Difference between revisions of "Standards:MUD Client Media Protocol"

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m (Added fadein and fadeout to Client.Media.Play and a Version section. Acknowledged agreement from co-author eric[at]oestrich.org on Mud discord before making the change.)
 
(9 intermediate revisions by the same user not shown)
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   "fadein": 5000,
 
   "fadein": 5000,
 
   "fadeout": 7000,
 
   "fadeout": 7000,
 +
  "start": 1000,
 +
  "finish": 20000,
 
   "loops": 3,
 
   "loops": 3,
 
   "priority": 60,
 
   "priority": 60,
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| style="text-align:center;"| No
 
| style="text-align:center;"| No
 
| "volume"
 
| "volume"
| milliseconds (1000 = 1 second)
+
| 1 to 100
|  
+
| 50
 
| style="text-align:left;"|
 
| style="text-align:left;"|
 
* Relative to the volume set on the player's client.
 
* Relative to the volume set on the player's client.
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|  
 
|  
 
| style="text-align:left;"|
 
| style="text-align:left;"|
* Volume increases, or fades in, ranged across a linear pattern from zero to the volume set with the "volume" key.
+
* Volume increases, or fades in, ranged across a linear pattern from one to the volume set with the "volume" key.
 
* Start position: Start of media.
 
* Start position: Start of media.
 
* End position: Start of media plus the number of milliseconds (msec) specified.
 
* End position: Start of media plus the number of milliseconds (msec) specified.
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|  
 
|  
 
| style="text-align:left;"|
 
| style="text-align:left;"|
* Volume decreases, or fades out, ranged across a linear pattern from the volume set with the "volume" key to zero.
+
* Volume decreases, or fades out, ranged across a linear pattern from the volume set with the "volume" key to one.
 
* Start position: End of the media minus the number of milliseconds (msec) specified.
 
* Start position: End of the media minus the number of milliseconds (msec) specified.
 
* End position: End of the media.
 
* End position: End of the media.
 +
* 1000 milliseconds = 1 second.
 +
|-
 +
| style="text-align:center;"| No
 +
| "start"
 +
| <msec>
 +
| 0
 +
| style="text-align:left;"|
 +
* Begin play at the specified position in milliseconds.
 +
* 1000 milliseconds = 1 second.
 +
|-
 +
| style="text-align:center;"| No
 +
| "finish"
 +
| <msec>
 +
| 0
 +
| style="text-align:left;"|
 +
* End play at the specified position in milliseconds.
 
* 1000 milliseconds = 1 second.
 
* 1000 milliseconds = 1 second.
 
|-
 
|-
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| true
 
| true
 
| style="text-align:left;"|
 
| style="text-align:left;"|
* Only valid for media files with a "type" of "music".
 
 
* Continues playing matching new music files when true.
 
* Continues playing matching new music files when true.
 
* Restarts matching new music files when false.  
 
* Restarts matching new music files when false.  
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   "tag": "environment",
 
   "tag": "environment",
 
   "priority": 60,
 
   "priority": 60,
   "key": "area-background-music"
+
   "key": "area-background-music",
 +
  "fadeaway": true,
 +
  "fadeout": 7000
 
}</syntaxhighlight>
 
}</syntaxhighlight>
  
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| style="text-align:left;"|
 
| style="text-align:left;"|
 
* Stops playing media by key matching the value specified.
 
* Stops playing media by key matching the value specified.
 +
|-
 +
| style="text-align:center;"| No
 +
| "fadeaway"
 +
| true or false
 +
| style="text-align:left;" |
 +
* Decrease volume from the current position for a given duration, then stops the track.
 +
* Given duration is the lesser of the remaining track duration or the fadeout specified in Client.Media.Play.
 +
* If fadeout was not specified in Client.Media.Play, then the optional fadeout parameter from Client.Media.Stop or a default of 5000 milliseconds will be applied.
 +
|-
 +
| style="text-align:center;"| No
 +
| "fadeout"
 +
|
 +
| style="text-align:left;" |
 +
* Default duration in milliseconds to decrease volume to the end of the track.
 +
* Only used if fadeout was not defined in Client.Media.Play.
 
|-
 
|-
 
|}
 
|}
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* Version 1.0: Initial specification.
 
* Version 1.0: Initial specification.
* Version 1.0.1: fadein and fadeout added to Client.Media.Play by Mike Conley (mike.conley[at]stickmud.com) on 22-DEC-2021.
+
* Version 1.0.1: fadein, fadeout and start added to Client.Media.Play by Mike Conley (mike.conley[at]stickmud.com) on 22-DEC-2021.
 +
* Version 1.0.2: finish added to Client.Media.Play and fadeaway and fadeout added to Client.Media.Stop by Mike Conley (mike.conley[at]stickmud.com) on 10-DEC-2023.
  
 
== Advertise Support for MCMP ==
 
== Advertise Support for MCMP ==
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* Known clients implementing this specification:
 
* Known clients implementing this specification:
 
** Mudlet version 4.4+. See [[Special:MyLanguage/Manual:Scripting#MUD_Client_Media_Protocol|documentation]].
 
** Mudlet version 4.4+. See [[Special:MyLanguage/Manual:Scripting#MUD_Client_Media_Protocol|documentation]].
 +
** BeipMU version 4.00.298 implements basic load/play/stop commands.
 
</translate>
 
</translate>

Latest revision as of 14:30, 10 December 2023

MUD Client Media Protocol (MCMP)

A Standard for Loading, Playing and Stopping Media Files with MUD Clients over GMCP

Status of this Memo

This memo describes the addition of a standardized namespace of the Generic Mud Communication Protocol (GMCP) telnet sub-negotiation protocol (201) that provides syntax and usage guidance for sending JSON formatted messages from game servers to text-based game clients to load, play and stop media files.


Overview and Rationale

With renewed interest in the MUD genre of gaming, expectations are high to provide sight and sound content that competes for audience with other gaming platforms. The purpose of the MUD Client Media Protocol (MCMP) is to establish a method of delivering media, such as game sounds, background music and video snippets, to text-based game clients via their widely accepted messaging platform, GMCP, which uses JSON as its data-interchange format. The intended return for introducing this protocol is to improve the MUD gaming experience and accessibility through standardized messaging between game servers and game clients. MUD Client Media Protocol (MCMP) is inspired by its predecessor Mud Sound Protocol (MSP).


Overview of the GMCP (201) Sub-negotiation Protocol

To recap, the GMCP protocol is a bidirectional telnet sub-negotiation protocol (See RFC 854) which fulfills the following conditions:

  • GMCP is separated into several ‘namespaces’, which may be enabled or disabled by the client at any time. The ‘Core’ namespace is always enabled and may not be disabled. Namespaces should consist of case-insensitive alphabetical characters and stop characters (. - ASCII 46/0x2E), representable as [A-Za-z.].
  • GMCP messages consist of the namespace and a command (case insensitive alpha characters) delineated by a stop character, and optionally a space character and JSON-encoded payload.
  • GMCP messages may be sent by both the client or server at any time with no warning.


Update to namespace: Client.* for Client.Media

We are proposing an addition to the Client.* meta-namespace for Client.Media. This serves the purpose of reserving this namespace for handling game client media operations and supporting future expansion and integration.


Video Demonstration of Client.Media

Specification for Client.Media

The Client.Media family of GMCP packages provide a way for games to send sound, music and video events. GMCP media events are sent in one direction: from game server to to game client. Media files may be downloaded manually by the user and/or automatically via the game client. Game clients should advertise to servers that Client.Media is supported with a Core.Supports message from game client to server.

Core.Supports.Set ["Client.Media 1", ...]

Commands - Server[edit | edit source]

Due to the limitations for legacy gaming platforms supporting all JSON data types, such as boolean (true and false), game clients should support parsing of values within the Client.Media namespace also as strings (surrounded by quotes).

Client.Media.Default[edit | edit source]

  • Package: Client.Media.Default
  • Purpose: Identify to the game client a default URL directory to load media files from an external resource.
  • Guidance: For games that automatically download media files, perform a Client.Media.Default GMCP event once upon player login.

Syntax:

Client.Media.Default {"url": "hxxps://www.example.com/media/"}

Usage:

Required Key Value Purpose
Yes "url" <url>
  • Resource location where the media file may be downloaded.
  • Last character must be a / (slash).

Note Note:

Some examples are shown here.

Client.Media.Load[edit | edit source]

  • Package: Client.Media.Load
  • Purpose: Load media files from an external source.
  • Guidance: For games that automatically download media files and have the capability to cache with the game client.

Syntax:

Client.Media.Load {
  "name": "sword1.mp3",
  "url": "hxxps://www.example.com/media/"
}

Usage:

Required Key Value Purpose
Yes "name" <file name>
  • Name of the media file.
  • May contain directory information (i.e. weather/lightning.mp3).
Maybe "url" <url>
  • Resource location where the media file may be downloaded.
  • Last character must be a / (slash).
  • Only required if a url was not set with Client.Media.Default.

Note Note:

Some examples are shown here.


Client.Media.Play

  • Package: Client.Media.Play
  • Purpose: Play media files.
  • Guidance: Game clients could choose whether to play only one media file at one time or multiple files at one time.

Syntax:

Client.Media.Play {
  "name": "city.mp3",
  "url": "hxxps://www.example.com/media/",
  "type": "music",
  "tag": "environment",
  "volume": 25,
  "fadein": 5000,
  "fadeout": 7000,
  "start": 1000,
  "finish": 20000,
  "loops": 3,
  "priority": 60,
  "continue": true,
  "key": "area-background-music"
}

Usage:

Required Key Value Default Purpose
Yes "name" <file name>  
  • Name of the media file.
  • May contain directory information (i.e. weather/lightning.mp3).
Maybe "url" <url>  
  • Resource location where the media file may be downloaded.
  • Last character must be a / (slash).
  • Only required if the file is to be downloaded remotely and a url was not set above with Client.Media.Default or Client.Media.Load.
No "type" "sound", "music" or "video" "sound"
  • Identifies the type of media.
No "tag" <tag>  
  • Helps categorize media.
No "volume" 1 to 100 50
  • Relative to the volume set on the player's client.
No "fadein" <msec>  
  • Volume increases, or fades in, ranged across a linear pattern from one to the volume set with the "volume" key.
  • Start position: Start of media.
  • End position: Start of media plus the number of milliseconds (msec) specified.
  • 1000 milliseconds = 1 second.
No "fadeout" <msec>  
  • Volume decreases, or fades out, ranged across a linear pattern from the volume set with the "volume" key to one.
  • Start position: End of the media minus the number of milliseconds (msec) specified.
  • End position: End of the media.
  • 1000 milliseconds = 1 second.
No "start" <msec> 0
  • Begin play at the specified position in milliseconds.
  • 1000 milliseconds = 1 second.
No "finish" <msec> 0
  • End play at the specified position in milliseconds.
  • 1000 milliseconds = 1 second.
No "loops" -1, or >= 1 1
  • Number of iterations that the media plays.
  • A value of -1 allows the sound or music to loop indefinitely.
No "priority" 1 to 100  
  • Halts the play of current or future played media files with a lower priority while this media plays.
No "continue" true or false true
  • Continues playing matching new music files when true.
  • Restarts matching new music files when false.
No "key" <key>  
  • Uniquely identifies media files with a "key" that is bound to their "name" or "url".
  • Halts the play of current media files with the same "key" that have a different "name" or "url" while this media plays.


Note Note:

Some examples are shown here.

Client.Media.Stop

  • Package: Client.Media.Stop
  • Purpose: Stop playing media files.
  • Guidance: An empty body will stop all media.

Syntax:

Client.Media.Stop {
  "name": "city.mp3",
  "type": "music",
  "tag": "environment",
  "priority": 60,
  "key": "area-background-music",
  "fadeaway": true,
  "fadeout": 7000
}

Usage:

Required Key Value Purpose
No "name" <file name>
  • Stops playing media by name matching the value specified.
No "type" "sound", "music" or "video"
  • Stops playing media by type matching the value specified.
No "tag" <tag>
  • Stops playing media by tag matching the value specified.
No "priority" 1 to 100
  • Stops playing media with priority less than or equal to the value.
No "key" <key>
  • Stops playing media by key matching the value specified.
No "fadeaway" true or false
  • Decrease volume from the current position for a given duration, then stops the track.
  • Given duration is the lesser of the remaining track duration or the fadeout specified in Client.Media.Play.
  • If fadeout was not specified in Client.Media.Play, then the optional fadeout parameter from Client.Media.Stop or a default of 5000 milliseconds will be applied.
No "fadeout"
  • Default duration in milliseconds to decrease volume to the end of the track.
  • Only used if fadeout was not defined in Client.Media.Play.

Note Note:

Some examples are shown here.

Versions

  • Version 1.0: Initial specification.
  • Version 1.0.1: fadein, fadeout and start added to Client.Media.Play by Mike Conley (mike.conley[at]stickmud.com) on 22-DEC-2021.
  • Version 1.0.2: finish added to Client.Media.Play and fadeaway and fadeout added to Client.Media.Stop by Mike Conley (mike.conley[at]stickmud.com) on 10-DEC-2023.

Consider advertising your games support of MCMP (and GMCP) to mud lists via the Mud Server Status Protocol, MSSP, by providing a MSSP variable of "MCMP" and value of "1".

Authors

  • Mike Conley (Tamarindo, Co-Administrator at StickMUD and Mudlet contributor) mike.conley[at]stickmud.com
  • Eric Oestrich (Developer of ExVenture and Grapevine) eric[at]oestrich.org

Notes

  • Known clients implementing this specification:
    • Mudlet version 4.4+. See documentation.
    • BeipMU version 4.00.298 implements basic load/play/stop commands.