diff options
Diffstat (limited to 'src/libid3tag/tag.c')
-rw-r--r-- | src/libid3tag/tag.c | 909 |
1 files changed, 909 insertions, 0 deletions
diff --git a/src/libid3tag/tag.c b/src/libid3tag/tag.c new file mode 100644 index 000000000..4c9ad1929 --- /dev/null +++ b/src/libid3tag/tag.c @@ -0,0 +1,909 @@ +/* + * libid3tag - ID3 tag manipulation library + * Copyright (C) 2000-2003 Underbit Technologies, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * $Id: tag.c,v 1.1 2003/08/14 03:57:13 shank Exp $ + */ + +# ifdef HAVE_CONFIG_H +# include "config.h" +# endif + +# include "global.h" + +# include <string.h> +# include <stdlib.h> + +# ifdef HAVE_ASSERT_H +# include <assert.h> +# endif + +# include "id3tag.h" +# include "tag.h" +# include "frame.h" +# include "compat.h" +# include "parse.h" +# include "render.h" +# include "latin1.h" +# include "ucs4.h" +# include "genre.h" +# include "crc.h" +# include "field.h" +# include "util.h" + +/* + * NAME: tag->new() + * DESCRIPTION: allocate and return a new, empty tag + */ +struct id3_tag *id3_tag_new(void) +{ + struct id3_tag *tag; + + tag = malloc(sizeof(*tag)); + if (tag) { + tag->refcount = 0; + tag->version = ID3_TAG_VERSION; + tag->flags = 0; + tag->extendedflags = 0; + tag->restrictions = 0; + tag->options = /* ID3_TAG_OPTION_UNSYNCHRONISATION | */ + ID3_TAG_OPTION_COMPRESSION | ID3_TAG_OPTION_CRC; + tag->nframes = 0; + tag->frames = 0; + tag->paddedsize = 0; + } + + return tag; +} + +/* + * NAME: tag->delete() + * DESCRIPTION: destroy a tag and deallocate all associated memory + */ +void id3_tag_delete(struct id3_tag *tag) +{ + assert(tag); + + if (tag->refcount == 0) { + id3_tag_clearframes(tag); + + if (tag->frames) + free(tag->frames); + + free(tag); + } +} + +/* + * NAME: tag->addref() + * DESCRIPTION: add an external reference to a tag + */ +void id3_tag_addref(struct id3_tag *tag) +{ + assert(tag); + + ++tag->refcount; +} + +/* + * NAME: tag->delref() + * DESCRIPTION: remove an external reference to a tag + */ +void id3_tag_delref(struct id3_tag *tag) +{ + assert(tag && tag->refcount > 0); + + --tag->refcount; +} + +/* + * NAME: tag->version() + * DESCRIPTION: return the tag's original ID3 version number + */ +unsigned int id3_tag_version(struct id3_tag const *tag) +{ + assert(tag); + + return tag->version; +} + +/* + * NAME: tag->options() + * DESCRIPTION: get or set tag options + */ +int id3_tag_options(struct id3_tag *tag, int mask, int values) +{ + assert(tag); + + if (mask) + tag->options = (tag->options & ~mask) | (values & mask); + + return tag->options; +} + +/* + * NAME: tag->setlength() + * DESCRIPTION: set the minimum rendered tag size + */ +void id3_tag_setlength(struct id3_tag *tag, id3_length_t length) +{ + assert(tag); + + tag->paddedsize = length; +} + +/* + * NAME: tag->clearframes() + * DESCRIPTION: detach and delete all frames associated with a tag + */ +void id3_tag_clearframes(struct id3_tag *tag) +{ + unsigned int i; + + assert(tag); + + for (i = 0; i < tag->nframes; ++i) { + id3_frame_delref(tag->frames[i]); + id3_frame_delete(tag->frames[i]); + } + + tag->nframes = 0; +} + +/* + * NAME: tag->attachframe() + * DESCRIPTION: attach a frame to a tag + */ +int id3_tag_attachframe(struct id3_tag *tag, struct id3_frame *frame) +{ + struct id3_frame **frames; + + assert(tag && frame); + + frames = realloc(tag->frames, (tag->nframes + 1) * sizeof(*frames)); + if (frames == 0) + return -1; + + tag->frames = frames; + tag->frames[tag->nframes++] = frame; + + id3_frame_addref(frame); + + return 0; +} + +/* + * NAME: tag->detachframe() + * DESCRIPTION: detach (but don't delete) a frame from a tag + */ +int id3_tag_detachframe(struct id3_tag *tag, struct id3_frame *frame) +{ + unsigned int i; + + assert(tag && frame); + + for (i = 0; i < tag->nframes; ++i) { + if (tag->frames[i] == frame) + break; + } + + if (i == tag->nframes) + return -1; + + --tag->nframes; + while (i++ < tag->nframes) + tag->frames[i - 1] = tag->frames[i]; + + id3_frame_delref(frame); + + return 0; +} + +/* + * NAME: tag->findframe() + * DESCRIPTION: find in a tag the nth (0-based) frame with the given frame ID + */ +struct id3_frame *id3_tag_findframe(struct id3_tag const *tag, + char const *id, unsigned int index) +{ + unsigned int len, i; + + assert(tag); + + if (id == 0 || *id == 0) + return (index < tag->nframes) ? tag->frames[index] : 0; + + len = strlen(id); + + if (len == 4) { + struct id3_compat const *compat; + + compat = id3_compat_lookup(id, len); + if (compat && compat->equiv && !compat->translate) { + id = compat->equiv; + len = strlen(id); + } + } + + for (i = 0; i < tag->nframes; ++i) { + if (strncmp(tag->frames[i]->id, id, len) == 0 && index-- == 0) + return tag->frames[i]; + } + + return 0; +} + +enum tagtype { + TAGTYPE_NONE = 0, + TAGTYPE_ID3V1, + TAGTYPE_ID3V2, + TAGTYPE_ID3V2_FOOTER +}; + +static +enum tagtype tagtype(id3_byte_t const *data, id3_length_t length) +{ + if (length >= 3 && + data[0] == 'T' && data[1] == 'A' && data[2] == 'G') + return TAGTYPE_ID3V1; + + if (length >= 10 && + ((data[0] == 'I' && data[1] == 'D' && data[2] == '3') || + (data[0] == '3' && data[1] == 'D' && data[2] == 'I')) && + data[3] < 0xff && data[4] < 0xff && + data[6] < 0x80 && data[7] < 0x80 && data[8] < 0x80 && data[9] < 0x80) + return data[0] == 'I' ? TAGTYPE_ID3V2 : TAGTYPE_ID3V2_FOOTER; + + return TAGTYPE_NONE; +} + +static +void parse_header(id3_byte_t const **ptr, + unsigned int *version, int *flags, id3_length_t *size) +{ + *ptr += 3; + + *version = id3_parse_uint(ptr, 2); + *flags = id3_parse_uint(ptr, 1); + *size = id3_parse_syncsafe(ptr, 4); +} + +/* + * NAME: tag->query() + * DESCRIPTION: if a tag begins at the given location, return its size + */ +signed long id3_tag_query(id3_byte_t const *data, id3_length_t length) +{ + unsigned int version; + int flags; + id3_length_t size; + + assert(data); + + switch (tagtype(data, length)) { + case TAGTYPE_ID3V1: + return 128; + + case TAGTYPE_ID3V2: + parse_header(&data, &version, &flags, &size); + + if (flags & ID3_TAG_FLAG_FOOTERPRESENT) + size += 10; + + return 10 + size; + + case TAGTYPE_ID3V2_FOOTER: + parse_header(&data, &version, &flags, &size); + return -size - 10; + + case TAGTYPE_NONE: + break; + } + + return 0; +} + +static +void trim(char *str) +{ + char *ptr; + + ptr = str + strlen(str); + while (ptr > str && ptr[-1] == ' ') + --ptr; + + *ptr = 0; +} + +static +int v1_attachstr(struct id3_tag *tag, char const *id, + char *text, unsigned long number) +{ + struct id3_frame *frame; + id3_ucs4_t ucs4[31]; + + if (text) { + trim(text); + if (*text == 0) + return 0; + } + + frame = id3_frame_new(id); + if (frame == 0) + return -1; + + if (id3_field_settextencoding(&frame->fields[0], + ID3_FIELD_TEXTENCODING_ISO_8859_1) == -1) + goto fail; + + if (text) + id3_latin1_decode(text, ucs4); + else + id3_ucs4_putnumber(ucs4, number); + + if (strcmp(id, ID3_FRAME_COMMENT) == 0) { + if (id3_field_setlanguage(&frame->fields[1], "XXX") == -1 || + id3_field_setstring(&frame->fields[2], id3_ucs4_empty) == -1 || + id3_field_setfullstring(&frame->fields[3], ucs4) == -1) + goto fail; + } + else { + id3_ucs4_t *ptr = ucs4; + + if (id3_field_setstrings(&frame->fields[1], 1, &ptr) == -1) + goto fail; + } + + if (id3_tag_attachframe(tag, frame) == -1) + goto fail; + + return 0; + + fail: + id3_frame_delete(frame); + return -1; +} + +static +struct id3_tag *v1_parse(id3_byte_t const *data) +{ + struct id3_tag *tag; + + tag = id3_tag_new(); + if (tag) { + char title[31], artist[31], album[31], year[5], comment[31]; + unsigned int genre, track; + + tag->version = 0x0100; + + tag->options |= ID3_TAG_OPTION_ID3V1; + tag->options &= ~ID3_TAG_OPTION_COMPRESSION; + + tag->restrictions = + ID3_TAG_RESTRICTION_TEXTENCODING_LATIN1_UTF8 | + ID3_TAG_RESTRICTION_TEXTSIZE_30_CHARS; + + title[30] = artist[30] = album[30] = year[4] = comment[30] = 0; + + memcpy(title, &data[3], 30); + memcpy(artist, &data[33], 30); + memcpy(album, &data[63], 30); + memcpy(year, &data[93], 4); + memcpy(comment, &data[97], 30); + + genre = data[127]; + + track = 0; + if (comment[28] == 0 && comment[29] != 0) { + track = comment[29]; + tag->version = 0x0101; + } + + /* populate tag frames */ + + if (v1_attachstr(tag, ID3_FRAME_TITLE, title, 0) == -1 || + v1_attachstr(tag, ID3_FRAME_ARTIST, artist, 0) == -1 || + v1_attachstr(tag, ID3_FRAME_ALBUM, album, 0) == -1 || + v1_attachstr(tag, ID3_FRAME_YEAR, year, 0) == -1 || + (track && v1_attachstr(tag, ID3_FRAME_TRACK, 0, track) == -1) || + (genre < 0xff && v1_attachstr(tag, ID3_FRAME_GENRE, 0, genre) == -1) || + v1_attachstr(tag, ID3_FRAME_COMMENT, comment, 0) == -1) { + id3_tag_delete(tag); + tag = 0; + } + } + + return tag; +} + +static +struct id3_tag *v2_parse(id3_byte_t const *ptr) +{ + struct id3_tag *tag; + id3_byte_t *mem = 0; + + tag = id3_tag_new(); + if (tag) { + id3_byte_t const *end; + id3_length_t size; + + parse_header(&ptr, &tag->version, &tag->flags, &size); + + tag->paddedsize = 10 + size; + + if ((tag->flags & ID3_TAG_FLAG_UNSYNCHRONISATION) && + ID3_TAG_VERSION_MAJOR(tag->version) < 4) { + mem = malloc(size); + if (mem == 0) + goto fail; + + memcpy(mem, ptr, size); + + size = id3_util_deunsynchronise(mem, size); + ptr = mem; + } + + end = ptr + size; + + if (tag->flags & ID3_TAG_FLAG_EXTENDEDHEADER) { + switch (ID3_TAG_VERSION_MAJOR(tag->version)) { + case 2: + goto fail; + + case 3: + { + id3_byte_t const *ehptr, *ehend; + id3_length_t ehsize; + + enum { + EH_FLAG_CRC = 0x8000 /* CRC data present */ + }; + + if (end - ptr < 4) + goto fail; + + ehsize = id3_parse_uint(&ptr, 4); + + if (ehsize > end - ptr) + goto fail; + + ehptr = ptr; + ehend = ptr + ehsize; + + ptr = ehend; + + if (ehend - ehptr >= 6) { + int ehflags; + id3_length_t padsize; + + ehflags = id3_parse_uint(&ehptr, 2); + padsize = id3_parse_uint(&ehptr, 4); + + if (padsize > end - ptr) + goto fail; + + end -= padsize; + + if (ehflags & EH_FLAG_CRC) { + unsigned long crc; + + if (ehend - ehptr < 4) + goto fail; + + crc = id3_parse_uint(&ehptr, 4); + + if (crc != id3_crc_calculate(ptr, end - ptr)) + goto fail; + + tag->extendedflags |= ID3_TAG_EXTENDEDFLAG_CRCDATAPRESENT; + } + } + } + break; + + case 4: + { + id3_byte_t const *ehptr, *ehend; + id3_length_t ehsize; + unsigned int bytes; + + if (end - ptr < 4) + goto fail; + + ehptr = ptr; + ehsize = id3_parse_syncsafe(&ptr, 4); + + if (ehsize < 6 || ehsize > end - ehptr) + goto fail; + + ehend = ehptr + ehsize; + + bytes = id3_parse_uint(&ptr, 1); + + if (bytes < 1 || bytes > ehend - ptr) + goto fail; + + ehptr = ptr + bytes; + + /* verify extended header size */ + { + id3_byte_t const *flagsptr = ptr, *dataptr = ehptr; + unsigned int datalen; + int ehflags; + + while (bytes--) { + for (ehflags = id3_parse_uint(&flagsptr, 1); ehflags; + ehflags = (ehflags << 1) & 0xff) { + if (ehflags & 0x80) { + if (dataptr == ehend) + goto fail; + datalen = id3_parse_uint(&dataptr, 1); + if (datalen > 0x7f || datalen > ehend - dataptr) + goto fail; + dataptr += datalen; + } + } + } + } + + tag->extendedflags = id3_parse_uint(&ptr, 1); + + ptr = ehend; + + if (tag->extendedflags & ID3_TAG_EXTENDEDFLAG_TAGISANUPDATE) { + bytes = id3_parse_uint(&ehptr, 1); + ehptr += bytes; + } + + if (tag->extendedflags & ID3_TAG_EXTENDEDFLAG_CRCDATAPRESENT) { + unsigned long crc; + + bytes = id3_parse_uint(&ehptr, 1); + if (bytes < 5) + goto fail; + + crc = id3_parse_syncsafe(&ehptr, 5); + ehptr += bytes - 5; + + if (crc != id3_crc_calculate(ptr, end - ptr)) + goto fail; + } + + if (tag->extendedflags & ID3_TAG_EXTENDEDFLAG_TAGRESTRICTIONS) { + bytes = id3_parse_uint(&ehptr, 1); + if (bytes < 1) + goto fail; + + tag->restrictions = id3_parse_uint(&ehptr, 1); + ehptr += bytes - 1; + } + } + break; + } + } + + /* frames */ + + while (ptr < end) { + struct id3_frame *frame; + + if (*ptr == 0) + break; /* padding */ + + frame = id3_frame_parse(&ptr, end - ptr, tag->version); + if (frame == 0 || id3_tag_attachframe(tag, frame) == -1) + goto fail; + } + + if (ID3_TAG_VERSION_MAJOR(tag->version) < 4 && + id3_compat_fixup(tag) == -1) + goto fail; + } + + if (0) { + fail: + id3_tag_delete(tag); + tag = 0; + } + + if (mem) + free(mem); + + return tag; +} + +/* + * NAME: tag->parse() + * DESCRIPTION: parse a complete ID3 tag + */ +struct id3_tag *id3_tag_parse(id3_byte_t const *data, id3_length_t length) +{ + id3_byte_t const *ptr; + unsigned int version; + int flags; + id3_length_t size; + + assert(data); + + switch (tagtype(data, length)) { + case TAGTYPE_ID3V1: + return (length < 128) ? 0 : v1_parse(data); + + case TAGTYPE_ID3V2: + break; + + case TAGTYPE_ID3V2_FOOTER: + case TAGTYPE_NONE: + return 0; + } + + /* ID3v2.x */ + + ptr = data; + parse_header(&ptr, &version, &flags, &size); + + switch (ID3_TAG_VERSION_MAJOR(version)) { + case 4: + if (flags & ID3_TAG_FLAG_FOOTERPRESENT) + size += 10; + case 2: + case 3: + return (length < 10 + size) ? 0 : v2_parse(data); + } + + return 0; +} + +static +void v1_renderstr(struct id3_tag const *tag, char const *frameid, + id3_byte_t **buffer, id3_length_t length) +{ + struct id3_frame *frame; + id3_ucs4_t const *string; + + frame = id3_tag_findframe(tag, frameid, 0); + if (frame == 0) + string = id3_ucs4_empty; + else { + if (strcmp(frameid, ID3_FRAME_COMMENT) == 0) + string = id3_field_getfullstring(&frame->fields[3]); + else + string = id3_field_getstrings(&frame->fields[1], 0); + } + + id3_render_paddedstring(buffer, string, length); +} + +/* + * NAME: v1->render() + * DESCRIPTION: render an ID3v1 (or ID3v1.1) tag + */ +static +id3_length_t v1_render(struct id3_tag const *tag, id3_byte_t *buffer) +{ + id3_byte_t data[128], *ptr; + struct id3_frame *frame; + unsigned int i; + int genre = -1; + + ptr = data; + + id3_render_immediate(&ptr, "TAG", 3); + + v1_renderstr(tag, ID3_FRAME_TITLE, &ptr, 30); + v1_renderstr(tag, ID3_FRAME_ARTIST, &ptr, 30); + v1_renderstr(tag, ID3_FRAME_ALBUM, &ptr, 30); + v1_renderstr(tag, ID3_FRAME_YEAR, &ptr, 4); + v1_renderstr(tag, ID3_FRAME_COMMENT, &ptr, 30); + + /* ID3v1.1 track number */ + + frame = id3_tag_findframe(tag, ID3_FRAME_TRACK, 0); + if (frame) { + unsigned int track; + + track = id3_ucs4_getnumber(id3_field_getstrings(&frame->fields[1], 0)); + if (track > 0 && track <= 0xff) { + ptr[-2] = 0; + ptr[-1] = track; + } + } + + /* ID3v1 genre number */ + + frame = id3_tag_findframe(tag, ID3_FRAME_GENRE, 0); + if (frame) { + unsigned int nstrings; + + nstrings = id3_field_getnstrings(&frame->fields[1]); + + for (i = 0; i < nstrings; ++i) { + genre = id3_genre_number(id3_field_getstrings(&frame->fields[1], i)); + if (genre != -1) + break; + } + + if (i == nstrings && nstrings > 0) + genre = ID3_GENRE_OTHER; + } + + id3_render_int(&ptr, genre, 1); + + /* make sure the tag is not empty */ + + if (genre == -1) { + for (i = 3; i < 127; ++i) { + if (data[i] != ' ') + break; + } + + if (i == 127) + return 0; + } + + if (buffer) + memcpy(buffer, data, 128); + + return 128; +} + +/* + * NAME: tag->render() + * DESCRIPTION: render a complete ID3 tag + */ +id3_length_t id3_tag_render(struct id3_tag const *tag, id3_byte_t *buffer) +{ + id3_length_t size = 0; + id3_byte_t **ptr, + *header_ptr = 0, *tagsize_ptr = 0, *crc_ptr = 0, *frames_ptr = 0; + int flags, extendedflags; + unsigned int i; + + assert(tag); + + if (tag->options & ID3_TAG_OPTION_ID3V1) + return v1_render(tag, buffer); + + /* a tag must contain at least one (renderable) frame */ + + for (i = 0; i < tag->nframes; ++i) { + if (id3_frame_render(tag->frames[i], 0, 0) > 0) + break; + } + + if (i == tag->nframes) + return 0; + + ptr = buffer ? &buffer : 0; + + /* get flags */ + + flags = tag->flags & ID3_TAG_FLAG_KNOWNFLAGS; + extendedflags = tag->extendedflags & ID3_TAG_EXTENDEDFLAG_KNOWNFLAGS; + + extendedflags &= ~ID3_TAG_EXTENDEDFLAG_CRCDATAPRESENT; + if (tag->options & ID3_TAG_OPTION_CRC) + extendedflags |= ID3_TAG_EXTENDEDFLAG_CRCDATAPRESENT; + + extendedflags &= ~ID3_TAG_EXTENDEDFLAG_TAGRESTRICTIONS; + if (tag->restrictions) + extendedflags |= ID3_TAG_EXTENDEDFLAG_TAGRESTRICTIONS; + + flags &= ~ID3_TAG_FLAG_UNSYNCHRONISATION; + if (tag->options & ID3_TAG_OPTION_UNSYNCHRONISATION) + flags |= ID3_TAG_FLAG_UNSYNCHRONISATION; + + flags &= ~ID3_TAG_FLAG_EXTENDEDHEADER; + if (extendedflags) + flags |= ID3_TAG_FLAG_EXTENDEDHEADER; + + flags &= ~ID3_TAG_FLAG_FOOTERPRESENT; + if (tag->options & ID3_TAG_OPTION_APPENDEDTAG) + flags |= ID3_TAG_FLAG_FOOTERPRESENT; + + /* header */ + + if (ptr) + header_ptr = *ptr; + + size += id3_render_immediate(ptr, "ID3", 3); + size += id3_render_int(ptr, ID3_TAG_VERSION, 2); + size += id3_render_int(ptr, flags, 1); + + if (ptr) + tagsize_ptr = *ptr; + + size += id3_render_syncsafe(ptr, 0, 4); + + /* extended header */ + + if (flags & ID3_TAG_FLAG_EXTENDEDHEADER) { + id3_length_t ehsize = 0; + id3_byte_t *ehsize_ptr = 0; + + if (ptr) + ehsize_ptr = *ptr; + + ehsize += id3_render_syncsafe(ptr, 0, 4); + ehsize += id3_render_int(ptr, 1, 1); + ehsize += id3_render_int(ptr, extendedflags, 1); + + if (extendedflags & ID3_TAG_EXTENDEDFLAG_TAGISANUPDATE) + ehsize += id3_render_int(ptr, 0, 1); + + if (extendedflags & ID3_TAG_EXTENDEDFLAG_CRCDATAPRESENT) { + ehsize += id3_render_int(ptr, 5, 1); + + if (ptr) + crc_ptr = *ptr; + + ehsize += id3_render_syncsafe(ptr, 0, 5); + } + + if (extendedflags & ID3_TAG_EXTENDEDFLAG_TAGRESTRICTIONS) { + ehsize += id3_render_int(ptr, 1, 1); + ehsize += id3_render_int(ptr, tag->restrictions, 1); + } + + if (ehsize_ptr) + id3_render_syncsafe(&ehsize_ptr, ehsize, 4); + + size += ehsize; + } + + /* frames */ + + if (ptr) + frames_ptr = *ptr; + + for (i = 0; i < tag->nframes; ++i) + size += id3_frame_render(tag->frames[i], ptr, tag->options); + + /* padding */ + + if (!(flags & ID3_TAG_FLAG_FOOTERPRESENT)) { + if (size < tag->paddedsize) + size += id3_render_padding(ptr, 0, tag->paddedsize - size); + else if (tag->options & ID3_TAG_OPTION_UNSYNCHRONISATION) { + if (ptr == 0) + size += 1; + else { + if ((*ptr)[-1] == 0xff) + size += id3_render_padding(ptr, 0, 1); + } + } + } + + /* patch tag size and CRC */ + + if (tagsize_ptr) + id3_render_syncsafe(&tagsize_ptr, size - 10, 4); + + if (crc_ptr) { + id3_render_syncsafe(&crc_ptr, + id3_crc_calculate(frames_ptr, *ptr - frames_ptr), 5); + } + + /* footer */ + + if (flags & ID3_TAG_FLAG_FOOTERPRESENT) { + size += id3_render_immediate(ptr, "3DI", 3); + size += id3_render_binary(ptr, header_ptr + 3, 7); + } + + return size; +} |