This covers source files which were added in mplayer2 and mpv times
only, and where all code is covered by LGPL relicensing agreements.
There are probably more files to which this applies, but I'm being
conservative here.
A file named ao_sdl.c exists in MPlayer too, but the mpv one is a
complete rewrite, and was added some time after the original ao_sdl.c
was removed. The same applies to vo_sdl.c, for which the SDL2 API is
radically different in addition (MPlayer supports SDL 1.2 only).
common.c contains only code written by me. But common.h is a strange
case: although it originally was named mp_common.h and exists in MPlayer
too, by now it contains only definitions written by uau and me. The
exceptions are the CONTROL_ defines - thus not changing the license of
common.h yet.
codec_tags.c contained once large tables generated from MPlayer's
codecs.conf, but all of these tables were removed.
From demux_playlist.c I'm removing a code fragment from someone who was
not asked; this probably could be done later (see commit 15dccc37).
misc.c is a bit complicated to reason about (it was split off mplayer.c
and thus contains random functions out of this file), but actually all
functions have been added post-MPlayer. Except get_relative_time(),
which was written by uau, but looks similar to 3 different versions of
something similar in each of the Unix/win32/OSX timer source files. I'm
not sure what that means in regards to copyright, so I've just moved it
into another still-GPL source file for now.
screenshot.c once had some minor parts of MPlayer's vf_screenshot.c, but
they're all gone.
It's conceivable that the OS time source is subject to clock changes.
The time could jump back to before when mpv was started, which would
cause mp_time_us() to return values smaller than 1. This is unexpected
by the code and could trigger assertions. If there's no monotonic time
source there's not much we can do anyway, so just sanitize the return
value. It will cause strange behavior until the "lost" time offset has
passed, but if you make such huge changes to the system clock while
everything is running, you're asking for trouble anyway.
(Normally we try to get a monotonic time source, though. This problem
sometimes happened on Windows when compiled without winpthreads, when
the code was falling back to gettimeofday(). This was already fixed by
always using another method.)
There is not much of a reason to have these wrappers around. Use POSIX
standard functions directly, and use a separate utility function to take
care of the timespec calculations. (Course POSIX for using this weird
format for time values.)
This allows getting the log at all with --no-terminal and without having
to retrieve log messages manually with the client API. The log level is
hardcoded to -v. A higher log level would lead to too much log output
(huge file sizes and latency issues due to waiting on the disk), and
isn't too useful in general anyway. For debugging, the terminal can be
used instead.
This is mostly covered by the OSX workaround, if the timeout is very
high. It also means that with systems using 32 bit time_t, the time will
overflow 2036 already, instead of 2037, but we don't consider this a
problem.
Some operating systems apparently can't deal with really long timeouts
in pthread_cond_timedwait(). Passing a time about 300000 in the future
makes the call return immediately. (tv_sec/time_t doesn't overflow in
this situation.) Reduce the wait time to about 100 days, which seems
to work fine.
The list of affected OSes follows: OSX
Probably more correct and better readable. Although the special-casing
of 0x1p63 is weird in terms of readability (the value itself is
INT64_MAX+1, so it's already outside of range, but INT64_MAX is not
exactly representable with double precision).
This usually can't happen, because even if time_us (first input value)
is INT64_MAX, the value added to tv_sec will be about 2^43, and tv_sec
will be <2^31, far below a possible overflow in 64 bits. But should
time_t be 32 bits (32 bit Linux/Windows?), an overflow could happen.
It can easily happen that mp_time_us_to_timespec() gets a time in the
past, and then the time difference will be negative. Regression
introduced in commit f47a4fc3.
Also fix an underflow check in mp_add_timeout().
Use the time as returned by mp_time_us() for mpthread_cond_timedwait(),
instead of calculating the struct timespec value based on a timeout.
This (probably) makes it easier to wait for a specific deadline.
This avoids trouble if another mpv instance is initialized in the same
process.
Since timeBeginPeriod/timeEndPeriod are hereby not easily matched
anymore, use an atexit() handler to call timeEndPeriod, so that we
can be sure these calls are matched, even if we allow multiple
initializations later when introducing the client API.
GetTimer() is generally replaced with mp_time_us(). Both calls return
microseconds, but the latter uses int64_t, us defined to never wrap,
and never returns 0 or negative values.
GetTimerMS() has no direct replacement. Instead the other functions are
used.
For some code, switch to mp_time_sec(), which returns the time as double
float value in seconds. The returned time is offset to program start
time, so there is enough precision left to deliver microsecond
resolution for at least 100 years. Unless it's casted to a float
(or the CPU reduces precision), which is why we still use mp_time_us()
out of paranoia in places where precision is clearly needed.
Always switch to the correct time. The whole point of the new timer
calls is that they don't wrap, and storing microseconds in unsigned int
variables would negate this.
In some cases, remove wrap-around handling for time values.
Make OS specific timer code export a mp_raw_time_us() function, and
add generic implementations of GetTimer()/GetTimerMS() using this
function. New mpv code is supposed to call mp_time_us() in situations
where precision is absolutely needed, or mp_time_s() otherwise.
Make it so that mp_time_us() will return a value near program start.
We don't set it to 0 though to avoid confusion with relative vs.
absolute time. Instead, pick an arbitrary offset.
Move the test program in timer-darwin.c to timer.c, and modify it to
work with the generic timer functions.
