1 /* libSoX file format: HTK (c) 2008 robs@users.sourceforge.net
2 *
3 * See http://labrosa.ee.columbia.edu/doc/HTKBook21/HTKBook.html
4 *
5 * This library is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU Lesser General Public License as published by
7 * the Free Software Foundation; either version 2.1 of the License, or (at
8 * your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public License
16 * along with this library; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20 #include "sox_i.h"
21
22 typedef enum {
23 Waveform, Lpc, Lprefc, Lpcepstra, Lpdelcep, Irefc,
24 Mfcc, Fbank, Melspec, User, Discrete, Unknown} kind_t;
25 static char const * const str[] = {
26 "Sampled waveform", "Linear prediction filter", "Linear prediction",
27 "LPC cepstral", "LPC cepstra plus delta", "LPC reflection coef in",
28 "Mel-frequency cepstral", "Log mel-filter bank", "Linear mel-filter bank",
29 "User defined sample", "Vector quantised data", "Unknown"};
30
start_read(sox_format_t * ft)31 static int start_read(sox_format_t * ft)
32 {
33 uint32_t period_100ns, num_samples;
34 uint16_t bytes_per_sample, parmKind;
35
36 if (lsx_readdw(ft, &num_samples ) ||
37 lsx_readdw(ft, &period_100ns ) ||
38 lsx_readw (ft, &bytes_per_sample) ||
39 lsx_readw (ft, &parmKind )) return SOX_EOF;
40 if (parmKind != Waveform) {
41 int n = min(parmKind & 077, Unknown);
42 lsx_fail_errno(ft, SOX_EFMT, "unsupported HTK type `%s' (0%o)", str[n], parmKind);
43 return SOX_EOF;
44 }
45 return lsx_check_read_params(ft, 1, 1e7 / period_100ns, SOX_ENCODING_SIGN2,
46 (unsigned)bytes_per_sample << 3, (uint64_t)num_samples, sox_true);
47 }
48
write_header(sox_format_t * ft)49 static int write_header(sox_format_t * ft)
50 {
51 double period_100ns = 1e7 / ft->signal.rate;
52 uint64_t len = ft->olength? ft->olength:ft->signal.length;
53
54 if (len > UINT_MAX)
55 {
56 lsx_warn("length greater than 32 bits - cannot fit actual length in header");
57 len = UINT_MAX;
58 }
59 if (!ft->olength && floor(period_100ns) != period_100ns)
60 lsx_warn("rounding sample period %f (x 100ns) to nearest integer", period_100ns);
61 return lsx_writedw(ft, (unsigned)len)
62 || lsx_writedw(ft, (unsigned)(period_100ns + .5))
63 || lsx_writew(ft, ft->encoding.bits_per_sample >> 3)
64 || lsx_writew(ft, Waveform) ? SOX_EOF : SOX_SUCCESS;
65 }
66
LSX_FORMAT_HANDLER(htk)67 LSX_FORMAT_HANDLER(htk)
68 {
69 static char const * const names[] = {"htk", NULL};
70 static unsigned const write_encodings[] = {SOX_ENCODING_SIGN2, 16, 0, 0};
71 static sox_format_handler_t handler = {
72 SOX_LIB_VERSION_CODE,
73 "PCM format used for Hidden Markov Model speech processing",
74 names, SOX_FILE_BIG_END | SOX_FILE_MONO | SOX_FILE_REWIND,
75 start_read, lsx_rawread, NULL,
76 write_header, lsx_rawwrite, NULL,
77 lsx_rawseek, write_encodings, NULL, 0
78 };
79 return &handler;
80 }
81