system("/usr/bin/afconvert -f WAVE -c 1 -d UI8\@8000 /tmp/Untitled.m4a /tmp/waveform.wav");

#!/usr/bin/perl

# #########################################################
# Audio Oscillograph, (uncalibrated AF Oscilloscope).
# Oscillograph.pl
#
# This is perl 5, version 18, subversion 2 (v5.18.2) built for darwin-thread-multi-2level
# (with 2 registered patches, see perl -V for more detail
# Developed on a[n] MBP, OSX Mojave, Version 10.14.3.
# NOT tested on OSX greater than version 10.14.3!

# #########################################################
# Needed!
use warnings;
use strict;

# #########################################################
# Make sure a bare config file exists in the current directory.
unless(-e "Oscillograph.config")
{
    my $config='$capture_mode="DEMO";
1;
';
    open(my $config_file, '>', 'Oscillograph.config');
    print $config_file "$config";
    close($config_file);
}

# #########################################################
# Global variables...
my $blankline="                                                                                ";
my $horiz=9;
my $vert=9;
my $plot="";
my @hexdump_array=();
our $capture_mode="DEMO";

require 'Oscillograph.config';

# #########################################################
# Clear the screen and reset the terminal.
sub clrscn
{
    print "\033[0m\033c\033[2J\033[H";
}

# #########################################################
# Basic command processing...
sub commands
{
    print "\033[23;1f\033[0m$blankline";
    print "\033[23;1f\033[0mEnter 'QUIT'<CR> to quit or <CR> to [Re-]Run:- ";
    my $command=<STDIN>;
    chomp $command;
    if ( $command eq 'QUIT' )
    {
        my $config='$capture_mode="'."$capture_mode".'";
1;
';
        open(my $config_file, '>', 'Oscillograph.config');
        print $config_file "$config";
        close($config_file);
        &clrscn();
        print "Saved Oscillograph.config and resetting the terminal to the default state.\n";
        exit(0);
    }
    if ( $command eq 'DEMO' )
    {
        $capture_mode='DEMO';
    }
    if ( $command eq 'DSP' )
    {
        $capture_mode='DSP';
    }
    if ( $command eq 'ALSA' )
    {
        $capture_mode='ALSA';
    }
    if ( $command eq 'QT' )
    {
        $capture_mode='QT';
        &QT_script();
        system("/bin/sh", "/tmp/QT.scpt");
    }
    if ( $command eq 'RESTART' )
    {
        $capture_mode='DEMO';
        system("/bin/rm Oscillograph.config");
    }
}

# #########################################################
# This generates a shell script that runs an applescript to access QuickTime Player.
sub QT_script
{
my $AppleScript='/usr/bin/osascript << AppleSampler
    tell application "QuickTime Player"
        activate
        set savePath to "Macintosh HD:tmp:Untitled.m4a"
        set recording to new audio recording
        set visible of front window to false
        delay 2
        start recording
        delay 1
        stop recording
        export document "Untitled" in file savePath using settings preset "Audio Only"
        close (every document whose name contains "Untitled") saving no
        tell application "System Events" to click menu item "Hide Export Progress" of menu "Window" of menu bar 1 of process "QuickTime Player"
        delay 1
        quit
    end tell
AppleSampler
';
open(my $QuickTime, '>', '/tmp/QT.scpt');
print $QuickTime "$AppleScript";
close($QuickTime);
}

# #########################################################
# Screen DISPLAY setup function. For a terminal size of 80 x 24.
sub display
{
    # Set foreground and background graticule colours and foreground and background other window colours.
    print "\033[H\033[0;36;44m       +-------+-------+-------+---[\033[1;37;44mDISPLAY\033[0;36;44m]---+-------+-------+--------+       
       |       |       |       |       +       |       |       |        | \033[0;31;44mMAX\033[0;36;44m   
       |       |       |       |       +       |       |       |        |       
       |       |       |       |       +       |       |       |        |       
   \033[0;31;44m+ve\033[0;36;44m +-------+-------+-------+-------+-------+-------+-------+--------+       
       |       |       |       |       +       |       |       |        |       
       |       |       |       |       +       |       |       |        |       
       |       |       |       |       +       |       |       |        |       
     \033[1;32;44m0\033[0;36;44m +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+--+ \033[1;32;44mREF\033[0;36;44m   
       |       |       |       |       +       |       |       |        |       
       |       |       |       |       +       |       |       |        |       
       |       |       |       |       +       |       |       |        |       
   \033[0;30;44m-ve\033[0;36;44m +-------+-------+-------+-------+-------+-------+-------+--------+       
       |       |       |       |       +       |       |       |        |       
       |       |       |       |       +       |       |       |        |       
       |       |       |       |       +       |       |       |        |       
       |       |       |       |       +       |       |       |        | \033[0;30;44mMIN\033[0;36;44m   
       +-------+-------+-----[\033[1;37;44mAUDIO  OSCILLOGRAPH\033[0;36;44m]-----+-------+--------+       \033[0m

Commands available: QUIT, DEMO, DSP, ALSA, QT and RESTART.\n$blankline\n$blankline\n";
}

# #########################################################
# Capture methods, '/dev/urandom', '/dev/dsp', '/usr/bin/arecord' and 'QuickTime Player'.
sub capture
{
    if ("$capture_mode" eq 'DEMO')
    {
        # DEMO mode that requires no HW access, working as of 27-06-2019.
        system("/bin/dd if=/dev/urandom of=/tmp/waveform.raw bs=1 count=64 > /dev/null 2>&1");
        sleep(1);
    }
    if ($capture_mode eq 'DSP')
    {
        # DSP mode for the likes of old Linux boxes and CygWin, (OSS or PulseAudio).
        system("/bin/dd if=/dev/dsp of=/tmp/waveform.raw bs=1 count=64 > /dev/null 2>&1");
    }
    if ($capture_mode eq 'ALSA')
    {
        # ALSA mode for Linux boxes that have 'arecord'. !!! Not tested yet. !!!
        system("/usr/bin/arecord -d 1 -c 1 -f U8 -r 8000 -t raw /tmp/waveform.raw > /dev/null 2>&1");
    }
    if ($capture_mode eq 'QT')
    {
        # A crucifyingly SSLLOOWW mode for Apple, OSX Mojave.
        # Working as of 28-08-2019.
        system("/bin/sh", "/tmp/QT.scpt");
        system("/usr/bin/afconvert -f WAVE -c 1 -d UI8\@8000 /tmp/Untitled.m4a /tmp/waveform.wav");
        system("dd if=/tmp/waveform.wav of=/tmp/waveform.raw skip=5120 bs=1 count=64 > /dev/null 2>&1");
    }
    @hexdump_array=`/usr/bin/hexdump -v -e '1/1 "%u\n"' /tmp/waveform.raw`;
}

# #########################################################
# Plot the points in the terminal window.
sub plotter
{
    for($horiz=9; $horiz<=72; $horiz=$horiz+1)
    {
        # Simulate an 8 bit grab and divide by 16 to give 4 bit depth.
        # Add offset of 2 to allow for missing the top graticule line.
        chomp(${hexdump_array[($horiz-9)]});
        $vert="${hexdump_array[($horiz-9)]}";
        if ($vert == 127)
        {
            # This allows for centreline 0, zero, AC voltage bit error, (noise).
            $vert=128;
        }
        $vert=int(($vert/16)+2);
        # invert the signal. I'll let you work out why...
        $vert=(19-$vert);
        $plot="\033["."$vert".";"."$horiz"."f\033[1;37;44m*";
        print "$plot";
    }
}

# #########################################################
# Initialisation and main loop.
&clrscn();
&display();
if ($capture_mode eq 'QT')
{
    # Initialise Quicktime Player when 'QT' is selected.
    &QT_script();
    system("/bin/sh", "/tmp/QT.scpt");
}

while(1)
{
    &capture();
    &display();
    &plotter();
    &commands();
}