Class: SippyCup::Media

Inherits:
Object
  • Object
show all
Defined in:
lib/sippy_cup/media.rb,
lib/sippy_cup/media/rtp_header.rb,
lib/sippy_cup/media/rtp_payload.rb,
lib/sippy_cup/media/dtmf_payload.rb,
lib/sippy_cup/media/pcmu_payload.rb

Defined Under Namespace

Classes: DTMFPayload, PCMUPayload, RTPHeader, RTPPayload

Constant Summary collapse

VALID_STEPS = 
%w{silence dtmf}.freeze
USEC = 
1_000_000
MSEC = 
1_000

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(from_addr, from_port, to_addr, to_port, generator = PCMUPayload) ⇒ Media

Returns a new instance of Media.



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# File 'lib/sippy_cup/media.rb', line 13

def initialize(from_addr, from_port, to_addr, to_port, generator = PCMUPayload)
  @from_addr, @to_addr = IPAddr.new(from_addr), IPAddr.new(to_addr)
  @from_port, @to_port, @generator = from_port, to_port, generator
  reset!
end

Instance Attribute Details

#sequence ⇒ Object

Returns the value of attribute sequence.



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# File 'lib/sippy_cup/media.rb', line 11

def sequence
  @sequence
end

Instance Method Details

#<<(input) ⇒ Object 



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# File 'lib/sippy_cup/media.rb', line 23

def <<(input)
  get_step input # validation
  @sequence << input
end

#compile! ⇒ Object 



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# File 'lib/sippy_cup/media.rb', line 32

def compile!
  sequence_number = 0
  start_time = Time.now
  @pcap_file = PacketFu::PcapFile.new
  timestamp = 0
  elapsed = 0
  ssrc_id = rand 2147483648
  first_audio = true

  @sequence.each do |input|
    action, value = get_step input

    case action
    when 'silence'
      # value is the duration in milliseconds
      # append that many milliseconds of silent RTP audio
      (value.to_i / @generator::PTIME).times do
        packet = new_packet
        rtp_frame = @generator.new

        # The first RTP audio packet should have the marker bit set
        if first_audio
          rtp_frame.rtp_marker = 1
          first_audio = false
        end

        rtp_frame.rtp_timestamp = timestamp += rtp_frame.timestamp_interval
        elapsed += rtp_frame.ptime
        rtp_frame.rtp_sequence_num = sequence_number += 1
        rtp_frame.rtp_ssrc_id = ssrc_id
        packet.headers.last.body = rtp_frame.to_bytes
        packet.recalc
        @pcap_file.body << get_pcap_packet(packet, next_ts(start_time, elapsed))
      end
    when 'dtmf'
      # value is the DTMF digit to send
      # append that RFC2833 digit
      # Assume 0.25 second duration for now
      count = 250 / DTMFPayload::PTIME
      count.times do |i|
        packet = new_packet
        dtmf_frame = DTMFPayload.new value
        dtmf_frame.rtp_marker = 1 if i == 0
        dtmf_frame.rtp_timestamp = timestamp # Is this correct? This is what Blink does...
        #dtmf_frame.rtp_timestamp = timestamp += dtmf_frame.timestamp_interval
        dtmf_frame.rtp_sequence_num = sequence_number += 1
        dtmf_frame.rtp_ssrc_id = ssrc_id
        dtmf_frame.end_of_event = (count == i) # Last packet?
        packet.headers.last.body = dtmf_frame.to_bytes
        packet.recalc
        @pcap_file.body << get_pcap_packet(packet, next_ts(start_time, elapsed))
      end
      # Now bump up the timestamp to cover the gap
      timestamp += count * DTMFPayload::TIMESTAMP_INTERVAL
    else
    end
  end
  @pcap_file
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/sippy_cup/media.rb', line 28

def empty?
  @sequence.empty?
end

#reset! ⇒ Object 



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# File 'lib/sippy_cup/media.rb', line 19

def reset!
  @sequence = []
end