Added ruby class for controlling mpg123

git-svn-id: svn://scm.orgis.org/mpg123/trunk@1475 35dc7657-300d-0410-a2e5-dc2837fedb53

misc/ruby-mpg123.rb

@@ -0,0 +1,179 @@
+#!/usr/bin/ruby
+#
+# Ruby control interface for mpg123
+# By Nicholas Humfrey
+#
+# With thanks to Marc Lehmann (author of perl module Audio::Play::MPG123)
+#
+
+require "open3"
+
+class Mpg123
+	attr_reader :version, :state, :info, :error
+	attr_reader :frame, :time
+	
+	STATE_STOPPED = 0
+	STATE_PAUSED = 1
+	STATE_PLAYING = 2
+
+	def initialize(args=Array.new)
+	
+		## Set instance variable defaults
+		@version = nil
+		@state = STATE_STOPPED
+		@info = Hash.new
+		@error = nil	
+		@frame = 0	
+		@time = 0.0
+		
+		## Open pipe to mpg123 proccess
+		cmd = ['mpg123','--remote', *args]
+		@pipe_in, @pipe_out, pipe_err = Open3.popen3(*cmd)
+		## FIXME: redirect pipe_err to stderr
+		## FIXME: check for errors
+		
+		# Read in the first line from mpg123
+    parse_line( readline_nonblock(1.0) )
+    ## FIXME: ensure that @version is non-nil
+    	
+    # Start the reader thread
+    @thread = Thread.new {
+      loop do
+        line = @pipe_out.gets
+        if line.nil?
+          $stderr.puts "Reached EOF when reading from mpg123 pipe."
+          raise("Reached EOF when reading from mpg123 pipe.")
+        else
+          parse_line(line)
+        end
+      end
+    }
+	end
+
+  def self.finalize(id)
+    ## FIXME: cleanup mpg123 process and thread
+    puts "Mpg123.finalize(#{id})"
+  end
+  
+  def poll(timeout=0.1)
+    line = readline( timeout )
+    return if line == nil
+    
+    begin
+      parse_line( line )
+      # Check for more lines (without a timeout)
+      line = readline(0)
+    end until line == nil
+  end
+  
+  def load(path)
+    @pipe_in.puts("LOAD #{path}")
+  end
+  
+  def loadpause(path)
+    @pipe_in.puts("LOADPAUSE #{path}")
+  end
+  
+  def pause
+    @pipe_in.puts("PAUSE")
+  end
+  
+  def paused?
+   return (@state==STATE_PAUSED)
+  end
+  
+  def playing?
+   return (@state==STATE_PLAYING)
+  end
+  
+  def stopped?
+    return (@state==STATE_STOPPED)
+  end
+  
+  def stop
+    @pipe_in.puts("STOP")
+  end
+  
+  def jump(frame)
+    @pipe_in.puts("JUMP #{frame}")
+  end
+  
+  def volume(percent)
+    @pipe_in.puts("VOLUME #{percent}")
+  end
+  
+  def rva(mode)
+    @pipe_in.puts("RVA #{mode}")
+  end
+  
+  def eq(channel, band, value)
+    @pipe_in.puts("EQ #{channel} #{band} #{value}")
+  end
+  
+  def seek(sample)
+    @pipe_in.puts("SEEK #{sample}")
+  end
+  
+  def simple_eq(bass,mid,treble)
+    @pipe_in.puts("SEQ #{bass} #{mid} #{treble}")
+  end
+
+
+
+private
+	
+	## Parse a line sent to us from mpg123
+	def parse_line(line)
+
+		if (line =~ /^@F (\d+) (\d+) ([\d\.]+) ([\d\.]+)$/)
+			@frame = $1.to_i
+			#FIXME: @frames_remaining = $2.to_i
+			@time = $3.to_f
+			#FIXME: @time_remaining = $4.to_f
+		elsif (line =~ /^@S ([\d\.]+) (\d+) (\d+) (.+)/)
+			@info['mpeg_version'] = $1
+			@info['layer'] = $2
+			@info['sample_rate'] = $3
+			@info['mode'] = $4
+      ## FIXME: more available:
+      #@{$self}{qw(type layer samplerate mode mode_extension
+      #         bpf channels copyrighted error_protected
+      #         emphasis bitrate extension lsf)}=split /\s+/,$1;
+      @state = STATE_PLAYING
+    elsif (line =~ /^@I ID3:(.{30})(.{30})(.{30})(....)(.{30})(.*)$/)
+			@info['title']=$1;   @info['artist']=$2;
+			@info['album']=$3;   @info['year']=$4;
+			@info['comment']=$5; @info['genre']=$6;
+		elsif (line =~ /^@I ICY-META: StreamTitle='(.*)';$/)
+			@info['title']=$1;
+			#delete @{$self}{qw(artist album year comment genre)}
+		elsif (line =~ /^@I (.*)$/)
+			@info['title']=$1;
+			#delete @{$self}{qw(artist album year comment genre)}
+		elsif (line =~ /^@R (.+)/)
+			@version = $1
+		elsif (line =~ /^@P (\d)/)
+			@state = $1.to_i
+		elsif (line =~ /^@E (.*)$/)
+			@error = $1
+			$stderr.puts("Error: #{$1}")
+			raise("Error: #{$1}")
+		elsif (line =~ /^@/)
+			$stderr.puts "unrecognised line: #{line}"
+		else
+			$stderr.puts "unrecognised data: #{line}"
+		end         
+	end
+	
+	def readline_nonblock(timeout)
+    # Is there any data available?
+    unless IO.select([@pipe_out], nil, nil, timeout).nil?
+      # Yes; read the line in and parse it
+      return @pipe_out.gets
+    else
+      # No; nothing available
+      return nil
+		end
+	end
+
+end