Category:Myth Protocol

From MythTV Official Wiki
Revision as of 07:16, 30 November 2010 by Wagnerrp (Talk | contribs)

Jump to: navigation, search

Basic Guide

There is guide started, which describes how to use the Myth Protocol for watching Live TV.

List of proto bumps

Version Release Token Changeset Description
1 [3021]

+MYTH_PROTO_VERSION

2 [3078]
3 [3112]

+GET_NEXT_FREE_RECORDER

4 [3308]
5 [3503]

+REACTIVATE_RECORDING , +REFRESH_BACKEND

6 [3589]
7 [3617]
8 [3621]
9 [3838]

+GET_FREE_RECORDER_COUNT

10 [3966]
11 [3973]
12 [3988]
13 [4122]
14 [4508]
15 0.18 [5833]

+QUERY_LOAD , +QUERY_UPTIME , +QUERY_MEMSTATS , +QUERY_GUIDEDATATHROUGH , +RESCHEDULE_RECORDINGS

16 [6284]

+FORCE_DELETE_RECORDING , +OK , +UNKNOWN_COMMAND

17 [6482]

-QUERY_FREESPACE , +QUERY_FREE_SPACE , +QUERY_FREE_SPACE_LIST , +GET_FREE_RECORDER_LIST , +QUERY_PIXMAP_LASTMODIFIED , +QUERY_COMMBREAK , +QUERY_CUTLIST , +QUERY_BOOKMARK , +SET_BOOKMARK , +QUERY_SETTING , +SET_SETTING , *QUERY_REMOTEENCODER , *QUERY_RECORDER

18 [6865]

*QUERY_RECORDER

19 [7427]

-REACTIVATE_RECORDING , +ALLOW_SHUTDOWN , +BLOCK_SHUTDOWN , *QUERY_RECORDER

20 [7739]

*ANN , *QUERY_RECORDER

21 [7826]

-GET_PROGRAM_INFO , -GET_INPUT_NAME

22 [7883]

*ANN , +LIVETV_EXITED

23 [8553]

-QUEUE_TRANSCODE , -QUEUE_TRANSCODE_CUTLIST , -QUEUE_TRANSCODE_STOP , +QUERY_GETEXPIRING , +SCHEDULER_ADD_RECORDING , +CLEAR_SETTINGS_CACHE

24 [8617]
25 [8628]
26 0.19 [8754]

+SET_LIVE_RECORDING

27 [8973] Unification of the ChannelBase class???

-SCHEDULER_ADD_RECORDING , -TOGGLE_INPUTS , +GET_CONNECTED_INPUTS , +GET_INPUT , +SET_INPUT

28 [9524] Backend portion of Channel Editing patch.

+GET_CHANNEL_INFO , +SET_CHANNEL_INFO , +SET_TIMEOUT

29 [9592] Increments protocol to deal with new FileTransfer params

*ANN

30 0.20 [9968] Adds recorder keyed picture attribute adjustments

+GET_COLOUR , +GET_CONTRAST , +GET_BRIGHTNESS , +GET_HUE , *CHANGE_COLOUR , *CHANGE_CONTRAST , *CHANGE_BRIGHTNESS , *CHANGE_HUE

Version Release Token Changeset Description
31 0.20 [11278] Add parentid to the proginfo StringLists.
32 [12151] Introduction of StorageGroups

+QUERY_RECORDING , +QUERY_FREE_SPACE_SUMMARY , +SET_NEXT_LIVETV_DIR

33 [12904] Changes the format of the original airdate field in the ProgramInfo stringlist
34 [13230] Sends the start channel as additional parameter in SpawnLiveTV

*SPAWN_LIVETV

35 [13952] Replaces the current hdtv, stereo and closecaptioned flags with videoproperties, audioproperties and subtitletype vars
36 [14483]

+UNDELETE_RECORDING

37 [15437]

-GET_CONNECTED_INPUTS , +GET_FREE_INPUTS , +GET_FLAGS , +CANCEL_NEXT_RECORDING , +STOP_RECORDING

38 [15550]

+DELETE_FAILED_RECORDING

39 0.21 [15701] Revert [15549], because the scheduler (starting with [15566]) now uses its own temporary copy of the record table during the BUSQ.

-DELETE_FAILED_RECORDING

40 0.21 [16090] Patch from #4583, along with corresponding fixes in mythweb and the perl bindings. Switches QUERY_PIXMAP_LASTMODIFIED to send a unix timestamp instead of a localized string that would be affected by LANG settings.

*QUERY_PIXMAP_LASTMODIFIED

41 [18419] Adds the production year to the programinfo sent via the protocol.
42 [18574]

+QUERY_TIME_ZONE

43 [19417] (warning: huge changeset) Associated with the merging of the mythtv-vid branch to trunk.

*FILL_POSITION_MAP

and possibly GetChainWithRecording.  
44 [19978] Adds Videos storage group

+QUERY_SG_GETFILELIST , +QUERY_SG_FILEQUERY

45 [20523] Add channel grouping feature

*TOGGLE_CHANNEL_FAVORITE
+GO_TO_SLEEP

46 [21156] Adds ability to delete remote files

+DELETE_FILE , *ANN , *QUERY_FILETRANSFER

47 [21298] Adds filesystem block size to the FileSystemInfo structure

*QUERY_FREE_SPACE , *QUERY_FREE_SPACE_LIST

48 [21445] When ANN returns "ERROR", it is now followed by the reason for the error
49 [22164] Adds new pixmap query to speed up preview generation

+QUERY_PIXMAP_GET_IF_MODIFIED
Add a RemoteFile::Exists(QString &url) method for checking for the existence of a remote file.
+QUERY_FILE_EXISTS

50 0.22 [22170] Adds a hostname lookup to aid use of Storage Groups in MythVideo

+QUERY_HOSTNAME

51 [22892] Adds a remote hash function for files based of that used by OpenSubtitles.

+QUERY_FILE_HASH

52 [22932]
53 [22955]
54 [22976]

+MASTER_UPDATE_PROG_INFO , +UPDATE_PROG_INFO

55 [22992]

*MASTER_UPDATE_PROG_INFO

56 0.23 [23028] Added system events,

*DELETE_RECORDING , *ANN

23056 0.23.1 [25364]

*DELETE_RECORDING

57 [24694]

*ProgramInfo
object changes. From 47 fields down to 41 - filesize as a long, removed duplicate, shareable, previouslyshown, commfree, hasairdate, added year.

58 [25351]

+DOWNLOAD_FILE , +DOWNLOAD_FILE_NOW

59 [25858]

[25363]

Adds support for ISOs over remote file access.

*DELETE_RECORDING

60 [26101]

*ANN
Alters FileTransfer to accept timeout instead of number of retries

Version Release Token Changeset Description
61 [26106]

-QUERY_GENPIXMAP

+QUERY_GENPIXMAP2

62 78B5631E [26280]

*MYTH_PROTO_VERSION

63 0.24 3875641D [26518]

+GET_RECORDING_STATUS

64 8675309J [27308]

+SCAN_VIDEOS

Legend: - = removed command, + = added command, * = changed command

Packet Data Format

(This information is from reading the code and packet sniffing. Do not take this information as a specification, as the developers may not have intended some of the following behavior)

A MythTV protocol packet contains two fields, the size and the payload. The first field is the size, encoded as an 8 byte, UTF8 decimal string padded with spaces. If you are sending a 20 byte payload, the first 8 bytes should be the characters "20" followed by 6 spaces. The second field is the payload, an arbitrary length UTF8 string made up of a list of one or more strings seperated by a the delimeter "[]:[]". Commands are sent to port 6543.

Event Handling

When announcing ones self to the backend, the client can specify that it wants to receive update events. These events follow the same packet data format as outlined above and are sent asynchronously. These events will be identified as a backend message, and care must be taken to properly handle these when querying information from the backend.

Backend Commands

(This information is from reading the code and packet sniffing. Do not take this information as a specification, as the developers may not have intended some of the following behavior)

Backend commands are sent using the above packet format. The first string in the payload is the command, possibly with whitespace separated arguments. There may also be other arguments in successive strings in the list, separated by the delimiter "[]:[]". The two types of arguments are not interchangeable, each command may require specific whitespace separated arguments as well as specific list arguments.

Whitespace is spaces, tabs, carriage returns, linefeeds, etc. Multiple whitespace characters are treated as a single whitespace.

In general, commands and arguments are case sensitive.

When testing your code with the protocol, be warned that all commands except MYTH_PROTO_VERSION, ANN, and DONE will silently fail until a successful ANN command has been received by the backend. This includes non-existent commands.

For a list of all Myth protocol commands, see the Command List.

Some example MythTV protocol exchanges, taken from a packet sniffing capture of a 0.19 frontend to backend exchange:

Frontend sends Backend responds with
23      ANN Playback sycamore 0
2       OK
48      QUERY_FILETRANSFER 32[]:[]REQUEST_BLOCK[]:[]2048
4       2048
63      QUERY_FILETRANSFER 32[]:[]SEEK[]:[]0[]:[]0[]:[]0[]:[]0[]:[]2048
7       0[]:[]0

Third Party Code that implements the Myth Protocol

  • MythtvJ is a high-level Java client library. It currently supports the version 40 of the protocol. Currently streaming a file from the backend, reading the EPG and tuning a recorder is supported.
  • ruby-mythtv is a basic set of Ruby bindings providing a connected backend socket.

Third Party Code that implements the Myth Protocol ... badly

These implementations support an unknown protocol version, and repeatedly guess at what version the backend wants to use, in order to force a connection without actually maintaining the code. This should be considered very dangerous behavior, and should not be used to connect to any production backend.

  • libcmyth from mvpmc is a lightweight C client library which is also used by XBMC. It features livetv with epg, watching recordings and managing recordings.
  • GMyth is a library based on the Glib/GObject APIs. It is used in MobileMythtv, GMythStream and others.

Subcategories

This category has only the following subcategory.

Pages in category "Myth Protocol"

The following 2 pages are in this category, out of 2 total.