1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
## Copyright (C) 2019 John Donoghue <john.donoghue@ieee.org>
##
## This program is free software: you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
## This program is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program. If not, see
## <https://www.gnu.org/licenses/>.
## -*- texinfo -*-
## @deftypefn {} {@var{ismidi} =} ismidifile (@var{filename})
## Check if @var{filename} is a midi file.
##
## The function only checks whether it is an existing file and the
## file starts with a valid 'MThd' header.
##
## Non existing files, or files that do not meet the header criteria will return false.
##
## @subsubheading Inputs
## @var{filename} - filename of file to check.@*
##
## @subsubheading Outputs
## @var{ismidi} - true if it is a midi file, false otherwise
##
## @seealso{midifileread, midifilewrite}
## @end deftypefn
function ismidi = ismidifile(filename)
ismidi = false;
if nargin < 1
error ("Expected filename");
endif
fd = -1;
try
fd = fopen (filename, "rb");
unwind_protect
blockhdr = readheader (fd);
if !isempty(blockhdr)
if strcmp (blockhdr.blocktype, "MThd")
ismidi = true;
endif
endif
unwind_protect_cleanup
fclose (fd);
end_unwind_protect
catch
# do nothing
end_try_catch
endfunction
%!test
%! testname = file_in_loadpath("data/c_maj_melody.mid");
%! assert (ismidifile(testname), true);
%!test
%! testname = file_in_loadpath("data/sample.wav");
%! assert (ismidifile(testname), false);
%!test
%! testname = "X_DOES_NOT_EXIST_X";
%! assert (ismidifile(testname), false);
|
