This fixes a spurious "single" mode bug which occurs when using "play"
or "seek" to start playback on the song that is currently paused: in
that case, the main thread never queues the next song, and at the end
of the song, the player thread exits Run(), stopping playback, and
after that, the main thread starts the next song without considering
"single" mode.
By calling OnPlayerSync(), we ensure that the main thread gets a
chance to queue the next song before the player thread exits the Run()
loop.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/850
The log levels have always been very confusing (and badly named), but
this was most confusing: if there's a log level called "default", why
is it not the default?
Closes https://github.com/MusicPlayerDaemon/MPD/issues/926
Oh the horror! This plugin cannot possibly ever have worked. It was
broken from the start, when it was added in commit 37796699cf nearly
twelve (!) years ago.
The plugin would always read at sector boundaries, so it could only
ever work at multiples of 2 kB.
This fixes the Windows build. Linking failed because some packages
(e.g. libFLAC) default to enabling `_FORTIFY_SOURCE`, which is broken
in recent mingw versions
(https://github.com/msys2/MINGW-packages/issues/5803).
While libsndfile doesn't like partial reads in the middle of a file
(see commit 95ac6071b9), it allows partial reads at the end of a file.
It doesn't pay attention to the file size when issuing a read.
Commit ecb67a1ed1 (MPD 0.18.12) was a regression: previously,
partial reads at the end of a file were possible, but switching to
decoder_read_full() made this an error condition. This way, a portion
at the end of each file was lost, leading to corruption with gapless
playback (https://github.com/MusicPlayerDaemon/MPD/issues/936).
This fix switches to the newly introduced function
decoder_read_much(), which does the same as the code before commit
ecb67a1ed1.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/936
Our AudioObjectGetPropertyDataT() wrapper throws exception on error,
and calling it from OSXOutput::Disable() can cause MPD crash due to
std::terminate().
Closes https://github.com/MusicPlayerDaemon/MPD/issues/932
Mounting one storage URI twice on different mount points can lead to
conflicts with the database cache file, and it doesn't make a lot of
sense.
But most importantly, our udisks storage plugin will unmount the disk
from the kernel VFS, and if two exist, they will compete with each
others. We could (and should) fix this in the udisks storage plugin,
but for now, this workaround is good enough (and useful).
When mounting something over a directory that is already a mount
point, CompositeStorage::Mount() silently overwrites the previously
mounted storage, disposing it. After that, SimpleDatabase::Mount()
will fail and handle_mount() will roll back the
CompositeStorage::Mount() command, effectively unmounting what was
there before (and also leaking memory).
Closes https://github.com/MusicPlayerDaemon/MPD/issues/918
Bug #915 is about an I/O exception thrown where none was allowed,
leading to crash via std::terminate(). However, instead of catching
and logging the error inside the decoder plugin, it should be able to
propagate the I/O error to the MPD core, so MPD can avoid trying other
decoder plugins.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/915
This will keep track of AudioOutputUnitStart() and
AudioOutputUnitStop(). This will provide some separation between "not
(yet) (re)started" and "paused".
The formula in osx_output_score_sample_rate() to detect multiples of
the source sample rate was broken: when given a 44.1 kHz input file,
it preferred 16 kHz over 48 kHz, because its `frac_portion(16)=0.75`
is smaller than `frac_portion(48)=0.91`.
That formula, introduced by commit 40a1ebee29, looks completely
wrong. It doesn't do what the code comment pretends it does.
Instead of using that `frac_portion` to calculate a score, this patch
adds to the score only if `frac_portion` is nearly `0` or `1`. This
means that the factor is nearly integer.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/904
A bug report (https://github.com/MusicPlayerDaemon/MPD/issues/912)
suggests that on Linux, reading on `cifs` files may rarely return 0 (=
end of file) before the end of the file has really been reached. But
that's just a theory which I need to validate, so this runtime check
shall catch this condition before the assertion in
DecoderBridge::Read() crashes MPD. Let's see.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/912
An assertion failure in UpdateQueuedSong() could trigger because the
`prev` parameter is always `nullptr`, but `queued` may be set. And in
fact, calling UpdateQueuedSong() is only necessary when the queued
song was edited, to re-queue it with the new range.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/901
When the client wants to seek, but the decoder has already finished
decoding the current song, the player restarts the decoder with an
initial seek at the new position. When this initial seek fails, MPD
pretends nothing has happened and plays this song from the start.
With this new flag, a restarted decoder marks the initial seek as
"essential" and fails the decoder if that seek fails.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/895
This branch isn't yet ready for level 3 (`-Wpedantic`) due to several
C++ violations (e.g. variable length arrays). These are already
cleaned up in the master branch (0.22).
The WildMidi project added the pkg-config file in version 0.3.3, but
unfortunately, Debian still doesn't ship it 4 years later:
https://bugs.debian.org/916631
However, for cross-compiling, the pkg-config file is very helpful.
The command is used to configure the client's connection, and this
shouldn't require any permissions. The client should be able to do
that before sending a password.
libnfs is compiled with `-D_FILE_OFFSET_BITS=64`, but Meson decides
not to enable this mode. We could force this mode, but then again,
these days, nobody should be using 32-bit Windows ... so this is a
kludge only for debugging with 32-bit WINE.
This fixes a freeze bug in the NFS input/storage plugins: when libnfs
auto-reconnets after a failure, it installs the new socket on the same
file descriptor number. MPD's attempt to unregister the old socket by
calling SocketMonitor::Steal() from NfsConnection::ScheduleSocket()
fails because the new/old socket number is not registered in epoll, so
epoll_ctl() returns ENOENT. The problem is that it left
`scheduled_flags`, and so subsequent Schedule() calls will use
`EPOLL_CTL_MOD`, which will fail again and again. Instead, we need to
use `EPOLL_CTL_ADD` to register the new socket.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/806
Closes https://github.com/MusicPlayerDaemon/MPD/issues/756
LINGUISTIC_IGNORECASE is unimplemented on Wine, but since we don't
have any locale support (yet), and we're using LOCALE_NAME_INVARIANT,
NORM_IGNORECASE should essentially be the same, so why bother.
Unescape the base path and the path coming from the server (href) to fix the
comparison when the server uses different escaped characters.
The outputted name need to be unescaped. Doing that before or after the
HrefToEscapedName() call should not change the current behavior.
If the file name is "Hello & bye", 3 CharacterData events will be sent with the
State::HREF state:
- "Hello%20"
- "&"
- "%20bye"
Reproduced with files hosted on an apache2 DAV server: 2.4.38-3+deb10u3.
The _GLIBCXX_USE_C99_MATH macro is defined in glibcxx by c++config.h, which
gets included by every header. Which means a header needs to be present.
(cherry picked from commit 79e9aff338)
This method gets called a lot during MPD startup, via FindChild() and
directory_load_subdir(), so this is worth optimizing at the expense of
code readability.
This speeds up MPD startup by 10%.
This reverts commit eb192137d6.
This is no longer necessary because we require FFmpeg 3.1 or newer
since MPD 0.21.2.
This fixes a deprecation warning because the implicit AVPacket copy
constructor copies the deprecated attribute `convergence_duration`.
This seems to be required on recent Android versions (tested with Android 10).
This is also required for android TV services (cf. next commit).
This is done using Java reflection so that the project doesn't depend on
android compat libs.
This is the case with uClibc-ng currently.
Signed-off-by: Rosen Penev <rosenp@gmail.com>
(cherry picked from commit 769cd0ee9f0cf8ceb026aa751b5d4a390bb5dbdc)
(changed define to match master)
Documentation says the limit is 5, but it was really 10 (at least
since 2004). But since MPD wants to promote using many small clients
idling around, and these clients consume only very few resources, it
seems reasonable to raise this limit's default value.
Aparently, libcdio sometimes returns empty filenames, causing MPD
crashes. This shouldn't really happen, and I consider this a libcdio
bug - but if it happens, people blame MPD, so let's add a check.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/776
Fixes
../src/time/ISO8601.cxx:67:24: error: use of undeclared identifier 'strtoul'
unsigned long value = strtoul(s, &endptr, 10);
^
../src/time/ISO8601.cxx:77:14: error: use of undeclared identifier 'strtoul'
minutes = strtoul(s, &endptr, 10);
^
on NetBSD with clang 9.0.0.
Using libgme 0.6.2 on macOS, it appears that gme_info_t strings can be
empty, which creates weird track titles: (001/050)
This adds an additional check for an empty string.
"The issue is that ParseCommandArgSignedSongTime parses with
SongTime::FromS, not SignedSongTime::FromS, before casting back to a
SignedSongTime for the return. With x86 overflow rules this doesn't
matter, but on ARM the first cast turns negative values to zero."
Closes https://github.com/MusicPlayerDaemon/MPD/issues/757
When calling OggSeekFindEOS() from inside a OggVisitor callback, then
the #InputStream may be in the middle of an Ogg packet, and the newly
initialized #ogg_sync_state will not be able to load it without the
help of ogg_sync_pageseek(). By passing "synced=false" to
OggSeekFindEOS(), we force the use of ogg_sync_pageseek() even when
not actually seeking.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/719
It appears that [[fallthrough]] is valid in C++ but not in C. And
in some Clang versions (e.g. Clang 11 on macOS), Clang is pedantic
about this and considers it an error to use [[fallthrough]] in a
.c file such as src/util/format.c.
This changes makes gcc_fallthrough a no-op under Clang in C files.
This reverts commit 4475b8ca04. Further
testing revealed that the threaded resolver still uses a timeout of
0ms. This revert however lowers the bound to a minimum of 1ms instead
of 10ms.
This prepares the migration away from strptime() for Windows
portability.
But the real reason I'm doing this is that strptime() on Apple is
buggy: strptime("14", "%H%M%S") (without separating colons) succeeds
even though only the hour has been parsed. This fixes recent Travis
failures in the ParseISO8601() unit test.
Older clang versions don't support the GCC __attribute__ syntax. For
those, don't use anything at all, and new clang versions shall use the
standard syntax.
Expand $PATH at evaluation and not at assignment, which fixes the
problem that /usr/lib/ccache was added to $PATH between the
MATRIX_EVAL assignment and its evaluation.
This can cause request completion in the I/O thread before this
constructor returns, leaving the object in an abstract state, causing
a crash due to pure virtual method call. We should not start the
request until this object is fully constructed.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/665
The ALSA "null" driver opens /dev/null and returns the file handle
from snd_pcm_poll_descriptors(), but /dev/null cannot be used with
epoll, the epoll_ctl() system call returns -EPERM. This means that
the ALSA output hangs, eventually freezing the whole MPD process.
This commit adds a workaround to the MultiSocketMonitor class which is
used by the ALSA output plugin.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/695
Most importantly, this commit translates ZZIP_ENOENT to
std::system_error(ENOENT) so IsFileNotFound() returns true and
find_stream_art() can suppress the log line.
Commit 13208bf5a7 added range support to
the `move` command, but applied the wrong offset to the `to` variable.
When the source range is before the current song, and the song thus
gets decremented by the range size, then the final destination offset
must also be decremented by the range size.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/663
Without requesting the property, "good" WebDAV servers would not send
it, and so MPD could never recognize a directory, failing the database
update.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/660
Apparently, libmpcdec sets gain/peak variables to zero if they are not
present. This clashes with our formula and results in bogus values
which cause noise during playback.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/640
This header had been available for a long time on Linux, but was
removed in glibc 2.30. This commit moves the `#include` line inside
the `#ifdef __sun` block and adds a fake declaration of `I_FLUSH` for
the Linux build.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/630
The new Response instance in the `catch` block didn't have the
`command` attribute set, so the error response didn't indicate which
command had failed, which however is required in the MPD protocol.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/628
High Voltage SID Collection (HVSC) metadata fields are encoded in
windows-1252, as described in DOCUMENTS/SID_file_format.txt:
https://www.hvsc.c64.org/download/C64Music/DOCUMENTS/SID_file_format.txt
If utf-8 transcoding fails, or the ICU library is unavailable, fall
back to plain ASCII and replace other characters with '?'.
Version 10.2+0.93+1 was released five years ago in 2014 and is the
first version to feature cdio_cddap_free_messages(). There is no way
to check the libcdio-paranoia version at compile time, so let's just
remove support for older versions instead of attempting to fix the
cdio_cddap_free_messages() check at build time.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/613
This reverts commit f7ed7446ae. It was
a bad idea, because MAD_F_MIN and MAD_F_MAX do not represent the
clamping limits, but the theoretical minimum and maximum values of the
mad_fixed_t data type.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/617
The check IsSeekableCurrentSong() was added by commit
44b200240f in version 0.20.19, but it
caused a regression: by doing the branch only if the current song is
seekable, the player would restart the current song if it was not
seekable, and later the initial seek would fail; but we already know
it's not seekable, and so we should fail early.
libmad has a hard-coded maximum PCM buffer size; if we make our
output_buffer just as large, we can avoid the loop, because any
possible size will fit.
libmad requires padding the input buffer with "MAD_BUFFER_GUARD" zero
bytes at the end of the file, or else it is unable to decode the last
frame.
This fixes yet another bug which prevented this plugin from decoding
the last frame, see
https://github.com/MusicPlayerDaemon/MPD/issues/601
The Xing/LAME frame indicates how many frames there are, but that
excludes the initial Xing/LAME frame. Therefore, it should not be
counted.
This fixes an off-by-one bug which caused the last frame to be
skipped, fixing one part of
https://github.com/MusicPlayerDaemon/MPD/issues/601
MPD used to do that when this code lived in the player thread, but it
was removed by commit 98a7c62d7a4f716d90af6d78e18d1a3b10bc54b3; and
the replacement code in the ALSA output plugin didn't have it.
Without this timer, DispatchSockets() may disable the
MultiSocketMonitor and if Play() doesn't get called soon, it never
gets a chance to generate silence. However if Play() gets called,
generating silence isn't necessary anymore...
Resulting from this misdesign (added by commit ccafe3f3cf in 0.21.3),
the silence generator didn't work reliably.
In DispatchSockets(), when there was not enough data, but enough for
current playback, the method would disable the "active" flag so the
next Play() call would re-enable the MultiSocketMonitor.
This was an abuse of the flag which could result in a crash
in Cancel(), because that method asserts that the period_buffer is
empty, which it may be not.
The solution is to add anther flag called "waiting" which shares some
behavior with the old flag.
Apparently, if snd_pcm_drain() returns EAGAIN, it does not actually
want to be called again; the next call will snd_pcm_drain() will also
return EAGAIN, forever, even though the PCM state has meanwhile
switched to SND_PCM_STATE_SETUP. This causes a busy loop; to fix
this, we should always check snd_pcm_state() to see if draining is
really required.
Commit 1eae9339f2 added support for
multiple "groups" in the "list" command, and this change allows
clients to detect that this behavior, which had been documented for
several years, is now implemented properly.
Workaround for a regression caused by commit
a06bf388d9, revealing a problem with
discarding odd numer of frames in the DSD_U32 and DoP converters,
causing distortions with DSD_U32 and DoP on 32 bit CPUs.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/469
This can happen if the DoP converter doesn't get enough source samples
for one destination quad. This isn't a critical bug, because the OSS
plugin doesn't support DoP yet, but it's good to be prepared.
Instead of passing tag and group, pass an array of tags. To support a
nested return value, return a nested std::map of std::maps. Each key
specifies the tag value, and each value may be another nesting level.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/408
Since we now don't duplicate all items, we can easily remove the 64kB
limit from OpusReader::ReadString() and instead silently ignore and
skip all strings which are longer than 4 kB.
This fixes a tag duplication bug with Opus file containing a very long
`METADATA_BLOCK_PICTURE` tag, which occurred because the Opus plugin
returned false after parsing all tags, and then the MPD core fell back
to FFmpeg which scanned the tags again.
Return `404 not found` for some common well-known paths, as clients requesting them usually do that automatically and don't expect endless audio stram.
Closes#572
This reverts commit ff3e2c0514. The
check was necessary, after all, because this is what checked whether
the decoder had finished the current or the next song.
> The "queued" flag can only possibly be set if the decoder is still
> decoding the current song or if the decoder is stopped.
That was wrong because ProcessCommand() sets `queued=true` and also
starts the decoder (if it was idle).
> This is also what the following assert() checks.
That was also wrong, because the assert() has two conditions.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/566
If the decoder finishes decoding the current song between the two
IsIdle() checks, MPD stops playback instead of starting the decoder
for the next song.
This is usually not visible problem, because the main thread restarts
it via playlist::ResumePlayback(), but that way it, ignores "single"
mode.
As a workaround, this commit adds another "queued" check which
re-enters the player loop and checks again whether to start the
decoder.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/556
The "queued" flag can only possibly be set if the decoder is still
decoding the current song or if the decoder is stopped. This is also
what the following assert() checks. This check was not necessary.
ALSA is just one out of many output plugins, and detailed plugin
documentation should only live in the user manual, without having
duplicates in the (brief) manpage.
Also move "mixer_type" to the "optional audio output parameters"
section; it is a generic option, not specific to ALSA.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/552
Commit b3a458338a added a LocateUri()
call to several playlist commands, which applied InputPlugin URI
scheme verification to playlist URIs. This broke the SoundCloud
playlist plugin which uses "soundcloud://" URIs for which no input
plugin exists.
This commit allows the caller to specify the kind of plugin which
shall be used to verify the URI. Right now, only "input" is
implemented; "storage" uses the "input" verification for now; and
"playlist" has no verification at all (for now).
Closes https://github.com/MusicPlayerDaemon/MPD/issues/528
Expect OnSocketReady() to cancel events. If it returns false, the
SocketMonitor may be destructed already. This fixes a use-after-free
bug in the "httpd" output plugin.
This missing piece probably never really hurt, because
HttpdClient::OnSocketClosed() would be called right after a socket
error, but it's better to be explicit about closing on error.
Fixes:
src/net/IPv4Address.hxx: In member function 'constexpr IPv4Address::operator SocketAddress() const':
src/net/IPv4Address.hxx:171:24: error: a reinterpret_cast is not a constant expression
171 | return SocketAddress((const struct sockaddr *)&address,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/net/IPv6Address.hxx: In member function 'constexpr IPv6Address::operator SocketAddress() const':
src/net/IPv6Address.hxx:138:24: error: a reinterpret_cast is not a constant expression
138 | return SocketAddress((const struct sockaddr *)&address,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Closes https://github.com/MusicPlayerDaemon/MPD/issues/522
Fixes#184.
Semaphores are kernel-managed objects, calling delete_sem() twice is not more
dangerous than calling close() twice on an fd though, it would just return
an error.
The custom_command was run in src/haiku/ and created a file with only resources inside.
Since xres edits the file in-place and meson doesn't like it, we have to run a shell script for now.
Maybe later I'll add proper support in meson.
MPD sometimes uses version numbers like "0.22~git" to mark unreleased
versions. That makes the win32 resource compiler unhappy, because it
expects numbers only.
Since version 0.49.0 the Meson build system has native support for
finding and using the gcrypt library using the `dependency()` function.
`dependency()` has the advantage over `find_library()` as it queries the
required linker flags for proper linking with external libraries, e.g.
libgpg-error.
As the latest released version 1.8.4 of libgcrypt does not
provide a .pc file, using `libgcrypt-config` is the only way to query
the required linker flags.
Unfortunately, there is an issue when cross compiling mpd and the user does not
define `libgcrypt-config` in the cross file. If the user sets the qobuz feature
to `auto` and the target does not have libgcrypt installed, the Meson
build system will falsly assume libgcrypt is available for the target as
it uses the native `libgcrypt-config` on the host and pretend is has
found the library.
Therefore, we still rely on `find_library()` to workaround this buggy
behavior. This way, if qobuz feature detection is set to `auto`, the
feature is disabled in case there is no target libgcrypt available.
Fixes building mpd statically with the qobuz feature enabled. Otherwise
the build fails with undefined references because of the missing libgpg-error
dependency:
```
/sysroot/usr/lib/libgcrypt.a(libgcrypt_la-visibility.o): In function `gcry_strerror':
visibility.c:(.text+0x14): undefined reference to `gpg_strerror'
```
Meson 0.49.0 adds native support for `libgcrypt-config` which is
necessary for detecting libgcrypt dependencies, as the latest
version 1.8.4 of libgcrypt does not provide a .pc file.
And disable libvorbis detection if Tremor was explicitly enabled.
This fixes a crash bug caused by libvorbis/Tremor ABI conflict caused
by commit 4f7d52dbf2
Previously, MPD would skip the current song after attempting to seek
to its beginnig, because that was a seek to offset 0. At offset 0,
MPD will see the BOS packet again, which results in throwing
StopDecoder in MPDOpusDecoder::OnOggEnd().
Closes https://github.com/MusicPlayerDaemon/MPD/issues/470
Unlike pa_channel_map_init_auto(), pa_channel_map_init_extend() does
not fail if there is no valid mapping for the given channel count, but
instead maps additional "AUX" channels.
Closes https://github.com/MusicPlayerDaemon/MPD/issues/493
implement for the "load" command the same logic used for the "add"
command: local clients can load playlist specified as absolute paths.
For relative paths the old logic is preserved: first look for a stored
playlist, then look in the music directory.
Even if the LocalStorage is available, return the "udisks://" URI when
the MapUTF8() parameter is an empty string. This fixes the mount URI
in the state file.
This fixes use-after-free bug in SimpleDatabase::Close(), accessing
the `root` object which was already freed by the `catch` block in
Open().
By having the Database on the stack first, we can avoid calling
Close() on the failed-to-open Database from Instance's destructor.
Closes#482
This replaces the old `dead` flag which was unreliable; it was `false`
if the EventThread was not yet started, which could cause deadlocks in
BlockingCall().
Currently it falls back to system default device (either internal speaker or headphone) when device not found.
I believe it is a better to fail in this case, to make it better aligned with platforms (such as alsa).
GCC 9's libstdc++ is unable to use forward-declared types as
std::vector item because the compiler wants to resolve `noexcept()` on
the item destructor.
libcdio_paranoia was split from libcdio in version 90, and at the same
time, the header was moved from cdio/paranoia.h to
cdio/paranoia/paranoia.h. We can easily detect this version at
compile time which is faster than configure time.
Re-add build support for the fixed-point Vorbis (Tremor) decoder, which
was dropped when switching from Autotools to Meson.
Note, that it is not possible to build both, the Vorbis and the Tremor
decoder.
Closes: #405
libwrap is an obscure artefact from a past long ago, when source IP
address meant something.
And its API is "interesting"; it requires the application to expose
two global variables `allow_severity` and `deny_severity`. This led
to bug #437. I don't want to declare those variables; instead, I'd
like to remove libwrap support.
Closes#437
This is similar to b177bffa6a, in that it fixes the Windows issue of connecting to the open socket. Also, the listen_socket is set to AcceptNonBlock after the connection anyways.
This function is sparsely documented and a look at the bluez-alsa
source code shows that implementations make undocumented assumptions
on the `struct pollfd` array parameter which can lead to strange
effects.
Since we switched from autotools to Meson in commit
94592c1406, we don't need to include
`config.h` early to properly enable large file support. Meson passes
the required macros on the compiler command line instead of defining
them in `config.h`.
This means we can include `config.h` at any time, whenever we want to
check its macros, and there are no ordering constraints.
This version should have been incremented in 0.21.2 because this
version added new search operators. In 0.21.4, we'll have more
protocol bug fixes which may be important for clients to know.
Works around a problem where MPD goes into a busy loop because
snd_pcm_drain() always returns `-EAGAIN` without making any progress
(fixes#425).
This problem was triggered by snd_pcm_drain() after snd_pcm_cancel()
and snd_pcm_prepare(), but without submitting any data with
snd_pcm_writei().
I believe this is a kernel bug: in non-blocking mode, the kernel's
snd_pcm_drain() function returns early. In this mode, it only checks
whether snd_pcm_drain_done() has been called already, but
snd_pcm_drain_done() is never called if no data was submitted.
In blocking mode, the following `for` loop detects this condition, so
snd_pcm_drain_done() is not necessary, but without this extra check,
we get `-EAGAIN` forever.
test/run_storage.cxx depends on EventThread/EventLoop from libevent.a.
Depend on it explicitly. This addresses build failure with
-Dtest=true -Dcurl=disabled -Ddbus=disabled
This fixes a problem which caused a failure with snd_pcm_writei()
because snd_pcm_drain() had already been called in the previous
iteration. This commit makes sure that snd_pcm_drain() is only called
after the final snd_pcm_writei() call.
This fixes discarded samples at the end of playback.
MPD's default is 100ms, which is too long for the real-time I/O
thread. The OutputThread has 100us, but the real-time I/O thread
might have tighter deadlines.
This change has currently no effect (I believe), because nobody uses
timers on the RTIO thread.
If our `ring_buffer` is smaller than the ALSA-PCM buffer (if the
latter has more than the 4 periods we allocate), it can happen that
the start threshold is crossed and ALSA switches to
`SND_PCM_STATE_RUNNING`, but the `ring_buffer` is empty. In this
case, MPDD will generate silence, even though the ALSA-PCM buffer has
enough data. This causes stuttering (#420).
This commit amends an older workaround for a similar problem (commit
e08598e7e2) by adding a snd_pcm_avail()
check, and only generate silence if there is less than one period of
data in the ALSA-PCM buffer.
Fixes#420
The method Cancel() assumes that the `period_buffer` must be empty
when `active==false`, but that is not the case when Play() fails.
Of course the assertion in Cancel() is not 100% correct, but I decided
to rather fix this in LockCaughtError() because the `period_buffer`
should only be accessed from within the RTIO thread, and this is the
only code path where `active` can be set to `false` with a non-empty
`period_buffer`.
Fixes#423
This check was added 9 years ago in commit
4dc25d3908 to work around a dmix bug
which I assume has been fixed long ago.
Removing this fixes another corner case: if draining is requested
before the start threshold is reached, the PCM is still in
SND_PCM_STATE_PREPARED but not yet SND_PCM_STATE_RUNNING, which means
the submitted data will never be played. This corner case is
realistic when playing songs shorter than the ALSA buffer (if the
buffer is very large).
This fixes a corner case which has probably never occurred and
probably never will: if Cancel() is called, and then Play() followed
by Drain(), the plugin should really play that data. However
currently, this never happens, because snd_pcm_prepare() is never
called.
I added this sentence in commit
5271e81ebe, but this was merely
documented the legacy status quo, which has always been undocumented
for old-style filters.
But for new filters, using "==" for sub strings was a surprising
"feature", which I removed in commit
ac0852b4e3.
When `metadata_sent` is `false`, the plugin assumes there is metadata
which must be sent, even if no metadata page was passed to the plugin.
Initializing it to `true` avoids dereferencing this `nullptr`.
Fixes#412
If the output is already open, the `current_chunk` pointer may be
bogus and out of sync with `SharedPipeConsumer::chunk`, leading to an
assertion failure in `SharedPipeConsumer::Consume()`.
Fixes#411
Meson always enables large file support on the compiler command line,
thus config.h doesn't need to be included anymore. We'll remove the
whole `check.h` header soon.
Closes#409
`AVCodecParameters` contains values from the codec detected by
avformat_find_stream_info(), but after avcodec_open2(), a different
codec might be selected with a different `AVSampleFormat`. This leads
to misinterpretation of data returned from FFmpeg, leading to random
noise or silence.
This was observed with FFmpeg 4.0.2 and a TS container file containing
MP2. A mp3-float codec was detected returning `AV_SAMPLE_FMT_FLTP`,
but finally the `mpegaudiodec_fixed.c` was used, returning
`AV_SAMPLE_FMT_S16`.
By using the audio format from `AVCodecContext`, we ensure that MPD
and FFmpeg always agree on the actual audio format in the buffer.
This removes the FFmpeg bug workaround from commit e1b032cbad which I
assume is obsolete after 7 years.
Fixes#380
ensure that valid mixer values are set also when the ALSA driver
does not report a valid dB range ('set_raw' fallback)
correct a bug in which volume is assumed to lie in [0..100]
instead of [0..1]
The protocol documentation says that the difference between `find` and
`search` is that `search` is case insensitive, but that's only half
the truth: `search` also searches for sub strings instead of matching
the whole string. This part is undocumented and unfortunate, but at
this point, we can't change it.
However leaking this surprising behavior to the new filter expressions
was a bad idea; the "==" operator should never match substrings. For
people who need that, we should add a new operator.
Meson 0.47.1 suffers from a bug which breaks linking the MPD
executable because the `-lpthread` flag is not propagated from our
`thread.a`.
See https://github.com/mesonbuild/meson/pull/3895Closes#403
Thanks to C++14, we can declare and fill variables inside `constexpr`
functions. This means me can stop make assumptions on the `struct`
layouts without losing `constexpr`.
Closes#393
This is a guide for those who wish to hack on the MPD source code. MPD is an open project, and we are always happy about contributions. So far, more than 150 people have contributed patches. This document is work in progress. Most of it may be incomplete yet. Please help!
Code Style
==========
**********
* indent with tabs (width 8)
* don't write CPP when you can write C++: use inline functions and constexpr instead of macros
@@ -18,7 +18,6 @@ Code Style
* classes and functions names use CamelCase; variables are lower-case with words separated by underscore
@@ -59,7 +58,7 @@ possible, to be sure that you don't break any disabled code.
Don't mix several changes in one single patch. Create a separate patch for every change. Tools like :program:`stgit` help you with that. This way, we can review your patches more easily, and we can pick the patches we like most first.
Basic stgit usage
-----------------
=================
stgit allows you to create a set of patches and refine all of them: you can go back to any patch at any time, and re-edit it (both the code and the commit message). You can reorder patches and insert new patches at any position. It encourages creating separate patches for tiny changes.
@@ -94,35 +93,7 @@ When the whole patch series is finished, convert stgit patches to git commits:
stg commit
Submitting Patches
==================
******************
Send your patches to the mailing list:
Email: `mpd-devel <mpd-devel@musicpd.org>`_
:program:`git pull` requests are preferred.
Development Tools
=================
Clang Static Analyzer
---------------------
The `static analyzer <http://clang-analyzer.llvm.org/>`_ is a tool that helps find bugs. To run it on the MPD code base, install LLVM and clang. configure MPD to use clang:
The default plugin. Stores a copy of the database in memory. A file is used for permanent storage.
@@ -25,7 +25,7 @@ The default plugin. Stores a copy of the database in memory. A file is used for
- Compress the database file using gzip? Enabled by default (if built with zlib).
proxy
~~~~~
-----
Provides access to the database of another :program:`MPD` instance using libmpdclient. This is useful when you run mount the music directory via NFS/SMB, and the file server already runs a :program:`MPD` instance. Only the file server needs to update the database.
@@ -42,77 +42,94 @@ Provides access to the database of another :program:`MPD` instance using libmpdc
* - **password**
- The password used to log in to the "master" :program:`MPD` instance.
* - **keepalive yes|no**
- Send TCP keepalive packets to the "master" :program:`MPD` instance? This option can help avoid certain firewalls dropping inactive connections, at the expensive of a very small amount of additional network traffic. Disabled by default.
- Send TCP keepalive packets to the "master" :program:`MPD` instance? This option can help avoid certain firewalls dropping inactive connections, at the expense of a very small amount of additional network traffic. Disabled by default.
upnp
~~~~
----
Provides access to UPnP media servers.
Storage plugins
---------------
===============
local
~~~~~
-----
The default plugin which gives :program:`MPD` access to local files. It is used when music_directory refers to a local directory.
curl
~~~~
----
A WebDAV client using libcurl. It is used when :code:`music_directory` contains a http:// or https:// URI, for example :samp:`https://the.server/dav/`.
A WebDAV client using libcurl. It is used when :code:`music_directory`
contains a ``http://`` or ``https://`` URI, for example
:samp:`https://the.server/dav/`.
smbclient
~~~~~~~~~
---------
Load music files from a SMB/CIFS server. It is used when:code:`music_directory` contains a smb:// URI, for example :samp:`smb://myfileserver/Music`.
Load music files from a SMB/CIFS server. It is used when
:code:`music_directory` contains a ``smb://`` URI, for example
:samp:`smb://myfileserver/Music`.
nfs
~~~
---
Load music files from a NFS server. It is used when:code:`music_directory` contains a nfs:// URI according to RFC2224, for example :samp:`nfs://servername/path`.
Load music files from a NFS server. It is used when
:code:`music_directory` contains a ``nfs://`` URI according to
RFC2224, for example :samp:`nfs://servername/path`.
This plugin uses libnfs, which supports only NFS version 3. Since :program:`MPD` is not allowed to bind to "privileged ports", the NFS server needs to enable the "insecure" setting; example :file:`/etc/exports`:
..code-block::none
/srv/mp3 192.168.1.55(ro,insecure)
Don't fear: "insecure" does not mean that your NFS server is insecure. A few decades ago, people thought the concept of "privileged ports" would make network services "secure", which was a fallacy. The absence of this obsolete "security" measure means little.
See :ref:`input_nfs` for more information.
udisks
~~~~~~
------
Mount file systems (e.g. USB sticks or other removable media) using
the udisks2 daemon via D-Bus. To obtain a valid udisks2 URI, consult
:ref:`the according neighbor plugin <neighbor_plugin>`.
It might be necessary to grant :program:`MPD` privileges to control
:program:`udisks2` through :program:`policykit`. To do this, create a
file called :file:`/usr/share/polkit-1/rules.d/mpd-udisks.rules` with
the following text::
polkit.addRule(function(action, subject) {
if ((action.id == "org.freedesktop.udisks2.filesystem-mount" ||
If you run MPD as a different user, change ``mpd`` to the name of your
MPD user.
.._neighbor_plugin:
Neighbor plugins
----------------
================
smbclient
~~~~~~~~~
---------
Provides a list of SMB/CIFS servers on the local network.
udisks
~~~~~~
------
Queries the udisks2 daemon via D-Bus and obtain a list of file systems (e.g. USB sticks or other removable media).
upnp
~~~~
----
Provides a list of UPnP servers on the local network.
.._input_plugins:
Input plugins
-------------
=============
alsa
~~~~
----
Allows :program:`MPD` on Linux to play audio directly from a soundcard using the scheme alsa://. Audio is formatted as 44.1 kHz 16-bit stereo (CD format). Examples:
@@ -125,7 +142,7 @@ Allows :program:`MPD` on Linux to play audio directly from a soundcard using the
mpc add alsa://hw:1,0 plays audio from device hw:1,0 cdio_paranoia
cdio_paranoia
~~~~~~~~~~~~~
-------------
Plays audio CDs using libcdio. The URI has the form: "cdda://[DEVICE][/TRACK]". The simplest form cdda:// plays the whole disc in the default drive.
@@ -141,11 +158,14 @@ Plays audio CDs using libcdio. The URI has the form: "cdda://[DEVICE][/TRACK]".
- Request CDParanoia cap the extraction speed to Nx normal CD audio rotation speed, keeping the drive quiet.
curl
~~~~
----
Opens remote files or streams over HTTP using libcurl.
Note that unless overridden by the below settings (e.g. by setting them to a blank value), general curl configuration from environment variables such as http_proxy or specified in :file:`~/.curlrc` will be in effect.
Note that unless overridden by the below settings (e.g. by setting
them to a blank value), general curl configuration from environment
variables such as ``http_proxy`` or specified in :file:`~/.curlrc`
will be in effect.
..list-table::
:widths:20 80
@@ -163,44 +183,67 @@ Note that unless overridden by the below settings (e.g. by setting them to a bla
- Verify the certificate's name against host? `More information <http://curl.haxx.se/libcurl/c/CURLOPT_SSL_VERIFYHOST.html>`_.
ffmpeg
~~~~~~
------
Access to various network protocols implemented by the FFmpeg library: gopher://, rtp://, rtsp://, rtmp://, rtmpt://, rtmps://
Access to various network protocols implemented by the FFmpeg library:
Plays streams with the MMS protocol using `libmms <https://launchpad.net/libmms>`_.
nfs
~~~
.._input_nfs:
Allows :program:`MPD` to access files on NFSv3 servers without actually mounting them (i.e. in userspace, without help from the kernel's VFS layer). All URIs with the nfs:// scheme are used according to RFC2224. Example:
nfs
---
Allows :program:`MPD` to access files on NFS servers without actually
mounting them (i.e. with :program:`libnfs` in userspace, without help
from the kernel's VFS layer). All URIs with the ``nfs://`` scheme are
used according to RFC2224. Example:
..code-block::none
mpc add nfs://servername/path/filename.ogg
Note that this usually requires enabling the "insecure" flag in the server's /etc/exports file, because :program:`MPD` cannot bind to so-called "privileged" ports. Don't fear: this will not make your file server insecure; the flag was named in a time long ago when privileged ports were thought to be meaningful for security. By today's standards, NFSv3 is not secure at all, and if you believe it is, you're already doomed.
This plugin uses :program:`libnfs`, which supports only NFS version 3.
Since :program:`MPD` is not allowed to bind to so-called "privileged
ports", the NFS server needs to enable the ``insecure`` setting;
example :file:`/etc/exports`:
..code-block::none
/srv/mp3 192.168.1.55(ro,insecure)
Don't fear: this will not make your file server insecure; the flag was
named a time long ago when privileged ports were thought to be
meaningful for security. By today's standards, NFSv3 is not secure at
all, and if you believe it is, you're already doomed.
smbclient
~~~~~~~~~
---------
Allows :program:`MPD` to access files on SMB/CIFS servers (e.g. Samba or Microsoft Windows). All URIs with the smb:// scheme are used. Example:
Allows :program:`MPD` to access files on SMB/CIFS servers (e.g. Samba
or Microsoft Windows). All URIs with the ``smb://`` scheme are
Play songs from the commercial streaming service Qobuz. It plays URLs in the form qobuz://track/ID, e.g.:
Play songs from the commercial streaming service Qobuz. It plays URLs
in the form ``qobuz://track/ID``, e.g.:
..code-block::none
@@ -224,9 +267,16 @@ Play songs from the commercial streaming service Qobuz. It plays URLs in the for
- The `Qobuz format identifier <https://github.com/Qobuz/api-documentation/blob/master/endpoints/track/getFileUrl.md#parameters>`_, i.e. a number which chooses the format and quality to be requested from Qobuz. The default is "5" (320 kbit/s MP3).
tidal
~~~~~
-----
Play songs from the commercial streaming service `Tidal<http://tidal.com/>`_. It plays URLs in the form tidal://track/ID, e.g.:
Play songs from the commercial streaming service `Tidal
<http://tidal.com/>`_. It plays URLs in the form ``tidal://track/ID``,
e.g.:
..warning::
This plugin is currently defunct because Tidal has changed the
protocol and decided not to share documentation.
..code-block::none
@@ -250,10 +300,10 @@ Play songs from the commercial streaming service `Tidal <http://tidal.com/>`_. I
.._decoder_plugins:
Decoder plugins
---------------
===============
adplug
~~~~~~
------
Decodes AdLib files using libadplug.
@@ -267,17 +317,17 @@ Decodes AdLib files using libadplug.
- The sample rate that shall be synthesized by the plugin. Defaults to 48000.
audiofile
~~~~~~~~~
---------
Decodes WAV and AIFF files using libaudiofile.
faad
~~~~
----
Decodes AAC files using libfaad.
ffmpeg
~~~~~~
------
Decodes various codecs using FFmpeg.
@@ -293,12 +343,12 @@ Decodes various codecs using FFmpeg.
- Sets the FFmpeg muxer option probesize, which specifies probing size in bytes, i.e. the size of the data to analyze to get stream information. The `FFmpeg formats documentation <https://ffmpeg.org/ffmpeg-formats.html>`_ has more information.
flac
~~~~
----
Decodes FLAC files using libFLAC.
dsdiff
~~~~~~
------
Decodes DFF files containing DSDIFF data (e.g. SACD rips).
- This specifies whether to support gapless playback of MP3s which have the necessary headers. Useful if your MP3s have headers with incorrect information. If you have such MP3s, it is highly recommended that you fix them using `vbrfix <http://www.willwap.co.uk/Programs/vbrfix.php>`_ instead of disabling gapless MP3 playback. The default is to support gapless MP3 playback.
mad
~~~
---
Decodes MP3 files using `libmad <http://www.underbit.com/products/mad/>`_.
mikmod
~~~~~~
------
Module player based on `MikMod <http://mikmod.sourceforge.net/>`_.
@@ -391,7 +441,7 @@ Module player based on `MikMod <http://mikmod.sourceforge.net/>`_.
- Sets the sample rate generated by libmikmod. Default is 44100.
modplug
~~~~~~~
-------
Module player based on MODPlug.
@@ -405,27 +455,27 @@ Module player based on MODPlug.
- Number of times to loop the module if it uses backward loops. Default is 0 which prevents looping. -1 loops forever.
mpcdec
~~~~~~
------
Decodes Musepack files using `libmpcdec <http://www.musepack.net/>`_.
mpg123
~~~~~~
------
Decodes MP3 files using `libmpg123 <http://www.mpg123.de/>`_.
opus
~~~~
----
Decodes Opus files using `libopus <http://www.opus-codec.org/>`_.
pcm
~~~
---
Read raw PCM samples. It understands the "audio/L16" MIME type with parameters "rate" and "channels" according to RFC 2586. It also understands the MPD-specific MIME type "audio/x-mpd-float".
sidplay
~~~~~~~
-------
C64 SID decoder based on `libsidplayfp <https://sourceforge.net/projects/sidplay-residfp/>`_ or `libsidplay2 <https://sourceforge.net/projects/sidplay2/>`_.
@@ -447,23 +497,23 @@ C64 SID decoder based on `libsidplayfp <https://sourceforge.net/projects/sidplay
- Only libsidplayfp. Absolute path to basic rom image file.
sndfile
~~~~~~~
-------
Decodes WAV and AIFF files using `libsndfile <http://www.mega-nerd.com/libsndfile/>`_.
vorbis
~~~~~~
------
Decodes Ogg-Vorbis files using `libvorbis <http://www.xiph.org/ogg/vorbis/>`_.
wavpack
~~~~~~~
-------
Decodes WavPack files using `libwavpack <http://www.wavpack.com/>`_.
wildmidi
~~~~~~~~
--------
MIDI decoder based on `libwildmidi <http://www.mindwerks.net/projects/wildmidi/>`_.
@@ -479,10 +529,11 @@ MIDI decoder based on `libwildmidi <http://www.mindwerks.net/projects/wildmidi/>
.._encoder_plugins:
Encoder plugins
---------------
===============
flac
~~~~
----
Encodes into `FLAC <https://xiph.org/flac/>`_ (lossless).
..list-table::
@@ -495,7 +546,7 @@ Encodes into `FLAC <https://xiph.org/flac/>`_ (lossless).
- Sets the libFLAC compression level. The levels range from 0 (fastest, least compression) to 8 (slowest, most compression).
lame
~~~~
----
Encodes into MP3 using the `LAME <http://lame.sourceforge.net/>`_ library.
@@ -511,12 +562,12 @@ Encodes into MP3 using the `LAME <http://lame.sourceforge.net/>`_ library.
- Sets the bit rate in kilobit per second. Cannot be used with quality.
null
~~~~
----
Does not encode anything, passes the input PCM data as-is.
shine
~~~~~
-----
Encodes into MP3 using the `Shine <https://github.com/savonet/shine>`_ library.
@@ -530,7 +581,7 @@ Encodes into MP3 using the `Shine <https://github.com/savonet/shine>`_ library.
- Sets the bit rate in kilobit per second.
twolame
~~~~~~~
-------
Encodes into MP2 using the `TwoLAME <http://www.twolame.org/>`_ library.
@@ -546,7 +597,7 @@ Encodes into MP2 using the `TwoLAME <http://www.twolame.org/>`_ library.
- Sets the bit rate in kilobit per second. Cannot be used with quality.
opus
~~~~
----
Encodes into `Ogg Opus <http://www.opus-codec.org/>`_.
@@ -568,7 +619,7 @@ Encodes into `Ogg Opus <http://www.opus-codec.org/>`_.
.._vorbis_plugin:
vorbis
~~~~~~
------
Encodes into `Ogg Vorbis <http://www.vorbis.com/>`_.
@@ -584,13 +635,13 @@ Encodes into `Ogg Vorbis <http://www.vorbis.com/>`_.
- Sets the bit rate in kilobit per second. Cannot be used with quality.
wave
~~~~
----
Encodes into WAV (lossless).
.._resampler_plugins:
Resampler plugins
-----------------
=================
The resampler can be configured in a block named resampler, for example:
@@ -613,12 +664,12 @@ The following table lists the resampler options valid for all plugins:
- The name of the plugin.
internal
~~~~~~~~
--------
A resampler built into :program:`MPD`. Its quality is very poor, but its CPU usage is low. This is the fallback if :program:`MPD` was compiled without an external resampler.
libsamplerate
~~~~~~~~~~~~~
-------------
A resampler using `libsamplerate <http://www.mega-nerd.com/SRC/>`_ a.k.a. Secret Rabbit Code (SRC).
@@ -651,7 +702,7 @@ The following converter types are provided by libsamplerate:
- Linear interpolator, very fast, poor quality.
soxr
~~~~
----
A resampler using `libsoxr <http://sourceforge.net/projects/soxr/>`_, the SoX Resampler library
@@ -674,13 +725,15 @@ Valid quality values for libsoxr:
* "low"
* "quick"
.._output_plugins:
Output plugins
--------------
==============
.._alsa_plugin:
alsa
~~~~
----
The `Advanced Linux Sound Architecture (ALSA) <http://www.alsa-project.org/>`_ plugin uses libasound. It is recommended if you are using Linux.
@@ -739,7 +792,7 @@ The following attributes can be configured at runtime using the outputset comman
ao
~~
--
The ao plugin uses the portable `libao <https://www.xiph.org/ao/>`_ library. Use only if there is no native plugin for your operating system.
..list-table::
@@ -756,7 +809,8 @@ The ao plugin uses the portable `libao <https://www.xiph.org/ao/>`_ library. Use
- This specifies how many bytes to write to the audio device at once. This parameter is to work around a bug in older versions of libao on sound cards with very small buffers. The default is 1024.
sndio
~~~~~
-----
The sndio plugin uses the `sndio <http://www.sndio.org/>`_ library. It should normally be used on OpenBSD.
..list-table::
@@ -771,7 +825,7 @@ The sndio plugin uses the `sndio <http://www.sndio.org/>`_ library. It should no
- Set the application buffer time in milliseconds.
fifo
~~~~
----
The fifo plugin writes raw PCM data to a FIFO (First In, First Out) file. The data can be read by another program.
@@ -784,8 +838,18 @@ The fifo plugin writes raw PCM data to a FIFO (First In, First Out) file. The da
* - **path P**
- This specifies the path of the FIFO to write to. Must be an absolute path. If the path does not exist, it will be created when MPD is started, and removed when MPD is stopped. The FIFO will be created with the same user and group as MPD is running as. Default permissions can be modified by using the builtin shell command umask. If a FIFO already exists at the specified path it will be reused, and will not be removed when MPD is stopped. You can use the "mkfifo" command to create this, and then you may modify the permissions to your liking.
haiku
-----
Use the SoundPlayer API on the Haiku operating system.
This plugin is unmaintained and contains known bugs. It will be
removed soon, unless there is a new maintainer.
jack
~~~~
----
The jack plugin connects to a `JACK server <http://jackaudio.org/>`_.
..list-table::
@@ -808,7 +872,8 @@ The jack plugin connects to a `JACK server <http://jackaudio.org/>`_.
- Sets the size of the ring buffer for each channel. Do not configure this value unless you know what you're doing.
httpd
~~~~~
-----
The httpd plugin creates a HTTP server, similar to `ShoutCast <http://www.shoutcast.com/>`_ / `IceCast <http://icecast.org/>`_. HTTP streaming clients like mplayer, VLC, and mpv can connect to it.
It is highly recommended to configure a fixed format, because a stream cannot switch its audio format on-the-fly when the song changes.
@@ -822,14 +887,15 @@ It is highly recommended to configure a fixed format, because a stream cannot sw
* - **port P**
- Binds the HTTP server to the specified port.
* - **bind_to_address ADDR**
- Binds the HTTP server to the specified address (IPv4, IPv6 or UNIX socket). Multiple addresses in parallel are not supported.
- Binds the HTTP server to the specified address (IPv4, IPv6 or local socket). Multiple addresses in parallel are not supported.
* - **encoder NAME**
- Chooses an encoder plugin. A list of encoder plugins can be found in the encoder plugin reference :ref:`encoder_plugins`.
* - **max_clients MC**
- Sets a limit, number of concurrent clients. When set to 0 no limit will apply.
null
~~~~
----
The null plugin does nothing. It discards everything sent to it.
..list-table::
@@ -844,7 +910,8 @@ The null plugin does nothing. It discards everything sent to it.
.._oss_plugin:
oss
~~~
---
The "Open Sound System" plugin is supported on most Unix platforms.
On Linux, OSS has been superseded by ALSA. Use the ALSA output plugin :ref:`alsa_plugin` instead of this one on Linux.
@@ -872,7 +939,7 @@ The according hardware mixer plugin understands the following settings:
- Choose a mixer control, defaulting to PCM.
openal
~~~~~~
------
The "OpenAL" plugin uses `libopenal <http://kcat.strangesoft.net/openal.html>`_. It is supported on many platforms. Use only if there is no native plugin for your operating system.
..list-table::
@@ -885,7 +952,7 @@ The "OpenAL" plugin uses `libopenal <http://kcat.strangesoft.net/openal.html>`_.
- Sets the device which should be used. This can be any valid OpenAL device name. If not specified, then libopenal will choose a default device.
osx
~~~
---
The "Mac OS X" plugin uses Apple's CoreAudio API.
..list-table::
@@ -906,7 +973,7 @@ The "Mac OS X" plugin uses Apple's CoreAudio API.
The channel map may not refer to outputs that do not exist according to the format. If the format is "*:*:1" (mono) and you have a four-channel sound card then "-1,-1,0,0" (dual mono output on the second pair of sound card outputs) is a valid channel map but "-1,-1,0,1" is not because the second channel ('1') does not exist when the output is mono.
pipe
~~~~
----
The pipe plugin starts a program and writes raw PCM data into its standard input.
@@ -922,7 +989,7 @@ The pipe plugin starts a program and writes raw PCM data into its standard input
.._pulse_plugin:
pulse
~~~~~
-----
The pulse plugin connects to a `PulseAudio <http://www.freedesktop.org/wiki/Software/PulseAudio/>`_ server. Requires libpulse.
..list-table::
@@ -935,9 +1002,11 @@ The pulse plugin connects to a `PulseAudio <http://www.freedesktop.org/wiki/Soft
- Sets the host name of the PulseAudio server. By default, :program:`MPD` connects to the local PulseAudio server.
* - **sink NAME**
- Specifies the name of the PulseAudio sink :program:`MPD` should play on.
* - **scale_volume FACTOR**
- Specifies a linear scaling coefficient (ranging from 0.5 to 5.0) to apply when adjusting volume through :program:`MPD`. For example, chosing a factor equal to ``"0.7"`` means that setting the volume to 100 in :program:`MPD` will set the PulseAudio volume to 70%, and a factor equal to ``"3.5"`` means that volume 100 in :program:`MPD` corresponds to a 350% PulseAudio volume.
recorder
~~~~~~~~
--------
The recorder plugin writes the audio played by :program:`MPD` to a file. This may be useful for recording radio streams.
..list-table::
@@ -949,13 +1018,13 @@ The recorder plugin writes the audio played by :program:`MPD` to a file. This ma
* - **path P**
- Write to this file.
* - **format_path P**
- An alternative to path which provides a format string referring to tag values. The special tag iso8601 emits the current date and time in `ISO8601 <https://en.wikipedia.org/wiki/ISO_8601>`_ format (UTC). Every time a new song starts or a new tag gets received from a radio station, a new file is opened. If the format does not render a file name, nothing is recorded. A tag name enclosed in percent signs ('%') is replaced with the tag value. Example: :file:`~/.mpd/recorder/%artist% - %title%.ogg`. Square brackets can be used to group a substring. If none of the tags referred in the group can be found, the whole group is omitted. Example: [~/.mpd/recorder/[%artist% - ]%title%.ogg] (this omits the dash when no artist tag exists; if title also doesn't exist, no file is written). The operators "|" (logical "or") and "&" (logical "and") can be used to select portions of the format string depending on the existing tag values. Example: ~/.mpd/recorder/[%title%|%name%].ogg (use the "name" tag if no title exists)
- An alternative to path which provides a format string referring to tag values. The special tag iso8601 emits the current date and time in `ISO8601 <https://en.wikipedia.org/wiki/ISO_8601>`_ format (UTC). Every time a new song starts or a new tag gets received from a radio station, a new file is opened. If the format does not render a file name, nothing is recorded. A tag name enclosed in percent signs ('%') is replaced with the tag value. Example: :file:`-/.mpd/recorder/%artist% - %title%.ogg`. Square brackets can be used to group a substring. If none of the tags referred in the group can be found, the whole group is omitted. Example: [-/.mpd/recorder/[%artist% - ]%title%.ogg] (this omits the dash when no artist tag exists; if title also doesn't exist, no file is written). The operators "|" (logical "or") and "&" (logical "and") can be used to select portions of the format string depending on the existing tag values. Example: -/.mpd/recorder/[%title%|%name%].ogg (use the "name" tag if no title exists)
* - **encoder NAME**
- Chooses an encoder plugin. A list of encoder plugins can be found in the encoder plugin reference :ref:`encoder_plugins`.
shout
~~~~~
-----
The shout plugin connects to a ShoutCast or IceCast server using libshout. It forwards tags to this server.
You must set a format.
@@ -974,6 +1043,8 @@ You must set a format.
- Set the timeout for the shout connection in seconds. Defaults to 2 seconds.
* - **protocol icecast2|icecast1|shoutcast**
- Specifies the protocol that wil be used to connect to the server. The default is "icecast2".
line-based text records between client and server over TCP.
Once the client is connected to the server, they conduct a
conversation until the client closes the connection. The
conversation flow is always initiated by the client.
All data between the client and the server is encoded in
UTF-8.
The client transmits a command sequence, terminated by the
newline character ``\n``. The server will
respond with one or more lines, the last of which will be a
@@ -42,9 +45,6 @@ quotation marks.
Argument strings are separated from the command and any other
arguments by linear white-space (' ' or '\\t').
All data between the client and the server is encoded in
UTF-8.
Responses
=========
@@ -52,6 +52,28 @@ A command returns ``OK`` on completion or
``ACK some error`` on failure. These
denote the end of command execution.
Some commands return more data before the response ends with ``OK``.
Each line is usually in the form ``NAME: VALUE``. Example::
foo: bar
OK
.._binary:
Binary Responses
----------------
Some commands can return binary data. This is initiated by a line
containing ``binary: 1234`` (followed as usual by a newline). After
that, the specified number of bytes of binary data follows, then a
newline, and finally the ``OK`` line. Example::
foo: bar
binary: 42
<42 bytes>
OK
Failure responses
-----------------
@@ -112,9 +134,9 @@ list begins with `command_list_begin` or
`command_list_ok_begin` and ends with
`command_list_end`.
It does not execute any commands until the list has ended.
The return value is whatever the return for a list of commands
is. On success for all commands,
It does not execute any commands until the list has ended. The
response is a concatentation of all individual responses.
On success for all commands,
``OK`` is returned. If a command
fails, no more commands are executed and the appropriate
``ACK`` error is returned. If
@@ -144,18 +166,28 @@ syntax::
``EXPRESSION`` is a string enclosed in parantheses which can be one
of:
-``(TAG == 'VALUE')``: match a tag value.
``(TAG != 'VALUE')``: mismatch a tag value.
The special tag "*any*" checks all
tag values.
*albumartist* looks for
-``(TAG == 'VALUE')``: match a tag value; if there are multiple
values of the given type, at least one must match.
``(TAG != 'VALUE')``: mismatch a tag value; if there are multiple
values of the given type, none of them must match.
The special tag ``any`` checks all
tag types.
``AlbumArtist`` looks for
``VALUE`` in ``AlbumArtist``
and falls back to ``Artist`` tags if
``AlbumArtist`` does not exist.
``VALUE`` is what to find. The
`find` commands specify an exact value
and are case-sensitive; the `search`
commands specify a sub string and ignore case.
``VALUE`` is what to find.
An empty value string means: match only if the given tag type does
not exist at all; this implies that negation with an empty value
checks for the existence of the given tag type.
-``(TAG contains 'VALUE')`` checks if the given value is a substring
of the tag value.
-``(TAG =~ 'VALUE')`` and ``(TAG !~ 'VALUE')`` use a Perl-compatible
regular expression instead of doing a simple string comparison.
(This feature is only available if :program:`MPD` was compiled with
:file:`libpcre`)
-``(file == 'VALUE')``: match the full song URI
(relative to the music directory).
@@ -168,29 +200,66 @@ of:
file's time stamp with the given value (ISO 8601 or UNIX
time stamp).
-``(AudioFormat == 'SAMPLERATE:BITS:CHANNELS')``:
compares the audio format with the given value.
-``(AudioFormat == 'SAMPLERATE:BITS:CHANNELS')``: compares the audio
format with the given value. See :ref:`audio_output_format` for a
detailed explanation.
-``(AudioFormat =~ 'SAMPLERATE:BITS:CHANNELS')``:
matches the audio format with the given mask (i.e. one
or more attributes may be "*").
or more attributes may be ``*``).
-``(!EXPRESSION)``: negate an expression.
-``(!EXPRESSION)``: negate an expression. Note that each expression
must be enclosed in parantheses, e.g. :code:`(!(artist == 'VALUE'))`
(which is equivalent to :code:`(artist != 'VALUE')`)
-``(EXPRESSION1 AND EXPRESSION2 ...)``: combine two or
more expressions with logical "and".
more expressions with logical "and". Note that each expression must
be enclosed in parantheses, e.g. :code:`((artist == 'FOO') AND
(album == 'BAR'))`
The :command:`find` commands are case sensitive, which
:command:`search` and related commands ignore case.
Prior to MPD 0.21, the syntax looked like this::
find TYPE VALUE
Escaping String Values
----------------------
String values are quoted with single or double quotes, and special
characters within those values must be escaped with the backslash
(``\``). Keep in mind that the backslash is also the escape character
on the protocol level, which means you may need to use double
backslash.
Example expression which matches an artist named ``foo'bar"``::
(Artist == "foo\'bar\"")
At the protocol level, the command must look like this::
find "(Artist == \"foo\\'bar\\\"\")"
The double quotes enclosing the artist name must be escaped because
they are inside a double-quoted ``find`` parameter. The single quote
inside that artist name must be escaped with two backslashes; one to
escape the single quote, and another one because the backslash inside
the string inside the parameter needs to be escaped as well. The
double quote has three confusing backslashes: two to build one
backslash, and another one to escape the double quote on the protocol
level. Phew!
To reduce confusion, you should use a library such as `libmpdclient
<https://www.musicpd.org/libs/libmpdclient/>`_ which escapes command
arguments for you.
.._tags:
Tags
====
The following tags are supported by
``MPD``:
The following tags are supported by:program:`MPD`:
***artist**: the artist name. Its meaning is not well-defined; see "*composer*" and "*performer*" for more specific tags.
***artistsort**: same as artist, but for sorting. This usually omits prefixes such as "The".
@@ -216,7 +285,7 @@ The following tags are supported by
***musicbrainz_workid**: the work id in the `MusicBrainz <https://picard.musicbrainz.org/docs/mappings/>`_ database.
There can be multiple values for some of these tags. For
example, ``MPD`` may return multiple
example, :program:`MPD` may return multiple
lines with a ``performer`` tag. A tag value is
a UTF-8 string.
@@ -259,16 +328,17 @@ Recipes
Queuing
=======
Often, users run ``MPD`` with :ref:`random <command_random>` enabled,
but want to be able to insert songs "before" the rest of the playlist.
That is commonly called "queuing".
Often, users run :program:`MPD` with :ref:`random <command_random>`
enabled, but want to be able to insert songs "before" the rest of the
playlist. That is commonly called "queuing".
``MPD`` implements this by allowing the client to specify a "priority"
for each song in the playlist (commands :ref:`priod <command_prio>`
and :ref:`priodid <command_prioid>`). A higher priority means that
the song is going to be played before the other songs.
:program:`MPD` implements this by allowing the client to specify a
"priority" for each song in the playlist (commands :ref:`priod
<command_prio>` and :ref:`priodid <command_prioid>`). A higher
priority means that the song is going to be played before the other
songs.
In "random" mode, ``MPD`` maintains an
In "random" mode, :program:`MPD` maintains an
internal randomized sequence of songs. In this sequence,
songs with a higher priority come first, and all songs with
the same priority are shuffled (by default, all songs are
@@ -293,9 +363,9 @@ Command reference
commands using song ids should be used instead of the commands
that manipulate and control playback based on playlist
position. Using song ids is a safer method when multiple
clients are interacting with ``MPD``.
clients are interacting with :program:`MPD`.
Querying ``MPD``'s status
Querying :program:`MPD`'s status
================================
:command:`clearerror`
@@ -310,7 +380,7 @@ Querying ``MPD``'s status
:command:`idle [SUBSYSTEMS...]`[#since_0_14]_
Waits until there is a noteworthy change in one or more
of ``MPD``'s subsystems. As soon
of :program:`MPD`'s subsystems. As soon
as there is one, it lists all changed systems in a line
in the format ``changed:
SUBSYSTEM``, where SUBSYSTEM is one of the
@@ -319,7 +389,7 @@ Querying ``MPD``'s status
-``database``: the song database has been modified after :ref:`update <command_update>`.
-``update``: a database update has started or finished. If the database was modified during the update, the ``database`` event is also emitted.
-``stored_playlist``: a stored playlist has been modified, renamed, created or deleted
-``playlist``: the current playlist has been modified
-``playlist``: the queue (i.e. the current playlist) has been modified
-``player``: the player has been started, stopped or seeked
-``mixer``: the volume has been changed
-``output``: an audio output has been added, removed or modified (e.g. renamed, enabled or disabled)
@@ -340,11 +410,11 @@ Querying ``MPD``'s status
to wait for events as long as mpd runs. The
`idle` command can be canceled by
sending the command `noidle` (no other
commands are allowed). ``MPD``
commands are allowed). :program:`MPD`
will then leave `idle` mode and print
results immediately; might be empty at this time.
If the optional ``SUBSYSTEMS`` argument
is used, ``MPD`` will only send
is used, :program:`MPD` will only send
notifications when something changed in one of the
specified subsytems.
@@ -354,29 +424,38 @@ Querying ``MPD``'s status
Reports the current status of the player and the volume
level.
-``volume``: ``0-100``or``-1`` if the volume cannot be determined
-``volume``: ``0-100``(deprecated:``-1`` if the volume cannot
be determined)
-``repeat``: ``0`` or ``1``
-``random``: ``0`` or ``1``
-``single``[#since_0_15]_: ``0``, ``1``, or ``oneshot``[#since_0_21]_
-``consume``[#since_0_15]_: ``0`` or ``1``
-``playlist``: 31-bit unsigned integer, the playlist version number
-``playlistlength``: integer, the length of the playlist
-``state``: ``play``, ``stop, or ``pause``
-``state``: ``play``, ``stop``, or ``pause``
-``song``: playlist song number of the current song stopped on or playing
-``songid``: playlist songid of the current song stopped on or playing
-``nextsong``[#since_0_15]_: playlist song number of the next song to be played
-``nextsongid``[#since_0_15]_: playlist songid of the next song to be played
-``time``: total time elapsed (of current playing/paused song)
-``elapsed``[#since_0_16]_: Total time elapsed within the current song, but with higher resolution.
-``time``: total time elapsed (of current playing/paused song) in seconds
(deprecated, use``elapsed``instead)
-``elapsed``[#since_0_16]_: Total time elapsed within the
current song in seconds, but with higher resolution.
-``duration``[#since_0_20]_: Duration of the current song in seconds.
-``bitrate``: instantaneous bitrate in kbps
-``xfade``: ``crossfade`` in seconds
-``mixrampdb``: ``mixramp`` threshold in dB
-``mixrampdelay``: ``mixrampdelay`` in seconds
-``audio``: The format emitted by the decoder plugin during playback, format: ``*samplerate:bits:channels*``. Check the user manual for a detailed explanation.
-``audio``: The format emitted by the decoder plugin during
playback, format: ``samplerate:bits:channels``. See
:ref:`audio_output_format` for a detailed explanation.
-``updating_db``: ``job id``
-``error``: if there is an error, returns message here
:program:`MPD` may omit lines which have no (known) value. Older
:program:`MPD` versions used to have a "magic" value for
"unknown", e.g. ":samp:`volume: -1`".
:command:`stats`
Displays statistics.
@@ -384,8 +463,9 @@ Querying ``MPD``'s status
-``albums``: number of albums
-``songs``: number of songs
-``uptime``: daemon uptime in seconds
-``db_playtime``: sum of all song times in the db
-``db_update``: last db update in UNIX time
-``db_playtime``: sum of all song times in the database in seconds
-``db_update``: last db update in UNIX time (seconds since
1970-01-01 UTC)
-``playtime``: time length of music played
Playback options
@@ -490,8 +570,36 @@ Controlling playback
:command:`stop`
Stops playing.
The current playlist
====================
The Queue
=========
..note:: The "queue" used to be called "current playlist" or just
"playlist", but that was deemed confusing, because
"playlists" are also files containing a sequence of songs.
Those "playlist files" or "stored playlists" can be
:ref:`loaded into the queue <command_load>` and the queue
can be :ref:`saved into a playlist file <command_save>`, but
they are not to be confused with the queue.
Many of the command names in this section reflect the old
naming convention, but for the sake of compatibility, we
cannot rename commands.
There are two ways to address songs within the queue: by their
position and by their id.
The position is a 0-based index. It is unstable by design: if you
move, delete or insert songs, all following indices will change, and a
client can never be sure what song is behind a given index/position.
Song ids on the other hand are stable: an id is assigned to a song
when it is added, and will stay the same, no matter how much it is
moved around. Adding the same song twice will assign different ids to
them, and a deleted-and-readded song will have a new id. This way, a
client can always be sure the correct song is being used.
Many commands come in two flavors, one for each address type.
Whenever possible, ids should be used.
:command:`add {URI}`
Adds the file ``URI`` to the playlist
@@ -507,7 +615,7 @@ The current playlist
OK
:command:`clear`
Clears the current playlist.
Clears the queue.
.._command_delete:
@@ -518,7 +626,7 @@ The current playlist
Deletes the song ``SONGID`` from the
playlist
:command:`move {FROM} [{START:END} | {TO}]`
:command:`move [{FROM} | {START:END}] {TO}`
Moves the song at ``FROM`` or range of songs
at ``START:END``[#since_0_15]_ to ``TO``
in the playlist.
@@ -532,13 +640,13 @@ The current playlist
:command:`playlist`
Displays the current playlist.
Displays the queue.
Do not use this, instead use :ref:`playlistinfo
<command_playlistinfo>`.
:command:`playlistfind {TAG} {NEEDLE}`
Finds songs in the current playlist with strict
Finds songs in the queue with strict
matching.
:command:`playlistid {SONGID}`
@@ -556,7 +664,7 @@ The current playlist
:command:`playlistsearch {TAG} {NEEDLE}`
Searches case-insensitively for partial matches in the
current playlist.
queue.
:command:`plchanges {VERSION} [START:END]`
Displays changed songs currently in the playlist since
@@ -593,7 +701,7 @@ The current playlist
but address the songs with their id.
:command:`rangeid {ID} {START:END}`[#since_0_19]_
Since ``MPD``
Since :program:`MPD`
0.19 Specifies the portion of the
song that shall be played. ``START`` and
``END`` are offsets in seconds
@@ -603,7 +711,7 @@ The current playlist
playing cannot be manipulated this way.
:command:`shuffle [START:END]`
Shuffles the current playlist.
Shuffles the queue.
``START:END`` is optional and specifies
a range of songs.
@@ -638,7 +746,9 @@ and without the `.m3u` suffix).
Some of the commands described in this section can be used to
run playlist plugins instead of the hard-coded simple
`m3u` parser. They can access playlists in
the music directory (relative path including the suffix) or
the music directory (relative path including the suffix),
playlists in arbitrary location (absolute path including the suffix;
allowed only for clients that are connected via local socket), or
remote playlists (absolute URI with a supported scheme).
:command:`listplaylist {NAME}`
@@ -657,6 +767,8 @@ remote playlists (absolute URI with a supported scheme).
between clients and the server, clients should not
compare this value with their local clock.
.._command_load:
:command:`load {NAME} [START:END]`
Loads the playlist into the current queue. Playlist
plugins are supported. A range may be specified to load
@@ -687,8 +799,10 @@ remote playlists (absolute URI with a supported scheme).
Removes the playlist `NAME.m3u` from
the playlist directory.
.._command_save:
:command:`save {NAME}`
Saves the current playlist to
Saves the queue to
`NAME.m3u` in the playlist directory.
The music database
@@ -703,7 +817,7 @@ The music database
Returns the file size and actual number
of bytes read at the requested offset, followed
by the chunk requested as raw bytes, then a
by the chunk requested as raw bytes (see :ref:`binary`), then a
@@ -87,10 +88,12 @@ For example, the following installs a fairly complete list of build dependencies
libupnp-dev \
libavahi-client-dev \
libsqlite3-dev \
libsystemd-dev libwrap0-dev \
libsystemd-dev \
libgtest-dev \
libboost-dev \
libicu-dev
libicu-dev \
libchromaprint-dev \
libgcrypt20-dev
Now configure the source tree:
@@ -275,7 +278,9 @@ You can also use multiple storage plugins to assemble a virtual music directory
Configuring database plugins
----------------------------
If a music directory is configured, one database plugin is used. To configure this plugin, add a database block to :file:`mpd.conf`:
If a music directory is configured, one database plugin is used. To
configure this plugin, add a :code:`database` block to
:file:`mpd.conf`:
..code-block::none
@@ -290,7 +295,9 @@ reference.
Configuring neighbor plugins
----------------------------
All neighbor plugins are disabled by default to avoid unwanted overhead. To enable (and configure) a plugin, add a neighbor block to :file:`mpd.conf`:
All neighbor plugins are disabled by default to avoid unwanted
overhead. To enable (and configure) a plugin, add a :code:`neighbor`
block to :file:`mpd.conf`:
..code-block::none
@@ -303,7 +310,8 @@ More information can be found in the :ref:`neighbor_plugin` reference.
Configuring input plugins
-------------------------
To configure an input plugin, add ainput block to:file:`mpd.conf`:
To configure an input plugin, add an :code:`input` block to
:file:`mpd.conf`:
..code-block::none
@@ -331,7 +339,8 @@ More information can be found in the :ref:`input_plugins` reference.
Configuring decoder plugins
---------------------------
Most decoder plugins do not need any special configuration. To configure a decoder, add a decoder block to :file:`mpd.conf`:
Most decoder plugins do not need any special configuration. To
configure a decoder, add a :code:`decoder` block to :file:`mpd.conf`:
..code-block::none
@@ -358,16 +367,21 @@ More information can be found in the :ref:`decoder_plugins` reference.
Configuring encoder plugins
---------------------------
Encoders are used by some of the output plugins (such as shout). The encoder settings are included in the audio_output section.
Encoders are used by some of the output plugins (such as shout). The
encoder settings are included in the ``audio_output`` section, see :ref:`config_audio_output`.
More information can be found in the :ref:`encoder_plugins` reference.
.._config_audio_output:
Configuring audio outputs
-------------------------
Audio outputs are devices which actually play the audio chunks produced by :program:`MPD`. You can configure any number of audio output devices, but there must be at least one. If none is configured, :program:`MPD` attempts to auto-detect. Usually, this works quite well with ALSA, OSS and on Mac OS X.
To configure an audio output manually, add one or more audio_output blocks to :file:`mpd.conf`:
To configure an audio output manually, add one or more
:code:`audio_output` blocks to :file:`mpd.conf`:
..code-block::none
@@ -390,14 +404,9 @@ The following table lists the audio_output options valid for all plugins:
- The name of the plugin
* - **name**
- The name of the audio output. It is visible to the client. Some plugins also use it internally, e.g. as a name registered in the PULSE server.
* - **format**
- Always open the audio output with the specified audio format samplerate:bits:channels), regardless of the format of the input file. This is optional for most plugins.
Any of the three attributes may be an asterisk to specify that this attribute should not be enforced, example: 48000:16:*. *:*:* is equal to not having a format specification.
The following values are valid for bits: 8 (signed 8 bit integer samples), 16, 24 (signed 24 bit integer samples padded to 32 bit), 32 (signed 32 bit integer samples), f (32 bit floating point, -1.0 to 1.0), "dsd" means DSD (Direct Stream Digital). For DSD, there are special cases such as "dsd64", which allows you to omit the sample rate (e.g. dsd512:2 for stereo DSD512, i.e. 22.5792 MHz).
The sample rate is special for DSD: :program:`MPD` counts the number of bytes, not bits. Thus, a DSD "bit" rate of 22.5792 MHz (DSD512) is 2822400 from :program:`MPD`'s point of view (44100*512/8).
* - **format samplerate:bits:channels**
- Always open the audio output with the specified audio format, regardless of the format of the input file. This is optional for most plugins.
See :ref:`audio_output_format` for a detailed description of the value.
* - **enabed yes|no**
- Specifies whether this audio output is enabled when :program:`MPD` is started. By default, all audio outputs are enabled. This is just the default setting when there is no state file; with a state file, the previous state is restored.
* - **tags yes|no**
@@ -405,14 +414,30 @@ The following table lists the audio_output options valid for all plugins:
* - **always_on yes|no**
- If set to yes, then :program:`MPD` attempts to keep this audio output always open. This may be useful for streaming servers, when you don't want to disconnect all listeners even when playback is accidentally stopped.
* - **mixer_type hardware|software|null|none**
- Specifies which mixer should be used for this audio output: the hardware mixer (available for ALSA :ref:`alsa_plugin`, OSS :ref:`oss_plugin` and PulseAudio :ref:`pulse_plugin`), the software mixer, the "null" mixer (null; allows setting the volume, but with no effect; this can be used as a trick to implement an external mixer :ref:`external_mixer`) or no mixer (none). By default, the hardware mixer is used for devices which support it, and none for the others.
- Specifies which mixer should be used for this audio output: the
hardware mixer (available for ALSA :ref:`alsa_plugin`, OSS
:ref:`oss_plugin` and PulseAudio :ref:`pulse_plugin`), the
software mixer, the ":samp:`null`" mixer (allows setting the
volume, but with no effect; this can be used as a trick to
implement an external mixer :ref:`external_mixer`) or no mixer
(:samp:`none`). By default, the hardware mixer is used for
devices which support it, and none for the others.
* - **filters "name,...**"
- The specified configured filters are instantiated in the given
order. Each filter name refers to a ``filter`` block, see
:ref:`config_filter`.
More information can be found in the :ref:`output_plugins` reference.
.._config_filter:
Configuring filters
-------------------
Filters are plugins which modify an audio stream.
To configure a filter, add a filter block to :file:`mpd.conf`:
To configure a filter, add a :code:`filter` block to :file:`mpd.conf`:
..code-block::none
@@ -421,6 +446,9 @@ To configure a filter, add a filter block to :file:`mpd.conf`:
name "software volume"
}
Configured filters may then be added to the ``filters`` setting of an
``audio_output`` section, see :ref:`config_audio_output`.
The following table lists the filter options valid for all plugins:
..list-table::
@@ -434,12 +462,18 @@ The following table lists the filter options valid for all plugins:
* - **name**
- The name of the filter
More information can be found in the :ref:`filter_plugins` reference.
Configuring playlist plugins
----------------------------
Playlist plugins are used to load remote playlists (protocol commands load, listplaylist and listplaylistinfo). This is not related to :program:`MPD`'s playlist directory.
Playlist plugins are used to load remote playlists (protocol commands
load, listplaylist and listplaylistinfo). This is not related to
To configure a playlist plugin, add a playlist_plugin block to:file:`mpd.conf`:
To configure a playlist plugin, add a :code:`playlist_plugin` block to
:file:`mpd.conf`:
..code-block::none
@@ -467,13 +501,34 @@ reference.
Audio Format Settings
---------------------
Global Audio Format
~~~~~~~~~~~~~~~~~~~
.._audio_output_format:
The setting audio_output_format forces :program:`MPD` to use one audio format for all outputs. Doing that is usually not a good idea. The values are the same as in format in the audio_output section.
Global Audio Format
^^^^^^^^^^^^^^^^^^^
The setting ``audio_output_format`` forces :program:`MPD` to use one
audio format for all outputs. Doing that is usually not a good idea.
The value is specified as ``samplerate:bits:channels``.
Any of the three attributes may be an asterisk to specify that this
attribute should not be enforced, example: ``48000:16:*``.
``*:*:*`` is equal to not having a format specification.
The following values are valid for bits: ``8`` (signed 8 bit integer
samples), ``16``, ``24`` (signed 24 bit integer samples padded to 32
bit), ``32`` (signed 32 bit integer samples), ``f`` (32 bit floating
point, -1.0 to 1.0), ``dsd`` means DSD (Direct Stream Digital). For
DSD, there are special cases such as ``dsd64``, which allows you to
omit the sample rate (e.g. ``dsd512:2`` for stereo DSD512,
i.e. 22.5792 MHz).
The sample rate is special for DSD: :program:`MPD` counts the number
of bytes, not bits. Thus, a DSD "bit" rate of 22.5792 MHz (DSD512) is
2822400 from :program:`MPD`'s point of view (44100*512/8).
Resampler
~~~~~~~~~
^^^^^^^^^
Sometimes, music needs to be resampled before it can be played; for example, CDs use a sample rate of 44,100 Hz while many cheap audio chips can only handle 48,000 Hz. Resampling reduces the quality and consumes a lot of CPU. There are different options, some of them optimized for high quality and others for low CPU usage, but you can't have both at the same time. Often, the resampler is the component that is responsible for most of :program:`MPD`'s CPU usage. Since :program:`MPD` comes with high quality defaults, it may appear that :program:`MPD` consumes more CPU than other software.
@@ -486,7 +541,7 @@ Client Connections
.._listeners:
Listeners
~~~~~~~~~
^^^^^^^^^
The setting :code:`bind_to_address` specifies which addresses
:program:`MPD` listens on for connections from clients. It can be
@@ -513,6 +568,12 @@ choice::
bind_to_address "/var/run/mpd/socket"
On Linux, local sockets can be bound to a name without a socket inode
on the filesystem; MPD implements this by prepending ``@`` to the
address::
bind_to_address "@mpd"
If no port is specified, the default port is 6600. This default can
be changed with the port setting::
@@ -523,7 +584,7 @@ used.
Permissions and Passwords
~~~~~~~~~~~~~~~~~~~~~~~~~
^^^^^^^^^^^^^^^^^^^^^^^^^
By default, all clients are unauthenticated and have a full set of permissions. This can be restricted with the settings :code:`default_permissions` and :code:`password`.
@@ -586,7 +647,7 @@ Other Settings
Section :ref:`tags` contains a list of supported tags.
The State File
~~~~~~~~~~~~~~
^^^^^^^^^^^^^^
The state file is a file where :program:`MPD` saves and restores its state (play queue, playback position etc.) to keep it persistent across restarts and reboots. It is an optional setting.
@@ -604,7 +665,7 @@ The State File
- Auto-save the state file this number of seconds after each state change. Defaults to 120 (2 minutes).
The Sticker Database
~~~~~~~~~~~~~~~~~~~~
^^^^^^^^^^^^^^^^^^^^
"Stickers" are pieces of information attached to songs. Some clients
use them to store ratings and other volatile data. This feature
These settings are various limitations to prevent :program:`MPD` from using too many resources (denial of service).
@@ -634,7 +695,7 @@ These settings are various limitations to prevent :program:`MPD` from using too
* - **connection_timeout SECONDS**
- If a client does not send any new data in this time period, the connection is closed. Clients waiting in "idle" mode are excluded from this. Default is 60.
* - **max_connections NUMBER**
- This specifies the maximum number of clients that can be connected to :program:`MPD` at the same time. Default is 5.
- This specifies the maximum number of clients that can be connected to :program:`MPD` at the same time. Default is 100.
* - **max_playlist_length NUMBER**
- The maximum number of songs that can be in the playlist. Default is 16384.
* - **max_command_list_size KBYTES**
@@ -643,7 +704,7 @@ These settings are various limitations to prevent :program:`MPD` from using too
- The maximum size of the output buffer to a client (maximum response size). Default is 8192 (8 MiB).
Buffer Settings
~~~~~~~~~~~~~~~
^^^^^^^^^^^^^^^
Do not change these unless you know what you are doing.
@@ -657,7 +718,7 @@ Do not change these unless you know what you are doing.
- Adjust the size of the internal audio buffer. Default is 4096 (4 MiB).
Zeroconf
~~~~~~~~
^^^^^^^^
If Zeroconf support (`Avahi <http://avahi.org/>`_ or Apple's Bonjour)
was enabled at compile time with :code:`-Dzeroconf=...`,
@@ -743,10 +804,12 @@ You can verify whether the real-time scheduler is active with the ps command:
The CLS column shows the CPU scheduler; TS is the normal scheduler; FF and RR are real-time schedulers. In this example, two threads use the real-time scheduler: the output thread and the rtio (real-time I/O) thread; these two are the important ones. The database update thread uses the idle scheduler ("IDL in ps), which only gets CPU when no other process needs it.
Note
~~~~
..note::
There is a rumor that real-time scheduling improves audio quality. That is not true. All it does is reduce the probability of skipping (audio buffer xruns) when the computer is under heavy load.
There is a rumor that real-time scheduling improves audio
quality. That is not true. All it does is reduce the probability of
skipping (audio buffer xruns) when the computer is under heavy
load.
Using MPD
*********
@@ -774,7 +837,7 @@ Depending on the size of your music collection and the speed of the storage, thi
To exclude a file from the update, create a file called :file:`.mpdignore` in its parent directory. Each line of that file may contain a list of shell wildcards. Matching files in the current directory and all subdirectories are excluded.
Mounting other storages into the music directory
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
:program:`MPD` has various storage plugins of which multiple instances can be "mounted" into the music directory. This way, you can use local music, file servers and USB sticks at the same time. Example:
@@ -816,10 +879,16 @@ The queue
The queue (sometimes called "current playlist") is a list of songs to be played by :program:`MPD`. To play a song, add it to the queue and start playback. Most clients offer an interface to edit the queue.
.._stored_playlists:
Stored Playlists
----------------
Stored playlists are some kind of secondary playlists which can be created, saved, edited and deleted by the client. They are addressed by their names. Its contents can be loaded into the queue, to be played back. The playlist_directory setting specifies where those playlists are stored.
Stored playlists are some kind of secondary playlists which can be
created, saved, edited and deleted by the client. They are addressed
by their names. Its contents can be loaded into the queue, to be
played back. The :code:`playlist_directory` setting specifies where
those playlists are stored.
Advanced usage
**************
@@ -859,9 +928,11 @@ Obey the "format" row, which indicates that the current playback format is 16 bi
Check list for bit-perfect playback:
* Use the ALSA output plugin.
* Disable sound processing inside ALSA by configuring a "hardware" device (hw:0,0 or similar).
* Don't use software volume (setting mixer_type).
* Don't force :program:`MPD` to use a specific audio format (settings format, audio_output_format).
* Disable sound processing inside ALSA by configuring a "hardware"
device (:samp:`hw:0,0` or similar).
* Don't use software volume (setting :code:`mixer_type`).
* Don't force :program:`MPD` to use a specific audio format (settings
* Verify that you are really doing bit-perfect playback using :program:`MPD`'s verbose log and :file:`/proc/asound/card*/pcm*p/sub*/hw_params`. Some DACs can also indicate the audio format.
Direct Stream Digital (DSD)
@@ -876,7 +947,11 @@ DSD (`Direct Stream Digital <https://en.wikipedia.org/wiki/Direct_Stream_Digital
* DoP (DSD over PCM) playback. This wraps DSD inside fake 24 bit PCM according to the DoP standard. Requires a DAC that supports DSD. No support from ALSA and the sound chip required (except for bit-perfect 24 bit PCM support).
* Convert DSD to PCM on-the-fly.
Native DSD playback is used automatically if available. DoP is only used if enabled explicitly using the dop option, because there is no way for :program:`MPD` to find out whether the DAC supports it. DSD to PCM conversion is the fallback if DSD cannot be used directly.
Native DSD playback is used automatically if available. DoP is only
used if enabled explicitly using the :code:`dop` option, because there
is no way for :program:`MPD` to find out whether the DAC supports
it. DSD to PCM conversion is the fallback if DSD cannot be used
directly.
Client Hacks
************
@@ -908,18 +983,18 @@ Support
-------
Getting Help
~~~~~~~~~~~~
^^^^^^^^^^^^
The :program:`MPD` project runs a `forum <https://forum.musicpd.org/>`_ and an IRC channel (#mpd on Freenode) for requesting help. Visit the MPD help page for details on how to get help.
Common Problems
~~~~~~~~~~~~~~~
^^^^^^^^^^^^^^^
1. Database
^^^^^^^^^^^
"""""""""""
Question: I can't see my music in the MPD database!
* Does the MPD user have read permission on all music files, and read+execute permission on all music directories (and all of their parent directories)?
@@ -927,22 +1002,22 @@ Question: I can't see my music in the MPD database!
* Did you enable all relevant decoder plugins at compile time? :command:`mpd --version` will tell you.
Question: MPD doesn't read ID3 tags!
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* You probably compiled :program:`MPD` without libid3tag. :command:`mpd --version` will tell you.
2. Playback
^^^^^^^^^^^
"""""""""""
Question: I can't hear music on my client!
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* That problem usually follows a misunderstanding of the nature of :program:`MPD`. :program:`MPD` is a remote-controlled music player, not a music distribution system. Usually, the speakers are connected to the box where :program:`MPD` runs, and the :program:`MPD` client only sends control commands, but the client does not actually play your music.
:program:`MPD` has output plugins which allow hearing music on a remote host (such as httpd), but that is not :program:`MPD`'s primary design goal.
Question: "Device or resource busy"
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* This ALSA error means that another program uses your sound hardware exclusively. You can stop that program to allow :program:`MPD` to use it.
@@ -961,13 +1036,22 @@ Your bug report should contain:
* be clear about what you expect MPD to do, and what is actually happening
MPD crashes
~~~~~~~~~~~
^^^^^^^^^^^
All :program:`MPD` crashes are bugs which must be fixed by a developer, and you should write a bug report. (Many crash bugs are caused by codec libraries used by :program:`MPD`, and then that library must be fixed; but in any case, the :program:`MPD``bug tracker <https://github.com/MusicPlayerDaemon/MPD/issues>`_ is a good place to report it first if you don't know.)
A crash bug report needs to contain a "backtrace".
First of all, your :program:`MPD` executable must not be "stripped" (i.e. debug information deleted). The executables shipped with Linux distributions are usually stripped, but some have so-called "debug" packages (package mpd-dbg or mpd-dbgsym on Debian, mpd-debug on other distributions). Make sure this package is installed.
First of all, your :program:`MPD` executable must not be "stripped"
(i.e. debug information deleted). The executables shipped with Linux
distributions are usually stripped, but some have so-called "debug"
packages (package :file:`mpd-dbgsym` or :file:`mpd-dbg` on Debian,
:file:`mpd-debug` on other distributions). Make sure this package is
installed.
If you built :program:`MPD` from sources, please recompile with Meson
option ":code:`--buildtype=debug -Db_ndebug=false`", because this will
add more helpful information to the backtrace.
You can extract the backtrace from a core dump, or by running :program:`MPD` in a debugger, e.g.:
@@ -976,4 +1060,5 @@ You can extract the backtrace from a core dump, or by running :program:`MPD` in
gdb --args mpd --stdout --no-daemon --verbose
run
As soon as you have reproduced the crash, type "bt" on the gdb command prompt. Copy the output to your bug report.
As soon as you have reproduced the crash, type ":command:`bt`" on the
gdb command prompt. Copy the output to your bug report.
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