[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 1.19 by root, Sun Mar 26 17:15:18 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 = '1.01';
		227
		228	sub OBSID() { 0x10000000000000 } # 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);
		490
		491	$wbuf .= "$cmd\n";
153		492
154	$self->{ww} \|\|= AE::io $fh, 1, sub {	493	$self->{ww} \|\|= AE::io $fh, 1, 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	$cv
159	};	500	};
160		501
161	1	502	1
162	}	503	}
		504
		505	sub DESTROY {
		506	$_[0]->stop;
		507	}
		508
		509	=item $mpv->stop
		510
		511	Ensures that F<mpv> is being stopped, by killing F<mpv> with a C<TERM>
		512	signal if needed. After this, you can C<< ->start >> a new instance again.
		513
		514	=cut
		515
		516	sub stop {
		517	my ($self) = @_;
		518
		519	delete $self->{rw};
		520	delete $self->{ww};
		521
		522	if ($self->{pid}) {
		523
		524	close delete $self->{fh}; # current mpv versions should cleanup on their own on close
		525
		526	kill TERM => $self->{pid};
		527
		528	}
		529
		530	delete $self->{pid};
		531	delete $self->{cmdcv};
		532	delete $self->{evtid};
		533	delete $self->{evtcb};
		534	delete $self->{obsid};
		535	delete $self->{obscb};
		536	delete $self->{wbuf};
		537	}
		538
		539	=item $mpv->on_eof
		540
		541	This method is called when F<mpv> quits - usually unexpectedly. The
		542	default implementation will call the C<on_eof> code reference specified in
		543	the constructor, or do nothing if none was given.
		544
		545	For subclassing, see I<SUBCLASSING>, below.
		546
		547	=cut
163		548
164	sub on_eof {	549	sub on_eof {
165	my ($self) = @_;	550	my ($self) = @_;
166		551
167	$self->{on_eof}($self) if $self->{on_eof};	552	$self->{on_eof}($self) if $self->{on_eof};
168	}	553	}
169		554
		555	=item $mpv->on_event ($event, $data)
		556
		557	This method is called when F<mpv> sends an asynchronous event. The default
		558	implementation will call the C<on_event> code reference specified in the
		559	constructor, or do nothing if none was given.
		560
		561	The first/implicit argument is the C<$mpv> object, the second is the
		562	event name (same as C<< $data->{event} >>, purely for convenience), and
		563	the third argument is the event object as sent by F<mpv> (sans C<event>
		564	key). See L<List of events\|https://mpv.io/manual/stable/#list-of-events>
		565	in its documentation.
		566
		567	For subclassing, see I<SUBCLASSING>, below.
		568
		569	=cut
		570
170	sub on_event {	571	sub on_event {
171	my ($self, $key) = @_;	572	my ($self, $event, $data) = @_;
172		573
173	$self->{on_event}($self, $key) if $self->{on_event};	574	$self->{on_event}($self, $event, $data) if $self->{on_event};
174	}	575	}
		576
		577	=item $mpv->on_key ($string)
		578
		579	Invoked when a key declared by C<< ->bind_key >> is pressed. The default
		580	invokes the C<on_key> code reference specified in the constructor with the
		581	C<$mpv> object and the key name as arguments, or do nothing if none was
		582	given.
		583
		584	For more details and examples, see the C<bind_key> method.
		585
		586	For subclassing, see I<SUBCLASSING>, below.
		587
		588	=cut
175		589
176	sub on_key {	590	sub on_key {
177	my ($self, $key) = @_;	591	my ($self, $key) = @_;
178		592
179	$self->{on_key}($self, $key) if $self->{on_key};	593	$self->{on_key}($self, $key) if $self->{on_key};
180	}	594	}
181		595
		596	=item $mpv->cmd ($command => $arg, $arg...)
		597
		598	Queues a command to be sent to F<mpv>, using the given arguments, and
		599	immediately return a condvar.
		600
		601	See L<the mpv
		602	documentation\|https://mpv.io/manual/stable/#list-of-input-commands> for
		603	details on individual commands.
		604
		605	The condvar can be ignored:
		606
		607	$mpv->cmd (set_property => "deinterlace", "yes");
		608
		609	Or it can be used to synchronously wait for the command results:
		610
		611	$cv = $mpv->cmd (get_property => "video-format");
		612	$format = $cv->recv;
		613
		614	# or simpler:
		615
		616	$format = $mpv->cmd (get_property => "video-format")->recv;
		617
		618	# or even simpler:
		619
		620	$format = $mpv->cmd_recv (get_property => "video-format");
		621
		622	Or you can set a callback:
		623
		624	$cv = $mpv->cmd (get_property => "video-format");
		625	$cv->cb (sub {
		626	my $format = $_[0]->recv;
		627	});
		628
		629	On error, the condvar will croak when C<recv> is called.
		630
		631	=cut
		632
182	sub cmd {	633	sub cmd {
183	my ($self, @cmd) = @_;	634	my $self = shift;
184		635
185	my $cv = AE::cv;	636	$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	}	637	}
		638
		639	=item $result = $mpv->cmd_recv ($command => $arg, $arg...)
		640
		641	The same as calling C<cmd> and immediately C<recv> on its return
		642	value. Useful when you don't want to mess with F<mpv> asynchronously or
		643	simply needs to have the result:
		644
		645	$mpv->cmd_recv ("stop");
		646	$position = $mpv->cmd_recv ("get_property", "playback-time");
		647
		648	=cut
199		649
200	sub cmd_recv {	650	sub cmd_recv {
201	&cmd->recv	651	&cmd->recv
202	}	652	}
203		653
		654	=item $mpv->bind_key ($INPUT => $string)
		655
		656	This is an extension implement by this module to make it easy to get key
		657	events. The way this is implemented is to bind a C<client-message> witha
		658	first argument of C<AnyEvent::MPV> and the C<$string> you passed. This
		659	C<$string> is then passed to the C<on_key> handle when the key is
		660	proessed, e.g.:
		661
		662	my $mpv = AnyEvent::MPV->new (
		663	on_key => sub {
		664	my ($mpv, $key) = @_;
		665
		666	if ($key eq "letmeout") {
		667	print "user pressed escape\n";
		668	}
		669	},
		670	);
		671
		672	$mpv_>bind_key (ESC => "letmeout");
		673
		674	You cna find a list of key names L<in the mpv
		675	documentation\|https://mpv.io/manual/stable/#key-names>.
		676
		677	The key configuration is lost when F<mpv> is stopped and must be (re-)done
		678	after every C<start>.
		679
		680	=cut
		681
204	sub bind_key {	682	sub bind_key {
205	my ($self, $key, $event) = @_;	683	my ($self, $key, $event) = @_;
206		684
207	$event =~ s/([^A-Za-z0-9\-_])/sprintf "\\x%02x", ord $1/ge;	685	$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");	686	$self->cmd (keybind => $key => "no-osd script-message AnyEvent::MPV key $event");
209	}	687	}
210		688
211	sub stop {	689	=item [$guard] = $mpv->register_event ($event => $coderef->($mpv, $event, $data))
		690
		691	This method registers a callback to be invoked for a specific
		692	event. Whenever the event occurs, it calls the coderef with the C<$mpv>
		693	object, the C<$event> name and the event object, just like the C<on_event>
		694	method.
		695
		696	For a lst of events, see L<the mpv
		697	documentation\|https://mpv.io/manual/stable/#list-of-events>. Any
		698	underscore in the event name is replaced by a minus sign, so you can
		699	specify event names using underscores for easier quoting in Perl.
		700
		701	In void context, the handler stays registered until C<stop> is called. In
		702	any other context, it returns a guard object that, when destroyed, will
		703	unregister the handler.
		704
		705	You can register multiple handlers for the same event, and this method
		706	does not interfere with the C<on_event> mechanism. That is, you can
		707	completely ignore this method and handle events in a C<on_event> handler,
		708	or mix both approaches as you see fit.
		709
		710	Note that unlike commands, event handlers are registered immediately, that
		711	is, you can issue a command, then register an event handler and then get
		712	an event for this handler I<before> the command is even sent to F<mpv>. If
		713	this kind of race is an issue, you can issue a dummy command such as
		714	C<get_version> and register the handler when the reply is received.
		715
		716	=cut
		717
		718	sub AnyEvent::MPV::Unevent::DESTROY {
		719	my ($evtcb, $event, $evtid) = @{$_[0]};
		720	delete $evtcb->{$event}{$evtid};
		721	}
		722
		723	sub register_event {
		724	my ($self, $event, $cb) = @_;
		725
		726	$event =~ y/_/-/;
		727
		728	my $evtid = ++$self->{evtid};
		729	$self->{evtcb}{$event}{$evtid} = $cb;
		730
		731	defined wantarray
		732	and bless [$self->{evtcb}, $event, $evtid], AnyEvent::MPV::Unevent::
		733	}
		734
		735	=item [$guard] = $mpv->observe_property ($name => $coderef->($mpv, $name, $value))
		736
		737	=item [$guard] = $mpv->observe_property_string ($name => $coderef->($mpv, $name, $value))
		738
		739	These methods wrap a registry system around F<mpv>'s C<observe_property>
		740	and C<observe_property_string> commands - every time the named property
		741	changes, the coderef is invoked with the C<$mpv> object, the name of the
		742	property and the new value.
		743
		744	For a list of properties that you can observe, see L<the mpv
		745	documentation\|https://mpv.io/manual/stable/#property-list>.
		746
		747	Due to the (sane :) way F<mpv> handles these requests, you will always
		748	get a property cxhange event right after registering an observer (meaning
		749	you don't have to query the current value), and it is also possible to
		750	register multiple observers for the same property - they will all be
		751	handled properly.
		752
		753	When called in void context, the observer stays in place until F<mpv>
		754	is stopped. In any otrher context, these methods return a guard
		755	object that, when it goes out of scope, unregisters the observe using
		756	C<unobserve_property>.
		757
		758	Internally, this method uses observer ids of 2**52 (0x10000000000000) or
		759	higher - it will not interfere with lower ovserver ids, so it is possible
		760	to completely ignore this system and execute C<observe_property> commands
		761	yourself, whilst listening to C<property-change> events - as long as your
		762	ids stay below 2**52.
		763
		764	Example: register observers for changtes in C<aid> and C<sid>. Note that
		765	a dummy statement is added to make sure the method is called in void
		766	context.
		767
		768	sub register_observers {
212	my ($self) = @_;	769	my ($mpv) = @_;
213		770
214	if ($self->{pid}) {	771	$mpv->observe_property (aid => sub {
215	delete $self->{rw};	772	my ($mpv, $name, $value) = @_;
216	delete $self->{ww};	773	print "property aid (=$name) has changed to $value\n";
		774	});
217		775
218	close delete $self->{fh}; # current mpv versions should cleanup on their own on close	776	$mpv->observe_property (sid => sub {
		777	my ($mpv, $name, $value) = @_;
		778	print "property sid (=$name) has changed to $value\n";
		779	});
219		780
220	kill TERM => $self->{pid};	781	() # ensure the above method is called in void context
221
222	delete $self->{pid};
223	}	782	}
		783
		784	=cut
		785
		786	sub AnyEvent::MPV::Unobserve::DESTROY {
		787	my ($mpv, $obscb, $obsid) = @{$_[0]};
		788
		789	delete $obscb->{$obsid};
		790
		791	if ($obscb == $mpv->{obscb}) {
		792	$mpv->cmd (unobserve_property => $obsid+0);
		793	}
224	}	794	}
		795
		796	sub _observe_property {
		797	my ($self, $type, $property, $cb) = @_;
		798
		799	my $obsid = OBSID + ++$self->{obsid};
		800	$self->cmd ($type => $obsid+0, $property);
		801	$self->{obscb}{$obsid} = $cb;
		802
		803	defined wantarray and do {
		804	my $unobserve = bless [$self, $self->{obscb}, $obsid], AnyEvent::MPV::Unobserve::;
		805	Scalar::Util::weaken $unobserve->[0];
		806	$unobserve
		807	}
		808	}
		809
		810	sub observe_property {
		811	my ($self, $property, $cb) = @_;
		812
		813	$self->_observe_property (observe_property => $property, $cb)
		814	}
		815
		816	sub observe_property_string {
		817	my ($self, $property, $cb) = @_;
		818
		819	$self->_observe_property (observe_property_string => $property, $cb)
		820	}
		821
		822	=back
		823
		824	=head2 SUBCLASSING
		825
		826	Like most perl objects, C<AnyEvent::MPV> objects are implemented as
		827	hashes, with the constructor simply storing all passed key-value pairs in
		828	the object. If you want to subclass to provide your own C<on_*> methods,
		829	be my guest and rummage around in the internals as much as you wish - the
		830	only guarantee that this module dcoes is that it will not use keys with
		831	double colons in the name, so youc an use those, or chose to simply not
		832	care and deal with the breakage.
		833
		834	If you don't want to go to the effort of subclassing this module, you can
		835	also specify all event handlers as constructor keys.
		836
		837	=head1 EXAMPLES
		838
		839	Here are some real-world code snippets, thrown in here mainly to give you
		840	some example code to copy.
		841
		842	=head2 doomfrontend
		843
		844	At one point I replaced mythtv-frontend by my own terminal-based video
		845	player (based on rxvt-unicode). I toyed with the diea of using F<mpv>'s
		846	subtitle engine to create the user interface, but that is hard to use
		847	since you don't know how big your letters are. It is also where most of
		848	this modules code has originally been developed in.
		849
		850	It uses a unified input queue to handle various remote controls, so its
		851	event handling needs are very simple - it simply feeds all events into the
		852	input queue:
		853
		854	my $mpv = AnyEvent::MPV->new (
		855	mpv => $MPV,
		856	args => \@MPV_ARGS,
		857	on_event => sub {
		858	input_feed "mpv/$_[1]", $_[2];
		859	},
		860	on_key => sub {
		861	input_feed $_[1];
		862	},
		863	on_eof => sub {
		864	input_feed "mpv/quit";
		865	},
		866	);
		867
		868	...
		869
		870	$mpv->start ("--idle=yes", "--pause", "--force-window=no");
		871
		872	It also doesn't use complicated command line arguments - the file search
		873	options have the most impact, as they prevent F<mpv> from scanning
		874	directories with tens of thousands of files for subtitles and more:
		875
		876	--audio-client-name=doomfrontend
		877	--osd-on-seek=msg-bar --osd-bar-align-y=-0.85 --osd-bar-w=95
		878	--sub-auto=exact --audio-file-auto=exact
		879
		880	Since it runs on a TV without a desktop environemnt, it tries to keep complications such as dbus
		881	away and the screensaver happy:
		882
		883	# prevent xscreensaver from doing something stupid, such as starting dbus
		884	$ENV{DBUS_SESSION_BUS_ADDRESS} = "/"; # prevent dbus autostart for sure
		885	$ENV{XDG_CURRENT_DESKTOP} = "generic";
		886
		887	It does bind a number of keys to internal (to doomfrontend) commands:
		888
		889	for (
		890	List::Util::pairs qw(
		891	ESC return
		892	q return
		893	ENTER enter
		894	SPACE pause
		895	[ steprev
		896	] stepfwd
		897	j subtitle
		898	BS red
		899	i green
		900	o yellow
		901	b blue
		902	D triangle
		903	UP up
		904	DOWN down
		905	RIGHT right
		906	LEFT left
		907	),
		908	(map { ("KP$_" => "num$_") } 0..9),
		909	KP_INS => 0, # KP0, but different
		910	) {
		911	$mpv->bind_key ($_->[0] => $_->[1]);
		912	}
		913
		914	It also reacts to sponsorblock chapters, so it needs to know when vidoe
		915	chapters change. Preadting C<AnyEvent::MPV>, it handles observers
		916	manually:
		917
		918	$mpv->cmd (observe_property => 1, "chapter-metadata");
		919
		920	It also tries to apply an F<mpv> profile, if it exists:
		921
		922	eval {
		923	# the profile is optional
		924	$mpv->cmd ("apply-profile" => "doomfrontend");
		925	};
		926
		927	Most of the complicated parts deal with saving and restoring per-video
		928	data, such as bookmarks, playing position, selected audio and subtitle
		929	tracks and so on. However, since it uses L<Coro>, it can conveniently
		930	block and wait for replies, which is n ot possible in purely event based
		931	programs, as you are not allowed to block inside event callbacks in most
		932	event loops. This simplifies the code quite a bit.
		933
		934	When the file to be played is a Tv recording done by mythtv, it uses the
		935	C<appending> protocol and deinterlacing:
		936
		937	if (is_myth $mpv_path) {
		938	$mpv_path = "appending://$mpv_path";
		939	$initial_deinterlace = 1;
		940	}
		941
		942	Otherwise, it sets some defaults and loads the file (I forgot what the
		943	C<dummy> argument is for, but I am sure it is needed by some F<mpv>
		944	version):
		945
		946	$mpv->cmd ("script-message", "osc-visibility", "never", "dummy");
		947	$mpv->cmd ("set", "vid", "auto");
		948	$mpv->cmd ("set", "aid", "auto");
		949	$mpv->cmd ("set", "sid", "no");
		950	$mpv->cmd ("set", "file-local-options/chapters-file", $mpv->escape_binary ("$mpv_path.chapters"));
		951	$mpv->cmd ("loadfile", $mpv->escape_binary ($mpv_path));
		952	$mpv->cmd ("script-message", "osc-visibility", "auto", "dummy");
		953
		954	Handling events makes the main bulk of video playback code. For example,
		955	various ways of ending playback:
		956
		957	if ($INPUT eq "mpv/quit") { # should not happen, but allows user to kill etc. without consequence
		958	$status = 1;
		959	mpv_init; # try reinit
		960	last;
		961
		962	} elsif ($INPUT eq "mpv/idle") { # normal end-of-file
		963	last;
		964
		965	} elsif ($INPUT eq "return") {
		966	$status = 1;
		967	last;
		968
		969	Or the code that actually starts playback, once the file is loaded:
		970
		971	our %SAVE_PROPERTY = (aid => 1, sid => 1, "audio-delay" => 1);
		972
		973	...
		974
		975	my $oid = 100;
		976
		977	} elsif ($INPUT eq "mpv/file-loaded") { # start playing, configure video
		978	$mpv->cmd ("seek", $playback_start, "absolute+exact") if $playback_start > 0;
		979
		980	my $target_fps = eval { $mpv->cmd_recv ("get_property", "container-fps") } \|\| 60;
		981	$target_fps *= play_video_speed_mult;
		982	set_fps $target_fps;
		983
		984	unless (eval { $mpv->cmd_recv ("get_property", "video-format") }) {
		985	$mpv->cmd ("set", "file-local-options/lavfi-complex", "[aid1] asplit [ao], showcqt=..., format=yuv420p [vo]");
		986	};
		987
		988	for my $prop (keys %SAVE_PROPERTY) {
		989	if (exists $PLAYING_STATE->{"mpv_$prop"}) {
		990	$mpv->cmd ("set", "$prop", $PLAYING_STATE->{"mpv_$prop"} . "");
		991	}
		992
		993	$mpv->cmd ("observe_property", ++$oid, $prop);
		994	}
		995
		996	play_video_set_speed;
		997	$mpv->cmd ("set", "osd-level", "$OSD_LEVEL");
		998	$mpv->cmd ("observe_property", ++$oid, "osd-level");
		999	$mpv->cmd ("set", "pause", "no");
		1000
		1001	$mpv->cmd ("set_property", "deinterlace", "yes")
		1002	if $initial_deinterlace;
		1003
		1004	There is a lot going on here. First it seeks to the actual playback
		1005	position, if it is not at the start of the file (it would probaby be more
		1006	efficient to set the starting position before loading the file, though,
		1007	but this is good enough).
		1008
		1009	Then it plays with the display fps, to set it to something harmonious
		1010	w.r.t. the video framerate.
		1011
		1012	If the file does not have a video part, it assumes it is an audio file and
		1013	sets a visualizer.
		1014
		1015	Also, a number of properties are not global, but per-file. At the moment,
		1016	this is C<audio-delay>, and the current audio/subtitle track, which it
		1017	sets, and also creates an observer. Again, this doesn'T use the observe
		1018	functionality of this module, but handles it itself, assigning obsevrer
		1019	ids 100+ to temporary/per-file observers.
		1020
		1021	Lastly, it sets some global (or per-youtube-uploader) parameters, such as
		1022	speed, and unpauses. Property changes are handled like other input events:
		1023
		1024	} elsif ($INPUT eq "mpv/property-change") {
		1025	my $prop = $INPUT_DATA->{name};
		1026
		1027	if ($prop eq "chapter-metadata") {
		1028	if ($INPUT_DATA->{data}{TITLE} =~ /^\[SponsorBlock\]: (.*)/) {
		1029	my $section = $1;
		1030	my $skip;
		1031
		1032	$skip \|\|= $SPONSOR_SKIP{$_}
		1033	for split /\s,\s/, $section;
		1034
		1035	if (defined $skip) {
		1036	if ($skip) {
		1037	# delay a bit, in case we get two metadata changes in quick succession, e.g.
		1038	# because we have a skip at file load time.
		1039	$skip_delay = AE::timer 2/50, 0, sub {
		1040	$mpv->cmd ("no-osd", "add", "chapter", 1);
		1041	$mpv->cmd ("show-text", "skipped sponsorblock section \"$section\"", 3000);
		1042	};
		1043	} else {
		1044	undef $skip_delay;
		1045	$mpv->cmd ("show-text", "NOT skipping sponsorblock section \"$section\"", 3000);
		1046	}
		1047	} else {
		1048	$mpv->cmd ("show-text", "UNRECOGNIZED sponsorblock section \"$section\"", 60000);
		1049	}
		1050	} else {
		1051	# cancel a queued skip
		1052	undef $skip_delay;
		1053	}
		1054
		1055	} elsif (exists $SAVE_PROPERTY{$prop}) {
		1056	$PLAYING_STATE->{"mpv_$prop"} = $INPUT_DATA->{data};
		1057	::state_save;
		1058	}
		1059
		1060	This saves back the per-file properties, and also handles chapter changes
		1061	in a hacky way.
		1062
		1063	Most of the handlers are very simple, though. For example:
		1064
		1065	} elsif ($INPUT eq "pause") {
		1066	$mpv->cmd ("cycle", "pause");
		1067	$PLAYING_STATE->{curpos} = $mpv->cmd_recv ("get_property", "playback-time");
		1068	} elsif ($INPUT eq "right") {
		1069	$mpv->cmd ("osd-msg-bar", "seek", 30, "relative+exact");
		1070	} elsif ($INPUT eq "left") {
		1071	$mpv->cmd ("osd-msg-bar", "seek", -5, "relative+exact");
		1072	} elsif ($INPUT eq "up") {
		1073	$mpv->cmd ("osd-msg-bar", "seek", +600, "relative+exact");
		1074	} elsif ($INPUT eq "down") {
		1075	$mpv->cmd ("osd-msg-bar", "seek", -600, "relative+exact");
		1076	} elsif ($INPUT eq "select") {
		1077	$mpv->cmd ("osd-msg-bar", "add", "audio-delay", "-0.100");
		1078	} elsif ($INPUT eq "start") {
		1079	$mpv->cmd ("osd-msg-bar", "add", "audio-delay", "0.100");
		1080	} elsif ($INPUT eq "intfwd") {
		1081	$mpv->cmd ("no-osd", "frame-step");
		1082	} elsif ($INPUT eq "audio") {
		1083	$mpv->cmd ("osd-auto", "cycle", "audio");
		1084	} elsif ($INPUT eq "subtitle") {
		1085	$mpv->cmd ("osd-auto", "cycle", "sub");
		1086	} elsif ($INPUT eq "triangle") {
		1087	$mpv->cmd ("osd-auto", "cycle", "deinterlace");
		1088
		1089	Once a file has finished playing (or the user strops playback), it pauses,
		1090	unobserves the per-file observers, and saves the current position for to
		1091	be able to resume:
		1092
		1093	$mpv->cmd ("set", "pause", "yes");
		1094
		1095	while ($oid > 100) {
		1096	$mpv->cmd ("unobserve_property", $oid--);
		1097	}
		1098
		1099	$PLAYING_STATE->{curpos} = $mpv->cmd_recv ("get_property", "playback-time");
		1100
		1101	And thats most of the F<mpv>-related code.
		1102
		1103	=head2 F<Gtk2::CV>
		1104
		1105	F<Gtk2::CV> is low-feature image viewer that I use many times daily
		1106	because it can handle directories with millions of files without falling
		1107	over. It also had the ability to play videos for ages, but it used an
		1108	older, crappier protocol to talk to F<mpv> and used F<ffprobe> before
		1109	playing each file instead of letting F<mpv> handle format/size detection.
		1110
		1111	After writing this module, I decided to upgprade Gtk2::CV by making use
		1112	of it, with the goal of getting rid of F<ffprobe> and being ablew to
		1113	reuse F<mpv> processes, which would have a multitude of speed benefits
		1114	(for example, fork+exec of F<mpv> caused the kernel to close all file
		1115	descriptors, which could take minutes if a large file was being copied via
		1116	NFS, as the kernel waited for thr buffers to be flushed on close - not
		1117	having to start F<mpv> gets rid of this issue).
		1118
		1119	Setting up is only complicated by the fact that F<mpv> needs to be
		1120	embedded into an existing window. To keep control of all inputs,
		1121	F<Gtk2::CV> puts an eventbox in front of F<mpv>, so F<mpv> receives no
		1122	input events:
		1123
		1124	$self->{mpv} = AnyEvent::MPV->new (
		1125	trace => $ENV{CV_MPV_TRACE},
		1126	);
		1127
		1128	# create an eventbox, so we receive all input events
		1129	my $box = $self->{mpv_eventbox} = new Gtk2::EventBox;
		1130	$box->set_above_child (1);
		1131	$box->set_visible_window (0);
		1132	$box->set_events ([]);
		1133	$box->can_focus (0);
		1134
		1135	# create a drawingarea that mpv can display into
		1136	my $window = $self->{mpv_window} = new Gtk2::DrawingArea;
		1137	$box->add ($window);
		1138
		1139	# put the drawingarea intot he eventbox, and the eventbox into our display window
		1140	$self->add ($box);
		1141
		1142	# we need to pass the window id to F<mpv>, which means we need to realise
		1143	# the drawingarea, so an X window is allocated for it.
		1144	$self->show_all;
		1145	$window->realize;
		1146	my $xid = $window->window->get_xid;
		1147
		1148	Then it starts F<mpv> using this setup:
		1149
		1150	local $ENV{LC_ALL} = "POSIX";
		1151	$self->{mpv}->start (
		1152	"--no-terminal",
		1153	"--no-input-terminal",
		1154	"--no-input-default-bindings",
		1155	"--no-input-cursor",
		1156	"--input-conf=/dev/null",
		1157	"--input-vo-keyboard=no",
		1158
		1159	"--loop-file=inf",
		1160	"--force-window=yes",
		1161	"--idle=yes",
		1162
		1163	"--audio-client-name=CV",
		1164
		1165	"--osc=yes", # --osc=no displays fading play/pause buttons instead
		1166
		1167	"--wid=$xid",
		1168	);
		1169
		1170	$self->{mpv}->cmd ("script-message" => "osc-visibility" => "never", "dummy");
		1171	$self->{mpv}->cmd ("osc-idlescreen" => "no");
		1172
		1173	It also prepares a hack to force a ConfigureNotify event on every vidoe
		1174	reconfig:
		1175
		1176	# force a configurenotify on every video-reconfig
		1177	$self->{mpv_reconfig} = $self->{mpv}->register_event (video_reconfig => sub {
		1178	my ($mpv, $event, $data) = @_;
		1179
		1180	$self->mpv_window_update;
		1181	});
		1182
		1183	The way this is done is by doing a "dummy" resize to 1x1 and back:
		1184
		1185	$self->{mpv_window}->window->resize (1, 1),
		1186	$self->{mpv_window}->window->resize ($self->{w}, $self->{h});
		1187
		1188	Without this, F<mpv> often doesn't "get" the correct window size. Doing
		1189	it this way is not nice, but I didn't fine a nicer way to do it.
		1190
		1191	When no file is being played, F<mpv> is hidden and prepared:
		1192
		1193	$self->{mpv_eventbox}->hide;
		1194
		1195	$self->{mpv}->cmd (set_property => "pause" => "yes");
		1196	$self->{mpv}->cmd ("playlist_remove", "current");
		1197	$self->{mpv}->cmd (set_property => "video-rotate" => 0);
		1198	$self->{mpv}->cmd (set_property => "lavfi-complex" => "");
		1199
		1200	Loading a file is a bit more complicated, as bluray and DVD rips are
		1201	supported:
		1202
		1203	if ($moviedir) {
		1204	if ($moviedir eq "br") {
		1205	$mpv->cmd (set => "bluray-device" => $path);
		1206	$mpv->cmd (loadfile => "bd://");
		1207	} elsif ($moviedir eq "dvd") {
		1208	$mpv->cmd (set => "dvd-device" => $path);
		1209	$mpv->cmd (loadfile => "dvd://");
		1210	}
		1211	} elsif ($type eq "video/iso-bluray") {
		1212	$mpv->cmd (set => "bluray-device" => $path);
		1213	$mpv->cmd (loadfile => "bd://");
		1214	} else {
		1215	$mpv->cmd (loadfile => $mpv->escape_binary ($path));
		1216	}
		1217
		1218	After this, C<Gtk2::CV> waits for the file to be loaded, video to be
		1219	configured, and then queries the video size (to resize its own window)
		1220	and video format (to decide whether an audio visualizer is needed for
		1221	audio playback). The problematic word here is "wait", as this needs to be
		1222	imploemented using callbacks.
		1223
		1224	This made the code much harder to write, as the whole setup is very
		1225	asynchronous (C<Gtk2::CV> talks to the command interface in F<mpv>, which
		1226	talks to the decode and playback parts, all of which run asynchronously
		1227	w.r.t. each other. In practise, this can mean that C<Gtk2::CV> waits for
		1228	a file to be loaded by F<mpv> while the command interface of F<mpv> still
		1229	deals with the previous file and the decoder still handles an even older
		1230	file). Adding to this fact is that Gtk2::CV is bound by the glib event
		1231	loop, which means we cannot wait for replies form F<mpv> anywhere, so
		1232	everything has to be chained callbacks.
		1233
		1234	The way this is handled is by creating a new empty hash ref that is unique
		1235	for each loaded file, and use it to detect whether the event is old or
		1236	not, and also store C<AnyEvent::MPV> guard objects in it:
		1237
		1238	# every time we loaded a file, we create a new hash
		1239	my $guards = $self->{mpv_guards} = { };
		1240
		1241	Then, when we wait for an event to occur, delete the handler, and, if the
		1242	C<mpv_guards> object has changed, we ignore it. Something like this:
		1243
		1244	$guards->{file_loaded} = $mpv->register_event (file_loaded => sub {
		1245	delete $guards->{file_loaded};
		1246	return if $guards != $self->{mpv_guards};
		1247
		1248	Commands do not have guards since they cnanot be cancelled, so we don't
		1249	have to do this for commands. But what prevents us form misinterpreting
		1250	an old event? Since F<mpv> (by default) handles commands synchronously,
		1251	we can queue a dummy command, whose only purpose is to tell us when all
		1252	previous commands are done. We use C<get_version> for this.
		1253
		1254	The simplified code looks like this:
		1255
		1256	Scalar::Util::weaken $self;
		1257
		1258	$mpv->cmd ("get_version")->cb (sub {
		1259
		1260	$guards->{file_loaded} = $mpv->register_event (file_loaded => sub {
		1261	delete $guards->{file_loaded};
		1262	return if $guards != $self->{mpv_guards};
		1263
		1264	$mpv->cmd (get_property => "video-format")->cb (sub {
		1265	return if $guards != $self->{mpv_guards};
		1266
		1267	# video-format handling
		1268	return if eval { $_[0]->recv; 1 };
		1269
		1270	# no video? assume audio and visualize, cpu usage be damned
		1271	$mpv->cmd (set => "lavfi-complex" => ...");
		1272	});
		1273
		1274	$guards->{show} = $mpv->register_event (video_reconfig => sub {
		1275	delete $guards->{show};
		1276	return if $guards != $self->{mpv_guards};
		1277
		1278	$self->{mpv_eventbox}->show_all;
		1279
		1280	$w = $mpv->cmd (get_property => "dwidth");
		1281	$h = $mpv->cmd (get_property => "dheight");
		1282
		1283	$h->cb (sub {
		1284	$w = eval { $w->recv };
		1285	$h = eval { $h->recv };
		1286
		1287	$mpv->cmd (set_property => "pause" => "no");
		1288
		1289	if ($w && $h) {
		1290	# resize our window
		1291	}
		1292
		1293	});
		1294	});
		1295
		1296	});
		1297
		1298	});
		1299
		1300	Most of the rest of the code is much simpler and just deals with forwarding user commands:
		1301
		1302	} elsif ($key == $Gtk2::Gdk::Keysyms{Right}) { $mpv->cmd ("osd-msg-bar" => seek => "+10");
		1303	} elsif ($key == $Gtk2::Gdk::Keysyms{Left} ) { $mpv->cmd ("osd-msg-bar" => seek => "-10");
		1304	} elsif ($key == $Gtk2::Gdk::Keysyms{Up} ) { $mpv->cmd ("osd-msg-bar" => seek => "+60");
		1305	} elsif ($key == $Gtk2::Gdk::Keysyms{Down} ) { $mpv->cmd ("osd-msg-bar" => seek => "-60");
		1306	} elsif ($key == $Gtk2::Gdk::Keysyms{a}) ) { $mpv->cmd ("osd-msg-msg" => cycle => "audio");
		1307	} elsif ($key == $Gtk2::Gdk::Keysyms{j} ) { $mpv->cmd ("osd-msg-msg" => cycle => "sub");
		1308	} elsif ($key == $Gtk2::Gdk::Keysyms{o} ) { $mpv->cmd ("no-osd" => "cycle-values", "osd-level", "2", "3", "0", "2");
		1309	} elsif ($key == $Gtk2::Gdk::Keysyms{p} ) { $mpv->cmd ("no-osd" => cycle => "pause");
		1310	} elsif ($key == $Gtk2::Gdk::Keysyms{9} ) { $mpv->cmd ("osd-msg-bar" => add => "ao-volume", "-2");
		1311	} elsif ($key == $Gtk2::Gdk::Keysyms{0} ) { $mpv->cmd ("osd-msg-bar" => add => "ao-volume", "+2");
225		1312
226	=head1 SEE ALSO	1313	=head1 SEE ALSO
227		1314
228	L<AnyEvent>.	1315	L<AnyEvent>, L<the mpv command documentation\|https://mpv.io/manual/stable/#command-interface>.
229		1316
230	=head1 AUTHOR	1317	=head1 AUTHOR
231		1318
232	Marc Lehmann <schmorp@schmorp.de>	1319	Marc Lehmann <schmorp@schmorp.de>
233	http://home.schmorp.de/	1320	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 1.19 by root, Sun Mar 26 17:15:18 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 1.19 by root, Sun Mar 26 17:15:18 2023 UTC