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view main/audio/sound.m @ 0:6b33357c7561 octave-forge
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author | pkienzle |
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date | Wed, 10 Oct 2001 19:54:49 +0000 |
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children | f442d0aca116 |
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## Copyright (C) 1999-2000 Paul Kienzle ## ## This program is free software; you can redistribute it and/or modify ## it under the terms of the GNU General Public License as published by ## the Free Software Foundation; either version 2 of the License, or ## (at your option) any later version. ## ## This program is distributed in the hope that it will be useful, ## but WITHOUT ANY WARRANTY; without even the implied warranty of ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ## GNU General Public License for more details. ## ## You should have received a copy of the GNU General Public License ## along with this program; if not, write to the Free Software ## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA ## usage: sound(x [, fs]) ## ## Play the signal through the speakers. Data is a matrix with ## one column per channel. Rate fs defaults to 8000 Hz. The signal ## is clipped to [-1, 1]. ## ## Note that if $DISPLAY != $HOSTNAME:n then a remote shell is opened ## to the host specified in $HOSTNAME to play the audio. See manual ## pages for rsh and .rhosts for your system to learn how to set it up. ## ## This function writes the audio data through a pipe to the program ## "play" from the sox distribution. sox runs pretty much anywhere, ## but it only has audio drivers for OSS (primarily linux and freebsd) ## and SunOS. In case your local machine is not one of these, write ## a shell script such as ~/bin/octaveplay, substituting AUDIO_UTILITY ## with whatever audio utility you happen to have on your system: ## #!/bin/sh ## cat > ~/.octave_play.au ## SYSTEM_AUDIO_UTILITY ~/.octave_play.au ## rm -f ~/.octave_play.au ## and set the global variable (e.g., in .octaverc) ## global sound_play_utility="~/bin/octaveplay"; ## ## If your audio utility can accept an AU file via a pipe, then you ## can use it directly: ## global sound_play_utility="SYSTEM_AUDIO_UTILITY flags" ## where flags are whatever you need to tell it that it is receiving ## an AU file. ## ## With clever use of the command dd, you can chop out the header and ## dump the data directly to the audio device in big-endian format: ## global sound_play_utility="dd of=/dev/audio ibs=2 skip=12" ## or little-endian format: ## global sound_play_utility="dd of=/dev/dsp ibs=2 skip=12 conv=swab" ## but you lose the sampling rate in the process. ## ## Finally, you could modify sound.m to produce data in a format that ## you can dump directly to your audio device and use "cat >/dev/audio" ## as your sound_play_utility. Things you may want to do are resample ## so that the rate is appropriate for your machine and convert the data ## to mulaw and output as bytes. function sound(data, rate) if nargin<1 || nargin>2 usage("sound(x [, fs])"); endif if nargin<2 || isempty(rate), rate = 8000; endif if rows(data) != length(data), data=data'; endif [samples, channels] = size(data); ## Check if the octave engine is running locally by seeing if the ## DISPLAY environment variable is empty or if it is the same as the ## host name of the machine running octave. The host name is ## taken from the HOSTNAME environment variable if it is available, ## otherwise it is taken from the "uname -n" command. display=getenv("DISPLAY"); colon = rindex(display,":"); if isempty(display) || colon==1 islocal = 1; else if colon, display = display(1:colon-1); endif host=getenv("HOSTNAME"); if isempty(host), host = system("uname -n"); # trim newline from end of hostname if !isempty(host), host = host(1:length(host)-1); endif endif islocal = strcmp(tolower(host),tolower(display)); endif ## If not running locally, then must use rsh to execute play command global sound_play_utility="play -t AU -"; if islocal fid=popen(sound_play_utility, "w"); else fid=popen(["rsh ", host, " ", sound_play_utility], "w"); end if fid < 0, warning("sound could not open play process"); else ## write sun .au format header to the pipe fwrite(fid, toascii(".snd"), 'char'); fwrite(fid, 24, 'long', 0, 'ieee-be'); fwrite(fid, -1, 'long', 0, 'ieee-be'); fwrite(fid, 3, 'long', 0, 'ieee-be'); fwrite(fid, rate, 'long', 0, 'ieee-be'); fwrite(fid, channels, 'long', 0, 'ieee-be'); fwrite(fid, 32767*clip(data,[-1, 1])', 'short', 0, 'ieee-be'); pclose(fid); endif end ###### auplay based version: not needed if using sox ## ## If not running locally, then must use rsh to execute play command ## global sound_play_utility="~/bin/auplay" ## if islocal ## fid=popen(sound_play_utility, "w"); ## else ## fid=popen(["rsh ", host, " ", sound_play_utility], "w"); ## end ## fwrite(fid, rate, 'long'); ## fwrite(fid, channels, 'long'); ## fwrite(fid, 32767*clip(data,[-1, 1])', 'short'); ## pclose(fid); %!demo %! [x, fs] = auload(file_in_loadpath("sample.wav")); %! sound(x,fs);