samer@0: % lineout - Live audio output 
samer@0: %
samer@0: % lineout ::
samer@0: %    C:natural ~'desired no. of channels',
samer@0: %    R:nonneg  ~'desired sample rate',
samer@0: %    options {
samer@0: %       bufsize :: natural/[] ~'desired buffer size'
samer@0: %    }
samer@0: % -> sink(C,R).
samer@0: classdef lineout < sink
samer@0: 	properties (GetAccess=private, SetAccess=immutable)
samer@0: 		fs
samer@0: 		chans
samer@0: 		opts
samer@0: 	end
samer@0: 	methods
samer@0: 		function s=lineout(channels,rate,varargin)
samer@42: 			s.opts = options('bufsize',0,'bits',16,'pad',0,'quiet',0,varargin{:});
samer@0: 			s.chans=channels;
samer@0: 			s.fs=rate;
samer@0: 		end
samer@0: 
samer@0: 		function c=tostring(sig), c=sprintf('lineout(%d,%d)',sig.chans,sig.fs); end
samer@0: 		function c=channels(s), c=s.chans; end
samer@0: 		function c=rate(s), c=s.fs; end
samer@0: 		function s=construct(sig)
samer@46: 			import ishara.audio.*;
samer@0: 
samer@0: 			snk=LineSink(audio_format(sig.chans,sig.fs,sig.opts.bits),sig.opts.bufsize);
samer@0: 			snk.setScale(0.999);
samer@0: 			line=snk.getLine();
samer@0: 			ref=disposables('reg',snk);
samer@42: 			if ~sig.opts.quiet
samer@42: 				fprintf('\nOpened audio output device:\n  %s\n',char(snk.toString));
samer@42: 				fprintf('  Actual buffer size is %d.\n',snk.getLine.getBufferSize);
samer@42: 			end
samer@0: 
samer@0: 			if sig.opts.pad>0, 
samer@0: 				fprintf('  Padding start and stop with %d samples.\n',sig.opts.pad);
samer@0: 				pad=zeros(sig.chans*sig.opts.pad,1);
samer@0: 				padwr=snk.writer(length(pad));
samer@0: 				maybe_pad=@()padwr.write(pad);
samer@0: 			else
samer@0: 				maybe_pad=@nop;
samer@0: 			end
samer@0: 
samer@0: 			s.stop    = @stop;
samer@0: 			s.start   = @start;
samer@0: 			s.dispose = @dispose;
samer@0: 			s.writer = @writer;
samer@0: 
samer@0: 			s.getLine = @()line;
samer@0: 			s.setGain = @(s)snk.setScale(s);
samer@0: 
samer@0: 			function start, line.flush(); line.start(); maybe_pad(); snk.check(); end
samer@0: 			function stop, snk.check(); maybe_pad(); line.drain(); line.stop(); end
samer@0: 
samer@0: 			function r=writer(n)
samer@0: 				ch=sig.chans;
samer@0: 				wr=snk.writer(ch*n);
samer@0: 				r=@next;
samer@0: 				function rem=next(x)
samer@0: 					rem=wr.write(x(:))/ch;
samer@0: 				end
samer@0: 			end
samer@0: 
samer@0: 			function dispose
samer@0: 				disposables('dereg',ref);
samer@0: 				snk.dispose();
samer@0: 			end
samer@0: 		end
samer@0: 	end
samer@0: end