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

Comparing AnyEvent-MPV/MPV.pm (file contents):
Revision 1.4 by root, Sun Mar 19 20:56:59 2023 UTC vs.
Revision 1.20 by root, Sat Apr 1 06:32:32 2023 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 = '1.03';
		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 0 if $self->{fh};	369	return 0 if $self->{fh};
57		370
…		…
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 $reply->{args}[0] eq "AnyEvent::MPV"
110	) {	422	) {
111	if ($reply->{args}[1] eq "key") {	423	if ($reply->{args}[1] eq "key") {
112	(my $key = $reply->{args}[2]) =~ s/\\x(..)/chr hex $1/ge;	424	(my $key = $reply->{args}[2]) =~ s/\\x(..)/chr hex $1/ge;
113	$self->on_key ($key);	425	$self->on_key ($key);
114	}	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	}
115	} 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
116	$self->on_event ($reply);	443	$self->on_event ($event, $reply);
117	}	444	}
118	} elsif (exists $reply->{request_id}) {	445	} elsif (exists $reply->{request_id}) {
119	my $cv = delete $self->{cmd_cv}{$reply->{request_id}};	446	my $cv = delete $self->{cmdcv}{$reply->{request_id}};
120		447
121	unless ($cv) {	448	unless ($cv) {
122	warn "no cv found for request id <$reply->{request_id}>\n";	449	warn "no cv found for request id <$reply->{request_id}>\n";
123	next;	450	next;
124	}	451	}
…		…
144	$self->stop;	471	$self->stop;
145	$self->on_eof;	472	$self->on_eof;
146	}	473	}
147	};	474	};
148		475
		476	my $wbuf;
		477	my $reqid;
		478
149	$self->{_send} = sub {	479	$self->{_cmd} = sub {
150	$wbuf .= "$_[0]\n";	480	my $cv = AE::cv;
151		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
152	$trace->(">mpv" => "$_[0]");	489	$trace->(">mpv" => $cmd);
153		490
154	$self->{ww} \|\|= AE::io $fh, 1, sub {	491	$wbuf .= "$cmd\n";
		492
		493	my $wcb = sub {
155	my $len = syswrite $fh, $wbuf;	494	my $len = syswrite $fh, $wbuf;
156	substr $wbuf, 0, $len, "";	495	substr $wbuf, 0, $len, "";
157	undef $self->{ww} unless length $wbuf;	496	undef $self->{ww} unless length $wbuf;
158	};	497	};
		498
		499	$wcb->();
		500	$self->{ww} \|\|= AE::io $fh, 1, $wcb if length $wbuf;
		501
		502	$cv
159	};	503	};
160		504
161	1	505	1
162	}	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	kill TERM => $self->{pid};
		530
		531	}
		532
		533	delete $self->{pid};
		534	delete $self->{cmdcv};
		535	delete $self->{evtid};
		536	delete $self->{evtcb};
		537	delete $self->{obsid};
		538	delete $self->{obscb};
		539	delete $self->{wbuf};
		540	}
		541
		542	=item $mpv->on_eof
		543
		544	This method is called when F<mpv> quits - usually unexpectedly. The
		545	default implementation will call the C<on_eof> code reference specified in
		546	the constructor, or do nothing if none was given.
		547
		548	For subclassing, see I<SUBCLASSING>, below.
		549
		550	=cut
163		551
164	sub on_eof {	552	sub on_eof {
165	my ($self) = @_;	553	my ($self) = @_;
166		554
167	$self->{on_eof}($self) if $self->{on_eof};	555	$self->{on_eof}($self) if $self->{on_eof};
168	}	556	}
169		557
		558	=item $mpv->on_event ($event, $data)
		559
		560	This method is called when F<mpv> sends an asynchronous event. The default
		561	implementation will call the C<on_event> code reference specified in the
		562	constructor, or do nothing if none was given.
		563
		564	The first/implicit argument is the C<$mpv> object, the second is the
		565	event name (same as C<< $data->{event} >>, purely for convenience), and
		566	the third argument is the event object as sent by F<mpv> (sans C<event>
		567	key). See L<List of events\|https://mpv.io/manual/stable/#list-of-events>
		568	in its documentation.
		569
		570	For subclassing, see I<SUBCLASSING>, below.
		571
		572	=cut
		573
170	sub on_event {	574	sub on_event {
171	my ($self, $key) = @_;	575	my ($self, $event, $data) = @_;
172		576
173	$self->{on_event}($self, $key) if $self->{on_event};	577	$self->{on_event}($self, $event, $data) if $self->{on_event};
174	}	578	}
		579
		580	=item $mpv->on_key ($string)
		581
		582	Invoked when a key declared by C<< ->bind_key >> is pressed. The default
		583	invokes the C<on_key> code reference specified in the constructor with the
		584	C<$mpv> object and the key name as arguments, or do nothing if none was
		585	given.
		586
		587	For more details and examples, see the C<bind_key> method.
		588
		589	For subclassing, see I<SUBCLASSING>, below.
		590
		591	=cut
175		592
176	sub on_key {	593	sub on_key {
177	my ($self, $key) = @_;	594	my ($self, $key) = @_;
178		595
179	$self->{on_key}($self, $key) if $self->{on_key};	596	$self->{on_key}($self, $key) if $self->{on_key};
180	}	597	}
181		598
		599	=item $mpv->cmd ($command => $arg, $arg...)
		600
		601	Queues a command to be sent to F<mpv>, using the given arguments, and
		602	immediately return a condvar.
		603
		604	See L<the mpv
		605	documentation\|https://mpv.io/manual/stable/#list-of-input-commands> for
		606	details on individual commands.
		607
		608	The condvar can be ignored:
		609
		610	$mpv->cmd (set_property => "deinterlace", "yes");
		611
		612	Or it can be used to synchronously wait for the command results:
		613
		614	$cv = $mpv->cmd (get_property => "video-format");
		615	$format = $cv->recv;
		616
		617	# or simpler:
		618
		619	$format = $mpv->cmd (get_property => "video-format")->recv;
		620
		621	# or even simpler:
		622
		623	$format = $mpv->cmd_recv (get_property => "video-format");
		624
		625	Or you can set a callback:
		626
		627	$cv = $mpv->cmd (get_property => "video-format");
		628	$cv->cb (sub {
		629	my $format = $_[0]->recv;
		630	});
		631
		632	On error, the condvar will croak when C<recv> is called.
		633
		634	=cut
		635
182	sub cmd {	636	sub cmd {
183	my ($self, @cmd) = @_;	637	my $self = shift;
184		638
185	my $cv = AE::cv;	639	$self->{_cmd}->(@_)
186
187	my $reqid = ++$self->{reqid};
188	$self->{cmd_cv}{$reqid} = $cv;
189
190	my $cmd = JSON::XS::encode_json { command => ref $cmd[0] ? $cmd[0] : \@cmd, request_id => $reqid*1 };
191
192	# (un-)apply escape_binary hack
193	$cmd =~ s/\xf4\x8e\x97\x9f(..)/sprintf sprintf "\\x%02x", hex $1/ges; # f48e979f == 10e5df in utf-8
194
195	$self->{_send}($cmd);
196
197	$cv
198	}	640	}
		641
		642	=item $result = $mpv->cmd_recv ($command => $arg, $arg...)
		643
		644	The same as calling C<cmd> and immediately C<recv> on its return
		645	value. Useful when you don't want to mess with F<mpv> asynchronously or
		646	simply needs to have the result:
		647
		648	$mpv->cmd_recv ("stop");
		649	$position = $mpv->cmd_recv ("get_property", "playback-time");
		650
		651	=cut
199		652
200	sub cmd_recv {	653	sub cmd_recv {
201	&cmd->recv	654	&cmd->recv
202	}	655	}
203		656
		657	=item $mpv->bind_key ($INPUT => $string)
		658
		659	This is an extension implement by this module to make it easy to get key
		660	events. The way this is implemented is to bind a C<client-message> witha
		661	first argument of C<AnyEvent::MPV> and the C<$string> you passed. This
		662	C<$string> is then passed to the C<on_key> handle when the key is
		663	proessed, e.g.:
		664
		665	my $mpv = AnyEvent::MPV->new (
		666	on_key => sub {
		667	my ($mpv, $key) = @_;
		668
		669	if ($key eq "letmeout") {
		670	print "user pressed escape\n";
		671	}
		672	},
		673	);
		674
		675	$mpv_>bind_key (ESC => "letmeout");
		676
		677	You cna find a list of key names L<in the mpv
		678	documentation\|https://mpv.io/manual/stable/#key-names>.
		679
		680	The key configuration is lost when F<mpv> is stopped and must be (re-)done
		681	after every C<start>.
		682
		683	=cut
		684
204	sub bind_key {	685	sub bind_key {
205	my ($self, $key, $event) = @_;	686	my ($self, $key, $event) = @_;
206		687
207	$event =~ s/([^A-Za-z0-9\-_])/sprintf "\\x%02x", ord $1/ge;	688	$event =~ s/([^A-Za-z0-9\-_])/sprintf "\\x%02x", ord $1/ge;
208	$self->cmd (keybind => $key => "no-osd script-message AnyEvent::MPV key $event");	689	$self->cmd (keybind => $key => "no-osd script-message AnyEvent::MPV key $event");
209	}	690	}
210		691
211	sub stop {	692	=item [$guard] = $mpv->register_event ($event => $coderef->($mpv, $event, $data))
		693
		694	This method registers a callback to be invoked for a specific
		695	event. Whenever the event occurs, it calls the coderef with the C<$mpv>
		696	object, the C<$event> name and the event object, just like the C<on_event>
		697	method.
		698
		699	For a lst of events, see L<the mpv
		700	documentation\|https://mpv.io/manual/stable/#list-of-events>. Any
		701	underscore in the event name is replaced by a minus sign, so you can
		702	specify event names using underscores for easier quoting in Perl.
		703
		704	In void context, the handler stays registered until C<stop> is called. In
		705	any other context, it returns a guard object that, when destroyed, will
		706	unregister the handler.
		707
		708	You can register multiple handlers for the same event, and this method
		709	does not interfere with the C<on_event> mechanism. That is, you can
		710	completely ignore this method and handle events in a C<on_event> handler,
		711	or mix both approaches as you see fit.
		712
		713	Note that unlike commands, event handlers are registered immediately, that
		714	is, you can issue a command, then register an event handler and then get
		715	an event for this handler I<before> the command is even sent to F<mpv>. If
		716	this kind of race is an issue, you can issue a dummy command such as
		717	C<get_version> and register the handler when the reply is received.
		718
		719	=cut
		720
		721	sub AnyEvent::MPV::Unevent::DESTROY {
		722	my ($evtcb, $event, $evtid) = @{$_[0]};
		723	delete $evtcb->{$event}{$evtid};
		724	}
		725
		726	sub register_event {
		727	my ($self, $event, $cb) = @_;
		728
		729	$event =~ y/_/-/;
		730
		731	my $evtid = ++$self->{evtid};
		732	$self->{evtcb}{$event}{$evtid} = $cb;
		733
		734	defined wantarray
		735	and bless [$self->{evtcb}, $event, $evtid], AnyEvent::MPV::Unevent::
		736	}
		737
		738	=item [$guard] = $mpv->observe_property ($name => $coderef->($mpv, $name, $value))
		739
		740	=item [$guard] = $mpv->observe_property_string ($name => $coderef->($mpv, $name, $value))
		741
		742	These methods wrap a registry system around F<mpv>'s C<observe_property>
		743	and C<observe_property_string> commands - every time the named property
		744	changes, the coderef is invoked with the C<$mpv> object, the name of the
		745	property and the new value.
		746
		747	For a list of properties that you can observe, see L<the mpv
		748	documentation\|https://mpv.io/manual/stable/#property-list>.
		749
		750	Due to the (sane :) way F<mpv> handles these requests, you will always
		751	get a property cxhange event right after registering an observer (meaning
		752	you don't have to query the current value), and it is also possible to
		753	register multiple observers for the same property - they will all be
		754	handled properly.
		755
		756	When called in void context, the observer stays in place until F<mpv>
		757	is stopped. In any otrher context, these methods return a guard
		758	object that, when it goes out of scope, unregisters the observe using
		759	C<unobserve_property>.
		760
		761	Internally, this method uses observer ids of 2**52 (0x10000000000000) or
		762	higher - it will not interfere with lower ovserver ids, so it is possible
		763	to completely ignore this system and execute C<observe_property> commands
		764	yourself, whilst listening to C<property-change> events - as long as your
		765	ids stay below 2**52.
		766
		767	Example: register observers for changtes in C<aid> and C<sid>. Note that
		768	a dummy statement is added to make sure the method is called in void
		769	context.
		770
		771	sub register_observers {
212	my ($self) = @_;	772	my ($mpv) = @_;
213		773
214	if ($self->{pid}) {	774	$mpv->observe_property (aid => sub {
215	delete $self->{rw};	775	my ($mpv, $name, $value) = @_;
216	delete $self->{ww};	776	print "property aid (=$name) has changed to $value\n";
		777	});
217		778
218	close delete $self->{fh}; # current mpv versions should cleanup on their own on close	779	$mpv->observe_property (sid => sub {
		780	my ($mpv, $name, $value) = @_;
		781	print "property sid (=$name) has changed to $value\n";
		782	});
219		783
220	kill TERM => $self->{pid};	784	() # ensure the above method is called in void context
221
222	delete $self->{pid};
223	}	785	}
		786
		787	=cut
		788
		789	sub AnyEvent::MPV::Unobserve::DESTROY {
		790	my ($mpv, $obscb, $obsid) = @{$_[0]};
		791
		792	delete $obscb->{$obsid};
		793
		794	if ($obscb == $mpv->{obscb}) {
		795	$mpv->cmd (unobserve_property => $obsid+0);
		796	}
224	}	797	}
		798
		799	sub _observe_property {
		800	my ($self, $type, $property, $cb) = @_;
		801
		802	my $obsid = OBSID + ++$self->{obsid};
		803	$self->cmd ($type => $obsid+0, $property);
		804	$self->{obscb}{$obsid} = $cb;
		805
		806	defined wantarray and do {
		807	my $unobserve = bless [$self, $self->{obscb}, $obsid], AnyEvent::MPV::Unobserve::;
		808	Scalar::Util::weaken $unobserve->[0];
		809	$unobserve
		810	}
		811	}
		812
		813	sub observe_property {
		814	my ($self, $property, $cb) = @_;
		815
		816	$self->_observe_property (observe_property => $property, $cb)
		817	}
		818
		819	sub observe_property_string {
		820	my ($self, $property, $cb) = @_;
		821
		822	$self->_observe_property (observe_property_string => $property, $cb)
		823	}
		824
		825	=back
		826
		827	=head2 SUBCLASSING
		828
		829	Like most perl objects, C<AnyEvent::MPV> objects are implemented as
		830	hashes, with the constructor simply storing all passed key-value pairs in
		831	the object. If you want to subclass to provide your own C<on_*> methods,
		832	be my guest and rummage around in the internals as much as you wish - the
		833	only guarantee that this module dcoes is that it will not use keys with
		834	double colons in the name, so youc an use those, or chose to simply not
		835	care and deal with the breakage.
		836
		837	If you don't want to go to the effort of subclassing this module, you can
		838	also specify all event handlers as constructor keys.
		839
		840	=head1 EXAMPLES
		841
		842	Here are some real-world code snippets, thrown in here mainly to give you
		843	some example code to copy.
		844
		845	=head2 doomfrontend
		846
		847	At one point I replaced mythtv-frontend by my own terminal-based video
		848	player (based on rxvt-unicode). I toyed with the diea of using F<mpv>'s
		849	subtitle engine to create the user interface, but that is hard to use
		850	since you don't know how big your letters are. It is also where most of
		851	this modules code has originally been developed in.
		852
		853	It uses a unified input queue to handle various remote controls, so its
		854	event handling needs are very simple - it simply feeds all events into the
		855	input queue:
		856
		857	my $mpv = AnyEvent::MPV->new (
		858	mpv => $MPV,
		859	args => \@MPV_ARGS,
		860	on_event => sub {
		861	input_feed "mpv/$_[1]", $_[2];
		862	},
		863	on_key => sub {
		864	input_feed $_[1];
		865	},
		866	on_eof => sub {
		867	input_feed "mpv/quit";
		868	},
		869	);
		870
		871	...
		872
		873	$mpv->start ("--idle=yes", "--pause", "--force-window=no");
		874
		875	It also doesn't use complicated command line arguments - the file search
		876	options have the most impact, as they prevent F<mpv> from scanning
		877	directories with tens of thousands of files for subtitles and more:
		878
		879	--audio-client-name=doomfrontend
		880	--osd-on-seek=msg-bar --osd-bar-align-y=-0.85 --osd-bar-w=95
		881	--sub-auto=exact --audio-file-auto=exact
		882
		883	Since it runs on a TV without a desktop environemnt, it tries to keep complications such as dbus
		884	away and the screensaver happy:
		885
		886	# prevent xscreensaver from doing something stupid, such as starting dbus
		887	$ENV{DBUS_SESSION_BUS_ADDRESS} = "/"; # prevent dbus autostart for sure
		888	$ENV{XDG_CURRENT_DESKTOP} = "generic";
		889
		890	It does bind a number of keys to internal (to doomfrontend) commands:
		891
		892	for (
		893	List::Util::pairs qw(
		894	ESC return
		895	q return
		896	ENTER enter
		897	SPACE pause
		898	[ steprev
		899	] stepfwd
		900	j subtitle
		901	BS red
		902	i green
		903	o yellow
		904	b blue
		905	D triangle
		906	UP up
		907	DOWN down
		908	RIGHT right
		909	LEFT left
		910	),
		911	(map { ("KP$_" => "num$_") } 0..9),
		912	KP_INS => 0, # KP0, but different
		913	) {
		914	$mpv->bind_key ($_->[0] => $_->[1]);
		915	}
		916
		917	It also reacts to sponsorblock chapters, so it needs to know when vidoe
		918	chapters change. Preadting C<AnyEvent::MPV>, it handles observers
		919	manually:
		920
		921	$mpv->cmd (observe_property => 1, "chapter-metadata");
		922
		923	It also tries to apply an F<mpv> profile, if it exists:
		924
		925	eval {
		926	# the profile is optional
		927	$mpv->cmd ("apply-profile" => "doomfrontend");
		928	};
		929
		930	Most of the complicated parts deal with saving and restoring per-video
		931	data, such as bookmarks, playing position, selected audio and subtitle
		932	tracks and so on. However, since it uses L<Coro>, it can conveniently
		933	block and wait for replies, which is n ot possible in purely event based
		934	programs, as you are not allowed to block inside event callbacks in most
		935	event loops. This simplifies the code quite a bit.
		936
		937	When the file to be played is a Tv recording done by mythtv, it uses the
		938	C<appending> protocol and deinterlacing:
		939
		940	if (is_myth $mpv_path) {
		941	$mpv_path = "appending://$mpv_path";
		942	$initial_deinterlace = 1;
		943	}
		944
		945	Otherwise, it sets some defaults and loads the file (I forgot what the
		946	C<dummy> argument is for, but I am sure it is needed by some F<mpv>
		947	version):
		948
		949	$mpv->cmd ("script-message", "osc-visibility", "never", "dummy");
		950	$mpv->cmd ("set", "vid", "auto");
		951	$mpv->cmd ("set", "aid", "auto");
		952	$mpv->cmd ("set", "sid", "no");
		953	$mpv->cmd ("set", "file-local-options/chapters-file", $mpv->escape_binary ("$mpv_path.chapters"));
		954	$mpv->cmd ("loadfile", $mpv->escape_binary ($mpv_path));
		955	$mpv->cmd ("script-message", "osc-visibility", "auto", "dummy");
		956
		957	Handling events makes the main bulk of video playback code. For example,
		958	various ways of ending playback:
		959
		960	if ($INPUT eq "mpv/quit") { # should not happen, but allows user to kill etc. without consequence
		961	$status = 1;
		962	mpv_init; # try reinit
		963	last;
		964
		965	} elsif ($INPUT eq "mpv/idle") { # normal end-of-file
		966	last;
		967
		968	} elsif ($INPUT eq "return") {
		969	$status = 1;
		970	last;
		971
		972	Or the code that actually starts playback, once the file is loaded:
		973
		974	our %SAVE_PROPERTY = (aid => 1, sid => 1, "audio-delay" => 1);
		975
		976	...
		977
		978	my $oid = 100;
		979
		980	} elsif ($INPUT eq "mpv/file-loaded") { # start playing, configure video
		981	$mpv->cmd ("seek", $playback_start, "absolute+exact") if $playback_start > 0;
		982
		983	my $target_fps = eval { $mpv->cmd_recv ("get_property", "container-fps") } \|\| 60;
		984	$target_fps *= play_video_speed_mult;
		985	set_fps $target_fps;
		986
		987	unless (eval { $mpv->cmd_recv ("get_property", "video-format") }) {
		988	$mpv->cmd ("set", "file-local-options/lavfi-complex", "[aid1] asplit [ao], showcqt=..., format=yuv420p [vo]");
		989	};
		990
		991	for my $prop (keys %SAVE_PROPERTY) {
		992	if (exists $PLAYING_STATE->{"mpv_$prop"}) {
		993	$mpv->cmd ("set", "$prop", $PLAYING_STATE->{"mpv_$prop"} . "");
		994	}
		995
		996	$mpv->cmd ("observe_property", ++$oid, $prop);
		997	}
		998
		999	play_video_set_speed;
		1000	$mpv->cmd ("set", "osd-level", "$OSD_LEVEL");
		1001	$mpv->cmd ("observe_property", ++$oid, "osd-level");
		1002	$mpv->cmd ("set", "pause", "no");
		1003
		1004	$mpv->cmd ("set_property", "deinterlace", "yes")
		1005	if $initial_deinterlace;
		1006
		1007	There is a lot going on here. First it seeks to the actual playback
		1008	position, if it is not at the start of the file (it would probaby be more
		1009	efficient to set the starting position before loading the file, though,
		1010	but this is good enough).
		1011
		1012	Then it plays with the display fps, to set it to something harmonious
		1013	w.r.t. the video framerate.
		1014
		1015	If the file does not have a video part, it assumes it is an audio file and
		1016	sets a visualizer.
		1017
		1018	Also, a number of properties are not global, but per-file. At the moment,
		1019	this is C<audio-delay>, and the current audio/subtitle track, which it
		1020	sets, and also creates an observer. Again, this doesn'T use the observe
		1021	functionality of this module, but handles it itself, assigning obsevrer
		1022	ids 100+ to temporary/per-file observers.
		1023
		1024	Lastly, it sets some global (or per-youtube-uploader) parameters, such as
		1025	speed, and unpauses. Property changes are handled like other input events:
		1026
		1027	} elsif ($INPUT eq "mpv/property-change") {
		1028	my $prop = $INPUT_DATA->{name};
		1029
		1030	if ($prop eq "chapter-metadata") {
		1031	if ($INPUT_DATA->{data}{TITLE} =~ /^\[SponsorBlock\]: (.*)/) {
		1032	my $section = $1;
		1033	my $skip;
		1034
		1035	$skip \|\|= $SPONSOR_SKIP{$_}
		1036	for split /\s,\s/, $section;
		1037
		1038	if (defined $skip) {
		1039	if ($skip) {
		1040	# delay a bit, in case we get two metadata changes in quick succession, e.g.
		1041	# because we have a skip at file load time.
		1042	$skip_delay = AE::timer 2/50, 0, sub {
		1043	$mpv->cmd ("no-osd", "add", "chapter", 1);
		1044	$mpv->cmd ("show-text", "skipped sponsorblock section \"$section\"", 3000);
		1045	};
		1046	} else {
		1047	undef $skip_delay;
		1048	$mpv->cmd ("show-text", "NOT skipping sponsorblock section \"$section\"", 3000);
		1049	}
		1050	} else {
		1051	$mpv->cmd ("show-text", "UNRECOGNIZED sponsorblock section \"$section\"", 60000);
		1052	}
		1053	} else {
		1054	# cancel a queued skip
		1055	undef $skip_delay;
		1056	}
		1057
		1058	} elsif (exists $SAVE_PROPERTY{$prop}) {
		1059	$PLAYING_STATE->{"mpv_$prop"} = $INPUT_DATA->{data};
		1060	::state_save;
		1061	}
		1062
		1063	This saves back the per-file properties, and also handles chapter changes
		1064	in a hacky way.
		1065
		1066	Most of the handlers are very simple, though. For example:
		1067
		1068	} elsif ($INPUT eq "pause") {
		1069	$mpv->cmd ("cycle", "pause");
		1070	$PLAYING_STATE->{curpos} = $mpv->cmd_recv ("get_property", "playback-time");
		1071	} elsif ($INPUT eq "right") {
		1072	$mpv->cmd ("osd-msg-bar", "seek", 30, "relative+exact");
		1073	} elsif ($INPUT eq "left") {
		1074	$mpv->cmd ("osd-msg-bar", "seek", -5, "relative+exact");
		1075	} elsif ($INPUT eq "up") {
		1076	$mpv->cmd ("osd-msg-bar", "seek", +600, "relative+exact");
		1077	} elsif ($INPUT eq "down") {
		1078	$mpv->cmd ("osd-msg-bar", "seek", -600, "relative+exact");
		1079	} elsif ($INPUT eq "select") {
		1080	$mpv->cmd ("osd-msg-bar", "add", "audio-delay", "-0.100");
		1081	} elsif ($INPUT eq "start") {
		1082	$mpv->cmd ("osd-msg-bar", "add", "audio-delay", "0.100");
		1083	} elsif ($INPUT eq "intfwd") {
		1084	$mpv->cmd ("no-osd", "frame-step");
		1085	} elsif ($INPUT eq "audio") {
		1086	$mpv->cmd ("osd-auto", "cycle", "audio");
		1087	} elsif ($INPUT eq "subtitle") {
		1088	$mpv->cmd ("osd-auto", "cycle", "sub");
		1089	} elsif ($INPUT eq "triangle") {
		1090	$mpv->cmd ("osd-auto", "cycle", "deinterlace");
		1091
		1092	Once a file has finished playing (or the user strops playback), it pauses,
		1093	unobserves the per-file observers, and saves the current position for to
		1094	be able to resume:
		1095
		1096	$mpv->cmd ("set", "pause", "yes");
		1097
		1098	while ($oid > 100) {
		1099	$mpv->cmd ("unobserve_property", $oid--);
		1100	}
		1101
		1102	$PLAYING_STATE->{curpos} = $mpv->cmd_recv ("get_property", "playback-time");
		1103
		1104	And thats most of the F<mpv>-related code.
		1105
		1106	=head2 F<Gtk2::CV>
		1107
		1108	F<Gtk2::CV> is low-feature image viewer that I use many times daily
		1109	because it can handle directories with millions of files without falling
		1110	over. It also had the ability to play videos for ages, but it used an
		1111	older, crappier protocol to talk to F<mpv> and used F<ffprobe> before
		1112	playing each file instead of letting F<mpv> handle format/size detection.
		1113
		1114	After writing this module, I decided to upgprade Gtk2::CV by making use
		1115	of it, with the goal of getting rid of F<ffprobe> and being ablew to
		1116	reuse F<mpv> processes, which would have a multitude of speed benefits
		1117	(for example, fork+exec of F<mpv> caused the kernel to close all file
		1118	descriptors, which could take minutes if a large file was being copied via
		1119	NFS, as the kernel waited for thr buffers to be flushed on close - not
		1120	having to start F<mpv> gets rid of this issue).
		1121
		1122	Setting up is only complicated by the fact that F<mpv> needs to be
		1123	embedded into an existing window. To keep control of all inputs,
		1124	F<Gtk2::CV> puts an eventbox in front of F<mpv>, so F<mpv> receives no
		1125	input events:
		1126
		1127	$self->{mpv} = AnyEvent::MPV->new (
		1128	trace => $ENV{CV_MPV_TRACE},
		1129	);
		1130
		1131	# create an eventbox, so we receive all input events
		1132	my $box = $self->{mpv_eventbox} = new Gtk2::EventBox;
		1133	$box->set_above_child (1);
		1134	$box->set_visible_window (0);
		1135	$box->set_events ([]);
		1136	$box->can_focus (0);
		1137
		1138	# create a drawingarea that mpv can display into
		1139	my $window = $self->{mpv_window} = new Gtk2::DrawingArea;
		1140	$box->add ($window);
		1141
		1142	# put the drawingarea intot he eventbox, and the eventbox into our display window
		1143	$self->add ($box);
		1144
		1145	# we need to pass the window id to F<mpv>, which means we need to realise
		1146	# the drawingarea, so an X window is allocated for it.
		1147	$self->show_all;
		1148	$window->realize;
		1149	my $xid = $window->window->get_xid;
		1150
		1151	Then it starts F<mpv> using this setup:
		1152
		1153	local $ENV{LC_ALL} = "POSIX";
		1154	$self->{mpv}->start (
		1155	"--no-terminal",
		1156	"--no-input-terminal",
		1157	"--no-input-default-bindings",
		1158	"--no-input-cursor",
		1159	"--input-conf=/dev/null",
		1160	"--input-vo-keyboard=no",
		1161
		1162	"--loop-file=inf",
		1163	"--force-window=yes",
		1164	"--idle=yes",
		1165
		1166	"--audio-client-name=CV",
		1167
		1168	"--osc=yes", # --osc=no displays fading play/pause buttons instead
		1169
		1170	"--wid=$xid",
		1171	);
		1172
		1173	$self->{mpv}->cmd ("script-message" => "osc-visibility" => "never", "dummy");
		1174	$self->{mpv}->cmd ("osc-idlescreen" => "no");
		1175
		1176	It also prepares a hack to force a ConfigureNotify event on every vidoe
		1177	reconfig:
		1178
		1179	# force a configurenotify on every video-reconfig
		1180	$self->{mpv_reconfig} = $self->{mpv}->register_event (video_reconfig => sub {
		1181	my ($mpv, $event, $data) = @_;
		1182
		1183	$self->mpv_window_update;
		1184	});
		1185
		1186	The way this is done is by doing a "dummy" resize to 1x1 and back:
		1187
		1188	$self->{mpv_window}->window->resize (1, 1),
		1189	$self->{mpv_window}->window->resize ($self->{w}, $self->{h});
		1190
		1191	Without this, F<mpv> often doesn't "get" the correct window size. Doing
		1192	it this way is not nice, but I didn't fine a nicer way to do it.
		1193
		1194	When no file is being played, F<mpv> is hidden and prepared:
		1195
		1196	$self->{mpv_eventbox}->hide;
		1197
		1198	$self->{mpv}->cmd (set_property => "pause" => "yes");
		1199	$self->{mpv}->cmd ("playlist_remove", "current");
		1200	$self->{mpv}->cmd (set_property => "video-rotate" => 0);
		1201	$self->{mpv}->cmd (set_property => "lavfi-complex" => "");
		1202
		1203	Loading a file is a bit more complicated, as bluray and DVD rips are
		1204	supported:
		1205
		1206	if ($moviedir) {
		1207	if ($moviedir eq "br") {
		1208	$mpv->cmd (set => "bluray-device" => $path);
		1209	$mpv->cmd (loadfile => "bd://");
		1210	} elsif ($moviedir eq "dvd") {
		1211	$mpv->cmd (set => "dvd-device" => $path);
		1212	$mpv->cmd (loadfile => "dvd://");
		1213	}
		1214	} elsif ($type eq "video/iso-bluray") {
		1215	$mpv->cmd (set => "bluray-device" => $path);
		1216	$mpv->cmd (loadfile => "bd://");
		1217	} else {
		1218	$mpv->cmd (loadfile => $mpv->escape_binary ($path));
		1219	}
		1220
		1221	After this, C<Gtk2::CV> waits for the file to be loaded, video to be
		1222	configured, and then queries the video size (to resize its own window)
		1223	and video format (to decide whether an audio visualizer is needed for
		1224	audio playback). The problematic word here is "wait", as this needs to be
		1225	imploemented using callbacks.
		1226
		1227	This made the code much harder to write, as the whole setup is very
		1228	asynchronous (C<Gtk2::CV> talks to the command interface in F<mpv>, which
		1229	talks to the decode and playback parts, all of which run asynchronously
		1230	w.r.t. each other. In practise, this can mean that C<Gtk2::CV> waits for
		1231	a file to be loaded by F<mpv> while the command interface of F<mpv> still
		1232	deals with the previous file and the decoder still handles an even older
		1233	file). Adding to this fact is that Gtk2::CV is bound by the glib event
		1234	loop, which means we cannot wait for replies form F<mpv> anywhere, so
		1235	everything has to be chained callbacks.
		1236
		1237	The way this is handled is by creating a new empty hash ref that is unique
		1238	for each loaded file, and use it to detect whether the event is old or
		1239	not, and also store C<AnyEvent::MPV> guard objects in it:
		1240
		1241	# every time we loaded a file, we create a new hash
		1242	my $guards = $self->{mpv_guards} = { };
		1243
		1244	Then, when we wait for an event to occur, delete the handler, and, if the
		1245	C<mpv_guards> object has changed, we ignore it. Something like this:
		1246
		1247	$guards->{file_loaded} = $mpv->register_event (file_loaded => sub {
		1248	delete $guards->{file_loaded};
		1249	return if $guards != $self->{mpv_guards};
		1250
		1251	Commands do not have guards since they cnanot be cancelled, so we don't
		1252	have to do this for commands. But what prevents us form misinterpreting
		1253	an old event? Since F<mpv> (by default) handles commands synchronously,
		1254	we can queue a dummy command, whose only purpose is to tell us when all
		1255	previous commands are done. We use C<get_version> for this.
		1256
		1257	The simplified code looks like this:
		1258
		1259	Scalar::Util::weaken $self;
		1260
		1261	$mpv->cmd ("get_version")->cb (sub {
		1262
		1263	$guards->{file_loaded} = $mpv->register_event (file_loaded => sub {
		1264	delete $guards->{file_loaded};
		1265	return if $guards != $self->{mpv_guards};
		1266
		1267	$mpv->cmd (get_property => "video-format")->cb (sub {
		1268	return if $guards != $self->{mpv_guards};
		1269
		1270	# video-format handling
		1271	return if eval { $_[0]->recv; 1 };
		1272
		1273	# no video? assume audio and visualize, cpu usage be damned
		1274	$mpv->cmd (set => "lavfi-complex" => ...");
		1275	});
		1276
		1277	$guards->{show} = $mpv->register_event (video_reconfig => sub {
		1278	delete $guards->{show};
		1279	return if $guards != $self->{mpv_guards};
		1280
		1281	$self->{mpv_eventbox}->show_all;
		1282
		1283	$w = $mpv->cmd (get_property => "dwidth");
		1284	$h = $mpv->cmd (get_property => "dheight");
		1285
		1286	$h->cb (sub {
		1287	$w = eval { $w->recv };
		1288	$h = eval { $h->recv };
		1289
		1290	$mpv->cmd (set_property => "pause" => "no");
		1291
		1292	if ($w && $h) {
		1293	# resize our window
		1294	}
		1295
		1296	});
		1297	});
		1298
		1299	});
		1300
		1301	});
		1302
		1303	Most of the rest of the code is much simpler and just deals with forwarding user commands:
		1304
		1305	} elsif ($key == $Gtk2::Gdk::Keysyms{Right}) { $mpv->cmd ("osd-msg-bar" => seek => "+10");
		1306	} elsif ($key == $Gtk2::Gdk::Keysyms{Left} ) { $mpv->cmd ("osd-msg-bar" => seek => "-10");
		1307	} elsif ($key == $Gtk2::Gdk::Keysyms{Up} ) { $mpv->cmd ("osd-msg-bar" => seek => "+60");
		1308	} elsif ($key == $Gtk2::Gdk::Keysyms{Down} ) { $mpv->cmd ("osd-msg-bar" => seek => "-60");
		1309	} elsif ($key == $Gtk2::Gdk::Keysyms{a}) ) { $mpv->cmd ("osd-msg-msg" => cycle => "audio");
		1310	} elsif ($key == $Gtk2::Gdk::Keysyms{j} ) { $mpv->cmd ("osd-msg-msg" => cycle => "sub");
		1311	} elsif ($key == $Gtk2::Gdk::Keysyms{o} ) { $mpv->cmd ("no-osd" => "cycle-values", "osd-level", "2", "3", "0", "2");
		1312	} elsif ($key == $Gtk2::Gdk::Keysyms{p} ) { $mpv->cmd ("no-osd" => cycle => "pause");
		1313	} elsif ($key == $Gtk2::Gdk::Keysyms{9} ) { $mpv->cmd ("osd-msg-bar" => add => "ao-volume", "-2");
		1314	} elsif ($key == $Gtk2::Gdk::Keysyms{0} ) { $mpv->cmd ("osd-msg-bar" => add => "ao-volume", "+2");
225		1315
226	=head1 SEE ALSO	1316	=head1 SEE ALSO
227		1317
228	L<AnyEvent>.	1318	L<AnyEvent>, L<the mpv command documentation\|https://mpv.io/manual/stable/#command-interface>.
229		1319
230	=head1 AUTHOR	1320	=head1 AUTHOR
231		1321
232	Marc Lehmann <schmorp@schmorp.de>	1322	Marc Lehmann <schmorp@schmorp.de>
233	http://home.schmorp.de/	1323	http://home.schmorp.de/

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Comparing AnyEvent-MPV/MPV.pm (file contents): Revision 1.4 by root, Sun Mar 19 20:56:59 2023 UTC vs. Revision 1.20 by root, Sat Apr 1 06:32:32 2023 UTC

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Comparing AnyEvent-MPV/MPV.pm (file contents):
Revision 1.4 by root, Sun Mar 19 20:56:59 2023 UTC vs.
Revision 1.20 by root, Sat Apr 1 06:32:32 2023 UTC