Class: RTSP::Presentation

Inherits:
Object
  • Object
show all
Includes:
LogSwitch::Mixin
Defined in:
lib/rtsp/presentation.rb

Overview

Per the RFC definition:

A set of one or more streams presented to the client as a complete media
feed, using a presentation description [...].  In most cases in the RTSP
context, this implies aggregate control of those streams, but does not
have to.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(base_url) {|_self| ... } ⇒ Presentation

Returns a new instance of Presentation.

Yields:

  • (_self)

Yield Parameters:



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# File 'lib/rtsp/presentation.rb', line 28

def initialize(base_url)
  @base_url = base_url
  @streams = []
  @description = default_description

  yield self if block_given?
end

Instance Attribute Details

#description ⇒ Object (readonly)

The SDP description that describes all of the streams. Per the RFC definition:

A presentation description contains information about one or more media
streams within a presentation, such as the set of encodings, network
addresses and information about the content.



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# File 'lib/rtsp/presentation.rb', line 24

def description
  @description
end

#streams ⇒ Object (readonly)

The list of stream objects that a server controls.



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# File 'lib/rtsp/presentation.rb', line 17

def streams
  @streams
end

#url ⇒ Object

Returns the value of attribute url.



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# File 'lib/rtsp/presentation.rb', line 26

def url
  @url
end

Instance Method Details

#add_stream {|| ... } ⇒ Object

Yield Parameters:

  • (RTSP::Stream) 


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# File 'lib/rtsp/presentation.rb', line 37

def add_stream(&block)
  stream = RTSP::Stream.new
  yield stream

  log "Adding stream: #{stream}"

  @description.media_sections << {
    media: stream.media_type,
    port: stream.client_rtp_port,
    format: stream.format,
    protocol: stream.protocol,
    attributes: stream.attributes
  }

  @streams << stream
end

#default_description ⇒ SDP::Description

Returns:

  • (SDP::Description) 


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# File 'lib/rtsp/presentation.rb', line 90

def default_description
  sdp = SDP::Description.new
  sdp.username = Etc.getlogin
  sdp.id = Time.now.to_ntp
  sdp.version = sdp.id
  sdp.network_type = "IN"
  sdp.address_type = "IP4"

  sdp.unicast_address = UDPSocket.open do |s|
    s.connect('64.233.187.99', 1); s.addr.last
  end

  sdp.name = "Ruby RTSP Stream"
  sdp.information = "This is a Ruby RTSP stream"
  sdp.connection_network_type = "IN"
  sdp.connection_address_type = "IP4"
  sdp.connection_address = sdp.unicast_address
  sdp.start_time = 0
  sdp.stop_time = 0

  sdp.attributes << { tool: "RubyRTSP #{RTSP::VERSION}" }
  sdp.attributes << { control: "*" }
  # User must still define media section.

  sdp
end

#media_urls ⇒ Array

Returns The list of URLs that make up all of the media streams for this presentation.

Returns:

  • (Array) —

    The list of URLs that make up all of the media streams for this presentation.



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# File 'lib/rtsp/presentation.rb', line 67

def media_urls
  @streams.map do |stream|
    "#{@base_url}#{stream.uri}"
  end
end

#setup_rtp_sender(type) ⇒ Object 



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# File 'lib/rtsp/presentation.rb', line 117

def setup_rtp_sender(type)
  case type
  when :socat
    @rtp_sender = RTP::Sender.instance
    @rtp_sender.stream_module = RTP::Senders::Socat

    yield @rtp_sender if block_given?


  when :indirection
    # Get remote server's URL
    server_url = yield()

    # Get description from the remote RTSP server
    require_relative 'client'
    client = RTSP::Client.new(server_url)
    response = client.describe
    @description = response.body

    # Get the control URL for the main remote presentation and set that for
    # this URL
    control = @description.attributes.find { |a| a[:attribute] == "control" }
    self.url = control[:value]

    # Get the control URL for the first media section so we can get the
    # Stream object that was setup in configuration.
    media_control =
      @description.media_sections.first[:attributes].find { |a| a[:attribute] == "control" }
    redirected_stream = stream_at(media_control[:value])

    # Create a socket to redirect the RTP data that we'll start receiving.
    redirected_socket = UDPSocket.new
    redirected_socket.bind('0.0.0.0', redirected_stream.client_rtp_port)
    client.capturer.rtp_file = redirected_socket

    # Setup
    media_track = client.media_control_tracks.first
    aggregate_track = client.aggregate_control_track
    client.setup media_track
    client.play aggregate_track
  end
end

#stream_at(uri) ⇒ RTSP::Stream

Returns The stream that’s identified by the URI.

Parameters:

  • uri (String)

Returns:

  • (RTSP::Stream) —

    The stream that’s identified by the URI.



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# File 'lib/rtsp/presentation.rb', line 75

def stream_at(uri)
  puts "looking for stream at #{uri}"

  streams.find do |stream|
    log "Checking stream match on #{stream.uri}"

    if URI(uri).absolute?
      @base_url + stream.uri == uri
    else
      stream.uri == uri
    end
  end
end