mpv has a very weak and very annoying policy that determines whether a
playlist should be used or not. For example, if you play a remote
playlist, you usually don't want it to be able to read local filesystem
entries. (Although for a media player the impact is small I guess.)
It's weak and annoying as in that it does not prevent certain cases
which could be interpreted as bad in some cases, such as allowing
playlists on the local filesystem to reference remote URLs. It probably
barely makes sense, but we just want to exclude some other "definitely
not a good idea" things, all while playlists generally just work, so
whatever.
The policy is:
- from the command line anything is played
- local playlists can reference anything except "unsafe" streams
("unsafe" means special stream inputs like libavfilter graphs)
- remote playlists can reference only remote URLs
- things like "memory://" and archives are "transparent" to this
This commit does... something. It replaces the weird stream flags with a
slightly clearer "origin" value, which is now consequently passed down
and used everywhere. It fixes some deviations from the described policy.
I wanted to force archives to reference only content within them, but
this would probably have been more complicated (or required different
abstractions), and I'm too lazy to figure it out, so archives are now
"transparent" (playlists within archives behave the same outside).
There may be a lot of bugs in this.
This is unfortunately a very noisy commit because:
- every stream open call now needs to pass the origin
- so does every demuxer open call (=> params param. gets mandatory)
- most stream were changed to provide the "origin" value
- the origin value needed to be passed along in a lot of places
- I was too lazy to split the commit
Fixes: #7274
stream_skip() semantics were kind of bad, especially after the recent
change to the stream code. Forward stream_skip() calls could still
trigger a seek and fail, even if it was supposed to actually skip data.
(Maybe the idea that stream_skip() should try to seek is worthless in
the first place.)
Rename it to stream_seek_skip() (takes absolute position now because I
think that's better), and make it always skip if the stream is marked as
forward.
While we're at it, make EOF detection more robust. I guess s->eof
shouldn't exist at all, since it's valid only "sometimes". It should be
removed... but not today. A 1-byte stream_read_peek() call is good to
get the s->eof flag set to a correct value.
It was set, but its value was never used. The stream cache used to use
it, but it was removed. It controlled how much data it tried to read
from the underlying stream at once.
The user can now control the buffer size with --stream-buffer-size,
which achieves a similar effect, because the stream will in the common
case read half of the buffer size at once. In fact, the new default size
is 128KB, i.e. 64KB read size, which is as much as stream_file and
stream_cb requested by default. stream_memory requested more, but it
doesn't matter anyway. Only stream_smb set a larger size with 128KB.
stream_read_peek() duplicated what stream_read_more() checks for anyway
(whether the forward buffer is large enough). This can be skipped by
making the stream_read_more() return value more consistent.
(Only half of the buffer is actually used in a useful way, see manpage
or commit which added the option.)
Might have some advantages with broken network filesystem drivers.
See: #6802
Was probably worthless, and I can't measure a difference anymore (I used
to be able and it still seemed worth doing so back then).
When the default buffer size is enlarged in the next commit, the inline
buffer probably won't even be useful in theory, because the data will
rarely be on the same page as the other stream fields. It surely makes
the inline buffer seem like a ridiculous micro-optimization. Farewell...
In some corner cases (see #6802), it can be beneficial to use a larger
stream buffer size. Use this as argument to rewrite everything for no
reason.
Turn stream.c itself into a ring buffer, with configurable size. The
latter would have been easily achievable with minimal changes, and the
ring buffer is the hard part. There is no reason to have a ring buffer
at all, except possibly if ffmpeg don't fix their awful mp4 demuxer, and
some subtle issues with demux_mkv.c wanting to seek back by small
offsets (the latter was handled with small stream_peek() calls, which
are unneeded now).
In addition, this turns small forward seeks into reads (where data is
simply skipped). Before this commit, only stream_skip() did this (which
also mean that stream_skip() simply calls stream_seek() now).
Replace all stream_peek() calls with something else (usually
stream_read_peek()). The function was a problem, because it returned a
pointer to the internal buffer, which is now a ring buffer with
wrapping. The new function just copies the data into a buffer, and in
some cases requires callers to dynamically allocate memory. (The most
common case, demux_lavf.c, required a separate buffer allocation anyway
due to FFmpeg "idiosyncrasies".) This is the bulk of the demuxer_*
changes.
I'm not happy with this. There still isn't a good reason why there
should be a ring buffer, that is complex, and most of the time just
wastes half of the available memory. Maybe another rewrite soon.
It also contains bugs; you're an alpha tester now.
Add yet another variant of the stream open function. This time, make it
so that it's possible to add new open parameters in an extendable way,
which should put an end to having to change this every other year.
Effectively get rid of the overly special stream_create_instance()
function and use the new one instead, which requires changes in
stream_concat.c and stream_memory.c. The function is still in private in
stream.c, but I preferred to make the mentioned users go through the new
function for orthogonality. The error handling (mostly logging) was
adjusted accordingly.
This should not have any functional changes. (To preempt any excuses, I
didn't actually test stream_concat and stream_memory.)
Instead of having to rely on the protocol matching, make a function that
creates a stream from a stream_info_t directly. Instead of going through
a weird indirection with STREAM_CTRL, add a direct argument for non-text
arguments to the open callback. Instead of creating a weird dummy
mpv_global, just pass an existing one from all callers. (The latter one
is just an artifact from the past, where mpv_global wasn't available
everywhere.)
Actually I just wanted a function that creates a stream without any of
that bullshit. This goal was slightly missed, since you still need this
heavy "constructor" just to setup a shitty struct with some shitty
callbacks.
struct stream used to include the stream buffer, including peek buffer,
inline in the struct. It could not be resized, which means the maximum
peek size was set in stone. This meant demux_lavf.c could peek only so
much data.
Change it to use a dynamic buffer. Because it's possible, keep the
inline buffer for default buffer sizes (which are basically always used
outside of file opening). It's unknown whether it really helps with
anything. Probably not.
This is also the fallback plan in case we need something like the old
stream cache in order to deal with mp4 + unseekable http: the code can
now be easily changed to use any buffer size.
The intent of the line above the modified one code was raising the
amount of read data, so that many stream_peek() calls with small len
values would not degrade performance by effectively turning every
stream_peak() into an unbuffered read call to the stream implementation.
So this confusing looking MPMAX() was correct, but "chunk" could still
get beyond the buffer.
So just fix that and limit "chunk" correctly.
I'm not sure whether the commit referenced below accidentally removed
some intricate guarantee that this couldn't happen, since the code was
around since 2013. It could have relied on TOTAL_BUFFER_SIZE >
STREAM_BUFFER_SIZE. But not sure. I've rewritten all this code in my own
branch a year ago, so who knows.
Fixes: 162e0f5ad9Fixes: #6948
The write functionality is almost unused (only encoding 2-pass mode uses
it to write the log file). Moreover, it almost makes no sense to use
this in a not local scenario. This change is just to prevent people from
duplicating the short write logic across all streams that happen to
support writing. Mostly untested; local log file writing still works.
Linux analog TV support (via tv://) was excessively complex, and
whenever I attempted to use it (cameras or loopback devices), it didn't
work well, or would have required some major work to update it. It's
very much stuck in the analog past (my favorite are the frequency tables
in frequencies.c for analog TV channels which don't exist anymore).
Especially cameras and such work fine with libavdevice and better than
tv://, for example:
mpv av://v4l2:/dev/video0
(adding --profile=low-latency --untimed even makes it mostly realtime)
Adding a new input layer that targets such "modern" uses would be
acceptable, if anyone is interested in it. The old TV code is just too
focused on actual analog TV.
DVB is rather obscure, but has an active maintainer, so don't remove it.
However, the demux/stream ctrl layer must go, so remove controls for
channel switching. Most of these could be reimplemented by using the
normal method for option runtime changes.
This was possibly needed by libdvdread, and/or old CD drivers on some
system. It still works with on-filesystem DVD and BD test images, so
this can go.
stream_dvd.c contained large amounts of ancient, unmaintained code,
which has been historically moved to libdvdnav. Basically, it's full of
low level parsing of DVD on-disc structures.
Kill it for good. Users can use the remaining dvdnav support (which
basically operates in non-menu mode). Users have reported that
libdvdread sometimes works better, but this is just libdvdnav's problem
and not ours.
Seems to happen often with ytdl pseudo-DASH streams, so whatever. I
couldn't reproduce it and check what triggers it, I just remember seeing
the error message and found it annoying.
The demuxer cache is the only cache now. Might need another change to
combat seeking failures in mp4 etc. The only bad thing is the loss of
cache-speed, which was sort of nice to have.
It seems a bit inappropriate to have dumped this into stream.c, even if
it's roughly speaking its main user. At least it made its way somewhat
unfortunately to other components not related to the stream or demuxer
layer at all.
I'm too greedy to give this weird helper its own file, so dump it into
thread_tools.c.
Probably a somewhat pointless change.
When this happens, network calls are forcibly aborted (more or less),
but demuxers might keep going, as most of them do not check for forced
exits properly. This can possibly lead to broken packets being added.
Also do not attempt to read more packets in this situation.
Also do not print a stream open failed message if opening was aborted
anyway.
Remove our own hacky reconnection code, and use libavformat's feature for
that. It's disabled by default, and until recently it did not work too
well. This has been fixed in recent ffmpeg git master[1], so there's no reason
to keep our own code.
[1] FFmpeg/FFmpeg@8a108bdea0
We set "reconnect_delay_max" to 7, which limits the maximum time it
waits. Since libavformat doubles the wait time on each reconnect attempt
(starting with 1), and stops trying to reconnect once the wait time is
over the reconnect_delay_max value, this allows for 4 reconnection
attempts which should add to 11 seconds maximum wait time. The default
is 120, which seems too high for normal playback use.
(The user can still override these parameters with --stream-lavf-o.)
Don't drop the stream buffers, because the read call (that must have
been failing) might try to extend an existing read buffer in the first
place. Just move the messy seek logic to stream_lavf.c. (In theory,
stream_lavf should probably make libavformat connect at the correct
offset instead of using a seek to reconnect it again. This patch doesn't
fix it, but at least it's a good argument to have the messing with the
position not in the generic code.)
Also update the comment about avio not supporting reconnecting. It has
that feature now. Maybe we should use it, but only after it gets fixed.
I've decided that MP_TRACE means “noisy spam per frame”, whereas
MP_DBG just means “more verbose debugging messages than MSGL_V”.
Basically, MSGL_DBG shouldn't create spam per frame like it currently
does, and MSGL_V should make sense to the end-user and provide mostly
additional informational output.
MP_DBG is basically what I want to make the new default for --log-file,
so the cut-off point for MP_DBG is if we probably want to know if for
debugging purposes but the user most likely doesn't care about on the
terminal.
Also, the debug callbacks for libass and ffmpeg got bumped in their
verbosity levels slightly, because being external components they're a
bit less relevant to mpv debugging, and a bit too over-eager in what
they consider to be relevant information.
I exclusively used the "try it on my machine and remove messages from
MSGL_* until it does what I want it to" approach of refactoring, so
YMMV.
This affects small seeks backwards while within the buffer. Demuxers
usually avoid this, so it's probably not triggered very often. (Although
demux_mkv.c potentially triggers it often, and it uses stream_peek() to
explicitly guarantee that it can use this code to seek back.) The
condition is complex enough to warrant an assertion.
While this is perfectly OK on Unix, it causes annoying valgrind
warnings, and might be otherwise confusing to others.
On Windows, the runtime can actually abort the process if this is
called.
push.c part taken from a patch by Pedro Pombeiro.
All relevant authors have agreed.
There are two exceptions, patches by authors who could not be reached.
This commit tries to remove their copyright.
a0f08fbe: messes with the seeking code corner cases. The EOF flag logic
was changed at some point, and always had a flaky history (see e.g.
347cf97250274ca370411f275999efb90d5e6084ff08d0c32e2f77e3de5566f09554a844, all which happened after that patch, MPlayer ones without that
patch). I claim that all of the copyright the patch might have added is
gone. Except the message in stream_seek(), which this commit removes.
The other code removed/changed in stream_seek() is probably not from
that patch, but it doesn't hurt to be sure, and also makes it more
readable. (It might change the behavior so that sometimes the eof flag
is set after a seek, but it doesn't matter here.)
2aa6acd9: it looks like the seek_forward() modified by this patch was
later moved to stream.c and renamed to stream_skip_read() in a790f2133.
(Looking closer at it, it was actually modified again a bunch of times,
fixing the logic.) I rewrote it in this commit. The code ended up rather
similar, which probably could lead to doubts whether this was done
properly, but I guess the reader of this will just have to believe me. I
knew what stream_skip_read() was supposed to do (which was reinforced
when I tried to replace it on the caller side), without reading the
pre-existing code in detail. I had to "relearn" the logic how buf_pos
and bug_len work - it was actually easy to see from stream_read_char()
how to skip the data, essentially by generalizing its logic from 1 byte
to N bytes. From the old code I only "used" the fact that it's obviously
a while(len>0) look, that has to call stream_fill_buffer repeatedly to
make progress. At first I actually didn't use stream_fill_buffer_by(),
but the variant without _by, but readded it when I checked why the old
code used it (see cd7ec016e7). This has to be good enough. In the end,
it's hard to argue that this could be implemented in a way not using
such a loop.
Other than this, I could add the usual remarks about how this code was
not modularized in the past, and how stream.c contained DVD code, and
how this was later modularized, moving the copyright to other files, and
so on. Also, if someone wrote a stream module, and was not asked about
LGPL relicensing, we don't consider the entry in stream_list[]
copyrightable.
The original functions come from 24c6f11c8b, which says that these
functions were copied from another project. This other project is GPL
and was written by an unknown author, so there is no hope to relicense
them to LGPL.
Replace the existing functions with code written by Avi Halachmi. He did
not see the old code, but wrote it based on the function signature and
an extended description of what they should do (http://sprunge.us/edia).
Some additional help was provided by me (in particular the function of
the "ok" parameter and how to implement it - not in the original
ASFRecorder code).
Some of the code is hilariously similar, but these are coincidences. The
name of the variable "c" probably "leaked" from me, but "o" is a true
coincidence.
The code was integrated by me - my only change is changing the function
names to the old ones, moving the order of the top-level declarations,
and changing "default_ok" to "url_default_ok", and changing the strings
from char* to char[].
The author of the new code is Avi Halachmi.
Reallows enabling dvdnav without enabling dvdread which was broken
in 77cbb3543 when they were both disabled by default.
Since dvdnav requires dvdread, we can enable dvdread:// even if
--enable-dvdread isn't passed.
Fixes#4290
Because it's kind of dumb. (But not sure if it was worth the trouble.)
For stream_file.c, we add new explicit fields. The rest are rather
special uses and can be killed by comparing the stream impl. name.
The changes to DVD/BD/CD/TV are entirely untested.
"uncached_stream" is a pretty bad name. It could be mistaken for a
boolean, and then its meaning would be inverted. Rename it.
Also add a "caching" field, which signals that the stream is a cache or
reads from a cache. This is easier to understand and more flexible.
This is almost cosmetic, but removes the duplicated EOF-setting.
Somewhat oddly, this will enter the reconnect path and exit it
immediately again - should be fine.
Commit 7be495b3 added the cancellation test, but forgot to set the eof
flag. This could lead to demux_mkv.c not terminating if the stream was
cancelled in some code paths.
This function is what is supposed to set the EOF flag in the first
place, so just add the missing code.
Benefits demux_mkv.c, or demux_lavf.c during probing. In particular
demux_lavf.c can sometimes get "stuck" when reading from a slow/blocking
source, and if probing needs more than a few iterations.
Since this is a read of an atomic variable with relaxed semantics, this
should have no impact on reading speed at all, not even theoretically.
This was excessively useless, and I want my time back that was needed to
explain users why they don't want to use it.
It captured the byte stream only, and even for types of streams it was
designed for (like transport streams), it was rather questionable.
As part of the removal, un-inline demux_run_on_thread() (which has only
1 call-site now), and sort of reimplement --stream-dump to write the
data directly instead of using the removed capture code.
(--stream-dump is also very useless, and I struggled coming up with an
explanation for it in the manpage.)
--list-protocol was printing a *:// entry, which looked strange at best.
The "*" protocol was used to always match everything, so stream_cb.c
could hook in custom protocols with a prefix chosen by the API user.
Change it instead so that an empty protocol list means "match all",
which also gets rid of the special-cased "*" entry.
This has all been made unnecessary recently. The change not to copy the
global option struct in particular can be made because now nothing
accesses the global options anymore in the demux and stream layers.
Some code that was accidentally added/changed in commit 5e30e7a0 is also
removed, because it was simply committed accidentally, and was never
used.
wm4
Niklas Haas
Ricardo Constantino