Always assume the buffer is empty before calling the encoder.  Always
flush the buffer immediately after there has been added something.
This reduces the risk of buffer overruns, because there will never be
a "rest" in the current buffer.

Don't duplicate the tag received by the send_metadata() method - send
it to the shout server directly.

Removed the manual timer synchronization from the shout plugin.
libshout's shout_sync() function does it for us.

The non-blocking mode of libshout is sparsely documented, and MPD's
implementation had several bugs.  Also removed connect throttling
code, that is done by the MPD core since 0.14.

When shout_data.tag!=NULL, there is a "tag to send".  The tag_to_send
flag is redundant.

That variable is set in handle_shout_error(), but is never read.

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().

On some platforms, g_free() must be used for memory allocated by
GLib.  This patch intends to correct a lot of occurrences, but is
probably not complete.

All config_get_block_*() functions should accept constant config_param
pointers.

Eliminate some more getBlockParam() invocations.

This replaces lots of getBlockParam() invocations.

No "force" parameter, pass a default value instead.

Renamed functions, types, variables.

If the shout plugin is disabled, shout_plugin.c isn't compiled at all,
no need to check the macro definition.

removed unneed check for protocol in shout plugin, will assume icecast2 protocol if not exist in config

When an output plugin fails to play a chunk, close it.  This replaces
various manual close() calls in nearly all plugins.

Don't return 0/-1 on success/error, but true/false.  Instead of int,
use bool for storing flags.

Again, no CamelCase in the directory name.

Added configuration parameter "protocol" which lets the user choose
from 3 shout protocols.  This adds support for real shoutcast servers.

Case insensitivity isn't helpful, and comparing only the first 3 bytes
of a configured value may encourage users to supply wrong or
misleading values.

The last bit of CamelCase in audio_format.h.  Additionally, rename a
bunch of local variables.

"bits" and "channels" cannot be negative.

Having an array with disabled entries sucks.  Removed that
DISABLED_SHOUT_ENCODER_PLUGIN macro, and fill the plugin list only
with plugins which are actually enabled.  This should be done for all
plugin types.

When there are standardized headers, use these instead of the bloated
os_compat.h.

pause() puts the audio output into pause mode: if supported, it may
perform a special action, which keeps the device open, but does not
play anything.  Output plugins like "shout" might want to play silence
during pause, so their clients won't be disconnected.  Plugins which
do not support pausing will simply be closed, and have to be reopened
when unpaused.

This pach includes an implementation for the shout plugin, which
sends silence chunks.

The old struct initializers are error prone and don't allow moving
elements around.  Since we are going to overhaul some of the APIs
soon, it's easier to have all implementations use C99 initializers.

We have eliminated direct accesses to the audio_output struct from
the all output plugins.  Make it opaque for them, and move its real
declaration to output_internal.h, similar to decoder_internal.h.

Pass the opaque structure to plugin.init() only, which will return the
plugin's data pointer on success, and NULL on failure.  This data
pointer will be passed to all other methods instead of the
audio_output struct.

Since the output plugin returns a value indicating success or error,
we can have the output core code assign the "open" flag.

Pass the globally configured audio_format as a const pointer to
plugin.init().  plugin.open() gets a writable pointer which contains
the audio_format requested by the plugin.  Its initial value is either
the configured audio_format or the input file's audio_format.

Add a check to write_page() which checks if there is actually data.
Don't bother to call shout_send() if there is not.

The function is trivial, without a benefit.  Also don't initialize
buf.data[0], this is not a null terminated string.

Since the buffer size is known at compile time, we can save an
indirection by declaring it as a char array instead of a pointer.
That saves an extra allocation, and we can calculate with the
compile-time constant sizeof(data) instead of the attribute "max_len".

Declare both shout plugins "const", since they will never change, once
initialized at compile time.

Shout encoder plugins are known at compile time.  There is no reason
to use a complex data structure as "List" to manage them at runtime -
just put the pointers into a static array.

Don't typedef the structs at all.  It is easier to forward-declare
this way.

Don't typedef methods.  They are used exactly once, a few lines below.

[mk: moved this patch after "Refactor and cleanup of shout Ogg and MP3
audio outputs".  The original commit message follows, although it is
outdated:]

Creation of shout_mp3 audio output plugin. Basically I just copied the
existing shout plugin and replaced ogg with lame. Uses lame for mp3
encoding. Next step is to pull common functionality out of each shout
plugin and share it between them.

Configuration options for "shout_mp3" are the same as for "shout".