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comparison scripts/audio/wavwrite.m @ 15529:9a7f73fc304f

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Fix wavwrite to accept a row vector input (bug #37540) * wavwrite.m: Accept a row vector as a single audio channel. Update docstring and add a test case.
author Mike Miller <mtmiller@ieee.org>
date Mon, 15 Oct 2012 21:02:42 -0400
parents 72c96de7a403
children 221e71d2aef0
comparison
equal deleted inserted replaced
15528:8d2b3db8b5b0 15529:9a7f73fc304f
21 ## @deftypefnx {Function File} {} wavwrite (@var{y}, @var{Fs}, @var{filename}) 21 ## @deftypefnx {Function File} {} wavwrite (@var{y}, @var{Fs}, @var{filename})
22 ## @deftypefnx {Function File} {} wavwrite (@var{y}, @var{Fs}, @var{bps}, @var{filename}) 22 ## @deftypefnx {Function File} {} wavwrite (@var{y}, @var{Fs}, @var{bps}, @var{filename})
23 ## Write @var{y} to the canonical RIFF/WAVE sound file @var{filename} 23 ## Write @var{y} to the canonical RIFF/WAVE sound file @var{filename}
24 ## with sample rate @var{Fs} and bits per sample @var{bps}. The 24 ## with sample rate @var{Fs} and bits per sample @var{bps}. The
25 ## default sample rate is 8000 Hz with 16-bits per sample. Each column 25 ## default sample rate is 8000 Hz with 16-bits per sample. Each column
26 ## of the data represents a separate channel. 26 ## of the data represents a separate channel. If @var{y} is either a
27 ## row vector or a column vector, it is written as a single channel.
27 ## @seealso{wavread} 28 ## @seealso{wavread}
28 ## @end deftypefn 29 ## @end deftypefn
29 30
30 ## Author: Michael Zeising <michael@michaels-website.de> 31 ## Author: Michael Zeising <michael@michaels-website.de>
31 ## Created: 06 December 2005 32 ## Created: 06 December 2005
48 if (nargin > 3) 49 if (nargin > 3)
49 bits_per_sample = varargin{2}; 50 bits_per_sample = varargin{2};
50 endif 51 endif
51 endif 52 endif
52 53
54 ## calculate filesize
55 [n, channels] = size (y);
56
57 ## allow y to be a row vector
58 if (n == 1)
59 n = channels;
60 channels = 1;
61 endif
62
53 ## test arguments 63 ## test arguments
54 if (columns (y) < 1) 64 if (channels < 1)
55 error ("wavwrite: Y must have at least one column"); 65 error ("wavwrite: Y must have at least one column");
56 endif 66 endif
57 if (columns (y) > 0x7FFF) 67 if (channels > 0x7FFF)
58 error ("wavwrite: Y has more than 32767 columns (too many for a WAV-file)"); 68 error ("wavwrite: Y has more than 32767 columns (too many for a WAV-file)");
59 endif 69 endif
60 70
61 ## determine sample format 71 ## determine sample format
62 switch (bits_per_sample) 72 switch (bits_per_sample)
67 case 32 77 case 32
68 format = "int32"; 78 format = "int32";
69 otherwise 79 otherwise
70 error ("wavwrite: sample resolution not supported"); 80 error ("wavwrite: sample resolution not supported");
71 endswitch 81 endswitch
72
73 ## calculate filesize
74 [n, channels] = size (y);
75 82
76 ## size of data chunk 83 ## size of data chunk
77 ck_size = n*channels*(bits_per_sample/8); 84 ck_size = n*channels*(bits_per_sample/8);
78 85
79 if (! ischar (filename)) 86 if (! ischar (filename))
172 %! assert (samples_per_sec, 4000); 179 %! assert (samples_per_sec, 4000);
173 %! assert (bits_per_sample, 8); 180 %! assert (bits_per_sample, 8);
174 %! unlink (fname); 181 %! unlink (fname);
175 % 182 %
176 %!test 183 %!test
177 %! A = [-2:2]; 184 %! A = [-2:2]';
178 %! wavwrite (A, fname); 185 %! wavwrite (A, fname);
179 %! B = wavread (fname); 186 %! B = wavread (fname);
180 %! B *= 32768; 187 %! B *= 32768;
181 %! assert (B, [-32768 -32768 0 32767 32767]); 188 %! assert (B, [-32768 -32768 0 32767 32767]');
189 %! unlink (fname);
190 %
191 %!test
192 %! A = [-1:0.1:1];
193 %! wavwrite (A, fname);
194 %! [B, samples_per_sec, bits_per_sample] = wavread (fname);
195 %! assert (A', B, 1/2^15);
196 %! assert (samples_per_sec, 8000);
197 %! assert (bits_per_sample, 16);
182 %! unlink (fname); 198 %! unlink (fname);
183 199