Until now, they could be aborted only by ending playback, and calling
mpv_abort_async_command didn't do anything.
This requires furthering the mess how playback abort is done. The main
reason why mp_cancel exists at all is to avoid that a "frozen" demuxer
(blocked on network I/O or whatever) cannot freeze the core. The core
should always get its way. Previously, there was a single mp_cancel
handle, that could be signaled, and all demuxers would unfreeze. With
external files, we might want to abort loading of a certain external
file, which automatically means they need a separate mp_cancel. So give
every demuxer its own mp_cancel, and "slave" it to whatever parent
mp_cancel handles aborting.
Since the mpv demuxer API conflates creating the demuxer and reading the
file headers, mp_cancel strictly need to be created before the demuxer
is created (or we couldn't abort loading). Although we give every
demuxer its own mp_cancel (as "enforced" by cancel_and_free_demuxer),
it's still rather messy to create/destroy it along with the demuxer.
It seems a bit inappropriate to have dumped this into stream.c, even if
it's roughly speaking its main user. At least it made its way somewhat
unfortunately to other components not related to the stream or demuxer
layer at all.
I'm too greedy to give this weird helper its own file, so dump it into
thread_tools.c.
Probably a somewhat pointless change.
Before this change, only 1 command or so had named arguments. There is
no reason why other commands can't have them, except that it's a bit of
work to add them.
Commands with variable number of arguments are inherently incompatible
to named arguments, such as the "run" command. They still have dummy
names, but obviously you can't assign multiple values to a single named
argument (unless the argument has an array type, which would be
something different). For now, disallow using named argument APIs with
these commands. This might change later.
2 commands are adjusted to not need a separate default value by changing
flag constants. (The numeric values are C only and can't be set by
users.)
Make the command syntax in the manpage more consistent. Now none of the
allowed choice/flag names are in the command header, and all arguments
are shown with their proper name and quoted with <...>.
Some places in the manpage and the client.h doxygen are updated to
reflect that most commands support named arguments. In addition, try to
improve the documentation of the syntax and need for escaping etc. as
well.
(Or actually most uses of the word "argument" should be "parameter".)
When changing video filters during initialization, there was a small
time window where video was initialized, but playback restart was not
complete yet. In this time window, playback_pts is not set. But since
issue_refresh_seek() was using this, it could lead to no refresh being
done _if_ the "video" had only 1 frame (such as cover art).
Fix this by using get_current_time() instead, which is the current time
with corner cases such as ongoing loading or seeks taken into account.
See also the previous commit. Without that, get_current_time() could
return NOPTS during init.
Fixes#5831.
This is nonsense. Didn't matter in most situations, because seeking
itself set this after it was cleared. But some callers don't do this,
see e.g. commit ed73ba8964. There is no need to clear it at all, and
it causes issues with the next commit. It only needs to be reset on
loading.
Also move the initialization on loading up, which doesn't change
behavior, but makes the intention clearer.
This affects async commands started by client API, commands with async
capability run in a sync way by client API (think mpv_command_node()
with "subprocess"), and detached async work.
Since scripts might want to do some cleanup work (that might involve
launching processes, don't ask), we don't unconditionally kill
everything on exit, but apply an arbitrary timeout of 2 seconds until
async commands are aborted.
Many asynchronous commands are potentially long running operations, such
as loading something from network or running a foreign process.
Obviously it shouldn't just be possible for them to freeze the player if
they don't terminate as expected. Also, there will be situations where
you want to explicitly stop some of those operations explicitly. So add
an infrastructure for this.
Commands have to support this explicitly. The next commit uses this to
actually add support to a command.
If a struct as large as MPContext contains a field named "lock", it
creates the impression that it is the primary lock for MPContext. This
is wrong, the lock just protects a single field.
The "run" command is old. I'm not sure why the separate Lua
implementation was added. But maybe it as because the "run" command used
to be limited to a small number of arguments. This limit has been
removed a while ago. In any case, the old implementation is not needed
anymore.
We keep mp.subprocess() with roughly the same semantics for
compatibility with scripts (including the internal ytdl script).
Seems to work with rhe ytdl wrapper. Not tested further.
This supports named arguments. It benefits from the infrastructure of
async commands.
The plan is to reimplement Lua's utils.subprocess() on top of it.
Basically reimplement the async behavior on top of the async command
code. With this, all screenshot commands are async, and the "async"
prefix basically does nothing. The prefix now behaves exactly like with
other commands that use spawn_thread.
This also means using the prefix in the preset input.conf is pointless
(without effect) and misleading, so remove that.
The each_frame mode was actually particularly painful in making this
change, since the player wants to block for it when writing a
screenshot, and generally doesn't fit into the new infrastructure. It
was still relatively easy to reimplement by copying the original command
and then repeating it on each frame. The waiting is reentrant now, so
move the call in video.c to a "safer" spot.
One way to observe how the new semantics interact with everything is
using the mpv repl script and sending a screenshot command through it.
Without async flag, the script will freeze while writing the screenshot
(while playback continues), while with async flag it continues.
Commands are not a monolithic giant switch() statement anymore, but
individual functions. There's no reason to have the command handlers
themselves in command.c, with a weird under-defined API in between.
(In the future, I'd like to split up command.c further, and when I do
that, scrrenshot.c will probably gets its own mp_cmd_def[] array, and
define the commands locally instead of exporting the raw handlers.)
Basically, the ytdl_hook script will not terminate the script, even if
you change to a new playlist entry. This happens because ytdl_hook keeps
the player core in an early loading stage, and the forceful playback
abort is done only in the ermination code.
This does not handle the "stop" and "quit" commands, which can still
take longer than expected, but on the other hand have some weird special
handling (see below). I'm not doing this out of laziness. Playback
stopping will have to be somewhat redone anyway. Basically we want to
give everything a chance to terminate, and if it doesn't work, we want
to stop loading or playback forcefully after a small timeout. We also
want to remove the mess with input.c's special handling of "quit" and
some other commands (see abort_playback_cb stuff).
It seems the ytdl script like to continue loading external tracks even
if loading was aborted. Trying to do so will still quickly fail, but not
without a load of log noise. So check and error out early.
Pretty trivial, since commands can be async now, and the common code
even provides convenience like running commands on a worker thread.
The only ugly thing is that mp_add_external_file() needs an extra flag
for locking. This is because there's still some code which calls this
synchronously from the main thread, and unlocking the core makes no
sense there.
This enables two types of command behavior:
1. Plain async behavior, like "loadfile" not completing until the file
is fully loaded.
2. Running parts of the command on worker threads, e.g. for I/O, such as
"sub-add" doing network accesses on a thread while the core
continues.
Both have no implementation yet, and most new code is actually inactive.
The plan is to implement a number of useful cases in the following
commits.
The most tricky part is handling internal keybindings (input.conf) and
the multi-command feature (concatenating commands with ";"). It requires
a bunch of roundabout code to make it do the expected thing in
combination with async commands.
There is the question how commands should be handled that come in at a
higher rate than what can be handled by the core. Currently, it will
simply queue up input.conf commands as long as memory lasts. The client
API is limited by the size of the reply queue per client. For commands
which require a worker thread, the thread pool is limited to 30 threads,
and then will queue up work in memory. The number is completely
arbitrary.
The existing thread pool code is the most primitive thread pool
possible. That's fine, but one annoying thing was that it used a static
number of threads. Make it dynamic, so we don't need to "waste" idle
threads.
This tries to add threads as needed. If threads are idle for some time,
destroy them again until a minimum number of threads is reached.
Also change the license to ISC.
This has some tricky interactions. In particular, it requires the core
to be locked due to reading outstanding_async, which is documented on
the only caller only. It's probably better to merge it with its only
caller.
The new code should be strictly equivalent, other than the fact that it
doesn't temporarily unlock+lock when entering the loop for the first
time (which doesn't matter here).
Fixes several issues playing back mpegts with video streams marked
as having "still images". For example, see this video which has
frames only every 6s: https://s3.amazonaws.com/tmm1/music-choice.ts
Changes include:
- start playback right away, without waiting for first video frame
- do not consider the sparse video stream in demuxer underrun detection
- do not require multiple video frames for the VO
- use audio as the master stream for demuxer metadata events
- use audio stream for playback time
Signed-off-by: Aman Gupta <aman@tmm1.net>
Fixes `--ytdl-format="dash-fastly_skyfire-video-363357330+dash-fastly_skyfire_sep-audio-363357330" https://vimeo.com/108650530`
This happened because the video track also had audio available and after
adding it expecting an audio-only track, there were no more tracks with video.
Could make it behave differently (and leak memory) in certain cases.
Basically, m_option_parse() randomly returns 0 or 1, but most time 1,
with the difference due to legacy reasons that don't matter anymore.
The "if (prop.name)" check is redundant, because an assert above it
implies that it never can be NULL.
Deduplicate some code for initializing the "prop" variable.
This gets rid of run_command() and its big switch statement, which was
an idiotically big function of almost 1000 lines.
The switch is replaced with a callback per command, and each command is
now implemented in its own function. Command IDs are not needed anymore,
so the mp_command_type enum disappears.
There should be no functional changes, but since this refactors 64
commands, regressions are possible.
The handler() parameter is void*, because in theory the input code is
supposed to be independent of the player core code. For example, you
should be able to reuse the command parser code for some other part of
mpv. In practice, the variable containing command list is defined in the
player core anyway, so you could say this doesn't work. But I'm still
trying to hold onto this idea, so I went with void*.
The plan is to remove the command ID enum. This will happen by replacing
the big switch statement in command.c with dispatching to per-command
callbacks. As preparation, remove uses of the command IDs outside of the
actual dispatching mechanism.
Also remove some instances of checking cmd->def for NULL. We now require
this always to be set.
Until recently, ao_lavc and vo_lavc started encoding whenever the core
happened to send them data. Since audio and video are not initialized at
the same time, and the muxer was not necessarily opened when the first
encoder started to produce data, the resulting packets were put into a
queue. As soon as the muxer was opened, the queue was flushed.
Change this to make the core wait with sending data until all encoders
are initialized. This has the advantage that we don't need to queue up
the packets.
The video timing code could just decide that EOF was reached before it
was displayed. This is not really a problem for normal playback (if you
use something like --keep-open it'd show the last frame anyway,
otherwise it'd at best flash it on screen before destroying the window).
But in encode mode, it really matters, and makes the difference between
having one frame more or less in the output file.
Fix this by waiting for the VO before starting the real EOF.
vo_is_ready_for_frame() is normally used to determine when the VO frame
queue has enough space to send a new frame. Since the VO frame queue is
currently at most 1 frame, it being signaled means the remaining frame
was consumed and thus sent to the VO driver. If it returns false, it
will wake up the playloop as soon as the state changes.
I also considered using vo_still_displaying(), but it's not reliable,
because it checks the realtime of the frame end display time.
Instead of using an internal counter to keep track of the value that was
set last, attempt to find the current value of the property/option in
the value list, and then set the next value in the list.
There are some potential problems. If a property refuses to accept a
specific value, the cycle-values command will fail, and start from the
same position again. It can't know that it's supposed to skip the next
value. The same can happen to properties which behave "strangely", such
as the "aspect" property, which will return the current aspect if you
write "-1" to it. As a consequence, cycle-values can appear to get
"stuck".
I still think the new behavior is what users expect more, and which is
generally more useful. We won't restore the ability to get the old
behavior, unless we decide to revert this commit entirely.
Fixes#5772, and hopefully other complaints.
If playback has not been initialized yet (decoders not initialized
etc.), or if in idle mode, let the track properties cycle through "no"
and "auto". This should be slightly more helpful than making it simply
exit.
Depending on the stage of loading, more could be done. For example, if
youtube-dl loads additional subtitle files, it can happen that these get
added before the main file, and this could be cycled through to an
extent. This is probably too clever, and also sort of dangerous
(unintended interactions with messy in-loading state), so don't do it.
The main change is that we wait with opening the muxer ("writing
headers") until we have data from all streams. This fixes race
conditions at init due to broken assumptions in the old code.
This also changes a lot of other stuff. I found and fixed a few API
violations (often things for which better mechanisms were invented, and
the old ones are not valid anymore). I try to get away from the public
mutex and shared fields in encode_lavc_context. For now it's still
needed for some timestamp-related fields, but most are gone. It also
removes some bad code duplication between audio and video paths.
1. I want to get away from mp_image_params (maybe).
2. For encoding mode, it's convenient to get the nominal_fps, which is
a mp_image field, and not in mp_image_params.
wm4
Aman Gupta
sfan5
Ricardo Constantino