+[TOC]
+
+# Music Sampler
+
+## Description
+
+Music Sampler is a music player which associates each key on the keyboard to a
+set of actions to run.
+
+## Dependencies and installation
+
+- You need ffmpeg installed. For that, you can use package `libav-tools` (debian):
+
+ sudo apt-get install libav-tools
+
+If you use the compiled version of Music Sampler (cf. below for a download
+link), you need nothing else.
+
+- To use sources, the following modules are required:
+
+| module | minimum version | note |
+| ----------- | ---------------- | ------------------------------------------------------------- |
+| Cython | 0.24 | to compile Kivy |
+| Kivy | 1.9.1 | some features require to build/install with flag `USE_SDL2=1` |
+| Markdown | 2.6.6 | for documentation only |
+| pydub | 0.16.4 | |
+| Pygame | 1.9.2.dev1 | used by Kivy |
+| Pygments | 2.1.3 | for documentation only |
+| sounddevice | 0.3.3 | |
+| transitions | 0.4.1 | |
+| PyYAML | 3.11 | |
+
+The project is also available via `pip`:
+
+ pip install music_sampler
+
+The program makes use of fonts "Symbola" and "Ubuntu" (Regular / Bold), that
+must be available on your system, as well as the `portaudio` library:
+
+ sudo apt-get install ttf-ancient-fonts ttf-ubuntu-font-family portaudio
+
+Pour compiler kivy avec la librairie SDL2, il faut certains paquets installés:
+
+ sudo apt-get install libsdl2-dev libsdl2-image-dev libsdl2-mixer-dev libsdl2-ttf-dev
+
+cf [Installation
+Kivy](https://kivy.org/docs/installation/installation-linux.html)
+
+## Compiled version
+
+A compiled version can be created with `pyinstaller`:
+
+ :::bash
+ pyinstaller music_sampler.spec
+
+## Downloads
+
+- An example configuration together with some music examples can be found on
+ [owncloud](https://outils.immae.eu/owncloud/index.php/s/kSrIe15G1AiZ9YF)
+- A precompiled version of `music_sampler` can also be found
+ [in the same folder](https://outils.immae.eu/owncloud/index.php/s/kSrIe15G1AiZ9YF/download?path=%2F&files=music_sampler)
+ (beware, it might not be up-to-date, please run the program with `-V` to see
+ its corresponding version)
+
+## Usage
+
+The whole job consists in preparing all the transitions in the configuration
+file `config.yml`.
+
+The program should then be run in the folder in which the configuration file
+lies (see below for an advanced use). A window with a keyboard appears. The
+orange circle in the upper-right corner of the keyboard becomes green one every
+music is loaded (or red in case of problem). A key is semi-transparent and
+crossed when it is not usable at the moment: either because a music handled by
+this key is not loaded yet (it may take some time when the program launches), or
+because it has an action running.
+
+An example configuration file is given with some keys and transitions. The
+structure of the file (explained more in details below) should be easy to
+understand just by looking at it.
+
+### Possible actions
+
+ - Clic on a key: shows the associated actions in the bottom-left block of the
+ app.
+ - Key stroke: if available, runs the actions associated to this key. When a
+ key has currently running actions, his surround is black. Note that an
+ action like "play a music" is almost instantaneous as it is considered
+ "done" as soon as the music started playing.
+ To prevent accidents in case of repeated stroke on a key, `Music Sampler`
+ won't rerun the actions associated to that key if they are not already
+ finished.
+ - Ctrl+C or Ctrl+Q: leaves the program.
+ - Ctrl+R: reloads the configuration file
+
+### Options available at launch
+
+All the options below are optional; usually, running the program in the correct
+folder is enough
+
+ * `-h, --help`: shows a list of available options
+ * `-c CONFIG, --config CONFIG`: gives the configuration file to load (by
+ default, `config.yml` in the current folder).
+ * `-p MUSIC_PATH, --music-path MUSIC_PATH`: gives the path to find the musics
+ (by default, the current folder)
+ * `-d, --debug`: show debug informations in the terminal (disabled by default)
+ * `-V, --version`: show current version and exit (only for the compiled
+ version)
+ * `-L, --language`: change application language. Current languages: fr, en
+ (default 'fr')
+ * `--no-focus-warning`: don't show warning when focus gets lost.
+
+The following options are reserved for a more advanced use of Music Sampler, or
+in case of problem with the standard configuration:
+
+ * `-m, --builtin-mixing`: make the sound mixing locally. By default, Music
+ Sampler will let the system do it and open one channel per music loaded. Use
+ it only if the system cannot handle it.
+ * `-l LATENCY, --latency LATENCY`: "low", "high" or a number of seconds
+ (default "high")
+ * `-b BLOCKSIZE, --blocksize BLOCKSIZE`: Number of frames for each mixing
+ step. 0 (default) lets the program choose.
+ * `-f FRAME_RATE, --frame-rate FRAME_RATE`: default 44100Hz
+ * `-x CHANNELS, --channels CHANNELS` : Number of channels per music (default
+ 2, for stereo)
+ * `-s SAMPLE_WIDTH, --sample-width SAMPLE_WIDTH`: number of bytes per frame
+ (default 2).
+ * `--device DEVICE` : select another sound device.
+ * `--list-devices` : list available sound devices.
+ * `-- ARGS` : arguments for Kivy library.
+
+## Configure keys
+
+**Warning: the format of the configuration file is still a work in progress and
+may change without ensuring backward compatibility**
+
+The file `config.yml` uses yaml syntax. Categories and sub-categories are
+handled by space indentations (no tabs). Symbol `#` may be used for comments.
+
+In case of error in the configuration file, an error message will show up.
+Depending on its severity, Music Sampler may try to continue (ignoring
+corresponding problems) or abort.
+
+The file contains several sections:
+
+ :::yaml
+ aliases:
+ ...
+
+ music_properties:
+ ...
+
+ key_properties:
+ ...
+
+ keys:
+ ...
+
+
+### `music_properties`
+
+This section lets you define global properties for the musics.
+
+#### Examples
+
+ :::yaml
+ "music1.mp3":
+ name: My favorite music
+ gain: 1.4
+Music "music1.mp3" is named "My favorite music". She is loaded at 140% of its
+normal volume.
+
+ :::yaml
+ "music2.mp3":
+ gain: 0.7
+
+Music "music2.mp3" is loaded at 70% of its normal volume.
+
+#### List of available options
+- `name: My music` User-friendly name of the music, used in the interface
+ instead of the filename.
+
+- `gain: x` Loads the music with that initial gain x. This lets you equalize all
+ your music at desired level, independently of the volume afterwards.
+
+### `key_properties`: drawing and properties of keys
+
+This section lets you describe the drawing of the key: color, description. By
+default, a key assigned to one or more actions is shown in green
+
+#### Examples
+
+ :::yaml
+ 'ESC':
+ description:
+ -
+ - STOP!
+ color: [255, 0, 0]
+ repeat_delay: 2
+
+The "esc" key is red, and text "STOP!" is shown on the second line. The key is
+protected for 2 seconds after each stroke.
+
+#### List of availale options
+- `description`: the text on the key. Each item is shown on a line (no automatic
+ line break). First line is shown just next to the "key" name and is in bold.
+ On a standard screen, you may have about 3 lines visible (including the first
+ one)
+- `color: [r, g, b]`: the key color. r, g and b are the proportions respectively
+ of red, green and blue, and each value must be between 0 and 255
+- `repeat_delay: x` (default 0) : protection delay. Once all its actions are
+ done, the key will remain disabled (semi-transparent and crossed) for that
+ amount of time (in seconds).
+
+### `keys` : actions related to keys
+
+This section lets you describe for each key, the list of actions associated to
+it. Note that except for `wait` and some particular cases (see below), all the
+actions are almost instantaneous.
+
+
+#### Examples
+
+ :::yaml
+ 'a':
+ - play:
+ file: "music1.mp3"
+ volume: 70
+ start_at: 10
+ - wait:
+ duration: 5
+ - stop:
+ file: "music1.mp3"
+ fade_out: 2
+
+Runs music "music1.mp3" at 70% of its maximum volume, at 10 seconds from the
+start, then stops the music 5 seconds later with a 2 seconds fade out.
+
+ :::yaml
+ 'b':
+ - stop:
+ file: "music1.mp3"
+ fade_out: 5
+ wait: false
+ - play:
+ file: "music2.mp3"
+ fade_in: 5
+
+Make a cross fade of 5 seconds between "music1.mp3" and "music2.mp3"
+
+ :::yaml
+ 'c':
+ - stop:
+ file: "music1.mp3"
+ fade_out: 5
+ wait: true
+ - wait:
+ duration: 2
+ - play:
+ file: "music2.mp3"
+ - seek:
+ file: "music2.mp3"
+ delta: false
+ value: 60
+Stops music "music1.mp3" with a 5 seconds fade out, waits for the end of the
+fade out, plus 2 seconds, and then runs "music2.mp3" skipping the first minute.
+
+ :::yaml
+ 'd':
+ - volume:
+ file: "music1.mp3"
+ value: 50
+ - play:
+ file: "noise.mp3"
+ loop: 1
+ - wait:
+ file: "noise.mp3"
+ - volume:
+ file: "music1.mp3"
+ value: 100
+
+Lower volume of "music1.mp3" while "noise.mp3" is played above it (twice). Then
+the volume of the music comes back to normal.
+
+ :::yaml
+ 'e':
+ - pause:
+ file: "music1.mp3"
+ - wait:
+ duration: 10
+ - unpause:
+ file: "music1.mp3"
+ - seek:
+ file: "music1.mp3"
+ delta: true
+ value: 5
+
+Pauses "music1.mp3" for 10 seconds and reruns it afterward, seeking to 5 seconds
+later.
+
+#### List of all the actions:
+- `play` : start a music. Music Sampler only runs a music once (if you want to
+ have it playing several time concurrently, duplicate it or make symbolic
+ link). Parameters:
+ * `file: "music.mp3"` gives the played music (relative path).
+ * `fade_in: x` (optional) runs the music with x seconds fade in.
+ * `volume: x` (optional, default 100) sets the volume of the music.
+ * `loop: x` (optional, default 0) music should be repeated x times. Indicate
+ -1 for infinite loop. Note: x is the number of repetitions, thus the music
+ is actually played x+1 times.
+ * `start_at: x` (optional, default 0) start music skipping the first x
+ seconds.
+ * `restart_if_running: true/false` (optional, default false) if the music is
+ already running, stop it and restart it.
+- `stop` : stops a given music. Parameters:
+ * `file: "music.mp3"` (optional) gives the music to stop. If no music is
+ given, stops all of them.
+ * `fade_out: x` (optional) stops music with a x seconds fade out.
+ * `wait: true/false` (optional, default: false) when stopping with a fade
+ out, wait for the fade to finish before continuing to the next actions. If
+ the music stops naturally before the en of the fade out, the wait stops
+ there too. When several musics are stopped in fade out, the `wait` only
+ waits for the last one in the playlist (which can finish naturally before
+ the others).
+ * `set_wait_id: name` (optional, useless when `wait` is false) sets an id
+ `name` to the wait (see `interrupt_wait`). Any valid string may be used.
+- `volume` : change the volume of a given music. Parameters:
+ * `file: "music.mp3"` (optional) which music to change. If no music is
+ given, the global volume is changed.
+ * `delta: true/false` (optional, default false) add/remove to the volume
+ instead of setting an absolute value.
+ * `value: x` if delta is false, sets the volume to x%. Note that this factor
+ is applied to the music already loaded (with the initial gain). If delta
+ is true, adds or remove the percentage to the current volume.
+ * `fade: x` (optional) the volume change is applied with a x seconds fade.
+- `pause` : pause a music. Parameters:
+ * `file: "music.mp3"` (optional) gives the music to pause. If no music is
+ given, it applies to all playing musics.
+- `unpause` : unpause a music. Parameters:
+ * `file: "music.mp3"` (optional) gives the msuic to unpause. If no music is
+ given, it applies to all paused musics.
+- `wait` : wait for some time or for an event. Parameters:
+ * `file: "music.mp3"` (optional) wait for the end of music "music.mp3"
+ * `duration: x` (optional) wait x seconds. If `file` and `duration` are
+ given, wait the end of the music PLUS the `duration`.
+ * `set_wait_id: name` (optional) gives an id to the wait event (see
+ `interrupt_wait`). The id can be any valid string.
+Note again that this action is one of the only action that is not almost
+instantaneous. Use it wherever you need to make some time adjustments for other
+actions.
+- `seek` : seek to a specific position in a music. Parameters:
+ * `file: "music.mp3"` (optional) gives the music to seek. If no music is
+ given, applies to all playing musics.
+ * `delta: true/false` (optional, default false) If `delta` is true, the time
+ seek is relative. Otherwise, it is absolute.
+ * `value: x` If `delta` is true, then moves the music forward or backward by
+ x seconds. If delta is false, the music goes to that position. If the
+ music is fading (fade in or volume fade), the effect is immediately
+ interrupted. If the music is fading out, the "seek" is ignored. In case of
+ `loop`, a relative seek may jump to previous or next loop if possible,
+ while an absolute seek will jump to a position in the current loop.
+- `stop_all_actions:` Interrupts all the running and pending actions. Note that
+ a started music (even with a `loop` option) is the result of an action that is
+ already finished and thus will keep playing (see `stop` for that). Parameters:
+ * `other_only: true/false` (optional, default false): if `other_only` is
+ true, the interruption is valid for all keys except the one that ran the
+ action. When false, it is thus useless to add actions after that one.
+- `interrupt_wait`: stop a wait event (normal `wait` or fade out wait). The keys
+ that were waiting will move to the next actions. Parameters:
+ * `wait_id: name` : gives the id of the `wait` to interrupt (defined with
+ `set_wait_id`, see actions `wait` and `stop`). To interrupt several waits,
+ use the same action several times.
+- `run_command` : Run a command. Parameters:
+ * `command: my_command` : Gives the command to run.
+ * `wait: true/false` (optional, default false) if true, waits for the
+ command to finish (this wait is not interruptible by interrupt_wait)
+
+### `aliases` : define aliases
+
+It is possible to define some aliases for the parameters. Those aliases are
+internal to the configuration file. To give a nice name to a music, see
+"music_properties".
+
+The aliases syntax is the following:
+
+ :::yaml
+ aliases:
+ alias1:
+ param: value
+ alias2:
+ param1: value1
+ param2: value2
+
+You can then use in other places of the configuration file a special argument
+`include: alias1` or `include: [alias1, alias2]` instead of `param: value`. In
+the case of several aliases that have identical elements, only the last one is
+kept. In all cases, a value defined outside of an include takes precedence. See
+below examples.
+
+#### Examples
+
+ :::yaml
+ aliases:
+ music1:
+ file: "path/to/my/favourite/music.mp3"
+
+ keys:
+ 'a':
+ play:
+ include: music1
+
+`music1` is now an alias for `file: "path/to/my/favourite/music.mp3"`. You can
+use `include: music1` at any place where you would have written `file:
+"path/to/my/favourite/music.mp3"`. Aliases cannot be used in section
+"music_properties".
+
+ :::yaml
+ aliases:
+ blue:
+ color: [0, 0, 255]
+
+ keys_properties:
+ 'a':
+ description:
+ -
+ - blue key
+ include: blue
+
+`blue` is an alias for color `[0, 0, 255]`. Wherever you need to specify `color:
+[0, 0, 255]`, you may write `include: blue` instead.
+
+ :::yaml
+ aliases:
+ long_time:
+ duration: 42
+
+ keys:
+ 'b':
+ wait:
+ include: long_time
+ play:
+ file: "music1.mp3"
+
+`long_time` is an alias for a 42 seconds duration. Instead of `duration: 42`,
+you may use `include: long_time`.
+
+## Troubleshooting
+
+You'll find below a list of possible problems, and a possible solution. If you
+find some other problems, please contact the author.
+
+* The program starts and stops immediately.
+
+It is usually a syntax error in the config file. In that case, the terminal
+should give some informations.
+
+* The music sizzles
+
+It may be a latency problems (with slow computers). Try to adapt it to a higher
+value (~0.1 seconds)
+
+* Impossible to play more than one music at a time.
+
+The system cannot mix the musics by itself. You may have a look at the device
+list (`--list-devices`) and choose another. You may also try the integrated
+mixer, but the result may not be very fluid (you will certainly need to adjust
+blocksize and latency parameters if you do that)
+
+If your system uses PulseAudio, it may be a configuration problem for the ALSA
+plugin. In that case, try to put the following configuration in
+`/etc/asound.conf` and restart your system. This is an empirical solution that
+seems to have worked, there is no garanty that it will!
+
+ pcm.!default {
+ type pulse
+ fallback "sysdefault"
+ hint {
+ show on
+ description "Default ALSA Output (currently PulseAudio Sound Server)"
+ }
+ }
+
+ ctl.!default {
+ type pulse
+ fallback "sysdefault"
+ }
+
+* The terminal shows an error:
+
+ Exception in thread Thread-1:
+ Traceback (most recent call last):
+ File "threading.py", line 914, in _bootstrap_inner
+ File "threading.py", line 862, in run
+ File "kivy/input/providers/mtdev.py", line 219, in _thread_run
+ File "kivy/lib/mtdev.py", line 131, in __init__
+ PermissionError: [Errno 13] Permission denied: '/dev/input/event6'
+
+This is a device permission error. It can be safely ignored.
+
+* For other problems or bug, please see [Bug
+ Tracker](https://git.immae.eu/mantisbt/view_all_bug_page.php?project_id=1&sort=status%2Clast_updated&dir=ASC%2CDESC)
+
+## About
+
+The musics in the examples come from [Jamendo](https://jamendo.com). The
+complete version of those musics are available for free for a non-commercial
+use:
+
+[Short Blues](https://www.jamendo.com/track/340173/short-blues)
+
+[To the Fantasy war](https://www.jamendo.com/track/778560/to-the-fantasy-war)
+
+The crocodile noise comes from
+[Universal-Soundbank](http://www.universal-soundbank.com/).
+
+This program was developped originaly to help handling music for shows of the
+circus company [Les pieds jaloux](http://piedsjaloux.fr/). With no available
+sound manager, the artists sometimes had to run from the scene to make the sound
+transitions, making as little interaction as possible with the computed (one
+key).