1/*
2 * ID3v2 header writer
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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/avstring.h"
25#include "libavutil/dict.h"
26#include "libavutil/intreadwrite.h"
27#include "avformat.h"
28#include "avio.h"
29#include "avio_internal.h"
30#include "id3v2.h"
31
32static void id3v2_put_size(AVIOContext *pb, int size)
33{
34    avio_w8(pb, size >> 21 & 0x7f);
35    avio_w8(pb, size >> 14 & 0x7f);
36    avio_w8(pb, size >> 7  & 0x7f);
37    avio_w8(pb, size       & 0x7f);
38}
39
40static int string_is_ascii(const uint8_t *str)
41{
42    while (*str && *str < 128) str++;
43    return !*str;
44}
45
46static void id3v2_encode_string(AVIOContext *pb, const uint8_t *str,
47                               enum ID3v2Encoding enc)
48{
49    int (*put)(AVIOContext*, const char*);
50
51    if (enc == ID3v2_ENCODING_UTF16BOM) {
52        avio_wl16(pb, 0xFEFF);      /* BOM */
53        put = avio_put_str16le;
54    } else
55        put = avio_put_str;
56
57    put(pb, str);
58}
59
60/**
61 * Write a text frame with one (normal frames) or two (TXXX frames) strings
62 * according to encoding (only UTF-8 or UTF-16+BOM supported).
63 * @return number of bytes written or a negative error code.
64 */
65static int id3v2_put_ttag(ID3v2EncContext *id3, AVIOContext *avioc, const char *str1, const char *str2,
66                          uint32_t tag, enum ID3v2Encoding enc)
67{
68    int len;
69    uint8_t *pb;
70    AVIOContext *dyn_buf;
71    if (avio_open_dyn_buf(&dyn_buf) < 0)
72        return AVERROR(ENOMEM);
73
74    /* check if the strings are ASCII-only and use UTF16 only if
75     * they're not */
76    if (enc == ID3v2_ENCODING_UTF16BOM && string_is_ascii(str1) &&
77        (!str2 || string_is_ascii(str2)))
78        enc = ID3v2_ENCODING_ISO8859;
79
80    avio_w8(dyn_buf, enc);
81    id3v2_encode_string(dyn_buf, str1, enc);
82    if (str2)
83        id3v2_encode_string(dyn_buf, str2, enc);
84    len = avio_close_dyn_buf(dyn_buf, &pb);
85
86    avio_wb32(avioc, tag);
87    /* ID3v2.3 frame size is not synchsafe */
88    if (id3->version == 3)
89        avio_wb32(avioc, len);
90    else
91        id3v2_put_size(avioc, len);
92    avio_wb16(avioc, 0);
93    avio_write(avioc, pb, len);
94
95    av_freep(&pb);
96    return len + ID3v2_HEADER_SIZE;
97}
98
99static int id3v2_check_write_tag(ID3v2EncContext *id3, AVIOContext *pb, AVDictionaryEntry *t,
100                                 const char table[][4], enum ID3v2Encoding enc)
101{
102    uint32_t tag;
103    int i;
104
105    if (t->key[0] != 'T' || strlen(t->key) != 4)
106        return -1;
107    tag = AV_RB32(t->key);
108    for (i = 0; *table[i]; i++)
109        if (tag == AV_RB32(table[i]))
110            return id3v2_put_ttag(id3, pb, t->value, NULL, tag, enc);
111    return -1;
112}
113
114static void id3v2_3_metadata_split_date(AVDictionary **pm)
115{
116    AVDictionaryEntry *mtag = NULL;
117    AVDictionary *dst = NULL;
118    const char *key, *value;
119    char year[5] = {0}, day_month[5] = {0};
120    int i;
121
122    while ((mtag = av_dict_get(*pm, "", mtag, AV_DICT_IGNORE_SUFFIX))) {
123        key = mtag->key;
124        if (!av_strcasecmp(key, "date")) {
125            /* split date tag using "YYYY-MM-DD" format into year and month/day segments */
126            value = mtag->value;
127            i = 0;
128            while (value[i] >= '0' && value[i] <= '9') i++;
129            if (value[i] == '\0' || value[i] == '-') {
130                av_strlcpy(year, value, sizeof(year));
131                av_dict_set(&dst, "TYER", year, 0);
132
133                if (value[i] == '-' &&
134                    value[i+1] >= '0' && value[i+1] <= '1' &&
135                    value[i+2] >= '0' && value[i+2] <= '9' &&
136                    value[i+3] == '-' &&
137                    value[i+4] >= '0' && value[i+4] <= '3' &&
138                    value[i+5] >= '0' && value[i+5] <= '9' &&
139                    (value[i+6] == '\0' || value[i+6] == ' ')) {
140                    snprintf(day_month, sizeof(day_month), "%.2s%.2s", value + i + 4, value + i + 1);
141                    av_dict_set(&dst, "TDAT", day_month, 0);
142                }
143            } else
144                av_dict_set(&dst, key, value, 0);
145        } else
146            av_dict_set(&dst, key, mtag->value, 0);
147    }
148    av_dict_free(pm);
149    *pm = dst;
150}
151
152void ff_id3v2_start(ID3v2EncContext *id3, AVIOContext *pb, int id3v2_version,
153                    const char *magic)
154{
155    id3->version = id3v2_version;
156
157    avio_wb32(pb, MKBETAG(magic[0], magic[1], magic[2], id3v2_version));
158    avio_w8(pb, 0);
159    avio_w8(pb, 0); /* flags */
160
161    /* reserve space for size */
162    id3->size_pos = avio_tell(pb);
163    avio_wb32(pb, 0);
164}
165
166static int write_metadata(AVIOContext *pb, AVDictionary **metadata,
167                          ID3v2EncContext *id3, int enc)
168{
169    AVDictionaryEntry *t = NULL;
170    int ret;
171
172    ff_metadata_conv(metadata, ff_id3v2_34_metadata_conv, NULL);
173    if (id3->version == 3)
174        id3v2_3_metadata_split_date(metadata);
175    else if (id3->version == 4)
176        ff_metadata_conv(metadata, ff_id3v2_4_metadata_conv, NULL);
177
178    while ((t = av_dict_get(*metadata, "", t, AV_DICT_IGNORE_SUFFIX))) {
179        if ((ret = id3v2_check_write_tag(id3, pb, t, ff_id3v2_tags, enc)) > 0) {
180            id3->len += ret;
181            continue;
182        }
183        if ((ret = id3v2_check_write_tag(id3, pb, t, id3->version == 3 ?
184                                         ff_id3v2_3_tags : ff_id3v2_4_tags, enc)) > 0) {
185            id3->len += ret;
186            continue;
187        }
188
189        /* unknown tag, write as TXXX frame */
190        if ((ret = id3v2_put_ttag(id3, pb, t->key, t->value, MKBETAG('T', 'X', 'X', 'X'), enc)) < 0)
191            return ret;
192        id3->len += ret;
193    }
194
195    return 0;
196}
197
198static int write_chapter(AVFormatContext *s, ID3v2EncContext *id3, int id, int enc)
199{
200    const AVRational time_base = {1, 1000};
201    AVChapter *ch = s->chapters[id];
202    uint8_t *dyn_buf = NULL;
203    AVIOContext *dyn_bc = NULL;
204    char name[123];
205    int len, start, end, ret;
206
207    if ((ret = avio_open_dyn_buf(&dyn_bc)) < 0)
208        goto fail;
209
210    start = av_rescale_q(ch->start, ch->time_base, time_base);
211    end   = av_rescale_q(ch->end,   ch->time_base, time_base);
212
213    snprintf(name, 122, "ch%d", id);
214    id3->len += avio_put_str(dyn_bc, name);
215    avio_wb32(dyn_bc, start);
216    avio_wb32(dyn_bc, end);
217    avio_wb32(dyn_bc, 0xFFFFFFFFu);
218    avio_wb32(dyn_bc, 0xFFFFFFFFu);
219
220    if ((ret = write_metadata(dyn_bc, &ch->metadata, id3, enc)) < 0)
221        goto fail;
222
223    len = avio_close_dyn_buf(dyn_bc, &dyn_buf);
224    id3->len += 16 + ID3v2_HEADER_SIZE;
225
226    avio_wb32(s->pb, MKBETAG('C', 'H', 'A', 'P'));
227    avio_wb32(s->pb, len);
228    avio_wb16(s->pb, 0);
229    avio_write(s->pb, dyn_buf, len);
230
231fail:
232    if (dyn_bc && !dyn_buf)
233        avio_close_dyn_buf(dyn_bc, &dyn_buf);
234    av_freep(&dyn_buf);
235
236    return ret;
237}
238
239int ff_id3v2_write_metadata(AVFormatContext *s, ID3v2EncContext *id3)
240{
241    int enc = id3->version == 3 ? ID3v2_ENCODING_UTF16BOM :
242                                  ID3v2_ENCODING_UTF8;
243    int i, ret;
244
245    if ((ret = write_metadata(s->pb, &s->metadata, id3, enc)) < 0)
246        return ret;
247
248    for (i = 0; i < s->nb_chapters; i++) {
249        if ((ret = write_chapter(s, id3, i, enc)) < 0)
250            return ret;
251    }
252
253    return 0;
254}
255
256int ff_id3v2_write_apic(AVFormatContext *s, ID3v2EncContext *id3, AVPacket *pkt)
257{
258    AVStream *st = s->streams[pkt->stream_index];
259    AVDictionaryEntry *e;
260
261    AVIOContext *dyn_buf;
262    uint8_t     *buf;
263    const CodecMime *mime = ff_id3v2_mime_tags;
264    const char  *mimetype = NULL, *desc = "";
265    int enc = id3->version == 3 ? ID3v2_ENCODING_UTF16BOM :
266                                  ID3v2_ENCODING_UTF8;
267    int i, len, type = 0;
268
269    /* get the mimetype*/
270    while (mime->id != AV_CODEC_ID_NONE) {
271        if (mime->id == st->codec->codec_id) {
272            mimetype = mime->str;
273            break;
274        }
275        mime++;
276    }
277    if (!mimetype) {
278        av_log(s, AV_LOG_ERROR, "No mimetype is known for stream %d, cannot "
279               "write an attached picture.\n", st->index);
280        return AVERROR(EINVAL);
281    }
282
283    /* get the picture type */
284    e = av_dict_get(st->metadata, "comment", NULL, 0);
285    for (i = 0; e && i < FF_ARRAY_ELEMS(ff_id3v2_picture_types); i++) {
286        if (!av_strcasecmp(e->value, ff_id3v2_picture_types[i])) {
287            type = i;
288            break;
289        }
290    }
291
292    /* get the description */
293    if ((e = av_dict_get(st->metadata, "title", NULL, 0)))
294        desc = e->value;
295
296    /* use UTF16 only for non-ASCII strings */
297    if (enc == ID3v2_ENCODING_UTF16BOM && string_is_ascii(desc))
298        enc = ID3v2_ENCODING_ISO8859;
299
300    /* start writing */
301    if (avio_open_dyn_buf(&dyn_buf) < 0)
302        return AVERROR(ENOMEM);
303
304    avio_w8(dyn_buf, enc);
305    avio_put_str(dyn_buf, mimetype);
306    avio_w8(dyn_buf, type);
307    id3v2_encode_string(dyn_buf, desc, enc);
308    avio_write(dyn_buf, pkt->data, pkt->size);
309    len = avio_close_dyn_buf(dyn_buf, &buf);
310
311    avio_wb32(s->pb, MKBETAG('A', 'P', 'I', 'C'));
312    if (id3->version == 3)
313        avio_wb32(s->pb, len);
314    else
315        id3v2_put_size(s->pb, len);
316    avio_wb16(s->pb, 0);
317    avio_write(s->pb, buf, len);
318    av_freep(&buf);
319
320    id3->len += len + ID3v2_HEADER_SIZE;
321
322    return 0;
323}
324
325void ff_id3v2_finish(ID3v2EncContext *id3, AVIOContext *pb,
326                     int padding_bytes)
327{
328    int64_t cur_pos;
329
330    if (padding_bytes < 0)
331        padding_bytes = 10;
332
333    /* The ID3v2.3 specification states that 28 bits are used to represent the
334     * size of the whole tag.  Therefore the current size of the tag needs to be
335     * subtracted from the upper limit of 2^28-1 to clip the value correctly. */
336    /* The minimum of 10 is an arbitrary amount of padding at the end of the tag
337     * to fix cover art display with some software such as iTunes, Traktor,
338     * Serato, Torq. */
339    padding_bytes = av_clip(padding_bytes, 10, 268435455 - id3->len);
340    ffio_fill(pb, 0, padding_bytes);
341    id3->len += padding_bytes;
342
343    cur_pos = avio_tell(pb);
344    avio_seek(pb, id3->size_pos, SEEK_SET);
345    id3v2_put_size(pb, id3->len);
346    avio_seek(pb, cur_pos, SEEK_SET);
347}
348
349int ff_id3v2_write_simple(struct AVFormatContext *s, int id3v2_version,
350                          const char *magic)
351{
352    ID3v2EncContext id3 = { 0 };
353    int ret;
354
355    ff_id3v2_start(&id3, s->pb, id3v2_version, magic);
356    if ((ret = ff_id3v2_write_metadata(s, &id3)) < 0)
357        return ret;
358    ff_id3v2_finish(&id3, s->pb, s->metadata_header_padding);
359
360    return 0;
361}
362