path: root/README

README
======

----
Paraslash is an acronym for

_Play, archive, rate and stream large audio sets happily_

It contains the following programs:

-----------------------
para_server (obligatory)
-----------------------

para_server streams binary audio data (mp3/oggvorbis/m4a files)
over local and/or remote networks. It listens on a tcp port and
accepts commands such as play, stop, pause, next from authenticated
clients. However, there are many more commands.

It supports three builtin network streaming methods (senders): http, dccp,
or rtp.

	* The http sender is recommended for public streams that can be played
	  by any player like mpg123, xmms, itunes, winamp...

	* The dccp sender is experimental and requires kernel support for the
	  rather new datagram congestion control protocol.

	* The ortp sender is recommended for multicast LAN streaming

It is possible to activate more than one sender simultaneously.

para_server needs an audio file selector to work, mainly to determine
which audio file to stream next. The following three selectors are
built in:

	* The random selector chooses audio files out of a given directory
	  by random

	* The playlist selector chooses files from a specified playlist

	* The (optional) mysql selector is more involved.  It connects
	  to a mysql server which holds information on your audio files
	  and maintains statistics on the available audio files. Audio
	  file selection works by sending a user-defined sql-query
	  to the mysql server. This allows rather sophisticated
	  configurations and is explained in detail in README.mysql.

It is possible to switch between all supported selectors at any time.

Despite of all these features, paraslash is lightweight. The
stripped binary of para_server with all its features compiled in
(mysql/random/playlist selector, mp3/ogg/aac support, http/dccp/ortp
support) is about 120K on i386 under Linux. para_audiod (see below)
is even smaller.

------------------------
para_client (obligatory)
------------------------

The client program to connect to para_server.  paraslash commands
are sent to para_server and the response is dumped to stdout. This
can be used by any scripting language to produce user interfaces with
little programming effort.

All connections between para_server and para_client are encrypted by
default.  For each user of paraslash you must create a public/secret
key pair for authentication. The (authenticated) connection is encrypted
with a symmetric rc4 session key.

--------------------
para_recv (optional)
--------------------

A command line http/dccp/rtp stream grabber. The http mode of this tool
can be used to receive date from any http streaming source.

----------------------
para_filter (optional)
----------------------

A filter program that converts from stdin and writes to stdout. It
is completely independent from the rest of paraslash, so it might be
useful also for different purposes.

para_filter combines several decoders (mp3, oggvorbis, aac) and a
volume normalizer New filters can be added easily due to the modular
design. If more than one filter is specified, the given filters
are 'piped' together in-memory, i.e. without calling any of the
read(2)/write(2)/select(2) etc. functions.

-----------------------
para_write (obligatory)
-----------------------

A modular audio stream writer. It supports a simple file writer
output plug-in and optional wav/raw players for alsa (linux-only,
Debian package: libasound2-dev) and Mac OS. para_write can also be
used as a stand-alone wav or raw audio player.

---------------------------------------
para_audiod (optional, but recommended)
---------------------------------------

The local daemon that collects information from para_server.

It runs on the client side and connects to para_server. The audio stream is
read from the network and sent through any of paraslash's filters (decoder,
volume normalizer). The resulting stream is written to an output plug-in
(writer), e.g. the alsa writer on linux systems. It is possible to capture the
stream at any position in the filter chain.

para_audiod starts an appropriate receiver, filter and player as soon as
para_server announces the availability (and the type) of an audio stream.
Moreover, it listens on a local socket and sends status information about
para_server and para_audiod to local clients on request.

--------------------------------------
para_audioc (optional, but recommended)
--------------------------------------

The client program which talks with para_audiod. Used to control
para_audiod, to receive status info, or to grab the stream at any
point in the filter chain.

para_audioc (hence para_audiod) is needed by para_gui, para_sdl_gui
and para_krell, see below.

-------------------
para_gui (optional)
-------------------

Themable ncurses-based gui. It calls para_audioc and presents
the obtained information in an ncurses window. para_gui provides
key-bindings for the most common commands and new key-bindings can
be added easily.

-----------------------
para_sdl_gui (optional)
-----------------------

SDL-based gui. Similar to para_gui but presents its output in an X
window (fullscreen mode is also available) and can display jpg images
on a per song basis. para_sdl_gui provides an input prompt to enter
arbitrary commands. However, it can also be used non-interactively
(e.g. as a screen saver) via the -i switch.

-------------------------------------------------------------------------
para_krell (optional, only useful in conjunction with the mysql selector)
-------------------------------------------------------------------------

A plugin for gkrellm which shows small pictures of the current song. It
allows you to launch 27 different commands by clicking in different
areas of its picture (9 small squares x 3 mouse buttons).

--------------------
para_fade (optional)
--------------------

A (Linux-only) alarm clock and volume-fader.

-------------------------------------------------------------------------
para_dbadm (optional, only useful in conjunction with the mysql selector)
-------------------------------------------------------------------------

Very simple curses-based frontend which uses libmenu. Useful for
quickly changing the attributes of the current song (e.g. from para_gui
as an external command).

--------------------------------------------------------------------------
para_slider (optional, only useful in conjunction with the mysql selector)
--------------------------------------------------------------------------

A small X application which shows a scrollbar for each attribute
defined in the mysql database. It creates a stream definition from
the values of the scrollbars. This allows to smoothly change the mood
of the given stream without any file editing.

--------------------------
bash_completion (optional)
--------------------------

A small bash script for inclusion in ~/.bashrc. It gives you command
line completion for some paraslash commands.

------------
Requirements
------------

In any case you need

	- gcc, the gnu compiler collection (shipped with distro): gcc-3.3
	  or newer is required.
	- openssl (needed by server, client): usually shipped with
	  distro, but you might have to install the "development package"
	  (called libssl-dev on debian systems) as well:
	  http://www.openssl.org/
	- software mixing, e.g. ALSA and the direct mixing plugin (dmix)

If you want to use the mysql-based audio file selector, you also need

	- mysql-server
	- mysql-client
	- libmysqlclient

These are usually shipped with the distro but probably not installed
by default.

The mp3 decoder of para_filter is based on libmad: If you prefer to
use the libmad package provided by your distributor, make sure to
install the corresponding development package as well.  Otherwise,
just download libmad from http://www.underbit.com/products/mad/

For ogg vorbis streams you'll need libogg, libvorbis, libvorbisfile,
The corresponding Debian packages are called libogg-dev libvorbis-dev,
other distributors chose similar names.  All of these are also
available at http://www.xiph.org/downloads/

For aac files (m4a) you'll need libfaad. Get it at
http://www.audiocoding.com/modules/wiki/?page=AAC

If you intend to use the optional ortp streamer, you'll need libortp:
http://www.linphone.org/ortp/

For the optional SDL-based gui, the following packages must be installed:

	- X (usually shipped with distro): http://www.x.org/
	- libSDL (usually shipped with distro): http://www.libsdl.org/index.php
	- SDL_image: http://www.libsdl.org/projects/SDL_image/

For para_slider, the zero memory widget library is neccessary:
http://www710.univ-lyon1.fr/~exco/ZMW/

Finally, para_krell needs

	- gtk2: http://www.gtk.org/
	- gkrellm2: http://members.dslextreme.com/users/billw/gkrellm/gkrellm.html

-------
LICENSE
-------

Distribution of paraslash is covered by the GNU GPL. See file COPYING.

----------
THE AUTHOR
----------

Andre Noll <maan@systemlinux.org>
Comments and bug reports are welcome.