Mercurial > hg > smallbox
view util/matlab_midi/writemidi.m @ 230:8768cefe5753 luisf_dev
Fixed the issues that were preventing the Pierre Villars experiment to run correctly.
author | luisf <luis.figueira@eecs.qmul.ac.uk> |
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date | Wed, 18 Apr 2012 15:23:39 +0100 |
parents | a30e8bd6d948 |
children |
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function rawbytes=writemidi(midi,filename,do_run_mode) % rawbytes=writemidi(midi,filename,do_run_mode) % % writes to a midi file % % midi is a structure like that created by readmidi.m % % do_run_mode: flag - use running mode when possible. % if given, will override the msg.used_running_mode % default==0. (1 may not work...) % % TODO: use note-on for note-off... (for other function...) % % Copyright (c) 2009 Ken Schutte % more info at: http://www.kenschutte.com/midi %if (nargin<3) do_run_mode = 0; %end % do each track: Ntracks = length(midi.track); for i=1:Ntracks databytes_track{i} = []; for j=1:length(midi.track(i).messages) msg = midi.track(i).messages(j); msg_bytes = encode_var_length(msg.deltatime); if (msg.midimeta==1) % check for doing running mode run_mode = 0; run_mode = msg.used_running_mode; % should check that prev msg has same type to allow run % mode... % if (j>1 && do_run_mode && msg.type == midi.track(i).messages(j-1).type) % run_mode = 1; % end msg_bytes = [msg_bytes; encode_midi_msg(msg, run_mode)]; else msg_bytes = [msg_bytes; encode_meta_msg(msg)]; end % disp(msg_bytes') %if (msg_bytes ~= msg.rawbytes) % error('rawbytes mismatch'); %end databytes_track{i} = [databytes_track{i}; msg_bytes]; end end % HEADER % double('MThd') = [77 84 104 100] rawbytes = [77 84 104 100 ... 0 0 0 6 ... encode_int(midi.format,2) ... encode_int(Ntracks,2) ... encode_int(midi.ticks_per_quarter_note,2) ... ]'; % TRACK_CHUCKS for i=1:Ntracks a = length(databytes_track{i}); % double('MTrk') = [77 84 114 107] tmp = [77 84 114 107 ... encode_int(length(databytes_track{i}),4) ... databytes_track{i}']'; rawbytes(end+1:end+length(tmp)) = tmp; end % write to file fid = fopen(filename,'w'); %fwrite(fid,rawbytes,'char'); fwrite(fid,rawbytes,'uint8'); fclose(fid); % return a _column_ vector function A=encode_int(val,Nbytes) for i=1:Nbytes A(i) = bitand(bitshift(val, -8*(Nbytes-i)), 255); end function bytes=encode_var_length(val) binStr = dec2base(round(val),2); Nbytes = ceil(length(binStr)/7); binStr = ['00000000' binStr]; bytes = []; for i=1:Nbytes if (i==1) lastbit = '0'; else lastbit = '1'; end B = bin2dec([lastbit binStr(end-i*7+1:end-(i-1)*7)]); bytes = [B; bytes]; end function bytes=encode_midi_msg(msg, run_mode) bytes = []; if (run_mode ~= 1) bytes = msg.type; % channel: bytes = bytes + msg.chan; % lower nibble should be chan end bytes = [bytes; msg.data]; function bytes=encode_meta_msg(msg) bytes = 255; bytes = [bytes; msg.type]; bytes = [bytes; encode_var_length(length(msg.data))]; bytes = [bytes; msg.data];