The ogg/opus tagger.
[paraslash.git] / opus_afh.c
1 /*
2 * Copyright (C) 2012 Andre Noll <maan@tuebingen.mpg.de>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file opus_afh.c Audio format handler for ogg/opus files. */
8
9 #include <ogg/ogg.h>
10 #include <regex.h>
11
12 #include "para.h"
13 #include "afh.h"
14 #include "error.h"
15 #include "portable_io.h"
16 #include "string.h"
17 #include "opus_common.h"
18 #include "ogg_afh_common.h"
19
20 static const char* opus_suffixes[] = {"opus", NULL};
21
22 #define OPUS_COMMENT_HEADER "OpusTags"
23
24 static bool copy_if_tag_type(const char *tag, int taglen, const char *type,
25 char **p)
26 {
27 char *q = key_value_copy(tag, taglen, type);
28 if (!q)
29 return false;
30 free(*p);
31 *p = q;
32 return true;
33 }
34
35 static int opus_get_comments(char *comments, int length,
36 struct taginfo *tags)
37 {
38 char *p = comments, *end = comments + length;
39 int i;
40 uint32_t val, ntags;
41
42 /* min size of a opus header is 16 bytes */
43 if (length < 16)
44 return -E_OPUS_COMMENT;
45 if (memcmp(p, OPUS_COMMENT_HEADER, strlen(OPUS_COMMENT_HEADER)) != 0)
46 return -E_OPUS_COMMENT;
47 p += 8;
48 val = read_u32(p);
49 p += 4;
50 if (p + val > end)
51 return -E_OPUS_COMMENT;
52 tags->comment = safe_strdup(p, val);
53 p += val;
54 ntags = read_u32(p);
55 p += 4;
56 if (p + ntags * 4 > end)
57 return -E_OPUS_COMMENT;
58 PARA_INFO_LOG("found %d tag(s)\n", ntags);
59 for (i = 0; i < ntags; i++, p += val) {
60 char *tag;
61
62 if (p + 4 > end)
63 return -E_OPUS_COMMENT;
64 val = read_u32(p);
65 p += 4;
66 if (p + val > end)
67 return -E_OPUS_COMMENT;
68 if (copy_if_tag_type(p, val, "author", &tags->artist))
69 continue;
70 if (copy_if_tag_type(p, val, "artist", &tags->artist))
71 continue;
72 if (copy_if_tag_type(p, val, "title", &tags->title))
73 continue;
74 if (copy_if_tag_type(p, val, "album", &tags->album))
75 continue;
76 if (copy_if_tag_type(p, val, "year", &tags->year))
77 continue;
78 if (copy_if_tag_type(p, val, "comment", &tags->comment))
79 continue;
80 tag = safe_strdup(p, val);
81 PARA_NOTICE_LOG("unrecognized tag: %s\n", tag);
82 free(tag);
83 }
84 return 1;
85 }
86
87 static int opus_packet_callback(ogg_packet *packet, int packet_num,
88 __a_unused int serial, struct afh_info *afhi,
89 void *private_data)
90 {
91 int ret;
92 struct opus_header *oh = private_data;
93
94 if (packet_num == 0) {
95 ret = opus_parse_header((char *)packet->packet, packet->bytes, oh);
96 if (ret < 0)
97 return ret;
98 afhi->channels = oh->channels;
99 afhi->techinfo = make_message("header version %d, input sample rate: %dHz",
100 oh->version, oh->input_sample_rate);
101 /*
102 * The input sample rate is irrelevant for afhi->frequency as
103 * we always decode to 48kHz.
104 */
105 afhi->frequency = 48000;
106 return 1;
107 }
108 if (packet_num == 1) {
109 ret = opus_get_comments((char *)packet->packet, packet->bytes,
110 &afhi->tags);
111 if (ret < 0)
112 return ret;
113 return 0; /* header complete */
114 }
115 /* never reached */
116 assert(0);
117 }
118
119 static int opus_get_file_info(char *map, size_t numbytes, __a_unused int fd,
120 struct afh_info *afhi)
121 {
122 int ret, ms;
123 struct opus_header oh = {.version = 0};
124
125 struct ogg_afh_callback_info opus_callback_info = {
126 .packet_callback = opus_packet_callback,
127 .private_data = &oh,
128 };
129 ret = ogg_get_file_info(map, numbytes, afhi, &opus_callback_info);
130 if (ret < 0)
131 return ret;
132 ret = (afhi->chunk_table[afhi->chunks_total] - afhi->chunk_table[0]) * 8; /* bits */
133 ms = tv2ms(&afhi->chunk_tv) * afhi->chunks_total;
134 afhi->bitrate = ret / ms;
135 return 1;
136 }
137
138 static size_t opus_make_meta_packet(struct taginfo *tags, char **result)
139 {
140 size_t sz;
141 char *buf, *p;
142 size_t comment_len = strlen(tags->comment),
143 artist_len = strlen(tags->artist),
144 title_len = strlen(tags->title),
145 album_len = strlen(tags->album),
146 year_len = strlen(tags->year);
147 uint32_t comment_sz = comment_len,
148 artist_sz = artist_len + strlen("artist="),
149 title_sz = title_len + strlen("title="),
150 album_sz = album_len + strlen("album="),
151 year_sz = year_len + strlen("year=");
152 uint32_t num_tags;
153
154 sz = strlen(OPUS_COMMENT_HEADER)
155 + 4 /* comment length (always present) */
156 + comment_sz
157 + 4; /* number of tags */
158 num_tags = 0;
159 if (artist_len) {
160 num_tags++;
161 sz += 4 + artist_sz;
162 }
163 if (title_len) {
164 num_tags++;
165 sz += 4 + title_sz;
166 }
167 if (album_len) {
168 num_tags++;
169 sz += 4 + album_sz;
170 }
171 if (year_len) {
172 num_tags++;
173 sz += 4 + year_sz;
174 }
175 PARA_DEBUG_LOG("meta packet size: %zu bytes\n", sz);
176 /* terminating zero byte for the last sprintf() */
177 buf = p = para_malloc(sz + 1);
178 memcpy(p, OPUS_COMMENT_HEADER, strlen(OPUS_COMMENT_HEADER));
179 p += strlen(OPUS_COMMENT_HEADER);
180 write_u32(p, comment_sz);
181 p += 4;
182 strcpy(p, tags->comment);
183 p += comment_sz;
184 write_u32(p, num_tags);
185 p += 4;
186 if (artist_len) {
187 write_u32(p, artist_sz);
188 p += 4;
189 sprintf(p, "artist=%s", tags->artist);
190 p += artist_sz;
191 }
192 if (title_len) {
193 write_u32(p, title_sz);
194 p += 4;
195 sprintf(p, "title=%s", tags->title);
196 p += title_sz;
197 }
198 if (album_len) {
199 write_u32(p, album_sz);
200 p += 4;
201 sprintf(p, "album=%s", tags->album);
202 p += album_sz;
203 }
204 if (year_len) {
205 write_u32(p, year_sz);
206 p += 4;
207 sprintf(p, "year=%s", tags->year);
208 p += year_sz;
209 }
210 assert(p == buf + sz);
211 *result = buf;
212 return sz;
213 }
214
215 static int opus_rewrite_tags(const char *map, size_t mapsize,
216 struct taginfo *tags, int output_fd,
217 __a_unused const char *filename)
218 {
219 char *meta_packet;
220 size_t meta_sz;
221 int ret;
222
223 meta_sz = opus_make_meta_packet(tags, &meta_packet);
224 ret = ogg_rewrite_tags(map, mapsize, output_fd, meta_packet, meta_sz);
225 free(meta_packet);
226 return ret;
227 }
228
229 /**
230 * The init function of the ogg/opus audio format handler.
231 *
232 * \param afh Pointer to the struct to initialize.
233 */
234 void opus_afh_init(struct audio_format_handler *afh)
235 {
236 afh->get_file_info = opus_get_file_info,
237 afh->suffixes = opus_suffixes;
238 afh->rewrite_tags = opus_rewrite_tags;
239 }