NAME

MPV::Simple::Pipe

SYNOPSIS

use strict;
use warnings;
use utf8;
use MPV::Simple::Pipe;
use Tcl::Tk;
use Time::HiRes qw(usleep);

# 1) It is recommended to to create the MPV::Simple::Pipe object before TCL
# interpreter because this forks and copies the perl environment
# 2) If you want to handle events you have to pass a true value to the 
# option event_handling 
my $mpv = MPV::Simple::Pipe->new(event_handling => 1);

my $int = Tcl::Tk->new();
my $mw = $int->mainwindow();
$mw->title("MPV::Simple example");  

# Create the video frame
my $f = $mw->Frame(-width => 640, -height => 480)->pack(-expand =>1,-fill => "both");

# Until the video frame is mapped, we set up the MPV Player in this video frame
$f->bind('<Map>' => sub {
    $f->bind('<Map>' => sub {});
    
    $mpv->initialize();
    
    # The video shall start paused here
    $mpv->set_property_string("pause","yes");
    
    # With the MPV property "wid" you can embed MPV in a foreign window
    # (therefore it was important, that $f is already mapped!)
    $mpv->set_property_string("wid",$f->id());
    
    # Load a video file
    $mpv->command("loadfile", "path_to_video.ogg");
});

my $b1 = $mw->Button(
    -text   =>  "Play",
    -command => sub {$mpv->set_property_string('pause','no')}
)->pack(-side => 'left');
my $b2 = $mw->Button(
    -text   =>  "Pause",
    -command => sub {$mpv->set_property_string('pause','yes')}
)->pack(-side => 'left');
my $b3 = $mw->Button(
    -text   =>  "Backward",
    -command => sub {$mpv->command('seek',-5)}
)->pack(-side => 'left');
my $b4 = $mw->Button(
    -text   =>  "Forward",
    -command => sub {$mpv->command('seek',5)}
)->pack(-side => 'left');
my $b5 = $mw->Button(
    -text   =>  "Close",
    # I recommend to destroy first the Tcl::Tk main window, and
    # then the mpv instance
    -command => sub {$mw->destroy();$mpv->terminate_destroy();}
)->pack(-side => 'left');

# In this example the Tcl loop coexists with the MPV loop
# see L<https://docstore.mik.ua/orelly/perl3/tk/ch15_09.htm>
# Another approach (especially if coexisting loops are not possible) 
# would be using a timer, see MPV::Simple:JSON for an example
loop($int);

sub loop {
    my $int = shift;
    while ($int->Eval("info commands .")) { 
        while (my $stat = $int->DoOneEvent(Tcl::DONT_WAIT) ) {}
        while (my $event = $mpv->get_events() ){handle_event($event);}
        
        # Important: We add a little sleep to save CPU!
        usleep(100);
    }
    print "Shuting down..\n";
    $mpv->terminate_destroy();
}

# Event handler
# If you set $opt{event_handling} to a true value in the constructor
# the events are sent through a non-blocking pipe ($mpv->{evreader}) you can access 
# events by the method $mpv->get_events(); which returns a hashref of the event
# The event_ids can be translated to the event names with the global array 
# $MPV::Simple::event_names[$id]
sub handle_event {
    my $event = shift;
    if ($event->{event} eq "property-change") {
        print "prop ".$event->{name}." changed to ".$event->{data}." %\n";
    }
    else {
        print $event->{event}."\n";
    }
}

DESCRIPTION

Using MPV::Simple as a seperate process to integrate it in a foreign event loop, especially to interact with GUI toolkits. The module give access to the same methods as MPV::Simple. Furthermore, if the option $opt{event_handling} is passed to a true value, events are passed trough a pipe ($mpv->{evreader}) which can be accessed by $mpv->get_events(). In this case you can and must handle the events by a repeatly call of a subroutine. See the example above.

Methods

The following methods exist. See MPV::Simple for a detailled description.

• my $mpv = MPV::Simple->new()

• $mpv->initialize()

• $mpv->set_property_string('name','value');

• $mpv->get_property_string('name');

• $mpv->observe_property_string('name', id);

• $mpv->unobserve_property(registered_id);

• $mpv->command($command, @args);

• $mpv->terminate_destroy() Note: After terminating you cannot use the MPV object anymore. Instead you have to create a new MPV object.

Error handling

You can use MPV::Simple::error_names(), MPV::Simple::check_error() and MPV::Simple::warn_error() to handle errors. See MPV::Simple for details.

SEE ALSO

See the doxygen documentation at https://github.com/mpv-player/mpv/blob/master/libmpv/client.h and the manual of the mpv media player in http://mpv.io.