In this chapter we give an [overview](#Overview) of the interactions
of the programs contained in the paraslash package, followed by
-[brief descriptions](#The.paraslash.executables) of all executables.
+[brief descriptions](#The-paraslash-executables) of all executables.
Overview
--------
including information found in (ID3) tags. Simple playlists are also
supported. It is possible to store images (album covers) and lyrics
in the database and associate these to the corresponding audio files.
-The section on the [audio file selector](#The.audio.file.selector)
+The section on the [audio file selector](#The-audio-file-selector)
discusses this topic in more detail.
Another component of para_server is the virtual streaming system,
In addition to the three network streaming modes, para_recv can also
operate in local (afh) mode. In this mode it writes the content of
an audio file on the local file system in complete chunks to stdout,
-optionally 'just in time'. This allows to cut an audio file without
-first decoding it, and it enables third-party software which is unaware
-of the particular audio format to send complete frames in real time.
+optionally 'just in time'. This allows cutting audio files without
+decoding, and it enables third-party software which is unaware of
+the particular audio format to send complete frames in real time.
<h3> para_filter </h3>
------------
<h3> For the impatient </h3>
- git clone git://git.tuebingen.mpg.de/lopsub
+ git clone https://git.tuebingen.mpg.de/lopsub
cd lopsub && make && sudo make install
- git clone git://git.tuebingen.mpg.de/osl
+ git clone https://git.tuebingen.mpg.de/osl
cd osl && make && sudo make install && sudo ldconfig
sudo apt-get install autoconf libssl-dev m4 \
libmad0-dev libid3tag0-dev libasound2-dev libvorbis-dev \
- libfaad-dev libspeex-dev libFLAC-dev libsamplerate-dev realpath \
+ libfaad-dev libspeex-dev libflac-dev libsamplerate-dev \
libasound2-dev libao-dev libreadline-dev libncurses-dev \
libopus-dev
file parsers for all paraslash executables. Clone the source code
repository with
- git clone git://git.tuebingen.mpg.de/lopsub
+ git clone https://git.tuebingen.mpg.de/lopsub
- [gcc](ftp://ftp.gnu.org/pub/gnu/gcc) or
-[clang](http://clang.llvm.org). All gcc versions >= 4.2 are currently
-supported. Clang version 1.1 or newer should work as well.
+[clang](http://clang.llvm.org). All gcc versions >= 5.4 are currently
+supported. Moderately recent versions of clang should work as well.
- [gnu make](ftp://ftp.gnu.org/pub/gnu/make) is also shipped with the
disto. On BSD systems the gnu make executable is often called gmake.
Optional:
-- [libosl](http://people.tuebingen.mpg.de/maan/osl/). The _object
+- [libosl](https://people.tuebingen.mpg.de/maan/osl/). The _object
storage layer_ library is used by para_server. To clone the source
code repository, execute
- git clone git://git.tuebingen.mpg.de/osl
+ git clone https://git.tuebingen.mpg.de/osl
-- [openssl](http://www.openssl.org/) or
+- [openssl](https://www.openssl.org/) or
[libgcrypt](ftp://ftp.gnupg.org/gcrypt/libgcrypt/). At least one
of these two libraries is needed as the backend for cryptographic
routines on both the server and the client side. Both openssl and
to install the development package (`libssl-dev` or `libgcrypt-dev`
on debian systems) as well.
+- [flex](https://github.com/westes/flex) and
+[bison](https://www.gnu.org/software/bison/) are needed to build the
+mood parser of para_server. The build system will skip para_server
+if these tools are not installed.
+
- [libmad](http://www.underbit.com/products/mad/). To compile in MP3
support for paraslash, the development package must be installed. It
is called `libmad0-dev` on debian-based systems. Note that libmad is
not necessary on the server side, i.e., for sending MP3 files.
- [libid3tag](http://www.underbit.com/products/mad/). For version-2
-ID3 tag support, you willl need the libid3tag development package
+ID3 tag support, you will need the libid3tag development package
`libid3tag0-dev`. Without libid3tag, only version-1 tags are
recognized. The mp3 tagger also needs this library for modifying
(id3v1 and id3v2) tags.
-- [ogg vorbis](http://www.xiph.org/downloads/). For ogg vorbis streams
+- [ogg vorbis](https://www.xiph.org/downloads/). For ogg vorbis streams
you need libogg, libvorbis, libvorbisfile. The corresponding Debian
packages are called `libogg-dev` and `libvorbis-dev`.
-- [libfaad and mp4ff](http://www.audiocoding.com/). For aac files
+- [libfaad and mp4ff](https://sourceforge.net/projects/faac/). For aac files
(m4a) you need libfaad and libmp4ff (package: `libfaad-dev`). Note
that for some distributions, e.g. Ubuntu, mp4ff is not part of the
libfaad package. Install the faad library from sources (available
through the above link) to get the mp4ff library and header files.
-- [speex](http://www.speex.org/). In order to stream or decode speex
+- [speex](https://www.speex.org/). In order to stream or decode speex
files, libspeex (`libspeex-dev`) is required.
-- [flac](http://flac.sourceforge.net/). To stream or decode files
+- [flac](https://xiph.org/flac/). To stream or decode files
encoded with the _Free Lossless Audio Codec_, libFLAC (`libFLAC-dev`)
must be installed.
- [alsa-lib](ftp://ftp.alsa-project.org/pub/lib/). On Linux, you will
need to have the ALSA development package `libasound2-dev` installed.
-- [libao](http://downloads.xiph.org/releases/ao/). Needed to build
+- [libao](https://ftp.osuosl.org/pub/xiph/releases/ao/). Needed to build
the ao writer (ESD, PulseAudio,...). Debian package: `libao-dev`.
- [curses](ftp://ftp.gnu.org/pub/gnu/ncurses). Needed for
para_gui. Debian package: `libncurses-dev`.
- [GNU
-Readline](http://cnswww.cns.cwru.edu/php/chet/readline/rltop.html). If
+Readline](https://www.gnu.org/software/readline/). If
this library (`libreadline-dev`) is installed, para_client, para_audioc
and para_play support interactive sessions.
Next, change to the "bar" account on client_host and generate the
key pair with the commands
- ssh-keygen -q -t rsa -b 2048 -N '' -f $key
+ ssh-keygen -q -t rsa -b 2048 -N '' -m RFC4716
This generates the two files id_rsa and id_rsa.pub in ~/.ssh. Note
that para_server won't accept keys shorter than 2048 bits. Moreover,
para_client init
This initializes a couple of empty tables under
-~/.paraslash/afs_database-0.4. You normally don't need to look at these
+~/.paraslash/afs_database-0.7. You normally don't need to look at these
tables, but it's good to know that you can start from scratch with
- rm -rf ~/.paraslash/afs_database-0.4
+ rm -rf ~/.paraslash/afs_database-0.7
in case something went wrong.
Since no playlist has been specified yet, the "dummy" mode which
selects all known audio files is activated automatically. See the
-section on the [audio file selector](#The.audio.file.selector) for how
+section on the [audio file selector](#The-audio-file-selector) for how
to use playlists and moods to specify which files should be streamed
in which order.
the AES stream cipher in integer counter mode.
In this chapter we briefly describe RSA and AES, and sketch the
-[authentication handshake](#Client-server.authentication)
+[authentication handshake](#Client-2d-server-authentication)
between para_client and para_server. User management is discussed
-in the section on [the user_list file](#The.user_list.file).
+in the section on [the user_list file](#The-user_list-file).
These sections are all about communication between the client and the
server. Connecting para_audiod is a different matter and is described
-in a [separate section](#Connecting.para_audiod).
+in a [separate section](#Connecting-para_audiod).
RSA and AES
-----------
- para_client receives the encrypted buffer and decrypts it with the
user's private key, thereby obtaining the challenge buffer and the
-session key. It sends the SHA1 hash value of the challenge back to
-para_server and stores the session key for further use.
+session key. It hashes the challenge buffer with a crytographic hash
+function, sends the hash value back to para_server and stores the
+session key for further use.
-- para_server also computes the SHA1 hash of the challenge and compares
+- para_server also computes the hash value of the challenge and compares
it against what was sent back by the client.
- If the two hashes do not match, the authentication has failed and
paraslash relies on the quality of the pseudo-random bytes provided
by the crypto library (openssl or libgcrypt), on the security of
the implementation of the RSA and AES crypto routines and on the
-infeasibility to invert the SHA1 function.
+infeasibility to invert the hash function.
Neither para_server or para_client create RSA keys on their
own. This has to be done once for each user as sketched in
-[Quick start](#Quick.start) and discussed in more detail
-[below](#The.user_list.file).
+[Quick start](#Quick-start) and discussed in more detail
+[below](#The-user_list-file).
The user_list file
------------------
that can be associated with one or more audio files.
In this chapter we sketch the setup of the [AFS
-process](#The.AFS.process) during server startup and proceed with the
-description of the [layout](#Database.layout) of the various database
-tables. The section on [playlists and moods](#Playlists.and.moods)
+process](#The-AFS-process) during server startup and proceed with the
+description of the [layout](#Database-layout) of the various database
+tables. The section on [playlists and moods](#Playlists-and-moods)
explains these two audio file selection mechanisms in detail
and contains practical examples. The way [file renames and content
-changes](#File.renames.and.content.changes) are detected is discussed
-briefly before the [Troubleshooting](#Troubleshooting) section
+changes](#File-renames-and-content-changes) are detected is discussed
+briefly before the [Troubleshooting](#Common-problems) section
concludes the chapter.
The AFS process
to the database.
Note that AFS employs
-[libosl](http://people.tuebingen.mpg.de/maan/osl/), the object
+[libosl](https://people.tuebingen.mpg.de/maan/osl/), the object
storage layer library, as the database backend. This library offers
functionality similar to a relational database, but is much more
lightweight than a full featured database management system.
AFS database. It contains the information needed to stream each audio
file. In particular the following data is stored for each audio file.
-- SHA1 hash value of the audio file contents. This is computed once
-when the file is added to the database. Whenever AFS selects this
-audio file for streaming the hash value is recomputed and checked
-against the value stored in the database to detect content changes.
+- The cryptographic hash value of the audio file contents. This is
+computed once when the file is added to the database. Whenever AFS
+selects this audio file for streaming the hash value is recomputed
+and checked against the value stored in the database to detect
+content changes.
- The time when this audio file was last played.
<h3> Moods </h3>
-A mood consists of a unique name and its *mood definition*, which is
-a set of *mood lines* containing expressions in terms of attributes
-and other data contained in the database.
-
-At any time at most one mood can be *active* which means that
-para_server is going to select only files from that subset of
-admissible files.
-
-So in order to create a mood definition one has to write a set of
-mood lines. Mood lines come in three flavours: Accept lines, deny
-lines and score lines.
-
-The general syntax of the three types of mood lines is
-
-
- accept [with score <score>] [if] [not] <mood_method> [options]
- deny [with score <score>] [if] [not] <mood_method> [options]
- score <score> [if] [not] <mood_method> [options]
-
-
-Here <score> is either an integer or the string "random" which assigns
-a random score to all matching files. The score value changes the
-order in which admissible files are going to be selected, but is of
-minor importance for this introduction.
-
-So we concentrate on the first two forms, i.e. accept and deny
-lines. As usual, everything in square brackets is optional, i.e.
-accept/deny lines take the following form when ignoring scores:
-
- accept [if] [not] <mood_method> [options]
-
-and analogously for the deny case. The "if" keyword is only syntactic
-sugar and has no function. The "not" keyword just inverts the result,
-so the essence of a mood line is the mood method part and the options
-following thereafter.
-
-A *mood method* is realized as a function which takes an audio file
-and computes a number from the data contained in the database.
-If this number is non-negative, we say the file *matches* the mood
-method. The file matches the full mood line if it either
-
- - matches the mood method and the "not" keyword is not given,
-or
- - does not match the mood method, but the "not" keyword is given.
-
-The set of admissible files for the whole mood is now defined as those
-files which match at least one accept mood line, but no deny mood line.
-More formally, an audio file F is admissible if and only if
-
- (F ~ AL1 or F ~ AL2...) and not (F ~ DL1 or F ~ DN2 ...)
-
-where AL1, AL2... are the accept lines, DL1, DL2... are the deny
-lines and "~" means "matches".
-
-The cases where no mood lines of accept/deny type are defined need
-special treatment:
-
- - Neither accept nor deny lines: This treats all files as
- admissible (in fact, that is the definition of the dummy mood
- which is activated automatically if no moods are available).
-
- - Only accept lines: A file is admissible iff it matches at
- least one accept line:
-
- F ~ AL1 or F ~ AL2 or ...
-
- - Only deny lines: A file is admissible iff it matches no
- deny line:
-
- not (F ~ DL1 or F ~ DN2 ...)
-
-
-
-<h3> List of mood_methods </h3>
-
- no_attributes_set
-
-Takes no arguments and matches an audio file if and only if no
-attributes are set.
-
- is_set <attribute_name>
-
-Takes the name of an attribute and matches iff that attribute is set.
-
- path_matches <pattern>
-
-Takes a filename pattern and matches iff the path of the audio file
-matches the pattern.
-
- artist_matches <pattern>
- album_matches <pattern>
- title_matches <pattern>
- comment_matches <pattern>
-
-Takes an extended regular expression and matches iff the text of the
-corresponding tag of the audio file matches the pattern. If the tag
-is not set, the empty string is matched against the pattern.
-
- year ~ <num>
- bitrate ~ <num>
- frequency ~ <num>
- channels ~ <num>
- num_played ~ <num>
- image_id ~ <num>
- lyrics_id ~ <num>
-
-Takes a comparator ~ of the set {<, =, <=, >, >=, !=} and a number
-<num>. Matches an audio file iff the condition <val> ~ <num> is
-satisfied where val is the corresponding value of the audio file
-(value of the year tag, bitrate in kbit/s, etc.).
-
-The year tag is special as its value is undefined if the audio file
-has no year tag or the content of the year tag is not a number. Such
-audio files never match. Another difference is the special treatment
-if the year tag is a two-digit number. In this case either 1900 or
-2000 is added to the tag value, depending on whether the number is
-greater than 2000 plus the current year.
-
+A mood consists of a unique name and a definition. The definition
+is an expression which describes which audio files are considered
+admissible. At any time at most one mood can be active, meaning
+that para_server will only stream files which are admissible for the
+active mood.
+
+The expression may refer to attributes and other metadata stored in
+the database. Expressions may be combined by means of logical and
+arithmetical operators in a natural way. Moreover, string matching
+based on regular expression or wildcard patterns is supported.
+
+The set of admissible files is determined by applying the expression
+to each audio file in turn. For a mood definition to be valid, its
+expression must evaluate to a number, a string or a boolean value
+("true" or "false"). For numbers, any value other than zero means the
+file is admissible. For strings, any non-empty string indicates an
+admissible file. For boolean values, true means admissible and false
+means not admissible. As a special case, the empty expression treats
+all files as admissible.
+
+<h3> Mood grammar </h3>
+
+Expressions are based on a context-free grammar which distinguishes
+between several types for syntactic units or groupings. The grammar
+defines a set of keywords which have a type and a corresponding
+semantic value, as shown in the following table.
+
+Keyword | Type | Semantic value
+:--------------------|--------:|:----------------------------------
+`path` | string | Full path of the current audio file
+`artist` | string | Content of the artist meta tag
+`title` | string | Content of the title meta tag
+`album` | string | Content of the album meta tag
+`comment` | string | Content of the somment meta tag
+`num_attributes_set` | integer | Number of attributes which are set
+`year` | integer | Content of the year meta tag [\*]
+`num_played` | integer | How many times the file has been streamed
+`image_id` | integer | The identifier of the (cover art) image
+`lyrics_id` | integer | The identifier of the lyrics blob
+`bitrate` | integer | The average bitrate
+`frequency` | integer | The output sample rate
+`channels` | integer | The number of channels
+`duration` | integer | The number of milliseconds
+`is_set("foo")` | boolean | True if attribute "foo" is set.
+
+[\*] For most audio formats, the year tag is stored as a string. It
+is converted to an integer by the mood parser. If the audio file
+has no year tag or the content of the year tag is not a number, the
+semantic value is zero. A special convention applies if the year tag
+is a one-digit or a two-digit number. In this case 1900 is added to
+the tag value.
+
+Expressions may be grouped using parentheses, logical and
+arithmetical operators or string matching operators. The following
+table lists the available operators.
+
+Token | Meaning
+:------|:-------
+`\|\|` | Logical Or
+`&&` | Logical And
+`!` | Logical Not
+`==` | Equal (can be applied to all types)
+`!=` | Not equal. Likewise
+`<` | Less than
+`<=` | Less or equal
+`>=` | Greater or equal
+`+` | Arithmetical minus
+`-` | Binary/unary minus
+`*` | Multiplication
+`/` | Division
+`=~` | Regular expression match
+`=\|` | Filename match
+
+Besides integers, strings and booleans there is an additional type
+which describes regular expression or wildcard patterns. Patterns
+are not just strings because they also include a list of flags which
+modify matching behaviour.
+
+Regular expression patterns are of the form `/pattern/[flags]`. That
+is, the pattern is delimited by slashes, and is followed by zero or
+more characters, each specifying a flag according to the following
+table
+
+Flag | POSIX name | Meaning
+:----|--------------:|--------
+`i` | `REG_ICASE` | Ignore case in match
+`n` | `REG_NEWLINE` | Treat newline as an ordinary character
+
+Note that only extended regular expression patterns are supported. See
+regex(3) for details.
+
+Wildcard patterns are similar, but the pattern must be delimited by
+`'|'` characters rather than slashes. For wildcard patterns different
+flags exist, as shown below.
+
+Flag | POSIX name | Meaning
+:----|-----------------------:|--------
+`n` | `FNM_NOESCAPE` | Treat backslash as an ordinary character
+`p` | `FNM_PATHNAME` | Match a slash only with a slash in pattern
+`P` | `FNM_PERIOD` | Leading period has to be matched exactly
+`l` | `FNM_LEADING_DIR` [\*] | Ignore "/\*" rest after successful matching
+`i` | `FNM_CASEFOLD` [\*] | Ignore case in match
+`e` | `FNM_EXTMATCH` [\*\*] | Enable extended pattern matching
+
+[\*] Not in POSIX, but both FreeBSD and NetBSD have it.
+
+[\*\*] GNU extension, silently ignored on non GNU systems.
+
+See fnmatch(3) for details.
+
+Mood definitions may contain arbitrary whitespace and comments.
+A comment is a word beginning with #. This word and all remaining
+characters of the line are ignored.
+
+<h3> Example moods </h3>
+
+* Files with no/invalid year tag: `year == 0`
+
+* Only oldies: `year != 0 && year < 1980`
+
+* Only 80's Rock or Metal: `(year >= 1980 && year < 1990) &&
+ (is_set("rock") || is_set("metal"))`
+
+* Files with incomplete tags: `artist == "" || title == "" || album =
+"" || comment == "" || year == 0`
+
+* Files with no attributes defined so far: `num_attributes_set == 0`
+
+* Only newly added files: `num_played == 0`
+
+* Only poor quality files: `bitrate < 96`
+
+* Cope with different spellings of Motörhead: `artist =~ /mot(ö|oe{0,1})rhead/i`
+
+* The same with extended wildcard patterns: `artist =| |mot+(o\|oe\|ö)rhead|ie`
<h3> Mood usage </h3>
para ls -a
-
-<h3> Example mood definition </h3>
-
-Suppose you have defined attributes "punk" and "rock" and want to define
-a mood containing only Punk-Rock songs. That is, an audio file should be
-admissible if and only if both attributes are set. Since
-
- punk and rock
-
-is obviously the same as
-
- not (not punk or not rock)
-
-(de Morgan's rule), a mood definition that selects only Punk-Rock
-songs is
-
- deny if not is_set punk
- deny if not is_set rock
-
-
-
File renames and content changes
--------------------------------
-Since the audio file selector knows the SHA1 of each audio file that
+Since the audio file selector knows the hash of each audio file that
has been added to the afs database, it recognizes if the content of
a file has changed, e.g. because an ID3 tag was added or modified.
Also, if a file has been renamed or moved to a different location,
It is possible to change the behaviour of the add command by using the
"-l" (lazy add) or the "-f" (force add) option.
-Troubleshooting
+Common problems
---------------
Use the debug loglevel (-l debug) to show debugging info. All paraslash
case you'll have to run the oslfsck program of libosl to fix your
database:
- oslfsck -fd ~/.paraslash/afs_database-0.4
+ oslfsck -fd ~/.paraslash/afs_database-0.7
However, make sure para_server isn't running before executing oslfsck.
If you don't mind to recreate your database you can start
from scratch by removing the entire database directory, i.e.
- rm -rf ~/.paraslash/afs_database-0.4
+ rm -rf ~/.paraslash/afs_database-0.7
Be aware that this removes all attribute definitions, all playlists
and all mood definitions and requires to re-initialize the tables.
HTTP) can be chosen.
The chapter starts with the [control
-service](#The.paraslash.control.service), followed by a section
-on the various [streaming protocols](#Streaming.protocols)
+service](#The-paraslash-control-service), followed by a section
+on the various [streaming protocols](#Streaming-protocols)
in which the data connections are described. The way
audio file headers are embedded into the stream is discussed
-[briefly](#Streams.with.headers.and.headerless.streams) before the
-[example section](#Networking.examples) which illustrates typical
+[briefly](#Streams-with-headers-and-headerless-streams) before the
+[example section](#Networking-examples) which illustrates typical
commands for real-life scenarios.
Both IPv4 and IPv6 are supported.
fact, the child process can not change address space of server process.
The section on [client-server
-authentication](#Client-server.authentication) above described the
+authentication](#Client-2d-server-authentication) above described the
early connection establishment from the crypto point of view. Here
it is described what happens after the connection (including crypto
setup) has been established. There are four processes involved during
- UDP. Recommended for multicast LAN streaming.
-See the Appendix on [network protocols](#Network.protocols)
+See the Appendix on [network protocols](#Network-protocols)
for brief descriptions of the various protocols relevant for network
audio streaming with paraslash.
and may also be configured through the "sender" command. The FEC
parameters are encoded in the header of each network packet, so no
configuration is necessary on the receiver side. See the section on
-[FEC](#Forward.error.correction) below.
+[FEC](#Forward-error-correction) below.
Streams with headers and headerless streams
-------------------------------------------
para_client si
-The sender command of para_server prints information about senders,
-like the various access control lists, and it allows to (de-)activate
-senders and to change the access permissions at runtime.
-
--> List all senders
-
- para_client sender
-
--> Obtain general help for the sender command:
-
- para_client help sender
-
--> Get help for a specific sender (contains further examples):
-
- s=http # or dccp or udp
- para_client sender $s help
-
--> Show status of the http sender
-
- para_client sender http status
-
By default para_server activates both the HTTP and th DCCP sender on
startup. This can be changed via command line options or para_server's
config file.
para_server -h
-All senders share the "on" and "off" commands, so senders may be
-activated and deactivated independently of each other.
-
--> Switch off the http sender:
-
- para_client sender http off
-
-> Receive a DCCP stream using CCID2 and write the output into a file:
host=foo.org; ccid=2; filename=bar
line parser, so arguments for the dccp receiver must be protected
from being interpreted by para_recv.
--> Start UDP multicast, using the default multicast address:
-
- para_client sender udp add 224.0.1.38
-
-> Receive FEC-encoded multicast stream and write the output into a file:
filename=foo
para_recv -r udp > $filename
--> Add an UDP unicast for a client to the target list of the UDP sender:
-
- t=client.foo.org
- para_client sender udp add $t
-
-> Receive this (FEC-encoded) unicast stream:
filename=foo
Forward error correction
------------------------
-As already mentioned [earlier](#Streaming.protocols), paraslash
+As already mentioned [earlier](#Streaming-protocols), paraslash
uses forward error correction (FEC) for the unreliable UDP and
DCCP transports. FEC is a technique which was invented already in
1960 by Reed and Solomon and which is widely used for the parity
all. The wav filter is only useful with para_filter and in connection
with a decoder. It asks the decoder for the number of channels and the
sample rate of the stream and adds a Microsoft wave header containing
-this information at the beginning. This allows to write wav files
+this information at the beginning. This allows writing wav files
rather than raw PCM files (which do not contain any information about
the number of channels and the sample rate).
operating on uncompressed audio streams, since data buffers are simply
"pushed down" rather than copied.
-Examples
---------
-
--> Decode an mp3 file to wav format:
-
- para_filter -f mp3dec -f wav < file.mp3 > file.wav
-
--> Amplify a raw audio file by a factor of 1.5:
-
- para_filter -f amp --amp 32 < foo.raw > bar.raw
-
======
Output
======
also limited. For example only one application can open the device
at any time. The OSS writer is activated by default on BSD Systems.
-- *FILE*. The file writer allows to capture the audio stream and
-write the PCM data to a file on the file system rather than playing
+- *FILE*. The file writer allows capturing the audio stream and
+writing the PCM data to a file on the file system rather than playing
it through a sound device. It is supported on all platforms and is
always compiled in.
The "." and "," keys are used to switch between themes.
-Examples
---------
+Gui examples
+------------
-> Show server info:
paraslash project, some additional tools should be installed on a
developer machine.
-- [git](http://git.or.cz/). As described in more detail
-[below](#Git.branches), the git source code management tool is used for
+- [git](https://git-scm.com/). As described in more detail
+[below](#Git-branches), the git source code management tool is used for
paraslash development. It is necessary for cloning the git repository
and for getting updates.
the configure file which is shipped in the tarballs but has to be
generated when compiling from git.
-- [discount](http://www.pell.portland.or.us/~orc/Code/discount). The
+- [discount](http://www.pell.portland.or.us/~orc/Code/discount/). The
HTML version of this manual and some of the paraslash web pages are
written in the Markdown markup language and are translated into html
with the converter of the *Discount* package.
-- [doxygen](http://www.stack.nl/~dimitri/doxygen/). The documentation
+- [doxygen](https://www.doxygen.nl/). The documentation
of paraslash's C sources uses the doxygen documentation system. The
conventions for documenting the source code is described in the
[Doxygen section](#Doxygen).
The preferred coding style for paraslash coincides more or less
with the style of the Linux kernel. So rather than repeating what is
-written [there](http://www.kernel.org/doc/Documentation/process/coding-style.rst),
+written [there](https://www.kernel.org/doc/Documentation/process/coding-style.rst),
here are the most important points.
- Burn the GNU coding standards.
- Don't leave whitespace at the end of lines.
- The limit on the length of lines is 80 columns.
- Use K&R style for placing braces and spaces:
-
+<pre>
if (x is true) {
we do y
}
-
+</pre>
- Use a space after (most) keywords.
- Do not add spaces around (inside) parenthesized expressions.
- Use one space around (on each side of) most binary and ternary operators.
References
==========
-Articles
---------
-- [Polynomial Codes over Certain Finite
-Fields](http://kom.aau.dk/~heb/kurser/NOTER/KOFA01.PDF) by Reed, Irving
-S.; Solomon, Gustave (1960), Journal of the Society for Industrial
-and Applied Mathematics (SIAM) 8 (2): 300-304, doi:10.1137/0108018)
-
RFCs
----
-- [RFC 768](http://www.ietf.org/rfc/rfc768.txt) (1980): User Datagram
+- [RFC 768](https://www.ietf.org/rfc/rfc768.txt) (1980): User Datagram
Protocol
-- [RFC 791](http://www.ietf.org/rfc/rfc791.txt) (1981): Internet
+- [RFC 791](https://www.ietf.org/rfc/rfc791.txt) (1981): Internet
Protocol
-- [RFC 2437](http://www.ietf.org/rfc/rfc2437.txt) (1998): RSA
+- [RFC 2437](https://www.ietf.org/rfc/rfc2437.txt) (1998): RSA
Cryptography Specifications
-- [RFC 4340](http://www.ietf.org/rfc/rfc4340.txt) (2006): Datagram
+- [RFC 4340](https://www.ietf.org/rfc/rfc4340.txt) (2006): Datagram
Congestion Control Protocol (DCCP)
-- [RFC 4341](http://www.ietf.org/rfc/rfc4341.txt) (2006): Congestion
+- [RFC 4341](https://www.ietf.org/rfc/rfc4341.txt) (2006): Congestion
Control ID 2: TCP-like Congestion Control
-- [RFC 4342](http://www.ietf.org/rfc/rfc4342.txt) (2006): Congestion
+- [RFC 4342](https://www.ietf.org/rfc/rfc4342.txt) (2006): Congestion
Control ID 3: TCP-Friendly Rate Control (TFRC)
-- [RFC 6716](http://www.ietf.org/rfc/rfc6716.txt) (2012): Definition
+- [RFC 6716](https://www.ietf.org/rfc/rfc6716.txt) (2012): Definition
of the Opus Audio Codec
Application web pages
---------------------
-- [paraslash](http://people.tuebingen.mpg.de/maan/paraslash/)
-- [xmms](http://xmms2.org/wiki/Main_Page)
+- [paraslash](https://people.tuebingen.mpg.de/maan/paraslash/)
- [mpg123](http://www.mpg123.de/)
-- [gstreamer](http://gstreamer.freedesktop.org/)
-- [icecast](http://www.icecast.org/)
-- [Audio Compress](http://beesbuzz.biz/code/audiocompress.php)
+- [gstreamer](https://gstreamer.freedesktop.org/)
+- [icecast](https://www.icecast.org/)
+- [Audio Compress](https://github.com/fluffy-critter/audiocompress)
External documentation
----------------------
-- [The mathematics of
-Raid6](http://kernel.org/pub/linux/kernel/people/hpa/raid6.pdf)
-by H. Peter Anvin
-
- [Effective Erasure Codes for reliable Computer Communication
Protocols](http://info.iet.unipi.it/~luigi/fec_ccr.ps.gz) by Luigi
Rizzo
projects / paraslash.git / blobdiff