web based volume control


Forum: Programming and Scripting
Topic: web based volume control
started by: spark-o-matic
Posted by spark-o-matic on Nov. 16 2008,19:40
Morning all,

I use my DSL/Apache computer and xmms to play music.  Aumix works great but it's a pain to run to that computer to change volume or log in on ssh all the time.  So I spent last night and this morning working on this little bit of code to set volumes from a web page.

This is the part written in PERL.
Code Sample
#!/usr/bin/perl

$cmd="aumix";
@validappend=('w',
'v',
'l',
'i'
);


$postcmd="aumix -q >aumix.html";

if ($ENV{'REQUEST_METHOD'} eq 'GET') {
@pairs = split(/&/, $ENV{'QUERY_STRING'});
} elsif ($ENV{'REQUEST_METHOD'} eq 'POST') {
read(STDIN, $buffer, $ENV{'CONTENT_LENGTH'});
@pairs = split(/&/, $buffer);
} else {
print "Content-Type: text/html\n\n";
print "ERROR READING FORM DATA\n\n";
exit;
}
foreach $pair (@pairs) {
local($name, $value) = split(/=/, $pair);
$name =~ tr/+/ /;
$name =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
$value =~ tr/+/ /;
$value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
$value =~ s/<!--(.|\n)*-->//g;
if ($data{$name} && $value) { $data{$name} = "$data{$name}, $value"; }
elsif ($value) {
push(@Field_Order,$name);
$data{$name} = $value;
}}

$nappend=@validappend;
for ($cc0=0;$cc0<=$nappend;$cc0++) {
if ($data{$validappend[$cc0]}) {
$cmd="$cmd \-$validappend[$cc0] $data{$validappend[$cc0]}";
}

}
$ti=time();  


system "$cmd";

system "$postcmd";

print "location: aumix.html?$ti\n\n";

exit;


This is an example of what you might include in an html page.
Code Sample
MASTER VOLUME
<a href="aumix.cgi?v=1" target="plist">MUTE</a>
<a href="aumix.cgi?v=-1" target="plist">-1</a>
<a href="aumix.cgi?v=-3" target="plist">-3</a>
<a href="aumix.cgi?v=-7" target="plist">-7</a>
<a href="aumix.cgi?v=80" target="plist">80</a>
<a href="aumix.cgi?v=95" target="plist">95</a>
<a href="aumix.cgi?v=%2b7" target="plist">+7</a>
<a href="aumix.cgi?v=%2b3" target="plist">+3</a>
<a href="aumix.cgi?v=%2b1" target="plist">+1</a><br>
PCM WAVE
<a href="aumix.cgi?w=1" target="plist">MUTE</a>
<a href="aumix.cgi?w=-1" target="plist">-1</a>
<a href="aumix.cgi?w=-3" target="plist">-3</a>
<a href="aumix.cgi?w=-7" target="plist">-7</a>
<a href="aumix.cgi?w=35" target="plist">35</a>
<a href="aumix.cgi?w=50" target="plist">50</a>
<a href="aumix.cgi?w=85" target="plist">85</a>
<a href="aumix.cgi?w=99" target="plist">99</a>
<a href="aumix.cgi?w=%2b7" target="plist">+7</a>
<a href="aumix.cgi?w=%2b3" target="plist">+3</a>
<a href="aumix.cgi?w=%2b1" target="plist">+1</a><br>
<a href="aumix.cgi?w=55&v=80" target="plist">low</a>
<a href="aumix.cgi?w=85&v=80" target="plist">high</a>
<a href="aumix.cgi?w=95&v=95" target="plist">Crank It Up!!</a>
<br>

This also works directly typing in something like
Code Sample
http://192.168.1.2/aumix.cgi?v=80&w=75
which sets volume to 80 and pcm to 75.I designed this to use two frames and work without Java.  aumix -q shows up in the second frame.  I wrote it to be flexible and at least a little secure.  By changing the values of $cmd and @validappend I suppose most any command can be executed but they also limit what can be done.  $postcmd will change what shows up on the html page.  I used html because I am going to be doing more with this in the grander scheme of things.  It displays better as a txt and thats easy enough by changing the file name in two places.  

I have only tested this with the Apache extention.  If someone gets it working with Monkey I'd be interested to know.
Posted by chaostic on Nov. 16 2008,21:45
You mean you don't have a constant ssh session with your linux box? :p

It could probably be done through PHP to work with monkey.

< http://www.php-mysql-tutorial.com/qna....and.php >

So just a php script with just a bunch of
system('/full/path/to/aumix options > /dev/null 2>&1; /full/path/to/aumix -q')
and a way to select them.
Posted by spark-o-matic on Nov. 17 2008,03:39
Quote
It could probably be done through PHP to work with monkey.

I have done a very little with PERL/CGI under Monkey and it is supported but the problem I had was following simbolic links

As far as PHP I guess that turns into a bit of a phyilosophical discussion.  It is not so much that PHP has a lot of security flaws but PHP has become so popular amongst programmers with no talent or skill what-so-ever and no concern for security that it is developing a reputation of not being secure.  I mean, who would write a program that would write to itself or ever set permitions that the program could write to itself?  Who do you know who doesn't call themselves a 'programmer'?  I realize that ASP was Microsoft and PHP is not but I would like to see a language stick around for as long as Perl, HTML or c before I learn its intricacies.  Since I sat down in front of my first computer in 1982 I have become fluent in 9 languages (most of which are obsolite) and conversational in many others (many obsolite now).  I have been writing PERL to run on web servers for a decade now and I realy can't see it not being available to me in the near future.  The actual techniques havn't changed much over the years, its just a matter of learning a new set of comands and syntax which is time consuming.  For me, for now, a DWIM (do what I mean) language works for me as long as I know what I mean to do.. :p   The other perk for me is how heavily PERL is based on Linux.  I don't know how many times I have pressed the 'du' button when I realized that what I did with PERL was exactly what I needed to do with Linux.  Boy I guess I'm getting a bit  :O  but when someting just works, that works for me.

thanks all

edit:
Quote
You mean you don't have a constant ssh session with your linux box?
Only 1 Linux box? Of the 6 computers I use consistantly, only 1 still has Win98SE as part of a muti-boot.  It gets used less then once a month and only for a very few things I use rarely that I havn't learned to do under Linux in less then a year!
Posted by curaga on Nov. 17 2008,14:23
What, ssh? I only do that to my headless boxes, all the others have their own screens :D
Posted by stunix*com on Nov. 20 2008,23:57
i have a dsl thinkpad wired directly to a poweramp and control volume and selection using a 600x480 vnc server, the box also runs edna to serve any other machine from my TB usb drive.  it works for me, the vncclient can be configured to open from a menu or icon and just as easy as a webpage would.
if all fails i can open the thinkpads screen.

this solution has pushed me in to putting my Linn LP12, Revox R77 and Teac Transport and DAC in to storage, the wife has happily taken over the space with pictures of my nephew.
Posted by mikshaw on Nov. 21 2008,03:46
Personally I think LIRC would be the ideal thing to use, assuming the box is nearby.  Unfortunately I've never had an infrared-capable system with which to try this, so I don't know how well it works.
Posted by chaostic on Nov. 21 2008,08:50
Mikshaw, a free serial port and about 5 dollars worth of scrounged parts (Look for old vcrs and stbs) is all you need to make one lirc compatible (Irda is not lirc compatible)
Posted by spark-o-matic on Nov. 21 2008,16:42
So many simple solutions to any given problem, each with it's good and bad points, and users 'free' to choose any or develop their own.  This is fun.

@stunix*com: I used to use VNC all the time and still do sometimes.  The 2 problems I had were it slowing things way down on old computers and having to reconnect each time I loose the wireless signal on my laptop.

Quote
chaostic Posted on Nov. 21 2008,05:50
Mikshaw, a free serial port and about 5 dollars worth of scrounged parts (Look for old vcrs and stbs) is all you need to make one lirc compatible (Irda is not lirc compatible)
I did just that with an Apple IIC in about 1991 or so.  sensor from a vcr, built a simple circuit to convert the cmos signal level to ttl that went in one of the single bit inputs of the game controler.  Add a universal remote and a driver I wrote in assebly language and I now had an infared keyboard.  I have an external RF remote from one of my old C-Band satalites (worked in any room) that I want to try that with.  I'll have to take a look at lirc.

Quote
I used html because I am going to be doing more with this in the grander scheme of things.
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