Libav
id3v2enc.c
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1 /*
2  * ID3v2 header writer
3  *
4  * This file is part of Libav.
5  *
6  * Libav is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * Libav is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include <stdint.h>
22 #include <string.h>
23 
24 #include "libavutil/dict.h"
25 #include "libavutil/intreadwrite.h"
26 #include "avformat.h"
27 #include "avio.h"
28 #include "id3v2.h"
29 
30 static void id3v2_put_size(AVIOContext *pb, int size)
31 {
32  avio_w8(pb, size >> 21 & 0x7f);
33  avio_w8(pb, size >> 14 & 0x7f);
34  avio_w8(pb, size >> 7 & 0x7f);
35  avio_w8(pb, size & 0x7f);
36 }
37 
38 static int string_is_ascii(const uint8_t *str)
39 {
40  while (*str && *str < 128) str++;
41  return !*str;
42 }
43 
44 static void id3v2_encode_string(AVIOContext *pb, const uint8_t *str,
45  enum ID3v2Encoding enc)
46 {
47  int (*put)(AVIOContext*, const char*);
48 
49  if (enc == ID3v2_ENCODING_UTF16BOM) {
50  avio_wl16(pb, 0xFEFF); /* BOM */
51  put = avio_put_str16le;
52  } else
53  put = avio_put_str;
54 
55  put(pb, str);
56 }
57 
63 static int id3v2_put_ttag(ID3v2EncContext *id3, AVIOContext *avioc, const char *str1, const char *str2,
64  uint32_t tag, enum ID3v2Encoding enc)
65 {
66  int len;
67  uint8_t *pb;
68  AVIOContext *dyn_buf;
69  if (avio_open_dyn_buf(&dyn_buf) < 0)
70  return AVERROR(ENOMEM);
71 
72  /* check if the strings are ASCII-only and use UTF16 only if
73  * they're not */
74  if (enc == ID3v2_ENCODING_UTF16BOM && string_is_ascii(str1) &&
75  (!str2 || string_is_ascii(str2)))
77 
78  avio_w8(dyn_buf, enc);
79  id3v2_encode_string(dyn_buf, str1, enc);
80  if (str2)
81  id3v2_encode_string(dyn_buf, str2, enc);
82  len = avio_close_dyn_buf(dyn_buf, &pb);
83 
84  avio_wb32(avioc, tag);
85  /* ID3v2.3 frame size is not synchsafe */
86  if (id3->version == 3)
87  avio_wb32(avioc, len);
88  else
89  id3v2_put_size(avioc, len);
90  avio_wb16(avioc, 0);
91  avio_write(avioc, pb, len);
92 
93  av_freep(&pb);
94  return len + ID3v2_HEADER_SIZE;
95 }
96 
98  const char table[][4], enum ID3v2Encoding enc)
99 {
100  uint32_t tag;
101  int i;
102 
103  if (t->key[0] != 'T' || strlen(t->key) != 4)
104  return -1;
105  tag = AV_RB32(t->key);
106  for (i = 0; *table[i]; i++)
107  if (tag == AV_RB32(table[i]))
108  return id3v2_put_ttag(id3, pb, t->value, NULL, tag, enc);
109  return -1;
110 }
111 
112 void ff_id3v2_start(ID3v2EncContext *id3, AVIOContext *pb, int id3v2_version,
113  const char *magic)
114 {
115  id3->version = id3v2_version;
116 
117  avio_wb32(pb, MKBETAG(magic[0], magic[1], magic[2], id3v2_version));
118  avio_w8(pb, 0);
119  avio_w8(pb, 0); /* flags */
120 
121  /* reserve space for size */
122  id3->size_pos = avio_tell(pb);
123  avio_wb32(pb, 0);
124 }
125 
127 {
129  int enc = id3->version == 3 ? ID3v2_ENCODING_UTF16BOM :
131 
133  if (id3->version == 4)
135 
136  while ((t = av_dict_get(s->metadata, "", t, AV_DICT_IGNORE_SUFFIX))) {
137  int ret;
138 
139  if ((ret = id3v2_check_write_tag(id3, s->pb, t, ff_id3v2_tags, enc)) > 0) {
140  id3->len += ret;
141  continue;
142  }
143  if ((ret = id3v2_check_write_tag(id3, s->pb, t, id3->version == 3 ?
144  ff_id3v2_3_tags : ff_id3v2_4_tags, enc)) > 0) {
145  id3->len += ret;
146  continue;
147  }
148 
149  /* unknown tag, write as TXXX frame */
150  if ((ret = id3v2_put_ttag(id3, s->pb, t->key, t->value, MKBETAG('T', 'X', 'X', 'X'), enc)) < 0)
151  return ret;
152  id3->len += ret;
153  }
154 
155  return 0;
156 }
157 
159 {
160  AVStream *st = s->streams[pkt->stream_index];
162 
163  AVIOContext *dyn_buf;
164  uint8_t *buf;
165  const CodecMime *mime = ff_id3v2_mime_tags;
166  const char *mimetype = NULL, *desc = "";
167  int enc = id3->version == 3 ? ID3v2_ENCODING_UTF16BOM :
169  int i, len, type = 0;
170 
171  /* get the mimetype*/
172  while (mime->id != AV_CODEC_ID_NONE) {
173  if (mime->id == st->codec->codec_id) {
174  mimetype = mime->str;
175  break;
176  }
177  mime++;
178  }
179  if (!mimetype) {
180  av_log(s, AV_LOG_ERROR, "No mimetype is known for stream %d, cannot "
181  "write an attached picture.\n", st->index);
182  return AVERROR(EINVAL);
183  }
184 
185  /* get the picture type */
186  e = av_dict_get(st->metadata, "comment", NULL, 0);
187  for (i = 0; e && i < FF_ARRAY_ELEMS(ff_id3v2_picture_types); i++) {
188  if (strstr(ff_id3v2_picture_types[i], e->value) == ff_id3v2_picture_types[i]) {
189  type = i;
190  break;
191  }
192  }
193 
194  /* get the description */
195  if ((e = av_dict_get(st->metadata, "title", NULL, 0)))
196  desc = e->value;
197 
198  /* start writing */
199  if (avio_open_dyn_buf(&dyn_buf) < 0)
200  return AVERROR(ENOMEM);
201 
202  avio_w8(dyn_buf, enc);
203  avio_put_str(dyn_buf, mimetype);
204  avio_w8(dyn_buf, type);
205  id3v2_encode_string(dyn_buf, desc, enc);
206  avio_write(dyn_buf, pkt->data, pkt->size);
207  len = avio_close_dyn_buf(dyn_buf, &buf);
208 
209  avio_wb32(s->pb, MKBETAG('A', 'P', 'I', 'C'));
210  if (id3->version == 3)
211  avio_wb32(s->pb, len);
212  else
213  id3v2_put_size(s->pb, len);
214  avio_wb16(s->pb, 0);
215  avio_write(s->pb, buf, len);
216  av_freep(&buf);
217 
218  id3->len += len + ID3v2_HEADER_SIZE;
219 
220  return 0;
221 }
222 
224 {
225  int64_t cur_pos = avio_tell(pb);
226  avio_seek(pb, id3->size_pos, SEEK_SET);
227  id3v2_put_size(pb, id3->len);
228  avio_seek(pb, cur_pos, SEEK_SET);
229 }
230 
231 int ff_id3v2_write_simple(struct AVFormatContext *s, int id3v2_version,
232  const char *magic)
233 {
234  ID3v2EncContext id3 = { 0 };
235  int ret;
236 
237  ff_id3v2_start(&id3, s->pb, id3v2_version, magic);
238  if ((ret = ff_id3v2_write_metadata(s, &id3)) < 0)
239  return ret;
240  ff_id3v2_finish(&id3, s->pb);
241 
242  return 0;
243 }