Looks like a bunch of off-by-one errors.
The track number was mistakenly offset by 1 - this shifted all chapters
by one, and make the first chapter start on the second track (so the
"chapter" property returned -1 in the first track since it was before
the first chapter).
Also, the calculation of the sector destination was messed up. This
comes from commit 32d818f0, where I apparently attempted to calculate
the position to one byte before the section, but unfortunately math
doesn't work this way and it was nonsense. Just drop this idea; while it
may help with seeking (probably...), it also returns slightly different
times. The user shall use hr-seeks if accurate seeking is required.
Hopefully fixes#1560.
In my opinion, libavformat should be doing this. But a patch handling a
very safe case rejected, so I suppose we have to do it manually. (This
patch was only escaping spaces, which can never work because they break
the basic syntax of the HTTP protocol.)
This commit attempts to do 2 things:
- Try to guess whether libavformat will use the URL for http. This is
not always trivial, because some protocols will recursively pass part
of the user URL to http in some way.
- Try to fix invalid URLs. We fix only the simplest case: only
characters that are never valid are escaped. This excludes invalid
escape codes, which happen with freestanding '%' characters.
Fixes#1495.
libdvdnav is garbage. Seeking by time is incredibly inexact, which is in
part due to the fact that it does not use the DVD seek tables. Instead,
it assumes CBR for certain ranges within the DVD, which makes especially
small seeks unreliable.
I have no good fix for this, other than hacking libdvdnav (I'd rather
prefer to remove mpv DVD support completely than doing this). So here's
a shitty hack that tries to workaround these problems. A basic
observation is that seeking in VLC seems to work quite well; however it
seems to be based on seeking by blocks (unless there is a subtle "trick"
I didn't see in the source code). mpv usually seeks by timestamps, so
this is not an option for us. However, we can pretend we are doing this
in the DVD layer.
The previous commit added a way to pass through relative seeks. This
commit uses the relative seek. STREAM_CTRL_SEEK_TO_TIME is backwards
compatible (there's still dvdread and bluray), so most code is about
extracing the relative seek information and turning it into a block
seek.
(Another way would have been using SEEK_FACTOR stuff, but that would
probably make for a less reliable way to handle this situation.)
Additionally, if a hr-seek is done, add an offset by 10 seconds. As long
as the error done by libdvdnav is not worse, this should help with hr-
seeks - although it makes them much slower.
This complains within dvb_strtok_r() that savePtr is uninitialized.
There doesn't seem to be any code path where this can happen though, so
it's probably a false positive. Silence it anyway.
This causes more constant reading from the DVB device,
and seems not to hurt the stream-controls.
As the device cache seems to fill up when not
reading from it for several seconds, reading
into the cache fixes desync-issues after
the initial analyzeduration of the demuxer.
Was already possible before by injecting the magic PID
8192 into channels.conf, the flag makes this much more
useable and we also have it documented.
Useful not only for debugging, but also for incomplete
channels.conf (mplayer format...), multi-channel
recording, or channels which do dynamic PID switchng.
full-transponder is also useful for channels which switch PIDs on-the-fly.
ffmpeg can handle this, but it needs the full stream with all PIDs.
There is the STD which contains service-names
(ffmpeg can understand it),
and the EIT which contains the EPG
(ffmpeg does not parse it, but e.g. VLC does).
As we now have more PIDs in general, increase the maximum
number of demuxers we can open. ffmpeg has an internal
limit of 64 PIDs, we are still far from that.
If VDR-channel-config is used, we know the service_id.
Using that, PMT can be extracted from PAT (code for that
inspired by szap-s2 again).
For this, we need to demux PAT with a special filter-setup,
and once PMT was found it can be added to the PID-list.
PMT is only resolved the first time one tunes to a channel,
then stored in the channel-list in memory.
With PMT available, ffmpeg can safely decode the teletext-pids.
I also added a comment explaining the potentially occuring structures for future reference.
For tokenization, a custom strtok_r implementation is used,
inspired by strtok_r as implemented in musl and ffmpeg,
hopefully slightly more readable (av_strtok_r is not available in libav,
and strtok_r is not available everywhere).
Move PID-string parsing into a separate function, reduces code-duplication.
Drop TPID-parsing again since teletext-stream seems not really correctly identified (ffmpeg guessed mp3 in my test...).
Parsing now done using strtok + sscanf instead of sscanfs with fixed numbers of expected fields -
gives more correct checking of PID-overflow, will allow VDR-style PID-field parsing.
The PID-parsing is not really nicely done and also does not yet handle the special VDR-style syntax.
A later commit will move the parsing to a separate function handling that which also checks that the maximum PID-count is not exceeded.
In mplayer-style channels-config, we had a LNB-field used for that.
In old VDR times, the location-field was also containing DISEQc information,
now it does that only indirectly (location => LNB => vdr knows from lnb-config).
We only accept it as this if the field is fully numeric.
Now also "stream ID" (for DVB-S2) and "inversion" are understood.
The parameter-string can also provide information on FEC, rolloff etc. For DVB-S, "auto" which mpv uses by default should be fine, I can also confirm it works. For non-DVB-S cards, it might be useful to also parse this information in case of a vdr-channel list.
As I have no such hardware and thus would have to do it blindly, I added a FIXME.
Mostly complete vdr-channels.conf format documentation is at http://www.vdr-wiki.de/wiki/index.php/Channels.conf (german only).
Still incomplete. Initialize is_dvb_s2 boolean in channel-struct.
We first check whether the channels.conf-line at hand is sscanf'able with a vdr-style pattern. If yes, we assume it is a vdr-channel-config (we check whether sscanf consumed the full line).
The vdr-style config also contains a parameter-string which contains information about polarization + delivery type (e.g. DVB-S2).
With this change, S2-tuning works with a VDR-channel list.
Missing (later commits):
- vdr-parameter-string also contains other information, e.g. invert-flag, needs to be parsed.
- Diseqc-lnb-number is not present in VDR-config (I believe it is handled via the location-parameter + lnb-config there). For backwards compatibility, the location-parameter can be the lnb-number - we should test whether it is an int and assume this in this case.
- VID, AID and TID-lists are extremely ugly in their syntax for VDR. At the moment, only the first number is parsed (and TID fully ignored), needs to be fixed.
It contains now also a boolean which tells whether this is an DVB-S2 channel (not initialized yet - tbd in next commit).
We could also pass through the type of the delivery system (would be more flexible), but the delivery-system-enum is only available with S2API, so this is more backwards-compatible.
If someone has DVB-T2 / DVB-C2 hardware and extends the code to deal with it, this should be changed.
Also allows demuxers to buffer, and we explicitly discard stale QPSK events.
Inspiration taken from the szap-s2 implementation.
S2API is only used if available and for DVB-S cards - it might also be useful to have that for DVB-T2 / DVB-C2 tuning later, but I do not have the HW / no DVB-T2 broadcasting station nearby to test functionality.
This should do no functional changes, only usage of the different API. The S2API is more extensible and a requirement for all the HD-deliveries (e.g. DVB-S2) and since 2.6.28 is the successor of the old API.
Tuning to DVB-S2 channels actually already "works" like this if the delivery is hardcoded in - for a fully working implementation, the channels.conf.sat would need an additional field indicating the delivery type (VDR-type channels.conf have that).
This commit also:
- Cleans up some debug output.
- Moves an unneeded usleep(100000) (only needed for diseqc switching for SAT) into the DVB-S-only part of the implementation.
Define a new macro "DVB_USE_S2API" to be used to switch to S2API if available,
also document what is the main difference in the new S2API.
StreamID-handling is only supported since API 5.2, and some macros
were renamed or only added later with 5.8 (somewhere around kernel 3.6),
so some define-fixups are needed to support these intermediate
kernel header versions.
Apparently this is what users would expect.
Going the way of least resistance (in terms of messing with this old,
rarely used code), sorting them by some kind of addition timestamp
(called priority in the patch) is the easiest.
Fixes#1390.
stream_edl merely makes demux_edl act "special", which checks for the
stream type explicitly and then does something with its URL. If a cache
is added before the stream, it'll try to use the cache's URL (i.e. an
empty string), and will then obviously fail to parse the URL. While this
is slightly stupid, just disabling the entirely useless cache is the
most effective solution.
Fixes#1378.
As suggested in issue #1251. I think the main point is that it acts as
a hack to return to the DVD menu when jumping past the last chapter,
because it will reach title-EOF, instead of explicitly jumping to the
next file (which usually exits the player).
This basically reverts commit 8b7418d, except it doesn't include an
off-by-1 error (apparently).
Closes#1251.
This was requested.
It seems libdvdread can't get the duration for titlesets other than the
currently opened title. The data structures contain dangling pointers
for these, and MPlayer works this around by opening every title
separately for the purpose of dumping the title list.
Apparently, we treat different tracks as titles, so returning the number
of titles (which is user-visible as "disc-titles" property) is
completely misguided.
Apparently, libdvdnav always reports a last chapter that points to the
exact end of the title. This is useless for us.
Again, same possible caveats as with the previous commit.
This way, chapter 0 will always point to the start of the title.
At least this is the intention; it's likely that DVDs as well as
libdvdnav do random things that lead to random results.
This was completely breaking any low-level caching. Change it so that at
least demuxer caching will work.
Do this by using the metadata cache mechanism to funnel through the menu
commands.
For some incomprehensible reason, I had to reorder the events (which
affects their delivery priority), or they would be ignored. Probably
some crap about the event state being cleared before it could be
delivered. I don't give a shit.
All this code sucks. It would probably be better to let discnav.c access
the menu event "queue" directly, and to synchronize access with a mutex,
instead of going through all the caching layers, making things
complicated and slow.
...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.
Thanks to STREAM_CTRL_HAS_AVSEEK, we actually know whether CTRL_AVSEEK
is implemented at all, and we can avoid a blocking wait on the cache if
demux_lavf sends CTRL_AVSEEK even if it won't wait. I'm hoping this
can't currently happen, but why hope if we can explicitly prevent it.
It'll make us more robust against future changes in libavformat.
Basically, this will mark the demuxer as seekable with rtmp* and mmsh
protocols. These protocols have network-level time seeking, and whether
you can seek on the byte level does not matter.
Until now, seeking was typically only enabled because of the cache, and
a (nonsensical) warning was shown accordingly.
It still could happen that the server doesn't actually support thse
requests (or simply rejects them), so this is somewhat imperfect.
No development activity (or even any sign of life) for almost a year.
A replacement based on youtube-dl will probably be provided before the
next mpv release. Ask on the IRC channel if you want to test.
Simplify the Lua check too: libquvi linking against a different Lua
version than mpv was a frequent issue, but with libquvi gone, no
direct dependency uses Lua, and such a clash is rather unlikely.
The immediate mode (which is the default) uses a tiny ringbuffer and
doesn't grab timestamps. This leads to quite bad behavior due to the
fact that there's an additional buffer between playloop and TV code (the
demuxer thread, which doesn't exist in MPlayer).
Always grab the timestamps and use a decently-sized buffer. I still have
no clue what I'm doing, and hacked it until it appeared to work. Report
regressions if you experience any.
I can't believe how shitty this (MPlayer-derived) code is. Maybe it
should be fixed or be replaced with using libavdevice, but that doesn't
seem worth the effort.
Anyway, for now reduce the time it's blocking to wait for new frames
from 10ms to 1ms, because 10ms might be a bit too tight: it could
deliver the frame up to 10ms late - now it's only up to 1ms. (And yes,
it does that instead of using condition variables. It also abuses
volatile variables as atomics. It's hilarious.)
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.
Especially with other components (libavcodec, OSX stuff), the thread
list can get quite populated. Setting the thread name helps when
debugging.
Since this is not portable, we check the OS variants in waf configure.
old-configure just gets a special-case for glibc, since doing a full
check here would probably be a waste of effort.
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.
Normally, we pass libavformat demuxers a wrapped mpv stream. But in some
cases, such as HLS and RTSP, we let libavformat open the stream itself.
In these cases, set typical network properties like useragent according
to the mpv options.
(We still don't set it for the cases where libavformat opens other
streams on its own, e.g. when opening the companion .sub file for .idx
files - not sure if we maybe should always set these options.)
Apparently there's an use for this; see #1178.
I won't redocument obscure FFmpeg features, so add a hint to the
manpage that some protocols are documented in FFmpeg instead.
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.
This makes no sense to use with DVD/BD/DVB and some others, and these
streams happen to be unseekable.
Also, other kinds of unseekable streams (like reading from pipe) should
work, but will exhibit sketchy behavior if they need to seek. So just
disable it, and leave these problems to the memory cache (cache.c).
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.
stream_dvd.c includes a pseudo-protocol that recognizes .IFO files, and
plays them using libdvdread. This was relatively lazy, and could perhaps
easily trigger with files that just had the .ifo extension.
Make the checks stricter, and even probe the file header. Apparently the
first bytes in an .ifo file are always "DVDVIDEO-VTS", so check for
this.
Refuse to load the main "video_ts.ifo". The plan is to use stream_dvdnav
for it.
This also removes at least 1 memory leak.
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.
stream_cdda's output format is linked to demux_raw's default audio
format, and at least we don't care enough to provide a separate
mechanism to let stream_cdda explicitly set the format, so they must
match.
Judging from the existing code, it looks like CDDA always outputs little
endian. stream_cdda.c changed this back to native endian (what demux_raw
expects). Just make them both little endian. This requires less code,
and also having a raw demuxer's behavior depend on the endianness of the
machine isn't very sane anyway.
Until now, the audio chain could handle both little endian and big
endian formats. This actually doesn't make much sense, since the audio
API and the HW will most likely prefer native formats. Or at the very
least, it should be trivial for audio drivers to do the byte swapping
themselves.
From now on, the audio chain contains native-endian formats only. All
AOs and some filters are adjusted. af_convertsignendian.c is now wrongly
named, but the filter name is adjusted. In some cases, the audio
infrastructure was reused on the demuxer side, but that is relatively
easy to rectify.
This is a quite intrusive and radical change. It's possible that it will
break some things (especially if they're obscure or not Linux), so watch
out for regressions. It's probably still better to do it the bulldozer
way, since slow transition and researching foreign platforms would take
a lot of time and effort.
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.
Since we have to be portable, our options for creating temporary files
are somewhat limited. tmpfile() happens to be available everywhere, so
use that. This function doesn't allow having a "visible" filename or
location, so we use the magic string "TMP" for this.
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.
Got lost some time ago. Although I'm not sure if it actually does
anything on MPlayer (it exists there, but might broken, not sure).
Fixes#988 (untested).
Use OPT_KEYVALUELIST() for all places where AVOptions are directly set
from mpv command line options. This allows escaping values, better
diagnostics (also no more "pal"), and somehow reduces code size.
Remove the old crappy option parser (av_opts.c).
This didn't work, because the timebase was wrong. According to the
ffmpeg doxygen, if the stream index is -1 (which is what we used), the
timebase is AV_TIME_BASE. But this didn't work, and it really expected
the stream's timebase. Quite "surprising", since this feature
(avio_seek_time) is used by rtmp only.
Fixing this properly is too hard, so hack-fix our way around it.
STREAM_CTRL_SEEK_TO_TIME is also used by DVD/BD, so a new
STREAM_CTRL_AVSEEK is added. We simply pass-through the request
verbatim.
This adds a thread to the demuxer which reads packets asynchronously.
It will do so until a configurable minimum packet queue size is
reached. (See options.rst additions.)
For now, the thread is disabled by default. There are some corner cases
that have to be fixed, such as fixing cache behavior with webradios.
Note that most interaction with the demuxer is still blocking, so if
e.g. network dies, the player will still freeze. But this change will
make it possible to remove most causes for freezing.
Most of the new code in demux.c actually consists of weird caches to
compensate for thread-safety issues (with the previously single-threaded
design), or to avoid blocking by having to wait on the demuxer thread.
Most of the changes in the player are due to the fact that we must not
access the source stream directly. the demuxer thread already accesses
it, and the stream stuff is not thread-safe.
For timeline stuff (like ordered chapters), we enable the thread for the
current segment only. We also clear its packet queue on seek, so that
the remaining (unconsumed) readahead buffer doesn't waste memory.
Keep in mind that insane subtitles (such as ASS typesetting muxed into
mkv files) will practically disable the readahead, because the total
queue size is considered when checking whether the minimum queue size
was reached.
Happens when playing from a pipe.
Note that seeking forward doesn't work. It would be possible to create a
workaround for that by reading and skipping data until the target
position is reached (and writing the skipped data into the cache file),
but I'm not sure about that.
Fixes#928.
CC: @mpv-player/stable
There is no standard mechanism for detecting endianess. Doing it at
compile time in a portable way is probably hard. Doing it properly
with a configure check is probably hard too. Using the endian
definitions in <sys/types.h> (usually includes <endian.h>, which is
not available everywhere) works under circumstances, but the previous
commit broke it on OSX.
Ideally all code should be endian dependent, but that is not possible
due to the dependencies (such as FFmpeg, some video output APIs, some
audio output APIs).
Create a header osdep/endian.h, which contains various fallbacks.
Note that the last fallback uses libavutil; however, it's not clear
whether AV_HAVE_BIGENDIAN is a public symbol, or whether including
<libavutil/bswap.h> really makes it visible. And in fact we don't want
to pollute the namespace with libavutil definitions either. Thus it's
only the last fallback.
_GNU_SOURCE defines the kitchen sink, and also prefers glibc definitions
where glibc and POSIX conflict. Even though POSIX is worth less than
toilet paper, we still prefer the POSIX definitions.
rar.c needs asprintf(), which is _GNU_SOURCE-only. So we define
_GNU_SOURCE too specifically for this file.
We used a complicated and approximate method to cache the stream
timestamp, which is basically per-byte. (To reduce overhead, it was only
cached per 8KB-block, so it was approximate.)
Simplify this, and read/keep the timestamp only on discontinuities. This
is when demux_disc.c actually needs the timestamp.
Note that caching is currently disabled for dvdnav, but we still read
the timestamp only after some data is read. libdvdread behaves well, but
I don't know about libbluray, and the previous code also read the
timestamp only after reading data, so try to keep it safe.
Also drop the start_time offset. It wouldn't be correct anymore if used
with the cache, and the idea behind it wasn't very sane either (making
the player to offset the initial playback time to 0).
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.
(Again.)
This time, we simply make it event-based, as it should be. This is done
for both demuxer metadata and stream metadata.
For some ogg-over-icy streams, 2 updates are reported on stream start.
This is because libavformat reports an update right on start, while
including the same info in the "static" metadata. I don't know if that's
a bug or a feature.
When resizing the cache, the buffer for the DVD timestamps is
initialized with 0. This causes the player to always return playback
position 0 with any file format (not just DVD), and also makes all
relative seeks relative to position 0. Fix this by clearing the
timestamps explicitly.
Closes#899.
CC: @mpv-player/stable
Something like "char *s = ...; isdigit(s[0]);" triggers undefined
behavior, because char can be signed, and thus s[0] can be a negative
value. The is*() functions require unsigned char _or_ EOF. EOF is a
special value outside of unsigned char range, thus the argument to the
is*() functions can't be a char.
This undefined behavior can actually trigger crashes if the
implementation of these functions e.g. uses lookup tables, which are
then indexed with out-of-range values.
Replace all <ctype.h> uses with our own custom mp_is*() functions added
with misc/ctype.h. As a bonus, these functions are locale-independent.
(Although currently, we _require_ C locale for other reasons.)
Search $XDG_CONFIG_HOME and $XDG_CONFIG_DIRS for config files.
This also negates the need to have separate user and global variants of
mp_find_config_file()
Closes#864, #109.
Signed-off-by: wm4 <wm4@nowhere>
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.
When the reader is out of data, it tries to wake up the cache thread to
get more data. In theory, there's a small race condition, which could
cause the cache to miss the wakeup and idle before reaction.
Most certainly didn't cause real issues, because even if this extremely
unlikely race condition happens, the cache won't idle for longer than
1 second (the hardcoded cache idle time).
Well, not sure if this really improves anything, but at least it's less
of a WTF to the playback core than always returning the same timestamp
for every frame.
There's really no need to convert this to float and then back. This is
mostly of cosmetic nature, double precision was probably enough to avoid
rounding.
Not sure how this symbol becomes visible in glibc (probably accidental
or mandatory recursive inclusion via the other standard or Linux-
specific headers), but normally this include file is needed to get the
symbol.
Squashed from the following mplayer-svn commits. The '#' is removed from
the bug ID to prevent github from doing something stupid. Instead of
adding the mplayer configure check for clock_gettime(), the POSIX
identifiers are used for checking presence of the function.
Use correct type of timestamps when recording from v4l2. Fix 2176
Patch by Jarek Czekalski <jarekczek at poczta onet pl>.
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@37222 b3059339-0415-0410-9bf9-f77b7e298cf2
Allow building of v4l2 without clock_gettime().
Add overly verbose message in case monotone timestamps are required by the kernel.
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@37223 b3059339-0415-0410-9bf9-f77b7e298cf2
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.)
Pretty much nothing changes, but using -tv-scan with suboptions doesn't
work anymore (instead of "-tv-scan x" it's "-tv scan-x" now). Flat
options ("-tv-scan-x") stay compatible.
Convert all these commands to properties. (Except tv_last_channel, not
sure what to do with this.) Also, internally, don't access stream
details directly, but dispatch commands with stream ctrls.
Many of the new properties are a bit strange, because they're write-
only. Also remove some OSD output these commands produced, because I
couldn't be bothered to port these.
In general, this makes everything much cleaner, and will also make it
easier to e.g. move the demuxer to its own thread.
Don't bother updating input.conf, but changes.rst documents how old
commands map to the new ones.
Mostly untested, due to lack of hardware.
This could for example happen when serving an incomplete file from http,
and the demuxer tries reading data from the end of the file when opening
it (e.g. with avi). Seeking past EOF fails with http, so the file could
never be opened, and the cache would get stuck trying to seek to the
position.
We can't really make the cache report seek failure directly (it would
suck for various reasons), so just make the cache report EOF if seeking
fails.
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.
This call was used limited the buffer size if installed RAM was below 16
MB. This stopped being useful a decade ago. The check could also
overflow on 32 bit systems. Just get rid of it.
In most places where af_fmt2bits is called to get the bits/sample, the
result is immediately converted to bytes/sample. Avoid this by getting
bytes/sample directly by introducing af_fmt2bps.
The i_bps members of the sh_audio and dev_video structs are mostly used
for displaying the average audio and video bitrates. Keeping them in
bits-per-second avoids truncating them to bytes-per-second and changing
them back lateron.
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.
Also sneak in some cosmetics.
setmode() exists on Windows/msvcrt only, so there's no need for a
config test.
I couldn't reproduce the problem with seekable pipes on wine, so axe
it. (I'm aware that it still could be an issue on real Windows.)
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.
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.
Previous to this commit, read_chunk was not set in stream_smb. The
cache was therefore filled in small 8K chunks. This resulted in poor
performance when compared to, for example, smbnetfs on the same
network.
The value of 128k is chosen both because it is emperically
the "levelling off point" for throughput into mpv's cache, and because
it is the value chosen by smbnetfs when serving smb shares to
mpv.
Note that this change has no effect unless --cache is explicitly
specified as smb:// streams do not activate cache by default. This is
because the default cache size of 320K is so small it actually makes
smb:// perfomance worse. For best results use at least --cache=1024.
Also remove MSGL_SMODE and friends.
Note: The indent in options.rst was added to work around a bug in
ReportLab that causes the PDF manual build to fail.
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.
Fix all include statements of the form:
#include "libav.../..."
These come from MPlayer times, when FFmpeg was somehow part of the
MPlayer build tree, and this form was needed to prefer the local files
over system FFmpeg.
In some cases, the include statement wasn't needed or could be replaced
with mpv defined symbols.
This was accidentally completely destroyed with commit 24f1878e. I
didn't notice it when testing, because forward seeking still worked
mostly.
The issue was that dvd_seek_to_time() actually called stream_seek(),
which was supposed to call the byte-level seek function dvd_seek(). So
we have to restore this function, and replace all generic stream calls
with stream_dvd.c internal ones. This also affects stream->pos (now a
random number as far as stream_dvd.c is concerned) and stream_skip().
I hate tabs.
This replaces all tabs in all source files with spaces. The only
exception is old-makefile. The replacement was made by running the
GNU coreutils "expand" command on every file. Since the replacement was
automatic, it's possible that some formatting was destroyed (but perhaps
only if it was assuming that the end of a tab does not correspond to
aligning the end to multiples of 8 spaces).
This was broken at some unknown point (even before the recent cache
changes). There are several problems:
- stream_dvd returning a random stream position, confusing the cache
layer (cached data and stream data lost their 1:1 corrospondence by
position)
- this also confused the mechanism added with commit a9671524, which
basically triggered random seeking (although this was not the only
problem)
- demux_lavf requesting seeks in the stream layer, which resulted in
seeks in the cache or the real stream
Fix this by completely removing byte-based seeking from stream_dvd. This
already works fine for stream_dvdnav and stream_bluray. Now all these
streams do time-based seeks, and pretend to be infinite streams of data,
and the rest of the player simply doesn't care about the stream byte
positions.
resize_cache() checks the size itself and clamps the size to the valid
range if necessary, so we don't need these checks. In fact, the checks
are different. Also, output the cache size after clamping, instead of
before.
Use NtQueryVolumeInformationFile instead of GetDriveType for detecting
remote filesystems on Windows. This has the advantage of working
directly on the file handle instead of needing a path and it works
unmodified in Cygwin where the previous code wouldn't understand Cygwin
paths or symlinks.
There is some risk in using NtQueryVolumeInformationFile, since it's an
internal function and its behaviour could change at any time or it could
be removed in a future version of Windows, however it's documented[1] in
the WDK and it's used successfully by Cygwin, so it should be fine. If
it's removed, the code should fail gracefully by treating all files as
local.
[1]: http://msdn.microsoft.com/en-us/library/windows/hardware/ff567070.aspx
Signed-off-by: wm4 <wm4@nowhere>
Merge the cache_read function into cache_fill_buffer, since there's
not much reason to keep them separate. Also, simply call read_buffer()
to see if there's any readable data, instead of checking for the
condition manually.
The only tricky part is keeping the cache contents, which is made simple
by allocating the new cache while still keeping the old cache around,
and then copying the old data.
To explain the "Don't use this when playing DVD or Bluray." comment: the
cache also associates timestamps to blocks of bytes, but throws away the
timestamps on seek. Thus you will experience strange behavior after
resizing the cache until the old cached region is exhausted.
The only difference is that the MP_DBG message is not printed anymore if
the current user read position is outside of the current cache range.
(In order to handle seek_limit==0 gracefully in the normal case of
linear reading, change the comparison from ">=" to ">".)
Until now, this could never happen, because new data was simply always
appended to the end of the cache. But for making stream cache resizing
easier, doing it this way seems advantageous. It also makes it harder to
make the internal state inconsistent. (Before this change it could
happen that cache and stream position went out of sync if the read
position was adjusted "inappropriately".)
Until now, cache_read() (which calls read_buffer()) could return short
reads. This was a simplification allowed by the stream interface. But
for cache resizing, it will be more practical to make read_buffer() do
a full read.
Seems like a good idea. One possible bad effect would be slowing down
uncached controls, but they're already slow. The good thing is that
many controls make intrusive changes to the stream (at least controls
which do write accesses), so the cached parameters should be updated.
There are two kind of encryption for Blu-ray disc, AACS and BD+,
and both of them can be checked through BLURAY_DISC_INFO object.
This commit makes the bluray and bdnav streams refuse playback
if AACS/BD+ is detected and decryption is failed.
The angles should be set and queried only if a valid title is
selected. Also, in navigation mode, there are some limitations
which make it impossible to query current title/angle.
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 was actually supposed to be removed with pull reuqest #671, but
I accidentally re-added it with a rebasing mistake.
This probably also coincidentally fixes compilation with older
libbluray (issue #672).
Use bd_get_playlist_info() instead of bd_get_title_info(). The
previous implementation couldn't query current playlist and this
made it impossible to call bd_get_playlist_info() which is more
desirable than bd_get_title_info() because, for Blu-rays, playlist
is the unit of playback not title. This commit fixes that.
The cost of calling bd_get_title_info() is quite expensive and
requires lots of CPU usage. Using BD_EVENT_PLAYLIST and
BD_EVENT_TITLE, it's possible to cache BLURAY_TITLE_INFO object for
current title and BD_EVENT_ANGLE handler caches current angle. In
my test case, with this commit, CPU usage can be saved about 15-20%.
demux_mf.c explicitly checks for the stream type to check whether images
are opened via pattern (mf://..., i.e. stream_mf.c) or directly. Of
course the stream type is not set to STREAMTYPE_MF if the stream is
wrapped through the cache, so it tried to open the pattern directly as
file, which failed.
Fix this by disabling caching for mf://. The cache doesn't make sense
here anyway, because each file is opened and closed every frame (perhaps
to avoid memory bloat).
This cd_info_t struct was practically unused. The only thing it did was
storing the track name of the form "Track %d" in a very roundabout way.
Remove it. (It made more sense when there was still CDDB support.)
Don't use an integer division to get the time, since that would round on
second boundaries. Also round up the time by sector size. Seeking rounds
down due to alignment constraints, but if we round up the time, we can
make it land on the exact destination sector.
This fixes that the track change code printed the previous track when
seeking by chapter.
dvdnav.c did not handle event in regular sequence. Usually this
does not make any trouble except around MP_NAV_EVENT_RESET_ALL.
Those events should be handled in regular sequence. If they're
mixed, it can make wrong result.
For instance, MP_NAV_EVENT_HIGHLIGHT right after
MP_NAV_EVENT_RESET_ALL should not be ignored but it might be
because MP_NAV_EVENT_RESET_ALL makes the demuxer reloaded and osd
hidden.
Stream-level chapters (like DVD etc.) did potentially not have
timestamps for each chapter, so STREAM_CTRL_SEEK_TO_CHAPTER and
STREAM_CTRL_GET_CURRENT_CHAPTER were needed to navigate chapters. We've
switched everything to use timestamps and that seems to work, so we can
simplify the code and remove this old mechanism.
Report the time for each chapter (tracks are treated as chapters). This
allows us to get rid of the "old" chapter mechanism, and also behaves
better with the frontend.
This makes assumptions about the audio formats, but that format is
hardcoded anyway in the rawaudio demuxer defaults (and always was).
The title for stream_bluray DID start from 1 and I misunderstood
that it started from 0 because mpv accepted bd://0 as a proper
argument. In fact, 0 title was an alias for the longest title but
it was not handled as a special value. This commit fixes these
behavious. 'disc-title' property for Blu-ray now starts from 0 and
the default title can be specified by 'longest' title just like
stream_dvdnav: bd://longest. Of course, 'longest' can be omitted.
This commit makes 'disc-title' property writable using
STREAM_CTRL_SET_CURRENT_TITLE. This commit also contains
implementation of STREAM_CTRL_SET_CURRENT_TITLE for stream_bluray.
Currently, 'disc-title' is writable only for stream_dvdnav and
stream_bluray and stream_dvd is not supported.
This commit makes 'disc-title' properties for DVDs start from 0.
There was an inconsistency around 'disc-title' property between
DVDs (from 1) and Blu-rays (from 0). This fixes#648.
Signed-off-by: wm4 <wm4@nowhere>
This commit provides impelmentation of STREAM_CTRL_GET_NUM_TITLES
for dvdnav stream. Other streams for DVD or Blu-ray are already
provide STREAM_CTRL_GET_NUM_TITLES.
Detected 'protocols' are AFP, nfs, smb and webdav. This can be extended on
request.
This is currently only implemented for BSD systems (using fstatfs). This
addresses issue #558 on the above platforms.
Note that this still happens in the stream level, so we can't have
nice highlevel behavior restricting seeking. Instead, if a seek leads
to the demuxer requesting data outside of the cached range, the seek
will simply fail. This might confuse the demuxer, and the resulting
behavior is not necessarily useful.
Note that this also doesn't try to skip data on a forward seek. This
would just freeze the stream with slow unseekable streams.
One nice thing is that stream.h has a separate function for merely
skipping data (separate from seeking forward), which is pretty useful
in this case: we want skipping of data to work, even if we reject
seeking forward by skipping data as too expensive. This probably is
or will be useful for demux_mkv.c.
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.
Doesn't affect the generated code, but avoids confusion
in both humans and newer Coverity versions.
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36623 b3059339-0415-0410-9bf9-f77b7e298cf2
The struct we need to copy is actually a cdrom_msf0, not cdrom_msf.
Even though the kernel for no good reason reads it in as a
cdrom_msf struct, but only uses the part shared with cdrom_msf0 -
this is probably a kernel bug.
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@36622 b3059339-0415-0410-9bf9-f77b7e298cf2
Starting a network stream could stall by executing uncacheable stream
control requests (STREAM_CTRL_GET_LANG and STREAM_CTRL_GET_DVD_INFO).
Being uncacheable means the player has to wait until the cache is done
reading the current block of data. These requests can't be cached
because they're too complicated, so the only way to avoid them is
special casing the DVD and Bluray streams (which are the only things
which need these requests), and not doing them in other cases.
(This is kind of inelegant, but so is the rest of the DVD/BD code.)
This fixes two things:
1. Dropping files on the VO window will auto-load subtitles (since most
drag & drop code prefixes the filenames with 'file://', and the
subtitle auto-load code considers 'file://' non-local)
2. Fix behavior of the %x screenshot filename template (similar problem)
One could force all that code to special-case 'file://' URLs, but just
replacing the filename on playback start is simpler.
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).
There's a single mp_msg() in path.c, but all path lookup functions seem
to depend on it, so we get a rat-tail of stuff we have to change. This
is probably a good thing though, because we can have the path lookup
functions also access options, so we could allow overriding the default
config path, or ignore the MPV_HOME environment variable, and such
things.
Also take the chance to consistently add talloc_ctx parameters to the
path lookup functions.
Also, this change causes a big mess on configfiles.c. It's the same
issue: everything suddenly needs a (different) context argument. Make it
less wild by providing a mp_load_auto_profiles() function, which
isolates most of it to configfiles.c.
The TV code pretends to be part of stream/, but it's actually demuxer
code too. The audio_in code is shared between the TV code and
stream_radio.c, so stream_radio.c needs a small hack until stream.c is
converted.
Always pass around mp_log contexts in the option parser code. This of
course affects all users of this API as well.
In stream.c, pass a mp_null_log, because we can't do it properly yet.
This will be fixed later.
In my opinion, config.h inclusions should be kept to a minimum. MPlayer
code really liked including config.h everywhere, though, even in often
used header files. Try to reduce this.
Since m_option.h and options.h are extremely often included, a lot of
files have to be changed.
Moving path.c/h to options/ is a bit questionable, but since this is
mainly about access to config files (which are also handled in
options/), it's probably ok.
The tmsg stuff was for the internal gettext() based translation system,
which nobody ever attempted to use and thus was removed. mp_gtext() and
set_osd_tmsg() were also for this.
mp_dbg was once enabled in debug mode only, but since we have log level
for enabling debug messages, it seems utterly useless.
Before this, they were displayed forever. Since some dvd screens seem
not to allow escaping from the still frame using the menu, this could
get you stuck forever.