1 /* libSoX MP3 utilities Copyright (c) 2007-9 SoX contributors
2 *
3 * This library is free software; you can redistribute it and/or modify it
4 * under the terms of the GNU Lesser General Public License as published by
5 * the Free Software Foundation; either version 2.1 of the License, or (at
6 * your option) any later version.
7 *
8 * This library is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU Lesser General Public License
14 * along with this library; if not, write to the Free Software Foundation,
15 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
16 */
17
18 #include <sys/stat.h>
19
20 #if defined(HAVE_LAME)
21
write_comments(sox_format_t * ft)22 static void write_comments(sox_format_t * ft)
23 {
24 priv_t *p = (priv_t *) ft->priv;
25 const char* comment;
26
27 p->id3tag_init(p->gfp);
28 p->id3tag_set_pad(p->gfp, (size_t)ID3PADDING);
29
30 /* Note: id3tag_set_fieldvalue is not present in LAME 3.97, so we're using
31 the 3.97-compatible methods for all of the tags that 3.97 supported. */
32 /* FIXME: This is no more necessary, since support for LAME 3.97 has ended. */
33 if ((comment = sox_find_comment(ft->oob.comments, "Title")))
34 p->id3tag_set_title(p->gfp, comment);
35 if ((comment = sox_find_comment(ft->oob.comments, "Artist")))
36 p->id3tag_set_artist(p->gfp, comment);
37 if ((comment = sox_find_comment(ft->oob.comments, "Album")))
38 p->id3tag_set_album(p->gfp, comment);
39 if ((comment = sox_find_comment(ft->oob.comments, "Tracknumber")))
40 p->id3tag_set_track(p->gfp, comment);
41 if ((comment = sox_find_comment(ft->oob.comments, "Year")))
42 p->id3tag_set_year(p->gfp, comment);
43 if ((comment = sox_find_comment(ft->oob.comments, "Comment")))
44 p->id3tag_set_comment(p->gfp, comment);
45 if ((comment = sox_find_comment(ft->oob.comments, "Genre")))
46 {
47 if (p->id3tag_set_genre(p->gfp, comment))
48 lsx_warn("\"%s\" is not a recognized ID3v1 genre.", comment);
49 }
50
51 if ((comment = sox_find_comment(ft->oob.comments, "Discnumber")))
52 {
53 char* id3tag_buf = lsx_malloc(strlen(comment) + 6);
54 if (id3tag_buf)
55 {
56 sprintf(id3tag_buf, "TPOS=%s", comment);
57 p->id3tag_set_fieldvalue(p->gfp, id3tag_buf);
58 free(id3tag_buf);
59 }
60 }
61 }
62
63 #endif /* HAVE_LAME */
64
65 #ifdef HAVE_MAD_H
66
xing_frames(priv_t * p,struct mad_bitptr ptr,unsigned bitlen)67 static unsigned long xing_frames(priv_t * p, struct mad_bitptr ptr, unsigned bitlen)
68 {
69 #define XING_MAGIC ( ('X' << 24) | ('i' << 16) | ('n' << 8) | 'g' )
70 if (bitlen >= 96 && p->mad_bit_read(&ptr, 32) == XING_MAGIC &&
71 (p->mad_bit_read(&ptr, 32) & 1 )) /* XING_FRAMES */
72 return p->mad_bit_read(&ptr, 32);
73 return 0;
74 }
75
mp3_duration(sox_format_t * ft)76 static size_t mp3_duration(sox_format_t * ft)
77 {
78 priv_t * p = (priv_t *) ft->priv;
79 struct mad_stream mad_stream;
80 struct mad_header mad_header;
81 struct mad_frame mad_frame;
82 size_t initial_bitrate = 0; /* Initialised to prevent warning */
83 size_t tagsize = 0, consumed = 0, frames = 0;
84 sox_bool vbr = sox_false, depadded = sox_false;
85 size_t num_samples = 0;
86
87 p->mad_stream_init(&mad_stream);
88 p->mad_header_init(&mad_header);
89 p->mad_frame_init(&mad_frame);
90
91 do { /* Read data from the MP3 file */
92 int read, padding = 0;
93 size_t leftover = mad_stream.bufend - mad_stream.next_frame;
94
95 memmove(p->mp3_buffer, mad_stream.this_frame, leftover);
96 read = lsx_readbuf(ft, p->mp3_buffer + leftover, p->mp3_buffer_size - leftover);
97 if (read <= 0) {
98 lsx_debug("got exact duration by scan to EOF (frames=%" PRIuPTR " leftover=%" PRIuPTR ")", frames, leftover);
99 break;
100 }
101 for (; !depadded && padding < read && !p->mp3_buffer[padding]; ++padding);
102 depadded = sox_true;
103 p->mad_stream_buffer(&mad_stream, p->mp3_buffer + padding, leftover + read - padding);
104
105 while (sox_true) { /* Decode frame headers */
106 mad_stream.error = MAD_ERROR_NONE;
107 if (p->mad_header_decode(&mad_header, &mad_stream) == -1) {
108 if (mad_stream.error == MAD_ERROR_BUFLEN)
109 break; /* Normal behaviour; get some more data from the file */
110 if (!MAD_RECOVERABLE(mad_stream.error)) {
111 lsx_warn("unrecoverable MAD error");
112 break;
113 }
114 if (mad_stream.error == MAD_ERROR_LOSTSYNC) {
115 unsigned available = (mad_stream.bufend - mad_stream.this_frame);
116 tagsize = tagtype(mad_stream.this_frame, (size_t) available);
117 if (tagsize) { /* It's some ID3 tags, so just skip */
118 if (tagsize >= available) {
119 lsx_seeki(ft, (off_t)(tagsize - available), SEEK_CUR);
120 depadded = sox_false;
121 }
122 p->mad_stream_skip(&mad_stream, min(tagsize, available));
123 }
124 else lsx_warn("MAD lost sync");
125 }
126 else lsx_warn("recoverable MAD error");
127 continue; /* Not an audio frame */
128 }
129
130 num_samples += MAD_NSBSAMPLES(&mad_header) * 32;
131 consumed += mad_stream.next_frame - mad_stream.this_frame;
132
133 lsx_debug_more("bitrate=%lu", mad_header.bitrate);
134 if (!frames) {
135 initial_bitrate = mad_header.bitrate;
136
137 /* Get the precise frame count from the XING header if present */
138 mad_frame.header = mad_header;
139 if (p->mad_frame_decode(&mad_frame, &mad_stream) == -1)
140 if (!MAD_RECOVERABLE(mad_stream.error)) {
141 lsx_warn("unrecoverable MAD error");
142 break;
143 }
144 if ((frames = xing_frames(p, mad_stream.anc_ptr, mad_stream.anc_bitlen))) {
145 num_samples *= frames;
146 lsx_debug("got exact duration from XING frame count (%" PRIuPTR ")", frames);
147 break;
148 }
149 }
150 else vbr |= mad_header.bitrate != initial_bitrate;
151
152 /* If not VBR, we can time just a few frames then extrapolate */
153 if (++frames == 25 && !vbr) {
154 double frame_size = (double) consumed / frames;
155 size_t num_frames = (lsx_filelength(ft) - tagsize) / frame_size;
156 num_samples = num_samples / frames * num_frames;
157 lsx_debug("got approx. duration by CBR extrapolation");
158 break;
159 }
160 }
161 } while (mad_stream.error == MAD_ERROR_BUFLEN);
162
163 p->mad_frame_finish(&mad_frame);
164 mad_header_finish(&mad_header);
165 p->mad_stream_finish(&mad_stream);
166 lsx_rewind(ft);
167
168 return num_samples;
169 }
170
171 #endif /* HAVE_MAD_H */
172