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.
Named arguments should make it easier to have long time compatibility,
even if command arguments get added or removed. They're also much nicer
for commands with a large number of arguments, especially if many
arguments are optional.
As of this commit, this can not be used, because there is no command yet
which supports them. See the following commit.
Both asynchronous and synchronous calls used to be put into the core's
dispatch queue. Also, asynchronous calls were actually synchronous, just
without forcing a wait on the client's thread. This meant that both
kinds of calls were always strictly ordered.
A longer time ago, synchronous calls were changed to simply lock the
core. This could possibly lead to reordering. Recently, some commands
were changed to run on worker threads, which made the order even looser.
Also remove another now incorrect doxygen comment regarding async
commands.
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).
This is almost like rendezvous(), except it allows async wakeup, and
does not require global state. It will be used by a later commit.
struct mp_waiter is intended to be allocated on the stack, and uses an
initializer including PTHREAD_MUTEX_INITIALIZER. This is the first case
in mpv that it uses PTHREAD_MUTEX_INITIALIZER for stack-allocated
mutexes. It seems POSIX still does not allow this formally, but since
POSIX is worth less than used toilet paper, I don't really care. Modern
OSes use futexes, which means you can make _every_ memory location a
lock, and this code tries to make use of it, without using OS specific
code.
The name of the source file is rather generic, because I intend to dump
further small helpers there (or maybe move mp_rendezvous() to it).
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>
With the advent of actual HDR devices, my real measured ICC profile has
an "infinite" contrast, since the display is completely off on pure
black inputs. 100k:1 might not be enough, so let's just bump it up to
1m:1 to be safe.
Also, improve the logging in the case that the detected contrast is too
high by default.
This was there originally to detect too-old versions of ffmpeg. We now
only support >= 4.0, so it's not relevant. We just need the dependencies
to be present.
First fix a memory leak when skipping cursor planes by inverting the
check and putting everything, but the free, in the body.
Then fix a missed drmModeFreePlane by simply copying the fields of the
drmModePlane we are interested in and freeing the drmModePlane struct
early.
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.
