...because everything is terrible.
strerror() is not documented as having to be thread-safe by POSIX and
C11. (Which is pretty much bullshit, because both mandate threads and
some form of thread-local storage - so there's no excuse why
implementation couldn't implement this in a thread-safe way. Especially
with C11 this is ridiculous, because there is no way to use threads and
convert error numbers to strings at the same time!)
Since we heavily use threads now, we should avoid unsafe functions like
strerror().
strerror_r() is in POSIX, but GNU/glibc deliberately fucks it up and
gives the function different semantics than the POSIX one. It's a bit of
work to convince this piece of shit to expose the POSIX standard
function, and not the messed up GNU one.
strerror_l() is also in POSIX, but only since the 2008 standard, and
thus is not widespread.
The solution is using avlibc (libavutil, by its official name), which
handles the unportable details for us, mostly. We avoid some pain.
In addition to the messed-up expression, the endianness was also
inverted. The code reads big endian by default.
It "worked" by coincidence, but for little endian, codepoints outside of
latin1 were broken.
The broken expression was found by Coverity.
stream_rar.c peeks the first few bytes when trying to open, which means
that opening any stream reads at least 2KB of data (internal buffer
size) on opening. This broke --stream-dump, which saved only the data
following this initial buffer.
Hack it around by writing the current buffer to the capture file too,
and move stream_capture_write() above stream_set_capture_file() for this
purpose.
Cleaner solutions might include: handling the terrible rar thing
differently, or using the "proper" stream API for dumping. (The latter
is not done, because --stream-dump shares code with the --stream-capture
misfeature.)
Fixes#1215.
On win32, open() is a function-like macro. The line of code changed
with this commit accidentally expanded the macro. Prevent this macro
expansion. Not sure why that happened now. Since as far as I remember
system functions can be defined as macros, this affects in theory not
only win32.
Because 1) Lua is terrible, and 2) popen() is terrible. Unfortunately,
since Unix is also terrible, this turned out more complicated than I
hoped. As a consequence and to avoid that this code has to be maintained
forever, add a disclaimer that any function in Lua's utils module can
disappear any time. The complexity seems a bit ridiculous, especially
for a feature so far removed from actual video playback, so if it turns
out that we don't really need this function, it will be dropped again.
The motivation for this commit is the same as with 8e4fa5fc.
Note that there is an "#ifndef __GLIBC__". The GNU people are very
special people and thought it'd be convenient to actually declare
"environ", even though the POSIX people, which are also very special
people, state that no header declares this and that the user has to
declare this manually. Since the GNU people overtook the Unix world with
their very clever "embrace, extend, extinguish" strategy, but not 100%,
and trying to build without _GNU_SOURCE is hopeless; but since there
might be Unix environments which support _GNU_SOURCE features partially,
this means that in practice "environ" will be randomly declared or not
declared by system headers. Also, gcc was written by very clever people
too, and prints a warning if an external variable is declared twice (I
didn't check, but I suppose redeclaring is legal C, and not even the gcc
people are clever enough to only warn against a definitely not legal C
construct, although sometimes they do this), ...and since we at mpv hate
compiler warnings, we seek to silence them all. Adding a configure test
just for a warning seems too radical, so we special-case this against
__GLIBC__, which is hopefully not defined on other libcs, especially not
libcs which don't implement all aspects of _GNU_SOURCE, and redefine
"environ" on systems even if the headers define it already (because they
support _GNU_SOURCE - as I mentioned before, the clever GNU people wrote
software THAT portable that other libcs just gave up and implemented
parts of _GNU_SOURCE, although probably not all), which means that
compiling mpv will print a warning about "environ" being redefined, but
at least this won't happen on my system, so all is fine. However, should
someone complain about this warning, I will force whoever complained
about this warning to read this ENTIRE commit message, and if possible,
will also force them to eat a printed-out copy of the GNU Manifesto, and
if that is not enough, maybe this person could even be forced to
convince the very clever POSIX people of not doing crap like this:
having the user to manually declare somewhat central symbols - but I
doubt it's possible, because the POSIX people are too far gone and only
care about maintaining compatibility with old versions of AIX and HP-UX.
Oh, also, this code contains some subtle and obvious issues, but writing
about this is not fun.
stream provides a read buffer (so even something like stream_read_char()
is very fast). This means the stream reads ahead by a few KBs, and
implies that the internal position (s->pos, which would match e.g. the
file position in stream_file.c), and the external position
(stream_tell()) can be different. stream_tell() shows how these are
related.
When dropping buffers, which happens on byte-level discontinuities with
a bunch of streams (including DVB), we should not change the position as
seen by the demuxer. On the other hand, the internal position is not
really meaningful, since these streams aren't seekable anyway. So just
change the code such that stream_drop_buffers() doesn't change the
demuxer visible position.
I'm hoping that this will fix a few problems with DVB. (Also see
previous commit.)
Might matter when libavformat tries to do tiny seekbacks in an
unseekable stream, and the seekback buffer isn't large enough. In this
case, seeking would fail, and would drop the current buffer. The
seekback would end up dropping future data.
This change probably doesn't have any observable effects. libavformat
normally has its own stream buffer, and demux_mkv.c tries carefully
never to seek back.
Similar as the previous commits.
Most of the code is actually copied from the stream_dvdnav.c code, but
I'd rather prefer to duplicate it, than to entangle them. The latter
would probably result in terrible things in a few years.
Same hack as with stream_dvd.c.
VIDEO_TS.IFO files are now opened via stream_dvdnav.c. Directories
containing a VIDEO_TS.IFO or VIDEO_TS/VIDEO_TS.IFO file are also
opened with it.
This was once central, but now it's almost unused. Only vf_divtc still
uses it for extremely weird and incomprehensible reasons. The use in
stream.c is trivial. Replace these, and remove mpbswap.h.
This mechanism originates from MPlayer's way of dealing with blocking
network, but it's still useful. On opening and closing, mpv waits for
network synchronously, and also some obscure commands and use-cases can
lead to such blocking. In these situations, the stream is asynchronously
forced to stop by "interrupting" it.
The old design interrupting I/O was a bit broken: polling with a
callback, instead of actively interrupting it. Change the direction of
this. There is no callback anymore, and the player calls
mp_cancel_trigger() to force the stream to return.
libavformat (via stream_lavf.c) has the old broken design, and fixing it
would require fixing libavformat, which won't happen so quickly. So we
have to keep that part. But everything above the stream layer is
prepared for a better design, and more sophisticated methods than
mp_cancel_test() could be easily introduced.
There's still one problem: commands are still run in the central
playback loop, which we assume can block on I/O in the worst case.
That's not a problem yet, because we simply mark some commands as being
able to stop playback of the current file ("quit" etc.), so input.c
could abort playback as soon as such a command is queued. But there are
also commands abort playback only conditionally, and the logic for that
is in the playback core and thus "unreachable". For example,
"playlist_next" aborts playback only if there's a next file. We don't
want it to always abort playback.
As a quite ugly hack, abort playback only if at least 2 abort commands
are queued - this pretty much happens only if the core is frozen and
doesn't react to input.
Because that might be a bad idea.
Note that remote playlists still can use any protocol marked with
is_safe and is_network, because the case of http-hosted playlists
containing URLs using other streaming protocols is not unusual.
Until now, you had to use --load-unsafe-playlists or --playlist to get
playlists loaded. Change this and always load playlists by default.
This still attempts to reject unsafe URLs. For example, trying to invoke
libavdevice pseudo-demuxer is explicitly prevented. Local paths and any
http links (and some more) are always allowed.
bstr.c doesn't really deserve its own directory, and compat had just
a few files, most of which may as well be in osdep. There isn't really
any justification for these extra directories, so get rid of them.
The compat/libav.h was empty - just delete it. We changed our approach
to API compatibility, and will likely not need it anymore.
Don't reconnect to the cache (since the cached stream already handles
reconnection). This is necessary, because since commit 0b428e44 the
"streaming" field (which also controls whether attempting to reconnect
makes sense at all) is inherited to the cache stream wrapper.
Also, let the stream reset its own position on reconnect. This removes
some assumptions and messy handling from the reconnect function.
Make sure the cache is dropped on reconnect. This takes care of
readjusting the stream position if necessary. (Also drop the cache on
DVB channel switching commands.)
Add the --cache-secs option, which literally overrides the value of
--demuxer-readahead-secs if the stream cache is active. The default
value is very high (10 seconds), which means it can act as network
cache.
Remove the old behavior of trying to pause once the byte cache runs
low. Instead, do something similar wit the demuxer cache. The nice
thing is that we can guess how many seconds of video it has cached,
and we can make better decisions. But for now, apply a relatively
naive heuristic: if the cache is below 0.5 secs, pause, and wait
until at least 2 secs are available.
Note that due to timestamp reordering, the estimated cached duration
of video might be inaccurate, depending on the file format. If the
file format has DTS, it's easy, otherwise the duration will seemingly
jump back and forth.
DVD and Bluray (and to some extent cdda) require awful hacks all over
the codebase to make them work. The main reason is that they act like
container, but are entirely implemented on the stream layer. The raw
mpeg data resulting from these streams must be "extended" with the
container-like metadata transported via STREAM_CTRLs. The result were
hacks all over demux.c and some higher-level parts.
Add a "disc" pseudo-demuxer, and move all these hacks and special-cases
to it.
For remarks, pretty much see the manpage additions. Could help with
network streams that require too much seeking (maybe), or might be
extended to help with the use case of watching and downloading a file
at the same time.
In general, it might be a useless feature and could be removed again.
While I'm not very fond of "const", it's important for declarations
(it decides whether a symbol is emitted in a read-only or read/write
section). Fix all these cases, so we have writeable global data only
when we really need.
Usually, each stream driver declares the size and option list of its
private data. This was pretty natural for when most streams still used
global variables to setup their defaults. They did by pointing
priv_defaults to the (mutable) struct containing the option values. But
falls short when storing the option values in MPOpts. So provide a
somewhat inelegant but simple way to let the stream implementation setup
the priv struct at initialization time.
This is done with the get_defaults callback. It should return a copy of
the struct used in MPOpts. (A copy, because if MPOpts is changed, string
fields might be deallocated, and if that field is not described by
stream_info.options, it won't be copied on init.)
If a single person complains, I will readd it. But I don't expect that
this will happen.
The main reason for removing this is that it's some of the most unclean
code remaining, it's unmaintained, and I've never ever heard of someone
using it.
So, basically this worked only with streams that were not local files,
because stream_dvd.c "intercepts" local files to check whether they
point to DVD images. This means if a stream is not writeable, we have to
try the next stream implementation.
Unbreaks 2-pass encoding.
For some reason, we support writeable streams. (Only encoding uses that,
and the use of it looks messy enough that I want to replace it with FILE
or avio today.)
It's a chaos: most streams do not actually check the mode parameter like
they should. Simplify it, and let streams signal availability of write
mode by setting a flag in the stream info struct.
Stop using it in most places, and prefer STREAM_CTRL_GET_SIZE. The
advantage is that always the correct size will be used. There can be no
doubt anymore whether the end_pos value is outdated (as it happens often
with files that are being downloaded).
Some streams still use end_pos. They don't change size, and it's easier
to emulate STREAM_CTRL_GET_SIZE using end_pos, instead of adding a
STREAM_CTRL_GET_SIZE implementation to these streams.
Make sure int64_t is always used for STREAM_CTRL_GET_SIZE (it was
uint64_t before).
Remove the seek flags mess, and replace them with a seekable flag. Every
stream must set it consistently now, and an assertion in stream.c checks
this. Don't distinguish between streams that can only be forward or
backwards seeked, since we have no such stream types.
stream.start_pos was needed for optical media only, and (apparently) not
for very good reasons. Just get rid of it.
For stream_dvd, we don't need to do anything. Byte seeking was already
removed from it earlier.
For stream_cdda and stream_vcd, emulate the start_pos by offsetting the
stream pos as seen by the rest of mpv.
The bits in discnav.c and loadfile.c were for dealing with the code
seeking back to the start in demux.c. Handle this differently by
assuming the demuxer is always initialized with the stream at start
position, and instead seek back if initializing the demuxer fails.
Remove the --sb option, which worked by modifying stream.start_pos. If
someone really wants this option, it could be added back by creating a
"slice" stream (actually ffmpeg already has such a thing).
Some options change from percentages to number of kilobytes; there are
no cache options using percentages anymore.
Raise the default values. The cache is now 25000 kilobytes, although if
your connection is slow enough, the maximum is probably never reached.
(Although all the memory will still be used as seekback-cache.)
Remove the separate --audio-file-cache option, and use the cache default
settings for it.
This used global variables for the asynchronous interrupt callback.
Pick the simple and dumb solution and stuff the callback into
mpv_global. Do this because interrupt checking should also work in the
connect phase, and currently stream creation equates connecting.
Ideally, this would be passed to the stream on creation instead, or
connecting would be separated from creation. But since I don't know yet
which is better, and since moving stream/demuxer into their own thread
is something that will happen later, go with the mpv_global solution.
This is the only function which actually used the time argument of
stream_check_interrupt(). Considering that the whole player freezes
anyway, this is not worth the complication.
Also generally reduce the maximum wait time due to timeout. Introduce
exponential backoff, which makes the first reconnect retries faster, but
still waits up to 500ms in the later retries.
This commit introduces new stream protocols: bdnav(and others).
bdnav stream shares lots of codes with original bluray stream, so
it's not separated in different source file.
Major difference from bluray is that bdnav does not support longest
title because there is no way to query that information.
bdnav://menu and bdnav://first correspond to top menu title and
first play title respectively, though they often point same title.
Also, binary position based seeking has been removed, because it
didn't have no point.
This is probably ok. Probing could hit this case very often, since it'll
mean running this function on potentially binary data, but on the other
hand, probing usually uses a memory stream (to limit the amount of data
read), and memory streams have s->log silenced (details see
open_memory_stream()).
This simplifies the implementation and should make it more robust. For
example, we return an error if a line is longer than the provided buffer
(instead of splitting the line).
The code is much shorter, because now finding the new line and reading
characters is done in one go.
Streams like CDDA have special requirements in what quantities data can
be read: you can only read a sector at once, not more and not less. The
stream_peek() function didn't respect that and set less (used internal
buffer size of 2048 bytes, instead of CD sector size of 2352 bytes), so
no data was read and EOF was accidentally set, making playback with
cdda:// fail.
This is a regression since commit 9a723f, but that commit merely exposed
the issue (the redundant seek would clear the EOF flag).
