wolffd@0: function mp3write(D,SR,NBITS,FILE,OPTIONS)
wolffd@0: % MP3WRITE   Write MP3 file by use of external binary
wolffd@0: %   MP3WRITE(Y,FS,NBITS,FILE) writes waveform data Y to mp3-encoded
wolffd@0: %     file FILE at sampling rate FS using bitdepth NBITS.  
wolffd@0: %     The syntax exactly mirrors WAVWRITE.  NBITS must be 16.
wolffd@0: %   MP3WRITE(Y,FS,FILE) assumes NBITS is 16
wolffd@0: %   MP3WRITE(Y,FILE) further assumes FS = 8000.
wolffd@0: %
wolffd@0: %   MP3WRITE(..., OPTIONS) specifies additional compression control 
wolffd@0: %     options as a string passed directly to the lame encoder
wolffd@0: %     program; default is '--quiet -h' for high-quality model.
wolffd@0: %
wolffd@0: %   Example: 
wolffd@0: %   To convert a wav file to mp3 (assuming the sample rate is 
wolffd@0: %   supported):
wolffd@0: %     [Y,FS] = wavread('piano.wav');
wolffd@0: %     mp3write(Y,FS,'piano.mp3');
wolffd@0: %   To force lame to use 160 kbps (instead of default 128 kbps)
wolffd@0: %   with the default filename extension (mp3):
wolffd@0: %     mp3write(Y,FS,'piano','--quiet -h -b 160');
wolffd@0: %
wolffd@0: %   Note: The actual mp3 encoding is done by an external binary, 
wolffd@0: %     lame, which is available for multiple platforms.  Usable
wolffd@0: %     binaries are available from:
wolffd@0: %     http://labrosa.ee.columbia.edu/matlab/mp3read.html
wolffd@0: %
wolffd@0: %   Note: MP3WRITE will use the mex file popenw, if available, to
wolffd@0: %     open a pipe to the lame encoder.  Otherwise, it will have to
wolffd@0: %     write a large temporary file, then execute lame on that file.
wolffd@0: %     popenw is available at: 
wolffd@0: %       http://labrosa.ee.columbia.edu/matlab/popenrw.html
wolffd@0: %     This is a nice way to save large audio files as the
wolffd@0: %     incremental output of your code, but you'll have to adapt the
wolffd@0: %     central loop of this function (rather than using it directly).
wolffd@0: %
wolffd@0: %   See also: mp3read, wavwrite, popenw.
wolffd@0: 
wolffd@0: % 2005-11-10 Original version
wolffd@0: % 2007-02-04 Modified to exactly match wavwrite syntax, and to
wolffd@0: %   automatically find architecture-dependent binaries.
wolffd@0: % 2007-07-26 Writing of stereo files via tmp file fixed (thx Yu-ching Lin)
wolffd@0: %
wolffd@0: % $Header: /Users/dpwe/matlab/columbiafns/RCS/mp3write.m,v 1.2 2007/07/26 15:09:16 dpwe Exp $
wolffd@0: 
wolffd@0: % find our baseline directory
wolffd@0: [path] = fileparts(which('mp3write'));
wolffd@0: 
wolffd@0: % %%%%% Directory for temporary file (if needed)
wolffd@0: % % Try to read from environment, or use /tmp if it exists, or use CWD
wolffd@0: tmpdir = getenv('TMPDIR');
wolffd@0: if isempty(tmpdir) || exist(tmpdir,'file')==0
wolffd@0:   tmpdir = '/tmp';
wolffd@0: end
wolffd@0: if exist(tmpdir,'file')==0
wolffd@0:   tmpdir = '';
wolffd@0: end
wolffd@0: % ensure it exists
wolffd@0: %if length(tmpdir) > 0 && exist(tmpdir,'file')==0
wolffd@0: %  mkdir(tmpdir);
wolffd@0: %end
wolffd@0: 
wolffd@0: %%%%%% Command to delete temporary file (if needed)
wolffd@0: rmcmd = 'rm';
wolffd@0: 
wolffd@0: %%%%%% Location of the binary - attempt to choose automatically
wolffd@0: %%%%%% (or edit to be hard-coded for your installation)
wolffd@0: ext = lower(computer);
wolffd@0: if ispc
wolffd@0:   ext = 'exe';
wolffd@0:   rmcmd = 'del';
wolffd@0: end
wolffd@0: lame = fullfile(path,['lame.',ext]);
wolffd@0: 
wolffd@0: %%%% Process input arguments
wolffd@0: % Do we have NBITS?
wolffd@0: mynargin = nargin;
wolffd@0: if ischar(NBITS)
wolffd@0:   % NBITS is a string i.e. it's actually the filename
wolffd@0:   if mynargin > 3
wolffd@0:     OPTIONS = FILE;
wolffd@0:   end
wolffd@0:   FILE = NBITS;
wolffd@0:   NBITS = 16;
wolffd@0:   % it's as if NBITS had been specified...
wolffd@0:   mynargin = mynargin + 1;
wolffd@0: end
wolffd@0: 
wolffd@0: if mynargin < 5
wolffd@0:   OPTIONS = '--quiet -h';  % -h means high-quality psych model
wolffd@0: end
wolffd@0: 
wolffd@0: [nr, nc] = size(D);
wolffd@0: if nc < nr
wolffd@0:   D = D';
wolffd@0:   [nr, nc] = size(D);
wolffd@0: end
wolffd@0: % Now rows are channels, cols are time frames (so interleaving is right)
wolffd@0: 
wolffd@0: %%%%% add extension if none (like wavread)
wolffd@0: [path,file,ext] = fileparts(FILE);
wolffd@0: if isempty(ext)
wolffd@0:   FILE = [FILE, '.mp3'];
wolffd@0: end
wolffd@0: 
wolffd@0: nchan = nr;
wolffd@0: nfrm = nc;
wolffd@0: 
wolffd@0: if nchan == 1
wolffd@0:   monostring = ' -m m';
wolffd@0: else
wolffd@0:   monostring = '';
wolffd@0: end
wolffd@0: 
wolffd@0: lameopts = [' ', OPTIONS, monostring, ' '];
wolffd@0: 
wolffd@0: %if exist('popenw') == 3
wolffd@0: if length(which('popenw')) > 0
wolffd@0: 
wolffd@0:   % We have the writable stream process extensions
wolffd@0:   cmd = ['"',lame,'"', lameopts, '-r -s ',num2str(SR),' - "',FILE,'"'];
wolffd@0: 
wolffd@0:   p = popenw(cmd);
wolffd@0:   if p < 0
wolffd@0:     error(['Error running popen(',cmd,')']);
wolffd@0:   end
wolffd@0: 
wolffd@0:   % We feed the audio to the encoder in blocks of <blksize> frames.
wolffd@0:   % By adapting this loop, you can create your own code to 
wolffd@0:   % write a single, large, MP3 file one part at a time.
wolffd@0:   
wolffd@0:   blksiz = 10000;
wolffd@0: 
wolffd@0:   nrem = nfrm;
wolffd@0:   base = 0;
wolffd@0: 
wolffd@0:   while nrem > 0
wolffd@0:     thistime = min(nrem, blksiz);
wolffd@0:     done = popenw(p,32767*D(:,base+(1:thistime)),'int16be');
wolffd@0:     nrem = nrem - thistime;
wolffd@0:     base = base + thistime;
wolffd@0:     %disp(['done=',num2str(done)]);
wolffd@0:   end
wolffd@0: 
wolffd@0:   % Close pipe
wolffd@0:   popenw(p,[]);
wolffd@0: 
wolffd@0: else 
wolffd@0:   disp('Warning: popenw not available, writing temporary file');
wolffd@0:   
wolffd@0:   tmpfile = fullfile(tmpdir,['tmp',num2str(round(1000*rand(1))),'.wav']);
wolffd@0: 
wolffd@0:   wavwrite(D',SR,tmpfile);
wolffd@0:   
wolffd@0:   cmd = ['"',lame,'"', lameopts, '"',tmpfile, '" "', FILE, '"'];
wolffd@0: 
wolffd@0:   mysystem(cmd);
wolffd@0: 
wolffd@0:   % Delete tmp file
wolffd@0:   mysystem([rmcmd, ' "', tmpfile,'"']);
wolffd@0: 
wolffd@0: end 
wolffd@0: 
wolffd@0: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
wolffd@0: function w = mysystem(cmd)
wolffd@0: % Run system command; report error; strip all but last line
wolffd@0: [s,w] = system(cmd);
wolffd@0: if s ~= 0 
wolffd@0:   error(['unable to execute ',cmd,' (',w,')']);
wolffd@0: end
wolffd@0: % Keep just final line
wolffd@0: w = w((1+max([0,findstr(w,10)])):end);
wolffd@0: % Debug
wolffd@0: %disp([cmd,' -> ','*',w,'*']);