Module messages

The RTMP Messages

After handshake, both are required to negotiate what are needed for sending/receiving. Currently, following messages are used in negotiation:

• User Control
• Window Acknowledgement Size
• Command

Every message has headers. See sheave_core::messages::headers about them.

User Control

User Control messages are additional informations for starting streaming. These consist of following format:

Field	Length (in bytes)	Description
Event Type	2	A marker which indicates a kind of data sent.
Event Data	Various	Actual data of this message.

Events

Currently, following events are used:

• Stream Begin
• Set Buffer Length

Command

Command messages are contained basic informations actually required to negotiate. These encodes/decodes into/from [the Action Message Format 0]. These consist of following format:

Field	AMF Type	Description
Command Name	String	The command which is currently negotiated.
Transaction ID	Number	A number which indicates a step of this negotiation.
Setting Data	Various	Actually negotiated data.

Furthermore commands have following patterns:

• NetConnection
• NetStream

NetConnection

NetConnection commands are defined as following messages:

• connect
• releaseStream
• FCPublish
• createStream
• FCSubscribe
• getStreamLength (in FFmpeg) / set_playlist (in OBS) (note these mayn’t be sent.)

NetStream

NetStream commands are defined as following messages:

• publish
• play

Any data

After negotiation, the server receives actual audio/video data from clients. However also FLV metadata is received as the AMF (v0). The message what contains FLV metadata is called @setDataFrame. This consists of following format:

Field	AMF Type	Description
Command Name (probably)	String	"@setDataFrame"
Setting Data	Various	In this case, see ScriptDataTag.

Modules

amf

The Action Message Formats

headers

The Chunk Headers

Structs

Acknowledgement

The message to tell that some message length has exceeded the server-side bandwidth range. Note this must be input the total message length in receiving. (it’s not bytes received.)

Audio

ChunkSize

Tells a size to chunk its stream to the partner.

CommandError

The response message that some command failed.

Connect

The command to exchange an information about application using.

ConnectResult

The response message for Connect requests.

CreateStream

The command to request emitting a message ID to a server.

CreateStreamResult

The response message for CreateStream requests.

DeleteStream

The command to request to delete its message ID.

FcPublish

The command to tell a path to the server.

FcSubscribe

The command to tell the topic path.

FcUnpublish

This command is same as FcPublish except this requests to delete the topic path.

GetStreamLength

The command to tell the topic path. (e.g. something file name)

GetStreamLengthResult

The response message for GetStreamLength requests.

InconsistentCommand

An error that some command name differs you expect.

InconsistentEventType

An error that some event type differs you expect.

InvalidPublishingType

An error that some publishing type differs you expect.

NegativeChunkSize

An error that some chunk size is negative.

OnFcPublish

The response message for FcPublish requests.

OnStatus

The response message for Publish requests.

PeerBandwidth

The message to tell the client-side bandwidth. This has 2 ways of comparision by which field you specifies.

Play

The command to tell playing information.

PlaylistReady

The response message for SetPlaylist requests.

Publish

The command to tell publishing information.

PublishingFailure

An error that publishing has failed by something cause.

ReleaseStream

The command to tell some path to the server.

ReleaseStreamResult

The response message for ReleaseStream requests.

SetBufferLength

The event to tell that its stream will be buffered, to the server.

SetDataFrame

The message to handle something data.

SetPlaylist

The command to tell the Playlist of streams.

StreamBegin

The event to tell that the stream is ready to a client.

Video

WindowAcknowledgementSize

The message to tell the bandwidth limit as a receiver side.

Enums

Channel

The IDs which are assigned every roles of chunks. This is mainly used for the BasicHeader’s chunk ID.

EventType

The IDs which are types of user control messages.

LimitType

Representation of the limit type field in the PeerBandwidth message.

PlayMode

Representation of the way to subscribe its stream.

Traits

ChunkData

Uniforms chunk data by a channel numbers and a message type.

Command

UserControl

Uniforms user control messages by an event type.

Functions

inconsistent_command

A utility function of constructing an InconsistentCommand error.

inconsistent_event_type

A utility function of constructing an InconsistentEventType error.

invalid_publishing_type

A utility function of constructing an InvalidPublishingType error.

negative_chunk_size

A utility function of constructing a NegativeChunkSize error.

publishing_failure

A utility function of constructing a PublishingFailure error.