[ViewVC] Diff of: cvs/AnyEvent-MPV/MPV.pm

Comparing AnyEvent-MPV/MPV.pm (file contents):
Revision 1.2 by root, Sun Mar 19 20:30:48 2023 UTC vs.
Revision 1.21 by root, Sun May 26 01:53:22 2024 UTC

…		…
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use AnyEvent::MPV;	7	use AnyEvent::MPV;
8		8
		9	my $videofile = "path/to/file.mkv";
		10	use AnyEvent;
		11	my $mpv = AnyEvent::MPV->new (trace => 1);
		12	$mpv->start ("--idle=yes");
		13	$mpv->cmd (loadfile => $mpv->escape_binary ($videofile));
		14	my $quit = AE::cv;
		15	$mpv->register_event (end_file => $quit);
		16	$quit->recv;
		17
		18
9	=head1 DESCRIPTION	19	=head1 DESCRIPTION
10		20
		21	This module allows you to remote control F<mpv> (a video player). It also
11	This module is an L<AnyEvent> user, you need to make sure that you use and	22	is an L<AnyEvent> user, you need to make sure that you use and run a
12	run a supported event loop.	23	supported event loop.
		24
		25	There are other modules doing this, and I haven't looked much at them
		26	other than to decide that they don't handle encodings correctly, and since
		27	none of them use AnyEvent, I wrote my own. When in doubt, have a look at
		28	them, too.
		29
		30	Knowledge of the L<mpv command
		31	interface\|https://mpv.io/manual/stable/#command-interface> is required to
		32	use this module.
		33
		34	Features of this module are:
		35
		36	=over
		37
		38	=item uses AnyEvent, so integrates well into most event-based programs
		39
		40	=item supports asynchronous and synchronous operation
		41
		42	=item allows you to properly pass binary filenames
		43
		44	=item accepts data encoded in any way (does not crash when mpv replies with non UTF-8 data)
		45
		46	=item features a simple keybind/event system
		47
		48	=back
		49
		50	=head2 OVERVIEW OF OPERATION
		51
		52	This module forks an F<mpv> process and uses F<--input-ipc-client> (or
		53	equivalent) to create a bidirectional communication channel between it and
		54	the F<mpv> process.
		55
		56	It then speaks the somewhat JSON-looking (but not really being JSON)
		57	protocol that F<mpv> implements to both send it commands, decode and
		58	handle replies, and handle asynchronous events.
		59
		60	Here is a very simple client:
		61
		62	use AnyEvent;
		63	use AnyEvent::MPV;
		64
		65	my $videofile = "./xyzzy.mkv";
		66
		67	my $mpv = AnyEvent::MPV->new (trace => 1);
		68
		69	$mpv->start ("--", $videofile);
		70
		71	my $timer = AE::timer 2, 0, my $quit = AE::cv;
		72	$quit->recv;
		73
		74	This starts F<mpv> with the two arguments C<--> and C<$videofile>, which
		75	it should load and play. It then waits two seconds by starting a timer and
		76	quits. The C<trace> argument to the constructor makes F<mpv> more verbose
		77	and also prints the commands and responses, so you can have an idea what
		78	is going on.
		79
		80	In my case, the above example would output something like this:
		81
		82	[uosc] Disabled because original osc is enabled!
		83	mpv> {"event":"start-file","playlist_entry_id":1}
		84	mpv> {"event":"tracks-changed"}
		85	(+) Video --vid=1 (*) (h264 480x480 30.000fps)
		86	mpv> {"event":"metadata-update"}
		87	mpv> {"event":"file-loaded"}
		88	Using hardware decoding (nvdec).
		89	mpv> {"event":"video-reconfig"}
		90	VO: [gpu] 480x480 cuda[nv12]
		91	mpv> {"event":"video-reconfig"}
		92	mpv> {"event":"playback-restart"}
		93
		94	This is not usually very useful (you could just run F<mpv> as a simple
		95	shell command), so let us load the file at runtime:
		96
		97	use AnyEvent;
		98	use AnyEvent::MPV;
		99
		100	my $videofile = "./xyzzy.mkv";
		101
		102	my $mpv = AnyEvent::MPV->new (
		103	trace => 1,
		104	args => ["--pause", "--idle=yes"],
		105	);
		106
		107	$mpv->start;
		108	$mpv->cmd_recv (loadfile => $mpv->escape_binary ($videofile));
		109	$mpv->cmd ("set", "pause", "no");
		110
		111	my $timer = AE::timer 2, 0, my $quit = AE::cv;
		112	$quit->recv;
		113
		114	This specifies extra arguments in the constructor - these arguments are
		115	used every time you C<< ->start >> F<mpv>, while the arguments to C<<
		116	->start >> are only used for this specific clal to0 C<start>. The argument
		117	F<--pause> keeps F<mpv> in pause mode (i.e. it does not play the file
		118	after loading it), and C<--idle=yes> tells F<mpv> to not quit when it does
		119	not have a playlist - as no files are specified on the command line.
		120
		121	To load a file, we then send it a C<loadfile> command, which accepts, as
		122	first argument, the URL or path to a video file. To make sure F<mpv> does
		123	not misinterpret the path as a URL, it was prefixed with F<./> (similarly
		124	to "protecting" paths in perls C<open>).
		125
		126	Since commands send I<to> F<mpv> are send in UTF-8, we need to escape the
		127	filename (which might be in any encoding) using the C<esscape_binary>
		128	method - this is not needed if your filenames are just ascii, or magically
		129	get interpreted correctly, but if you accept arbitrary filenamews (e.g.
		130	from the user), you need to do this.
		131
		132	The C<cmd_recv> method then queues the command, waits for a reply and
		133	returns the reply data (or croaks on error). F<mpv> would, at this point,
		134	load the file and, if everything was successful, show the first frame and
		135	pause. Note that, since F<mpv> is implement rather synchronously itself,
		136	do not expect commands to fail in many circumstances - for example, fit
		137	he file does not exit, you will likely get an event, but the C<loadfile>
		138	command itself will run successfully.
		139
		140	To unpause, we send another command, C<set>, to set the C<pause> property
		141	to C<no>, this time using the C<cmd> method, which queues the command, but
		142	instead of waiting for a reply, it immediately returns a condvar that cna
		143	be used to receive results.
		144
		145	This should then cause F<mpv> to start playing the video.
		146
		147	It then again waits two seconds and quits.
		148
		149	Now, just waiting two seconds is rather, eh, unuseful, so let's look at
		150	receiving events (using a somewhat embellished example):
		151
		152	use AnyEvent;
		153	use AnyEvent::MPV;
		154
		155	my $videofile = "xyzzy.mkv";
		156
		157	my $quit = AE::cv;
		158
		159	my $mpv = AnyEvent::MPV->new (
		160	trace => 1,
		161	args => ["--pause", "--idle=yes"],
		162	);
		163
		164	$mpv->start;
		165
		166	$mpv->register_event (start_file => sub {
		167	$mpv->cmd ("set", "pause", "no");
		168	});
		169
		170	$mpv->register_event (end_file => sub {
		171	my ($mpv, $event, $data) = @_;
		172
		173	print "end-file<$data->{reason}>\n";
		174	$quit->send;
		175	});
		176
		177	$mpv->cmd (loadfile => $mpv->escape_binary ($videofile));
		178
		179	$quit->recv;
		180
		181	This example uses a global condvar C<$quit> to wait for the file to finish
		182	playing. Also, most of the logic is now implement in event handlers.
		183
		184	The two events handlers we register are C<start-file>, which is emitted by
		185	F<mpv> once it has loaded a new file, and C<end-file>, which signals the
		186	end of a file (underscores are internally replaced by minus signs, so you
		187	cna speicfy event names with either).
		188
		189	In the C<start-file> event, we again set the C<pause> property to C<no>
		190	so the movie starts playing. For the C<end-file> event, we tell the main
		191	program to quit by invoking C<$quit>.
		192
		193	This should conclude the basics of operation. There are a few more
		194	examples later in the documentation.
		195
		196	=head2 ENCODING CONVENTIONS
		197
		198	As a rule of thumb, all data you pass to this module to be sent to F<mpv>
		199	is expected to be in unicode. To pass something that isn't, you need to
		200	escape it using C<escape_binary>.
		201
		202	Data received from F<mpv>, however, is I<not> decoded to unicode, as data
		203	returned by F<mpv> is not generally encoded in unicode, and the encoding
		204	is usually unspecified. So if you receive data and expect it to be in
		205	unicode, you need to first decode it from UTF-8, but note that this might
		206	fail. This is not a limitation of this module - F<mpv> simply does not
		207	specify nor guarantee a specific encoding, or any encoding at all, in its
		208	protocol.
		209
		210	=head2 METHODS
		211
		212	=over
13		213
14	=cut	214	=cut
15		215
16	package AnyEvent::MPV;	216	package AnyEvent::MPV;
17		217
…		…
21	use Scalar::Util ();	221	use Scalar::Util ();
22		222
23	use AnyEvent ();	223	use AnyEvent ();
24	use AnyEvent::Util ();	224	use AnyEvent::Util ();
25		225
		226	our $VERSION = '1.04';
		227
		228	sub OBSID() { 2**52 }
		229
26	our $JSON = eval { require JSON::XS; JSON::XS:: }	230	our $JSON = eval { require JSON::XS; JSON::XS:: }
27	\|\| do { require JSON::PP; JSON::PP:: };	231	\|\| do { require JSON::PP; JSON::PP:: };
28		232
29	our $VERSION = '0.1';	233	our $JSON_ENCODER = $JSON->new->utf8;
		234	our $JSON_DECODER = $JSON->new->latin1;
30		235
31	our $mpv_path; # last mpv path used	236	our $mpv_path; # last mpv path used
32	our $mpv_optionlist; # output of mpv --list-options	237	our $mpv_optionlist; # output of mpv --list-options
		238
		239	=item $mpv = AnyEvent::MPV->new (key => value...)
		240
		241	Creates a new C<mpv> object, but does not yet do anything. The support key-value pairs are:
		242
		243	=over
		244
		245	=item mpv => $path
		246
		247	The path to the F<mpv> binary to use - by default, C<mpv> is used and
		248	therefore, uses your C<PATH> to find it.
		249
		250	=item args => [...]
		251
		252	Arguments to pass to F<mpv>. These arguments are passed after the
		253	hardcoded arguments used by this module, but before the arguments passed
		254	ot C<start>. It does not matter whether you specify your arguments using
		255	this key, or in the C<start> call, but when you invoke F<mpv> multiple
		256	times, typically the arguments used for all invocations go here, while
		257	arguments used for specific invocations (e..g filenames) are passed to
		258	C<start>.
		259
		260	=item trace => false\|true\|coderef
		261
		262	Enables tracing if true. In trace mode, output from F<mpv> is printed to
		263	standard error using a C<< mpv> >> prefix, and commands sent to F<mpv>
		264	are printed with a C<< >mpv >> prefix.
		265
		266	If a code reference is passed, then instead of printing to standard
		267	errort, this coderef is invoked with a first arfgument being either
		268	C<< mpv> >> or C<< >mpv >>, and the second argument being a string to
		269	display. The default implementation simply does this:
		270
		271	sub {
		272	warn "$_[0] $_[1]\n";
		273	}
		274
		275	=item on_eof => $coderef->($mpv)
		276
		277	=item on_event => $coderef->($mpv, $event, $data)
		278
		279	=item on_key => $coderef->($mpv, $string)
		280
		281	These are invoked by the default method implementation of the same name -
		282	see below.
		283
		284	=back
		285
		286	=cut
33		287
34	sub new {	288	sub new {
35	my ($class, %kv) = @_;	289	my ($class, %kv) = @_;
36		290
37	bless {	291	bless {
38	mpv => "mpv",	292	mpv => "mpv",
39	args => [],	293	args => [],
40	%kv,	294	%kv,
41	}, $class	295	}, $class
42	}	296	}
		297
		298	=item $string = $mpv->escape_binary ($string)
		299
		300	This module excects all command data sent to F<mpv> to be in unicode. Some
		301	things are not, such as filenames. To pass binary data such as filenames
		302	through a comamnd, you need to escape it using this method.
		303
		304	The simplest example is a C<loadfile> command:
		305
		306	$mpv->cmd_recv (loadfile => $mpv->escape_binary ($path));
		307
		308	=cut
43		309
44	# can be used to escape filenames	310	# can be used to escape filenames
45	sub escape_binary {	311	sub escape_binary {
46	shift;	312	shift;
47	local $_ = shift;	313	local $_ = shift;
48	# we escape every "illegal" octet using U+10e5df HEX. this is later undone in cmd	314	# we escape every "illegal" octet using U+10e5df HEX. this is later undone in cmd
49	s/([\x00-\x1f\x80-\xff])/sprintf "\x{10e5df}%02x", ord $1/ge;	315	s/([\x00-\x1f\x80-\xff])/sprintf "\x{10e5df}%02x", ord $1/ge;
50	$_	316	$_
51	}	317	}
52		318
		319	=item $started = $mpv->start (argument...)
		320
		321	Starts F<mpv>, passing the given arguemnts as extra arguments to
		322	F<mpv>. If F<mpv> is already running, it returns false, otherwise it
		323	returns a true value, so you can easily start F<mpv> on demand by calling
		324	C<start> just before using it, and if it is already running, it will not
		325	be started again.
		326
		327	The arguments passwd to F<mpv> are a set of hardcoded built-in arguments,
		328	followed by the arguments specified in the constructor, followed by the
		329	arguments passwd to this method. The built-in arguments currently are
		330	F<--no-input-terminal>, F<--really-quiet> (or F<--quiet> in C<trace>
		331	mode), and C<--input-ipc-client> (or equivalent).
		332
		333	Some commonly used and/or even useful arguments you might want to pass are:
		334
		335	=over
		336
		337	=item F<--idle=yes> or F<--idle=once> to keep F<mpv> from quitting when you
		338	don't specify a file to play.
		339
		340	=item F<--pause>, to keep F<mpv> from instantly starting to play a file, in case you want to
		341	inspect/change properties first.
		342
		343	=item F<--force-window=no> (or similar), to keep F<mpv> from instantly opening a window, or to force it to do so.
		344
		345	=item F<--audio-client-name=yourappname>, to make sure audio streams are associated witht eh right program.
		346
		347	=item F<--wid=id>, to embed F<mpv> into another application.
		348
		349	=item F<--no-terminal>, F<--no-input-default-bindings>, F<--no-input-cursor>, F<--input-conf=/dev/null>, F<--input-vo-keyboard=no> - to ensure only you control input.
		350
		351	=back
		352
		353	The return value can be used to decide whether F<mpv> needs initializing:
		354
		355	if ($mpv->start) {
		356	$mpv->bind_key (...);
		357	$mpv->cmd (set => property => value);
		358	...
		359	}
		360
		361	You can immediately starting sending commands when this method returns,
		362	even if F<mpv> has not yet started.
		363
		364	=cut
		365
53	sub start {	366	sub start {
54	my ($self, @extra_args) = @_;	367	my ($self, @extra_args) = @_;
55		368
56	return if $self->{fh};	369	return 0 if $self->{fh};
57		370
58	# cache optionlist for same "path"	371	# cache optionlist for same "path"
59	($mpv_path, $mpv_optionlist) = ($self->{mpv}, scalar qx{\Q$self->{mpv}\E --list-options})	372	($mpv_path, $mpv_optionlist) = ($self->{mpv}, scalar qx{\Q$self->{mpv}\E --list-options})
60	if $self->{mpv} ne $mpv_path;	373	if $self->{mpv} ne $mpv_path;
61		374
…		…
73	fcntl $slave, Fcntl::F_SETFD, 0;	386	fcntl $slave, Fcntl::F_SETFD, 0;
74		387
75	my $input_file = $options =~ /\s--input-ipc-client\s/ ? "input-ipc-client" : "input-file";	388	my $input_file = $options =~ /\s--input-ipc-client\s/ ? "input-ipc-client" : "input-file";
76		389
77	exec $self->{mpv},	390	exec $self->{mpv},
78	qw(--no-input-terminal --idle=yes --pause),	391	qw(--no-input-terminal),
79	($self->{trace} ? "--quiet" : "--really-quiet"),	392	($self->{trace} ? "--quiet" : "--really-quiet"),
80	"--$input_file=fd://" . (fileno $slave),	393	"--$input_file=fd://" . (fileno $slave),
81	@{ $self->{args} },	394	@{ $self->{args} },
82	@extra_args;	395	@extra_args;
83	exit 1;	396	exit 1;
84	}	397	}
85		398
86	$self->{fh} = $fh;	399	$self->{fh} = $fh;
87		400
88	my $trace = delete $self->{trace} \|\| sub { };	401	my $trace = $self->{trace} \|\| sub { };
89		402
90	$trace = sub { warn "$_[0] $_[1]\n" } if $trace && !ref $trace;	403	$trace = sub { warn "$_[0] $_[1]\n" } if $trace && !ref $trace;
91		404
92	my $buf;	405	my $buf;
93	my $wbuf;
94		406
95	Scalar::Util::weaken $self;	407	Scalar::Util::weaken $self;
96		408
97	$self->{rw} = AE::io $fh, 0, sub {	409	$self->{rw} = AE::io $fh, 0, sub {
98	if (sysread $fh, $buf, 8192, length $buf) {	410	if (sysread $fh, $buf, 8192, length $buf) {
99	while ($buf =~ s/^([^\n]+)\n//) {	411	while ($buf =~ s/^([^\n]+)\n//) {
100	$trace->("mpv>" => "$1");	412	$trace->("mpv>" => "$1");
101		413
102	if ("{" eq substr $1, 0, 1) {	414	if ("{" eq substr $1, 0, 1) {
103	eval {	415	eval {
104	my $reply = JSON::XS->new->latin1->decode ($1);	416	my $reply = $JSON_DECODER->decode ($1);
105		417
106	if (exists $reply->{event}) {	418	if (defined (my $event = delete $reply->{event})) {
107	if (	419	if (
108	$reply->{event} eq "client-message"	420	$event eq "client-message"
109	and $reply->{args}[0] eq "AnyEvent::MPV"	421	and $reply->{args}[0] eq "AnyEvent::MPV"
110	and $reply->{args}[1] eq "keyhack"
111	) {	422	) {
		423	if ($reply->{args}[1] eq "key") {
		424	(my $key = $reply->{args}[2]) =~ s/\\x(..)/chr hex $1/ge;
112	$self->on_key ($reply->{args}[2]);	425	$self->on_key ($key);
		426	}
		427	} elsif (
		428	$event eq "property-change"
		429	and OBSID <= $reply->{id}
		430	) {
		431	if (my $cb = $self->{obscb}{$reply->{id}}) {
		432	$cb->($self, $event, $reply->{data});
		433	}
113	} else {	434	} else {
		435	if (my $cbs = $self->{evtcb}{$event}) {
		436	for my $evtid (keys %$cbs) {
		437	my $cb = $cbs->{$evtid}
		438	or next;
		439	$cb->($self, $event, $reply);
		440	}
		441	}
		442
114	$self->on_event ($reply->{event});	443	$self->on_event ($event, $reply);
115	}	444	}
116	} elsif (exists $reply->{request_id}) {	445	} elsif (exists $reply->{request_id}) {
117	my $cv = delete $self->{cmd_cv}{$reply->{request_id}};	446	my $cv = delete $self->{cmdcv}{$reply->{request_id}};
118		447
119	unless ($cv) {	448	unless ($cv) {
120	warn "no cv found for request id <$reply->{request_id}>\n";	449	warn "no cv found for request id <$reply->{request_id}>\n";
121	next;	450	next;
122	}	451	}
…		…
142	$self->stop;	471	$self->stop;
143	$self->on_eof;	472	$self->on_eof;
144	}	473	}
145	};	474	};
146		475
		476	my $wbuf;
		477	my $reqid;
		478
147	$self->{_send} = sub {	479	$self->{_cmd} = sub {
148	$wbuf .= "$_[0]\n";	480	my $cv = AE::cv;
149		481
		482	$self->{cmdcv}{++$reqid} = $cv;
		483
		484	my $cmd = $JSON_ENCODER->encode ({ command => ref $_[0] ? $_[0] : \@_, request_id => $reqid*1 });
		485
		486	# (un-)apply escape_binary hack
		487	$cmd =~ s/\xf4\x8e\x97\x9f(..)/sprintf sprintf "\\x%02x", hex $1/ges; # f48e979f == 10e5df in utf-8
		488
150	$trace->(">mpv" => "$_[0]");	489	$trace->(">mpv" => $cmd);
151		490
152	$self->{ww} \|\|= AE::io $fh, 1, sub {	491	$wbuf .= "$cmd\n";
		492
		493	my $wcb = sub {
153	my $len = syswrite $fh, $wbuf;	494	my $len = syswrite $fh, $wbuf;
154	substr $wbuf, 0, $len, "";	495	substr $wbuf, 0, $len, "";
155	undef $self->{ww} unless length $wbuf;	496	undef $self->{ww} unless length $wbuf;
156	};	497	};
		498
		499	$wcb->();
		500	$self->{ww} \|\|= AE::io $fh, 1, $wcb if length $wbuf;
		501
		502	$cv
157	};	503	};
		504
		505	1
158	}	506	}
		507
		508	sub DESTROY {
		509	$_[0]->stop;
		510	}
		511
		512	=item $mpv->stop
		513
		514	Ensures that F<mpv> is being stopped, by killing F<mpv> with a C<TERM>
		515	signal if needed. After this, you can C<< ->start >> a new instance again.
		516
		517	=cut
		518
		519	sub stop {
		520	my ($self) = @_;
		521
		522	delete $self->{rw};
		523	delete $self->{ww};
		524
		525	if ($self->{pid}) {
		526
		527	close delete $self->{fh}; # current mpv versions should cleanup on their own on close
		528
		529	# clean up zombies, or die trying
		530	my $cw; $cw = AE::child $self->{pid}, sub { undef $cw };
		531
		532	kill TERM => $self->{pid};
		533
		534	}
		535
		536	delete $self->{pid};
		537	delete $self->{cmdcv};
		538	delete $self->{evtid};
		539	delete $self->{evtcb};
		540	delete $self->{obsid};
		541	delete $self->{obscb};
		542	delete $self->{wbuf};
		543	}
		544
		545	=item $mpv->on_eof
		546
		547	This method is called when F<mpv> quits - usually unexpectedly. The
		548	default implementation will call the C<on_eof> code reference specified in
		549	the constructor, or do nothing if none was given.
		550
		551	For subclassing, see I<SUBCLASSING>, below.
		552
		553	=cut
159		554
160	sub on_eof {	555	sub on_eof {
161	my ($self) = @_;	556	my ($self) = @_;
162		557
163	$self->{on_eof}($self) if $self->{on_eof};	558	$self->{on_eof}($self) if $self->{on_eof};
164	}	559	}
165		560
		561	=item $mpv->on_event ($event, $data)
		562
		563	This method is called when F<mpv> sends an asynchronous event. The default
		564	implementation will call the C<on_event> code reference specified in the
		565	constructor, or do nothing if none was given.
		566
		567	The first/implicit argument is the C<$mpv> object, the second is the
		568	event name (same as C<< $data->{event} >>, purely for convenience), and
		569	the third argument is the event object as sent by F<mpv> (sans C<event>
		570	key). See L<List of events\|https://mpv.io/manual/stable/#list-of-events>
		571	in its documentation.
		572
		573	For subclassing, see I<SUBCLASSING>, below.
		574
		575	=cut
		576
166	sub on_event {	577	sub on_event {
167	my ($self, $key) = @_;	578	my ($self, $event, $data) = @_;
168		579
169	$self->{on_event}($self, $key) if $self->{on_event};	580	$self->{on_event}($self, $event, $data) if $self->{on_event};
170	}	581	}
		582
		583	=item $mpv->on_key ($string)
		584
		585	Invoked when a key declared by C<< ->bind_key >> is pressed. The default
		586	invokes the C<on_key> code reference specified in the constructor with the
		587	C<$mpv> object and the key name as arguments, or do nothing if none was
		588	given.
		589
		590	For more details and examples, see the C<bind_key> method.
		591
		592	For subclassing, see I<SUBCLASSING>, below.
		593
		594	=cut
171		595
172	sub on_key {	596	sub on_key {
173	my ($self, $key) = @_;	597	my ($self, $key) = @_;
174		598
175	$self->{on_key}($self, $key) if $self->{on_key};	599	$self->{on_key}($self, $key) if $self->{on_key};
176	}	600	}
177		601
		602	=item $mpv->cmd ($command => $arg, $arg...)
		603
		604	Queues a command to be sent to F<mpv>, using the given arguments, and
		605	immediately return a condvar.
		606
		607	See L<the mpv
		608	documentation\|https://mpv.io/manual/stable/#list-of-input-commands> for
		609	details on individual commands.
		610
		611	The condvar can be ignored:
		612
		613	$mpv->cmd (set_property => "deinterlace", "yes");
		614
		615	Or it can be used to synchronously wait for the command results:
		616
		617	$cv = $mpv->cmd (get_property => "video-format");
		618	$format = $cv->recv;
		619
		620	# or simpler:
		621
		622	$format = $mpv->cmd (get_property => "video-format")->recv;
		623
		624	# or even simpler:
		625
		626	$format = $mpv->cmd_recv (get_property => "video-format");
		627
		628	Or you can set a callback:
		629
		630	$cv = $mpv->cmd (get_property => "video-format");
		631	$cv->cb (sub {
		632	my $format = $_[0]->recv;
		633	});
		634
		635	On error, the condvar will croak when C<recv> is called.
		636
		637	=cut
		638
178	sub cmd {	639	sub cmd {
		640	my $self = shift;
		641
		642	$self->{_cmd}->(@_)
		643	}
		644
		645	=item $result = $mpv->cmd_recv ($command => $arg, $arg...)
		646
		647	The same as calling C<cmd> and immediately C<recv> on its return
		648	value. Useful when you don't want to mess with F<mpv> asynchronously or
		649	simply needs to have the result:
		650
		651	$mpv->cmd_recv ("stop");
		652	$position = $mpv->cmd_recv ("get_property", "playback-time");
		653
		654	=cut
		655
		656	sub cmd_recv {
		657	&cmd->recv
		658	}
		659
		660	=item $mpv->bind_key ($INPUT => $string)
		661
		662	This is an extension implement by this module to make it easy to get key
		663	events. The way this is implemented is to bind a C<client-message> witha
		664	first argument of C<AnyEvent::MPV> and the C<$string> you passed. This
		665	C<$string> is then passed to the C<on_key> handle when the key is
		666	proessed, e.g.:
		667
		668	my $mpv = AnyEvent::MPV->new (
		669	on_key => sub {
		670	my ($mpv, $key) = @_;
		671
		672	if ($key eq "letmeout") {
		673	print "user pressed escape\n";
		674	}
		675	},
		676	);
		677
		678	$mpv_>bind_key (ESC => "letmeout");
		679
		680	You cna find a list of key names L<in the mpv
		681	documentation\|https://mpv.io/manual/stable/#key-names>.
		682
		683	The key configuration is lost when F<mpv> is stopped and must be (re-)done
		684	after every C<start>.
		685
		686	=cut
		687
		688	sub bind_key {
		689	my ($self, $key, $event) = @_;
		690
		691	$event =~ s/([^A-Za-z0-9\-_])/sprintf "\\x%02x", ord $1/ge;
		692	$self->cmd (keybind => $key => "no-osd script-message AnyEvent::MPV key $event");
		693	}
		694
		695	=item [$guard] = $mpv->register_event ($event => $coderef->($mpv, $event, $data))
		696
		697	This method registers a callback to be invoked for a specific
		698	event. Whenever the event occurs, it calls the coderef with the C<$mpv>
		699	object, the C<$event> name and the event object, just like the C<on_event>
		700	method.
		701
		702	For a lst of events, see L<the mpv
		703	documentation\|https://mpv.io/manual/stable/#list-of-events>. Any
		704	underscore in the event name is replaced by a minus sign, so you can
		705	specify event names using underscores for easier quoting in Perl.
		706
		707	In void context, the handler stays registered until C<stop> is called. In
		708	any other context, it returns a guard object that, when destroyed, will
		709	unregister the handler.
		710
		711	You can register multiple handlers for the same event, and this method
		712	does not interfere with the C<on_event> mechanism. That is, you can
		713	completely ignore this method and handle events in a C<on_event> handler,
		714	or mix both approaches as you see fit.
		715
		716	Note that unlike commands, event handlers are registered immediately, that
		717	is, you can issue a command, then register an event handler and then get
		718	an event for this handler I<before> the command is even sent to F<mpv>. If
		719	this kind of race is an issue, you can issue a dummy command such as
		720	C<get_version> and register the handler when the reply is received.
		721
		722	=cut
		723
		724	sub AnyEvent::MPV::Unevent::DESTROY {
		725	my ($evtcb, $event, $evtid) = @{$_[0]};
		726	delete $evtcb->{$event}{$evtid};
		727	}
		728
		729	sub register_event {
179	my ($self, @cmd) = @_;	730	my ($self, $event, $cb) = @_;
180		731
181	my $cv = AE::cv;	732	$event =~ y/_/-/;
182		733
183	my $reqid = ++$self->{reqid};	734	my $evtid = ++$self->{evtid};
184	$self->{cmd_cv}{$reqid} = $cv;	735	$self->{evtcb}{$event}{$evtid} = $cb;
185		736
186	my $cmd = JSON::XS::encode_json { command => ref $cmd[0] ? $cmd[0] : \@cmd, request_id => $reqid*1 };	737	defined wantarray
187		738	and bless [$self->{evtcb}, $event, $evtid], AnyEvent::MPV::Unevent::
188	# (un-)apply escape_binary hack
189	$cmd =~ s/\xf4\x8e\x97\x9f(..)/sprintf sprintf "\\x%02x", hex $1/ges; # f48e979f == 10e5df in utf-8
190
191	$self->{_send}($cmd);
192
193	$cv
194	}	739	}
195		740
196	sub stop {	741	=item [$guard] = $mpv->observe_property ($name => $coderef->($mpv, $name, $value))
		742
		743	=item [$guard] = $mpv->observe_property_string ($name => $coderef->($mpv, $name, $value))
		744
		745	These methods wrap a registry system around F<mpv>'s C<observe_property>
		746	and C<observe_property_string> commands - every time the named property
		747	changes, the coderef is invoked with the C<$mpv> object, the name of the
		748	property and the new value.
		749
		750	For a list of properties that you can observe, see L<the mpv
		751	documentation\|https://mpv.io/manual/stable/#property-list>.
		752
		753	Due to the (sane :) way F<mpv> handles these requests, you will always
		754	get a property cxhange event right after registering an observer (meaning
		755	you don't have to query the current value), and it is also possible to
		756	register multiple observers for the same property - they will all be
		757	handled properly.
		758
		759	When called in void context, the observer stays in place until F<mpv>
		760	is stopped. In any otrher context, these methods return a guard
		761	object that, when it goes out of scope, unregisters the observe using
		762	C<unobserve_property>.
		763
		764	Internally, this method uses observer ids of 2**52 (0x10000000000000) or
		765	higher - it will not interfere with lower ovserver ids, so it is possible
		766	to completely ignore this system and execute C<observe_property> commands
		767	yourself, whilst listening to C<property-change> events - as long as your
		768	ids stay below 2**52.
		769
		770	Example: register observers for changtes in C<aid> and C<sid>. Note that
		771	a dummy statement is added to make sure the method is called in void
		772	context.
		773
		774	sub register_observers {
197	my ($self) = @_;	775	my ($mpv) = @_;
198		776
199	if ($self->{pid}) {	777	$mpv->observe_property (aid => sub {
200	delete $self->{rw};	778	my ($mpv, $name, $value) = @_;
201	delete $self->{ww};	779	print "property aid (=$name) has changed to $value\n";
		780	});
202		781
203	close delete $self->{fh}; # current mpv versions should cleanup on their own on close	782	$mpv->observe_property (sid => sub {
		783	my ($mpv, $name, $value) = @_;
		784	print "property sid (=$name) has changed to $value\n";
		785	});
204		786
205	kill TERM => $self->{pid};	787	() # ensure the above method is called in void context
206
207	delete $self->{pid};
208	}	788	}
		789
		790	=cut
		791
		792	sub AnyEvent::MPV::Unobserve::DESTROY {
		793	my ($mpv, $obscb, $obsid) = @{$_[0]};
		794
		795	delete $obscb->{$obsid};
		796
		797	if ($obscb == $mpv->{obscb}) {
		798	$mpv->cmd (unobserve_property => $obsid+0);
		799	}
209	}	800	}
		801
		802	sub _observe_property {
		803	my ($self, $type, $property, $cb) = @_;
		804
		805	my $obsid = OBSID + ++$self->{obsid};
		806	$self->cmd ($type => $obsid+0, $property);
		807	$self->{obscb}{$obsid} = $cb;
		808
		809	defined wantarray and do {
		810	my $unobserve = bless [$self, $self->{obscb}, $obsid], AnyEvent::MPV::Unobserve::;
		811	Scalar::Util::weaken $unobserve->[0];
		812	$unobserve
		813	}
		814	}
		815
		816	sub observe_property {
		817	my ($self, $property, $cb) = @_;
		818
		819	$self->_observe_property (observe_property => $property, $cb)
		820	}
		821
		822	sub observe_property_string {
		823	my ($self, $property, $cb) = @_;
		824
		825	$self->_observe_property (observe_property_string => $property, $cb)
		826	}
		827
		828	=back
		829
		830	=head2 SUBCLASSING
		831
		832	Like most perl objects, C<AnyEvent::MPV> objects are implemented as
		833	hashes, with the constructor simply storing all passed key-value pairs in
		834	the object. If you want to subclass to provide your own C<on_*> methods,
		835	be my guest and rummage around in the internals as much as you wish - the
		836	only guarantee that this module dcoes is that it will not use keys with
		837	double colons in the name, so youc an use those, or chose to simply not
		838	care and deal with the breakage.
		839
		840	If you don't want to go to the effort of subclassing this module, you can
		841	also specify all event handlers as constructor keys.
		842
		843	=head1 EXAMPLES
		844
		845	Here are some real-world code snippets, thrown in here mainly to give you
		846	some example code to copy.
		847
		848	=head2 doomfrontend
		849
		850	At one point I replaced mythtv-frontend by my own terminal-based video
		851	player (based on rxvt-unicode). I toyed with the diea of using F<mpv>'s
		852	subtitle engine to create the user interface, but that is hard to use
		853	since you don't know how big your letters are. It is also where most of
		854	this modules code has originally been developed in.
		855
		856	It uses a unified input queue to handle various remote controls, so its
		857	event handling needs are very simple - it simply feeds all events into the
		858	input queue:
		859
		860	my $mpv = AnyEvent::MPV->new (
		861	mpv => $MPV,
		862	args => \@MPV_ARGS,
		863	on_event => sub {
		864	input_feed "mpv/$_[1]", $_[2];
		865	},
		866	on_key => sub {
		867	input_feed $_[1];
		868	},
		869	on_eof => sub {
		870	input_feed "mpv/quit";
		871	},
		872	);
		873
		874	...
		875
		876	$mpv->start ("--idle=yes", "--pause", "--force-window=no");
		877
		878	It also doesn't use complicated command line arguments - the file search
		879	options have the most impact, as they prevent F<mpv> from scanning
		880	directories with tens of thousands of files for subtitles and more:
		881
		882	--audio-client-name=doomfrontend
		883	--osd-on-seek=msg-bar --osd-bar-align-y=-0.85 --osd-bar-w=95
		884	--sub-auto=exact --audio-file-auto=exact
		885
		886	Since it runs on a TV without a desktop environemnt, it tries to keep complications such as dbus
		887	away and the screensaver happy:
		888
		889	# prevent xscreensaver from doing something stupid, such as starting dbus
		890	$ENV{DBUS_SESSION_BUS_ADDRESS} = "/"; # prevent dbus autostart for sure
		891	$ENV{XDG_CURRENT_DESKTOP} = "generic";
		892
		893	It does bind a number of keys to internal (to doomfrontend) commands:
		894
		895	for (
		896	List::Util::pairs qw(
		897	ESC return
		898	q return
		899	ENTER enter
		900	SPACE pause
		901	[ steprev
		902	] stepfwd
		903	j subtitle
		904	BS red
		905	i green
		906	o yellow
		907	b blue
		908	D triangle
		909	UP up
		910	DOWN down
		911	RIGHT right
		912	LEFT left
		913	),
		914	(map { ("KP$_" => "num$_") } 0..9),
		915	KP_INS => 0, # KP0, but different
		916	) {
		917	$mpv->bind_key ($_->[0] => $_->[1]);
		918	}
		919
		920	It also reacts to sponsorblock chapters, so it needs to know when vidoe
		921	chapters change. Preadting C<AnyEvent::MPV>, it handles observers
		922	manually:
		923
		924	$mpv->cmd (observe_property => 1, "chapter-metadata");
		925
		926	It also tries to apply an F<mpv> profile, if it exists:
		927
		928	eval {
		929	# the profile is optional
		930	$mpv->cmd ("apply-profile" => "doomfrontend");
		931	};
		932
		933	Most of the complicated parts deal with saving and restoring per-video
		934	data, such as bookmarks, playing position, selected audio and subtitle
		935	tracks and so on. However, since it uses L<Coro>, it can conveniently
		936	block and wait for replies, which is n ot possible in purely event based
		937	programs, as you are not allowed to block inside event callbacks in most
		938	event loops. This simplifies the code quite a bit.
		939
		940	When the file to be played is a Tv recording done by mythtv, it uses the
		941	C<appending> protocol and deinterlacing:
		942
		943	if (is_myth $mpv_path) {
		944	$mpv_path = "appending://$mpv_path";
		945	$initial_deinterlace = 1;
		946	}
		947
		948	Otherwise, it sets some defaults and loads the file (I forgot what the
		949	C<dummy> argument is for, but I am sure it is needed by some F<mpv>
		950	version):
		951
		952	$mpv->cmd ("script-message", "osc-visibility", "never", "dummy");
		953	$mpv->cmd ("set", "vid", "auto");
		954	$mpv->cmd ("set", "aid", "auto");
		955	$mpv->cmd ("set", "sid", "no");
		956	$mpv->cmd ("set", "file-local-options/chapters-file", $mpv->escape_binary ("$mpv_path.chapters"));
		957	$mpv->cmd ("loadfile", $mpv->escape_binary ($mpv_path));
		958	$mpv->cmd ("script-message", "osc-visibility", "auto", "dummy");
		959
		960	Handling events makes the main bulk of video playback code. For example,
		961	various ways of ending playback:
		962
		963	if ($INPUT eq "mpv/quit") { # should not happen, but allows user to kill etc. without consequence
		964	$status = 1;
		965	mpv_init; # try reinit
		966	last;
		967
		968	} elsif ($INPUT eq "mpv/idle") { # normal end-of-file
		969	last;
		970
		971	} elsif ($INPUT eq "return") {
		972	$status = 1;
		973	last;
		974
		975	Or the code that actually starts playback, once the file is loaded:
		976
		977	our %SAVE_PROPERTY = (aid => 1, sid => 1, "audio-delay" => 1);
		978
		979	...
		980
		981	my $oid = 100;
		982
		983	} elsif ($INPUT eq "mpv/file-loaded") { # start playing, configure video
		984	$mpv->cmd ("seek", $playback_start, "absolute+exact") if $playback_start > 0;
		985
		986	my $target_fps = eval { $mpv->cmd_recv ("get_property", "container-fps") } \|\| 60;
		987	$target_fps *= play_video_speed_mult;
		988	set_fps $target_fps;
		989
		990	unless (eval { $mpv->cmd_recv ("get_property", "video-format") }) {
		991	$mpv->cmd ("set", "file-local-options/lavfi-complex", "[aid1] asplit [ao], showcqt=..., format=yuv420p [vo]");
		992	};
		993
		994	for my $prop (keys %SAVE_PROPERTY) {
		995	if (exists $PLAYING_STATE->{"mpv_$prop"}) {
		996	$mpv->cmd ("set", "$prop", $PLAYING_STATE->{"mpv_$prop"} . "");
		997	}
		998
		999	$mpv->cmd ("observe_property", ++$oid, $prop);
		1000	}
		1001
		1002	play_video_set_speed;
		1003	$mpv->cmd ("set", "osd-level", "$OSD_LEVEL");
		1004	$mpv->cmd ("observe_property", ++$oid, "osd-level");
		1005	$mpv->cmd ("set", "pause", "no");
		1006
		1007	$mpv->cmd ("set_property", "deinterlace", "yes")
		1008	if $initial_deinterlace;
		1009
		1010	There is a lot going on here. First it seeks to the actual playback
		1011	position, if it is not at the start of the file (it would probaby be more
		1012	efficient to set the starting position before loading the file, though,
		1013	but this is good enough).
		1014
		1015	Then it plays with the display fps, to set it to something harmonious
		1016	w.r.t. the video framerate.
		1017
		1018	If the file does not have a video part, it assumes it is an audio file and
		1019	sets a visualizer.
		1020
		1021	Also, a number of properties are not global, but per-file. At the moment,
		1022	this is C<audio-delay>, and the current audio/subtitle track, which it
		1023	sets, and also creates an observer. Again, this doesn'T use the observe
		1024	functionality of this module, but handles it itself, assigning obsevrer
		1025	ids 100+ to temporary/per-file observers.
		1026
		1027	Lastly, it sets some global (or per-youtube-uploader) parameters, such as
		1028	speed, and unpauses. Property changes are handled like other input events:
		1029
		1030	} elsif ($INPUT eq "mpv/property-change") {
		1031	my $prop = $INPUT_DATA->{name};
		1032
		1033	if ($prop eq "chapter-metadata") {
		1034	if ($INPUT_DATA->{data}{TITLE} =~ /^\[SponsorBlock\]: (.*)/) {
		1035	my $section = $1;
		1036	my $skip;
		1037
		1038	$skip \|\|= $SPONSOR_SKIP{$_}
		1039	for split /\s,\s/, $section;
		1040
		1041	if (defined $skip) {
		1042	if ($skip) {
		1043	# delay a bit, in case we get two metadata changes in quick succession, e.g.
		1044	# because we have a skip at file load time.
		1045	$skip_delay = AE::timer 2/50, 0, sub {
		1046	$mpv->cmd ("no-osd", "add", "chapter", 1);
		1047	$mpv->cmd ("show-text", "skipped sponsorblock section \"$section\"", 3000);
		1048	};
		1049	} else {
		1050	undef $skip_delay;
		1051	$mpv->cmd ("show-text", "NOT skipping sponsorblock section \"$section\"", 3000);
		1052	}
		1053	} else {
		1054	$mpv->cmd ("show-text", "UNRECOGNIZED sponsorblock section \"$section\"", 60000);
		1055	}
		1056	} else {
		1057	# cancel a queued skip
		1058	undef $skip_delay;
		1059	}
		1060
		1061	} elsif (exists $SAVE_PROPERTY{$prop}) {
		1062	$PLAYING_STATE->{"mpv_$prop"} = $INPUT_DATA->{data};
		1063	::state_save;
		1064	}
		1065
		1066	This saves back the per-file properties, and also handles chapter changes
		1067	in a hacky way.
		1068
		1069	Most of the handlers are very simple, though. For example:
		1070
		1071	} elsif ($INPUT eq "pause") {
		1072	$mpv->cmd ("cycle", "pause");
		1073	$PLAYING_STATE->{curpos} = $mpv->cmd_recv ("get_property", "playback-time");
		1074	} elsif ($INPUT eq "right") {
		1075	$mpv->cmd ("osd-msg-bar", "seek", 30, "relative+exact");
		1076	} elsif ($INPUT eq "left") {
		1077	$mpv->cmd ("osd-msg-bar", "seek", -5, "relative+exact");
		1078	} elsif ($INPUT eq "up") {
		1079	$mpv->cmd ("osd-msg-bar", "seek", +600, "relative+exact");
		1080	} elsif ($INPUT eq "down") {
		1081	$mpv->cmd ("osd-msg-bar", "seek", -600, "relative+exact");
		1082	} elsif ($INPUT eq "select") {
		1083	$mpv->cmd ("osd-msg-bar", "add", "audio-delay", "-0.100");
		1084	} elsif ($INPUT eq "start") {
		1085	$mpv->cmd ("osd-msg-bar", "add", "audio-delay", "0.100");
		1086	} elsif ($INPUT eq "intfwd") {
		1087	$mpv->cmd ("no-osd", "frame-step");
		1088	} elsif ($INPUT eq "audio") {
		1089	$mpv->cmd ("osd-auto", "cycle", "audio");
		1090	} elsif ($INPUT eq "subtitle") {
		1091	$mpv->cmd ("osd-auto", "cycle", "sub");
		1092	} elsif ($INPUT eq "triangle") {
		1093	$mpv->cmd ("osd-auto", "cycle", "deinterlace");
		1094
		1095	Once a file has finished playing (or the user strops playback), it pauses,
		1096	unobserves the per-file observers, and saves the current position for to
		1097	be able to resume:
		1098
		1099	$mpv->cmd ("set", "pause", "yes");
		1100
		1101	while ($oid > 100) {
		1102	$mpv->cmd ("unobserve_property", $oid--);
		1103	}
		1104
		1105	$PLAYING_STATE->{curpos} = $mpv->cmd_recv ("get_property", "playback-time");
		1106
		1107	And thats most of the F<mpv>-related code.
		1108
		1109	=head2 F<Gtk2::CV>
		1110
		1111	F<Gtk2::CV> is low-feature image viewer that I use many times daily
		1112	because it can handle directories with millions of files without falling
		1113	over. It also had the ability to play videos for ages, but it used an
		1114	older, crappier protocol to talk to F<mpv> and used F<ffprobe> before
		1115	playing each file instead of letting F<mpv> handle format/size detection.
		1116
		1117	After writing this module, I decided to upgprade Gtk2::CV by making use
		1118	of it, with the goal of getting rid of F<ffprobe> and being ablew to
		1119	reuse F<mpv> processes, which would have a multitude of speed benefits
		1120	(for example, fork+exec of F<mpv> caused the kernel to close all file
		1121	descriptors, which could take minutes if a large file was being copied via
		1122	NFS, as the kernel waited for thr buffers to be flushed on close - not
		1123	having to start F<mpv> gets rid of this issue).
		1124
		1125	Setting up is only complicated by the fact that F<mpv> needs to be
		1126	embedded into an existing window. To keep control of all inputs,
		1127	F<Gtk2::CV> puts an eventbox in front of F<mpv>, so F<mpv> receives no
		1128	input events:
		1129
		1130	$self->{mpv} = AnyEvent::MPV->new (
		1131	trace => $ENV{CV_MPV_TRACE},
		1132	);
		1133
		1134	# create an eventbox, so we receive all input events
		1135	my $box = $self->{mpv_eventbox} = new Gtk2::EventBox;
		1136	$box->set_above_child (1);
		1137	$box->set_visible_window (0);
		1138	$box->set_events ([]);
		1139	$box->can_focus (0);
		1140
		1141	# create a drawingarea that mpv can display into
		1142	my $window = $self->{mpv_window} = new Gtk2::DrawingArea;
		1143	$box->add ($window);
		1144
		1145	# put the drawingarea intot he eventbox, and the eventbox into our display window
		1146	$self->add ($box);
		1147
		1148	# we need to pass the window id to F<mpv>, which means we need to realise
		1149	# the drawingarea, so an X window is allocated for it.
		1150	$self->show_all;
		1151	$window->realize;
		1152	my $xid = $window->window->get_xid;
		1153
		1154	Then it starts F<mpv> using this setup:
		1155
		1156	local $ENV{LC_ALL} = "POSIX";
		1157	$self->{mpv}->start (
		1158	"--no-terminal",
		1159	"--no-input-terminal",
		1160	"--no-input-default-bindings",
		1161	"--no-input-cursor",
		1162	"--input-conf=/dev/null",
		1163	"--input-vo-keyboard=no",
		1164
		1165	"--loop-file=inf",
		1166	"--force-window=yes",
		1167	"--idle=yes",
		1168
		1169	"--audio-client-name=CV",
		1170
		1171	"--osc=yes", # --osc=no displays fading play/pause buttons instead
		1172
		1173	"--wid=$xid",
		1174	);
		1175
		1176	$self->{mpv}->cmd ("script-message" => "osc-visibility" => "never", "dummy");
		1177	$self->{mpv}->cmd ("osc-idlescreen" => "no");
		1178
		1179	It also prepares a hack to force a ConfigureNotify event on every vidoe
		1180	reconfig:
		1181
		1182	# force a configurenotify on every video-reconfig
		1183	$self->{mpv_reconfig} = $self->{mpv}->register_event (video_reconfig => sub {
		1184	my ($mpv, $event, $data) = @_;
		1185
		1186	$self->mpv_window_update;
		1187	});
		1188
		1189	The way this is done is by doing a "dummy" resize to 1x1 and back:
		1190
		1191	$self->{mpv_window}->window->resize (1, 1),
		1192	$self->{mpv_window}->window->resize ($self->{w}, $self->{h});
		1193
		1194	Without this, F<mpv> often doesn't "get" the correct window size. Doing
		1195	it this way is not nice, but I didn't fine a nicer way to do it.
		1196
		1197	When no file is being played, F<mpv> is hidden and prepared:
		1198
		1199	$self->{mpv_eventbox}->hide;
		1200
		1201	$self->{mpv}->cmd (set_property => "pause" => "yes");
		1202	$self->{mpv}->cmd ("playlist_remove", "current");
		1203	$self->{mpv}->cmd (set_property => "video-rotate" => 0);
		1204	$self->{mpv}->cmd (set_property => "lavfi-complex" => "");
		1205
		1206	Loading a file is a bit more complicated, as bluray and DVD rips are
		1207	supported:
		1208
		1209	if ($moviedir) {
		1210	if ($moviedir eq "br") {
		1211	$mpv->cmd (set => "bluray-device" => $path);
		1212	$mpv->cmd (loadfile => "bd://");
		1213	} elsif ($moviedir eq "dvd") {
		1214	$mpv->cmd (set => "dvd-device" => $path);
		1215	$mpv->cmd (loadfile => "dvd://");
		1216	}
		1217	} elsif ($type eq "video/iso-bluray") {
		1218	$mpv->cmd (set => "bluray-device" => $path);
		1219	$mpv->cmd (loadfile => "bd://");
		1220	} else {
		1221	$mpv->cmd (loadfile => $mpv->escape_binary ($path));
		1222	}
		1223
		1224	After this, C<Gtk2::CV> waits for the file to be loaded, video to be
		1225	configured, and then queries the video size (to resize its own window)
		1226	and video format (to decide whether an audio visualizer is needed for
		1227	audio playback). The problematic word here is "wait", as this needs to be
		1228	imploemented using callbacks.
		1229
		1230	This made the code much harder to write, as the whole setup is very
		1231	asynchronous (C<Gtk2::CV> talks to the command interface in F<mpv>, which
		1232	talks to the decode and playback parts, all of which run asynchronously
		1233	w.r.t. each other. In practise, this can mean that C<Gtk2::CV> waits for
		1234	a file to be loaded by F<mpv> while the command interface of F<mpv> still
		1235	deals with the previous file and the decoder still handles an even older
		1236	file). Adding to this fact is that Gtk2::CV is bound by the glib event
		1237	loop, which means we cannot wait for replies form F<mpv> anywhere, so
		1238	everything has to be chained callbacks.
		1239
		1240	The way this is handled is by creating a new empty hash ref that is unique
		1241	for each loaded file, and use it to detect whether the event is old or
		1242	not, and also store C<AnyEvent::MPV> guard objects in it:
		1243
		1244	# every time we loaded a file, we create a new hash
		1245	my $guards = $self->{mpv_guards} = { };
		1246
		1247	Then, when we wait for an event to occur, delete the handler, and, if the
		1248	C<mpv_guards> object has changed, we ignore it. Something like this:
		1249
		1250	$guards->{file_loaded} = $mpv->register_event (file_loaded => sub {
		1251	delete $guards->{file_loaded};
		1252	return if $guards != $self->{mpv_guards};
		1253
		1254	Commands do not have guards since they cnanot be cancelled, so we don't
		1255	have to do this for commands. But what prevents us form misinterpreting
		1256	an old event? Since F<mpv> (by default) handles commands synchronously,
		1257	we can queue a dummy command, whose only purpose is to tell us when all
		1258	previous commands are done. We use C<get_version> for this.
		1259
		1260	The simplified code looks like this:
		1261
		1262	Scalar::Util::weaken $self;
		1263
		1264	$mpv->cmd ("get_version")->cb (sub {
		1265
		1266	$guards->{file_loaded} = $mpv->register_event (file_loaded => sub {
		1267	delete $guards->{file_loaded};
		1268	return if $guards != $self->{mpv_guards};
		1269
		1270	$mpv->cmd (get_property => "video-format")->cb (sub {
		1271	return if $guards != $self->{mpv_guards};
		1272
		1273	# video-format handling
		1274	return if eval { $_[0]->recv; 1 };
		1275
		1276	# no video? assume audio and visualize, cpu usage be damned
		1277	$mpv->cmd (set => "lavfi-complex" => ...");
		1278	});
		1279
		1280	$guards->{show} = $mpv->register_event (video_reconfig => sub {
		1281	delete $guards->{show};
		1282	return if $guards != $self->{mpv_guards};
		1283
		1284	$self->{mpv_eventbox}->show_all;
		1285
		1286	$w = $mpv->cmd (get_property => "dwidth");
		1287	$h = $mpv->cmd (get_property => "dheight");
		1288
		1289	$h->cb (sub {
		1290	$w = eval { $w->recv };
		1291	$h = eval { $h->recv };
		1292
		1293	$mpv->cmd (set_property => "pause" => "no");
		1294
		1295	if ($w && $h) {
		1296	# resize our window
		1297	}
		1298
		1299	});
		1300	});
		1301
		1302	});
		1303
		1304	});
		1305
		1306	Most of the rest of the code is much simpler and just deals with forwarding user commands:
		1307
		1308	} elsif ($key == $Gtk2::Gdk::Keysyms{Right}) { $mpv->cmd ("osd-msg-bar" => seek => "+10");
		1309	} elsif ($key == $Gtk2::Gdk::Keysyms{Left} ) { $mpv->cmd ("osd-msg-bar" => seek => "-10");
		1310	} elsif ($key == $Gtk2::Gdk::Keysyms{Up} ) { $mpv->cmd ("osd-msg-bar" => seek => "+60");
		1311	} elsif ($key == $Gtk2::Gdk::Keysyms{Down} ) { $mpv->cmd ("osd-msg-bar" => seek => "-60");
		1312	} elsif ($key == $Gtk2::Gdk::Keysyms{a}) ) { $mpv->cmd ("osd-msg-msg" => cycle => "audio");
		1313	} elsif ($key == $Gtk2::Gdk::Keysyms{j} ) { $mpv->cmd ("osd-msg-msg" => cycle => "sub");
		1314	} elsif ($key == $Gtk2::Gdk::Keysyms{o} ) { $mpv->cmd ("no-osd" => "cycle-values", "osd-level", "2", "3", "0", "2");
		1315	} elsif ($key == $Gtk2::Gdk::Keysyms{p} ) { $mpv->cmd ("no-osd" => cycle => "pause");
		1316	} elsif ($key == $Gtk2::Gdk::Keysyms{9} ) { $mpv->cmd ("osd-msg-bar" => add => "ao-volume", "-2");
		1317	} elsif ($key == $Gtk2::Gdk::Keysyms{0} ) { $mpv->cmd ("osd-msg-bar" => add => "ao-volume", "+2");
210		1318
211	=head1 SEE ALSO	1319	=head1 SEE ALSO
212		1320
213	L<AnyEvent>.	1321	L<AnyEvent>, L<the mpv command documentation\|https://mpv.io/manual/stable/#command-interface>.
214		1322
215	=head1 AUTHOR	1323	=head1 AUTHOR
216		1324
217	Marc Lehmann <schmorp@schmorp.de>	1325	Marc Lehmann <schmorp@schmorp.de>
218	http://home.schmorp.de/	1326	http://home.schmorp.de/

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Comparing AnyEvent-MPV/MPV.pm (file contents): Revision 1.2 by root, Sun Mar 19 20:30:48 2023 UTC vs. Revision 1.21 by root, Sun May 26 01:53:22 2024 UTC

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Comparing AnyEvent-MPV/MPV.pm (file contents):
Revision 1.2 by root, Sun Mar 19 20:30:48 2023 UTC vs.
Revision 1.21 by root, Sun May 26 01:53:22 2024 UTC