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wavread, wavwrite: Overhaul functions. * wavread.m, wavwrite.m: Rewrite as wrappers around the new audioread and audiowrite functions. Redo docstrings and add seealso links to audioread and audiowrite. Improve input validation. Fix %!tests and make conditional on HAVE_SNDFILE.
author Mike Miller <mtmiller@ieee.org>
date Sat, 21 Feb 2015 11:58:20 -0500
parents 4197fc428c7d
children 9fc020886ae9
comparison
equal deleted inserted replaced
19813:879cff0c05dc 19814:71770cf07c30
1 ## Copyright (C) 2015 Mike Miller
1 ## Copyright (C) 2005-2015 Michael Zeising 2 ## Copyright (C) 2005-2015 Michael Zeising
2 ## 3 ##
3 ## This file is part of Octave. 4 ## This file is part of Octave.
4 ## 5 ##
5 ## Octave is free software; you can redistribute it and/or modify it 6 ## Octave is free software; you can redistribute it and/or modify it
16 ## along with Octave; see the file COPYING. If not, see 17 ## along with Octave; see the file COPYING. If not, see
17 ## <http://www.gnu.org/licenses/>. 18 ## <http://www.gnu.org/licenses/>.
18 19
19 ## -*- texinfo -*- 20 ## -*- texinfo -*-
20 ## @deftypefn {Function File} {@var{y} =} wavread (@var{filename}) 21 ## @deftypefn {Function File} {@var{y} =} wavread (@var{filename})
21 ## @deftypefnx {Function File} {[@var{y}, @var{Fs}, @var{bps}] =} wavread (@var{filename}) 22 ## @deftypefnx {Function File} {[@var{y}, @var{fs}, @var{nbits}] =} wavread (@var{filename})
22 ## @deftypefnx {Function File} {[@dots{}] =} wavread (@var{filename}, @var{n}) 23 ## @deftypefnx {Function File} {[@dots{}] =} wavread (@var{filename}, @var{n})
23 ## @deftypefnx {Function File} {[@dots{}] =} wavread (@var{filename}, [@var{n1} @var{n2}]) 24 ## @deftypefnx {Function File} {[@dots{}] =} wavread (@var{filename}, [@var{n1} @var{n2}])
24 ## @deftypefnx {Function File} {[@var{samples}, @var{channels}] =} wavread (@var{filename}, "size") 25 ## @deftypefnx {Function File} {[@dots{}] =} wavread (@dots{}, @var{datatype})
26 ## @deftypefnx {Function File} {@var{sz} =} wavread (@var{filename}, "size")
27 ## Read the audio signal @var{y} from the RIFF/WAVE sound file @var{filename}.
28 ## If the file contains multichannel data, then @var{y} is a matrix with the
29 ## channels represented as columns.
25 ## 30 ##
26 ## Load the RIFF/WAVE sound file @var{filename}, and return the samples 31 ## The optional return value @var{fs} is the sample rate of the audio file in
27 ## in vector @var{y}. If the file contains multichannel data, then 32 ## Hz. The optional return value @var{nbits} is the number of bits per sample
28 ## @var{y} is a matrix with the channels represented as columns. 33 ## as encoded in the file.
29 ## 34 ##
30 ## @code{[@var{y}, @var{Fs}, @var{bps}] = wavread (@var{filename})} 35 ## If @var{n} is specified, only the first @var{n} samples of the file are
36 ## returned. If [@var{n1} @var{n2}] is specified, only the range of samples
37 ## from @var{n1} to @var{n2} is returned. A value of @code{Inf} can be used
38 ## to represent the total number of samples in the file.
31 ## 39 ##
32 ## Additionally return the sample rate (@var{fs}) in Hz and the number of bits 40 ## If the option @qcode{"size"} is given, then the size of the audio signal
33 ## per sample (@var{bps}). 41 ## is returned instead of the data. The size is returned in a row vector of
34 ## 42 ## the form [@var{samples} @var{channels}]. If there are two output arguments,
35 ## @code{[@dots{}] = wavread (@var{filename}, @var{n})} 43 ## the number of samples is assigned to the first and the number of channels
36 ## 44 ## is assigned to the second.
37 ## Read only the first @var{n} samples from each channel. 45 ## @seealso{audioread, audiowrite, wavwrite}
38 ##
39 ## @code{wavread (@var{filename}, [@var{n1} @var{n2}])}
40 ##
41 ## Read only samples @var{n1} through @var{n2} from each channel.
42 ##
43 ## @code{[@var{samples}, @var{channels}] = wavread (@var{filename}, "size")}
44 ##
45 ## Return the number of samples (@var{n}) and number of channels (@var{ch})
46 ## instead of the audio data.
47 ## @seealso{wavwrite}
48 ## @end deftypefn 46 ## @end deftypefn
49 47
50 ## Author: Michael Zeising <michael@michaels-website.de> 48 function [y, fs, nbits] = wavread (filename, varargin)
51 ## Created: 06 December 2005
52 49
53 function [y, samples_per_sec, bits_per_sample] = wavread (filename, param) 50 if (nargin < 1 || nargin > 3)
54
55 FORMAT_PCM = 0x0001; # PCM (8/16/32 bit)
56 FORMAT_IEEE_FLOAT = 0x0003; # IEEE float (32/64 bit)
57 BYTEORDER = "ieee-le";
58
59 if (nargin < 1 || nargin > 2)
60 print_usage (); 51 print_usage ();
61 endif 52 endif
62 53
63 if (! ischar (filename)) 54 if (! ischar (filename))
64 error ("wavread: FILENAME must be a character string"); 55 error ("wavread: FILENAME must be a character string");
65 endif 56 endif
66 57
67 fid = -1; 58 datatype = "double";
59 samples = [1, Inf];
60 do_file_size = false;
68 61
69 unwind_protect 62 if (nargin == 3)
70 63 samples = varargin{1};
71 [fid, msg] = fopen (filename, "rb"); 64 datatype = varargin{2};
72 65 elseif (nargin == 2)
73 if (fid < 0) 66 if (strcmp (varargin{1}, "size"))
74 error ("wavread: %s", msg); 67 do_file_size = true;
68 elseif (ischar (varargin{1}))
69 datatype = varargin{1};
70 else
71 samples = varargin{1};
75 endif 72 endif
76
77 ## Get file size.
78 fseek (fid, 0, "eof");
79 file_size = ftell (fid);
80 fseek (fid, 0, "bof");
81
82 ## Find RIFF chunk.
83 riff_size = find_chunk (fid, "RIFF", file_size);
84 riff_pos = ftell (fid);
85 if (riff_size == -1)
86 error ("wavread: file contains no RIFF chunk");
87 endif
88 riff_size = min (riff_size, file_size - riff_pos);
89
90 riff_type = char (fread (fid, 4))';
91 if (! strcmp (riff_type, "WAVE"))
92 error ("wavread: file contains no WAVE signature");
93 endif
94 riff_pos = riff_pos + 4;
95 riff_size = riff_size - 4;
96
97 ## Find format chunk inside the RIFF chunk.
98 fseek (fid, riff_pos, "bof");
99 fmt_size = find_chunk (fid, "fmt ", riff_size);
100 fmt_pos = ftell (fid);
101 if (fmt_size == -1)
102 error ("wavread: file contains no format chunk");
103 endif
104
105 ## Find data chunk inside the RIFF chunk.
106 ## We don't assume that it comes after the format chunk.
107 fseek (fid, riff_pos, "bof");
108 data_size = find_chunk (fid, "data", riff_size);
109 data_pos = ftell (fid);
110 if (data_size == -1)
111 error ("wavread: file contains no data chunk");
112 endif
113 data_size = min (data_size, file_size - data_pos);
114
115 ### Read format chunk.
116 fseek (fid, fmt_pos, "bof");
117
118 ## Sample format code.
119 format_tag = fread (fid, 1, "uint16", 0, BYTEORDER);
120 if (format_tag != FORMAT_PCM && format_tag != FORMAT_IEEE_FLOAT)
121 error ("wavread: sample format %#x is not supported", format_tag);
122 endif
123
124 ## Number of interleaved channels.
125 channels = fread (fid, 1, "uint16", 0, BYTEORDER);
126
127 ## Sample rate.
128 samples_per_sec = fread (fid, 1, "uint32", 0, BYTEORDER);
129
130 ## Bits per sample.
131 fseek (fid, 6, "cof");
132 bits_per_sample = fread (fid, 1, "uint16", 0, BYTEORDER);
133
134 ### Read data chunk.
135 fseek (fid, data_pos, "bof");
136
137 ## Determine sample data type.
138 if (format_tag == FORMAT_PCM)
139 switch (bits_per_sample)
140 case 8
141 format = "uint8";
142 case 16
143 format = "int16";
144 case 24
145 format = "uint8";
146 case 32
147 format = "int32";
148 otherwise
149 error ("wavread: %d bits sample resolution is not supported with PCM",
150 bits_per_sample);
151 endswitch
152 else
153 switch (bits_per_sample)
154 case 32
155 format = "float32";
156 case 64
157 format = "float64";
158 otherwise
159 error ("wavread: %d bits sample resolution is not supported with IEEE float",
160 bits_per_sample);
161 endswitch
162 endif
163
164 ## Parse arguments.
165 if (nargin == 1)
166 length = idivide (8 * data_size, bits_per_sample);
167 else
168 nparams = numel (param);
169 if (nparams == 1)
170 ## Number of samples is given.
171 length = param * channels;
172 elseif (nparams == 2)
173 ## Sample range is given.
174 if (fseek (fid, (param(1)-1) * channels * (bits_per_sample/8), "cof") < 0)
175 warning ("wavread: seeking failed");
176 endif
177 length = (param(2)-param(1)+1) * channels;
178 elseif (nparams == 4 && char (param) == "size")
179 ## Size of the file is requested.
180 y = idivide (8 * data_size, channels * bits_per_sample);
181 samples_per_sec = channels;
182 return;
183 else
184 error ("wavread: invalid PARAM argument");
185 endif
186 endif
187
188 ## Read samples and close file.
189 if (bits_per_sample == 24)
190 length *= 3;
191 endif
192
193 [yi, n] = fread (fid, length, format, 0, BYTEORDER);
194
195 unwind_protect_cleanup
196
197 if (fid >= 0)
198 fclose (fid);
199 endif
200
201 end_unwind_protect
202
203 ## Check data.
204 if (mod (numel (yi), channels) != 0)
205 error ("wavread: data in %s doesn't match the number of channels",
206 filename);
207 endif 73 endif
208 74
209 if (bits_per_sample == 24) 75 if (isscalar (samples))
210 yi = reshape (yi, 3, rows (yi) / 3)'; 76 samples = [1, samples];
211 yi(yi(:,3) >= 128, 3) -= 256;
212 yi = yi * [1; 256; 65536];
213 endif 77 endif
214 78
215 if (format_tag == FORMAT_PCM) 79 if (! (isrow (samples) && numel (samples) == 2 && all (samples > 0)
216 ## Normalize samples. 80 && all (fix (samples) == samples)))
217 switch (bits_per_sample) 81 error ("wavread: SAMPLES must be a 1- or 2-element integer row vector");
218 case 8
219 yi = (yi - 128)/128;
220 case 16
221 yi /= 32768;
222 case 24
223 yi /= 8388608;
224 case 32
225 yi /= 2147483648;
226 endswitch
227 endif 82 endif
228 83
229 ## Deinterleave. 84 if (! (ischar (datatype) && any (strcmp (datatype, {"double", "native"}))))
230 nr = numel (yi) / channels; 85 error ('wavread: DATATYPE must be either "double" or "native"');
231 y = reshape (yi, channels, nr)'; 86 endif
87
88 info = audioinfo (filename);
89
90 if (do_file_size)
91 if (nargout > 1)
92 [y, fs] = deal (info.TotalSamples, info.NumChannels);
93 else
94 y = [info.TotalSamples, info.NumChannels];
95 endif
96 else
97 [y, fs] = audioread (filename, samples, datatype);
98 nbits = info.BitsPerSample;
99 endif
232 100
233 endfunction 101 endfunction
234 102
235 ## Given a chunk_id, scan through chunks from the current file position
236 ## though at most size bytes. Return the size of the found chunk, with
237 ## file position pointing to the start of the chunk data. Return -1 for
238 ## size if chunk is not found.
239 103
240 function chunk_size = find_chunk (fid, chunk_id, size) 104 ## Functional tests for wavread/wavwrite pair are in wavwrite.m.
241 id = "";
242 offset = 8;
243 chunk_size = 0;
244 105
245 while (! strcmp (id, chunk_id) && (offset < size)) 106 %% Test input validation
246 fseek (fid, chunk_size, "cof"); 107 %!error wavread ()
247 id = char (fread (fid, 4))'; 108 %!error wavread (1)
248 chunk_size = fread (fid, 1, "uint32", 0, "ieee-le"); 109 %!error wavread ("foo.wav", 2, 3, 4)
249 ## Chunk sizes must be word-aligned (2 byte) 110 %!error wavread ("foo.wav", "foo")
250 chunk_size += rem (chunk_size, 2); 111 %!error wavread ("foo.wav", -1)
251 offset = offset + 8 + chunk_size; 112 %!error wavread ("foo.wav", [1, Inf], "foo");
252 endwhile
253 if (! strcmp (id, chunk_id))
254 chunk_size = -1;
255 endif
256 endfunction
257 113
258
259 ## Mark file as tested. Tests for wavread/wavwrite pair are in wavwrite.m.
260 %!assert (1)
261