/* * 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); if(version==3){ tlen = get_be32(s->pb); }else tlen = get_size(s->pb, 4); get_be16(s->pb); /* flags */ } else { tag = get_be24(s->pb); tlen = get_be24(s->pb); } 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); }