lose the sampling rate in the process.
52 ##
53 ## Finally, you could modify sound.m to produce data in a format that
54 ## you can dump directly to your audio device and use "cat >/dev/audio"
55 ## as your sound_play_utility. Things you may want to do are resample
56 ## so that the rate is appropriate for your machine and convert the data
57 ## to mulaw and output as bytes.
58 function sound(data, rate)
59
60 if nargin<1 || nargin>2
61 usage("sound(x [, fs])");
62 endif
63 if nargin<2 || isempty(rate), rate = 8000; endif
64 if rows(data) != length(data), data=data'; endif
65 [samples, channels] = size(data);
66
67 ## Check if the octave engine is running locally by seeing if the
68 ## DISPLAY environment variable is empty or if it is the same as the
69 ## host name of the machine running octave. The host name is
70 ## taken from the HOSTNAME environment variable if it is available,
71 ## otherwise it is taken from the "uname -n" command.
72 display=getenv("DISPLAY");
73 colon = rindex(display,":");
74 if isempty(display) || colon==1
75 islocal = 1;
76 else
77 if colon, display = display(1:colon-1); endif
78 host=getenv("HOSTNAME");
79 if isempty(host),
80 host = system("uname -n");
81 # trim newline from end of hostname
82 if !isempty(host), host = host(1:length(host)-1); endif
83 endif
84 islocal = strcmp(tolower(host),tolower(display));
85 endif
86
87 ## If not running locally, then must use rsh to execute play command
88 global sound_play_utility="play -t AU -";
89 if islocal
90 fid=popen(sound_play_utility, "w");
91 else
92 fid=popen(["rsh ", host, " ", sound_play_utility], "w");
93 end
94 if fid < 0,
95 warning("sound could not open play process");
96 else
97 ## write sun .au format header to the pipe
98 fwrite(fid, toascii(".snd"), 'char');
99 fwrite(fid, 24, 'long', 0, 'ieee-be');
100 fwrite(fid, -1, 'long', 0, 'ieee-be');
101 fwrite(fid, 3, 'long', 0, 'ieee-be');
102 fwrite(fid, rate, 'long', 0, 'ieee-be');
103 fwrite(fid, channels, 'long', 0, 'ieee-be');
104 fwrite(fid, 32767*clip(data,[-1, 1])', 'short', 0, 'ieee-be');
105 pclose(fid);
106 endif
107 end
108
109 ###### auplay based version: not needed if using sox
110 ## ## If not running locally, then must use rsh to execute play command
111 ## global sound_play_utility="~/bin/auplay"
112 ## if islocal
113 ## fid=popen(sound_play_utility, "w");
114 ## else
115 ## fid=popen(["rsh ", host, " ", sound_play_utility], "w");
116 ## end
117 ## fwrite(fid, rate, 'long');
118 ## fwrite(fid, channels, 'long');
119 ## fwrite(fid, 32767*clip(data,[-1, 1])', 'short');
120 ## pclose(fid);
121
122 %!demo
123 %! [x, fs] = auload(file_in_loadpath("sample.wav"));
124 %! sound(x,fs);