When the update thread is started before MPD has forked (for
daemonization), it is killed, because threads do not survive a fork().
This induces an inconsistent state where MPD won't start any update
thread at all, because it thinks the thread is already running.

Move the "while" loop which checks for commands to the caller
ao_pause().  This simplifies the pause() method, and lets us remove
audio_output_is_pending().

This fixes an assertion failure: when the last song in the playlist
was playing, and you deleted it, MPD aborted.

The macro is unused.

The function is only used by the MVP output plugin, and this one call
is wrong.

If no ports are configured, don't overwrite the (NULL) configuration
with the port names of the first JACK server.  If the server changes
after a JACK reconnect, MPD won't attempt to auto-detect again.

Currently, the JACK plugin manipulates the audio_format struct which
was passed to the open() method.  This is very likely to break,
because the plugin must not permanently store this pointer.  After
this patch, MPD ignores sample rate changes.  It looks like other
software is doing the same, and I guess this is a non-issue.

This patch converts the audio_format pointer within jack_data into a
static audio_format struct.

jack_set_info_function() is not provided by older libjack versions.
Attempt to detect if it is available.

Hi -
independently of libmikmod's other problems - there seems
to be a problem in mpd's wrapper: MikMod_Exit() is called
after the first file is decoded, which frees some ressources
within the mikmod library. An attempt to play a second file
leads to a crash. The appended patch fixes this for me.
(I don't know what the "dup" entry is good for - someone
who knows should review that too.)
best regards
Matthias

[mk: removed 3 more MikMod_Exit() invocations]

The wavpack library seems to use the .wvc stream even if the OPEN_WVC
flag is not set.  In this case, pass NULL to be sure libwavpack won't
use it.

Use jack_set_info_function() to install an info callback.  Don't let
libjack print them to stderr.

When we do not explicitly catch G_IO_ERR and G_IO_HUP, GLib can go
into an infinite loop, because it won't deliver the socket error to
MPD.

When there are duplicate slashes in the song paths, eliminate them;
example:

 /var/lib/mpd/music//foo.mp3

becomes:

 /var/lib/mpd/music/foo.mp3

The slash is only detected at the border between the music_directory
and the local part.

When the user configures a music_directory with a trailing slash, it
may break playlist loading, because MPD expects a double slash.  Chop
off the trailing slash.

ffmpeg_tag_internal() does not look for a few tags that mpd
supports. Most noteably:

 comment -> TAG_ITEM_COMMENT -> Description
 genre -> TAG_ITEM_GENRE -> WM/Genre (not WM/GenreID)
 year -> TAG_ITEM_DATE -> WM/Year

I *think* that this is the last of the tags that AVFormatContext() in
ffmpeg supports that mpd also uses.

Make those two methods optional to implement, and let input_stream.c
provide fallbacks.  The buffer() method will be removed one day, and
there is now only one implementation left (input_curl.c).

The open_stream() method opens the input_stream.  This allows the
archive plugin to do its own initialization, and it also allows it to
use input_stream.data.  We can remove input_stream.archive now, which
was unnatural to have in the first place.

This way, plugins can manipulate the plugin pointer during open().

MMS streaming is experimental; sync the default value with the help
text.

Return false from mpd_jack_play(), let the MPD core close the device.

Don't leave uninitialized bytes in the jack_data struct.

When MPD stops playback, close the JACK client connection.

The "bps" attribute is calculated, but never used.

Return true/false instead of 1/-1.

Preparation for supporting other channel numbers than stereo: use
loops instead of duplicating code for the second channel.  Most
likely, gcc will unroll these loops, so the binary won't be any
different.

When jack_get_ports() returns NULL, we cannot have any ports to
connect to, and the device cannot play anything.

libjack's jack_port_name() function returns the effective port name,
we don't need to do it manually.

Do the global libjack initialization in the global plugin
initialization function.

This patch implements the MMS protocol, by using libmms.  It is quite
experimental: it does not support seeking yet, and it is currently
using synchronous I/O, which causes MPD to hang while waiting for the
server.

When the playlist is cleared, pc.errored_song is also cleared.  This
causes pc_errored_song_uri() to crash, because it assumes that
pc.errored_song is set.  Reset pc.error to fix that assumption.

Moved people who havn't contributed during the 0.14 development cycle.

When waiting for free space in the ring buffer, the JACK plugin
sleeped 10ms until there is enough space.  This delay was too large
for low-latency setups (<10ms), and created a lot of xruns.  Work
around that by reducing the sleep time to 1ms.

A proper solution for this would be to use an event based approach,
and we will do it, just not now.

When the connection failed once, you had to restart MPD, because it
never cleared the jack_data.shutdown flag.  Instead, it refused to
play anything "because there is no client thread" (which is wrong at
that point).

If the ring buffers are allocated after jack_activate(),
mpd_jack_process() might segfault because it attempts to access them.

Call jack_port_register() before jack_activate().

The variable "serviceName" is initialized with SERVICE_NAME, but was
overwritten with NULL when the setting is not configured.