Chris@162: 
Chris@162: module yetilab.stream.filter;
Chris@162: 
Chris@162: mat = load yetilab.matrix.matrix;
Chris@162: 
Chris@162: load yetilab.stream.streamtype;
Chris@162: 
Chris@171: minDurationOf d1 d2 =
Chris@171:     case d1 of 
Chris@171:     Known a:
Chris@171:         case d2 of 
Chris@171:         Known b: Known (min a b);
Chris@171:         Unknown (): Unknown ();
Chris@171:         Infinite (): Known a;
Chris@171:         esac;
Chris@171:     Unknown ():
Chris@171:         case d2 of 
Chris@171:         Known b: Known b;
Chris@171:         Unknown (): Unknown ();
Chris@171:         Infinite (): Unknown ();
Chris@171:         esac;
Chris@171:     Infinite ():
Chris@171:         d2;
Chris@171:     esac;
Chris@171: 
Chris@171: truncatedTo nsamples s = //!!! should nsamples be a time in seconds?
Chris@162:     {
Chris@162:         get position () = s.position,
Chris@162:         get channels () = s.channels, 
Chris@162:         get sampleRate () = s.sampleRate,
Chris@162:         get available () = Known (nsamples - s.position),
Chris@162:         get finished? () = not (nsamples > s.position),
Chris@162:         read count =
Chris@162:             if nsamples > s.position + count then
Chris@162:                 s.read count;
Chris@162:             elif nsamples > s.position then
Chris@162:                 s.read (nsamples - s.position)
Chris@162:             else
Chris@162:                 mat.zeroMatrix { columns = 0, rows = s.channels }
Chris@162:             fi,
Chris@162:         close = s.close,
Chris@162:     };
Chris@162: 
Chris@171: 
Chris@171: //!!! not really mixed -- what's the word for it? one per channel
Chris@171: mixed s1 s2 = //!!! could generalise to list of streams
Chris@171:     {
Chris@172:         get position () = min s1.position s2.position, // can differ after EOS
Chris@171:         get channels () = s1.channels + s2.channels,
Chris@171:         get sampleRate () = s1.sampleRate,
Chris@171:         get available () = minDurationOf s1.available s2.available,
Chris@171:         get finished? () = s1.finished? or s2.finished?,
Chris@171:         read count =
Chris@171:            (outs = map do s: s.read count done [ s1, s2 ];
Chris@171:             minlen = head (sort (map do m: m.size.columns done outs));
Chris@171:             outs = map do m:
Chris@171:                 mat.resizedTo { rows = m.size.rows, columns = minlen } m
Chris@171:                 done outs;
Chris@171:             mat.newMatrix (RowMajor ())
Chris@171:                 (concat (map mat.asRows outs))
Chris@171:             ),
Chris@171:         close = (s1.close (); s2.close ())
Chris@171:     };
Chris@171: 
Chris@162: {
Chris@162:     truncatedTo, 
Chris@171:     mixed,
Chris@163: //!!!} as {
Chris@163: //    truncatedTo is number -> stream -> stream
Chris@162: }
Chris@162: 
Chris@162: 
Chris@162: 
Chris@162: