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/*
* ID3v2 header parser
* Copyright (c) 2003 Fabrice Bellard
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "id3v2.h"
#include "id3v1.h"
#include "libavutil/avstring.h"
int ff_id3v2_match(const uint8_t *buf)
{
return buf[0] == 'I' &&
buf[1] == 'D' &&
buf[2] == '3' &&
buf[3] != 0xff &&
buf[4] != 0xff &&
(buf[6] & 0x80) == 0 &&
(buf[7] & 0x80) == 0 &&
(buf[8] & 0x80) == 0 &&
(buf[9] & 0x80) == 0;
}
int ff_id3v2_tag_len(const uint8_t * buf)
{
int len = ((buf[6] & 0x7f) << 21) +
((buf[7] & 0x7f) << 14) +
((buf[8] & 0x7f) << 7) +
(buf[9] & 0x7f) +
ID3v2_HEADER_SIZE;
if (buf[5] & 0x10)
len += ID3v2_HEADER_SIZE;
return len;
}
void ff_id3v2_read(AVFormatContext *s)
{
int len, ret;
uint8_t buf[ID3v2_HEADER_SIZE];
ret = get_buffer(s->pb, buf, ID3v2_HEADER_SIZE);
if (ret != ID3v2_HEADER_SIZE)
return;
if (ff_id3v2_match(buf)) {
/* parse ID3v2 header */
len = ((buf[6] & 0x7f) << 21) |
((buf[7] & 0x7f) << 14) |
((buf[8] & 0x7f) << 7) |
(buf[9] & 0x7f);
ff_id3v2_parse(s, len, buf[3], buf[5]);
} else {
url_fseek(s->pb, 0, SEEK_SET);
}
}
static unsigned int get_size(ByteIOContext *s, int len)
{
int v = 0;
while (len--)
v = (v << 7) + (get_byte(s) & 0x7F);
return v;
}
static void read_ttag(AVFormatContext *s, int taglen, const char *key)
{
char *q, dst[512];
int len, dstlen = sizeof(dst) - 1;
unsigned genre;
dst[0] = 0;
if (taglen < 1)
return;
taglen--; /* account for encoding type byte */
switch (get_byte(s->pb)) { /* encoding type */
case 0: /* ISO-8859-1 (0 - 255 maps directly into unicode) */
q = dst;
while (taglen--) {
uint8_t tmp;
PUT_UTF8(get_byte(s->pb), tmp, if (q - dst < dstlen - 1) *q++ = tmp;)
}
*q = '\0';
break;
case 3: /* UTF-8 */
len = FFMIN(taglen, dstlen - 1);
get_buffer(s->pb, dst, len);
dst[len] = 0;
break;
}
if (!strcmp(key, "genre")
&& (sscanf(dst, "(%d)", &genre) == 1 || sscanf(dst, "%d", &genre) == 1)
&& genre <= ID3v1_GENRE_MAX)
av_strlcpy(dst, ff_id3v1_genre_str[genre], sizeof(dst));
if (*dst)
av_metadata_set(&s->metadata, key, dst);
}
void ff_id3v2_parse(AVFormatContext *s, int len, uint8_t version, uint8_t flags)
{
int isv34, tlen;
uint32_t tag;
int64_t next;
int taghdrlen;
const char *reason;
switch (version) {
case 2:
if (flags & 0x40) {
reason = "compression";
goto error;
}
isv34 = 0;
taghdrlen = 6;
break;
case 3:
case 4:
isv34 = 1;
taghdrlen = 10;
break;
default:
reason = "version";
goto error;
}
if (flags & 0x80) {
reason = "unsynchronization";
goto error;
}
if (isv34 && flags & 0x40) /* Extended header present, just skip over it */
url_fskip(s->pb, get_size(s->pb, 4));
while (len >= taghdrlen) {
if (isv34) {
tag = get_be32(s->pb);
tlen = get_size(s->pb, 4);
get_be16(s->pb); /* flags */
} else {
tag = get_be24(s->pb);
tlen = get_size(s->pb, 3);
}
len -= taghdrlen + tlen;
if (len < 0)
break;
next = url_ftell(s->pb) + tlen;
switch (tag) {
case MKBETAG('T', 'I', 'T', '2'):
case MKBETAG(0, 'T', 'T', '2'):
read_ttag(s, tlen, "title");
break;
case MKBETAG('T', 'P', 'E', '1'):
case MKBETAG(0, 'T', 'P', '1'):
read_ttag(s, tlen, "author");
break;
case MKBETAG('T', 'A', 'L', 'B'):
case MKBETAG(0, 'T', 'A', 'L'):
read_ttag(s, tlen, "album");
break;
case MKBETAG('T', 'C', 'O', 'N'):
case MKBETAG(0, 'T', 'C', 'O'):
read_ttag(s, tlen, "genre");
break;
case MKBETAG('T', 'C', 'O', 'P'):
case MKBETAG(0, 'T', 'C', 'R'):
read_ttag(s, tlen, "copyright");
break;
case MKBETAG('T', 'R', 'C', 'K'):
case MKBETAG(0, 'T', 'R', 'K'):
read_ttag(s, tlen, "track");
break;
case 0:
/* padding, skip to end */
url_fskip(s->pb, len);
len = 0;
continue;
}
/* Skip to end of tag */
url_fseek(s->pb, next, SEEK_SET);
}
if (version == 4 && flags & 0x10) /* Footer preset, always 10 bytes, skip over it */
url_fskip(s->pb, 10);
return;
error:
av_log(s, AV_LOG_INFO, "ID3v2.%d tag skipped, cannot handle %s\n", version, reason);
url_fskip(s->pb, len);
}
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