Class: Minicap::Stream

Inherits:
Object
  • Object
show all
Defined in:
lib/minicap/stream.rb

Constant Summary collapse

DEFAULT_BUFFER_SIZE = 
1024 * 1024
DEFAULT_SLEEP_SECS = 
0.001

Instance Method Summary collapse

Constructor Details

#initialize(host, port, options = {}) ⇒ Stream

Returns a new instance of Stream.



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# File 'lib/minicap/stream.rb', line 7

def initialize(host, port, options={})
  @host = host
  @port = port
  @options = options
end

Instance Method Details

#each ⇒ Object 



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# File 'lib/minicap/stream.rb', line 13

def each
  return enum_for(:each) unless block_given?

  buffer_size = @options[:buffer_size] || DEFAULT_BUFFER_SIZE
  sleep_secs = @options[:sleep_secs] || DEFAULT_SLEEP_SECS
  debug = @options[:debug]

  soc = nil
  begin
    soc = TCPSocket.open(@host, @port)

    buf = soc.recv(buffer_size).unpack('C*')
    fail 'unknown version' if buf[0] != 1
    header_size = buf[1]
    header = buf[0...header_size]
    data = buf[header_size..-1]

    in_frame = false
    n = 0
    loop do
      if !in_frame && data.size >= 4
        n = uint32le(data)
        in_frame = true
        STDERR.puts 'new frame with size %d' % n if debug
      end

      if in_frame && data.size >= 4 + n
        jpg_blob = data[4...4+n]
        yield jpg_blob
        data = data[4+n..-1]
        in_frame = false
      end

      sleep sleep_secs

      if in_frame
        fetch_size = [buffer_size, 4 + n - data.size].min
      else
        fetch_size = buffer_size
      end

      buf = soc.recv(fetch_size).unpack('C*')
      data += buf
    end
  ensure
    soc.close unless soc
  end
end