diff options
Diffstat (limited to 'src/libid3tag/frame.c')
| -rw-r--r-- | src/libid3tag/frame.c | 626 |
1 files changed, 0 insertions, 626 deletions
diff --git a/src/libid3tag/frame.c b/src/libid3tag/frame.c index 1c680d9e..e69de29b 100644 --- a/src/libid3tag/frame.c +++ b/src/libid3tag/frame.c @@ -1,626 +0,0 @@ -/* - * libid3tag - ID3 tag manipulation library - * Copyright (C) 2000-2004 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: frame.c,v 1.15 2004/01/23 09:41:32 rob Exp $ - */ - -# ifdef HAVE_CONFIG_H -# include "config.h" -# endif - -# include "global.h" - -# include <stdlib.h> -# include <string.h> - -# ifdef HAVE_ASSERT_H -# include <assert.h> -# endif - -# include "id3tag.h" -# include "frame.h" -# include "frametype.h" -# include "compat.h" -# include "field.h" -# include "render.h" -# include "parse.h" -# include "util.h" - -static -int valid_idchar(char c) -{ - return (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9'); -} - -/* - * NAME: frame->validid() - * DESCRIPTION: return true if the parameter string is a legal frame ID - */ -int id3_frame_validid(char const *id) -{ - return id && - valid_idchar(id[0]) && - valid_idchar(id[1]) && - valid_idchar(id[2]) && - valid_idchar(id[3]); -} - -/* - * NAME: frame->new() - * DESCRIPTION: allocate and return a new frame - */ -struct id3_frame *id3_frame_new(char const *id) -{ - struct id3_frametype const *frametype; - struct id3_frame *frame; - unsigned int i; - - if (!id3_frame_validid(id)) - return 0; - - frametype = id3_frametype_lookup(id, 4); - if (frametype == 0) { - switch (id[0]) { - case 'T': - frametype = &id3_frametype_text; - break; - - case 'W': - frametype = &id3_frametype_url; - break; - - case 'X': - case 'Y': - case 'Z': - frametype = &id3_frametype_experimental; - break; - - default: - frametype = &id3_frametype_unknown; - if (id3_compat_lookup(id, 4)) - frametype = &id3_frametype_obsolete; - break; - } - } - - frame = malloc(sizeof(*frame) + frametype->nfields * sizeof(*frame->fields)); - if (frame) { - frame->id[0] = id[0]; - frame->id[1] = id[1]; - frame->id[2] = id[2]; - frame->id[3] = id[3]; - frame->id[4] = 0; - - frame->description = frametype->description; - frame->refcount = 0; - frame->flags = frametype->defaultflags; - frame->group_id = 0; - frame->encryption_method = 0; - frame->encoded = 0; - frame->encoded_length = 0; - frame->decoded_length = 0; - frame->nfields = frametype->nfields; - frame->fields = (union id3_field *) &frame[1]; - - for (i = 0; i < frame->nfields; ++i) - id3_field_init(&frame->fields[i], frametype->fields[i]); - } - - return frame; -} - -void id3_frame_delete(struct id3_frame *frame) -{ - assert(frame); - - if (frame->refcount == 0) { - unsigned int i; - - for (i = 0; i < frame->nfields; ++i) - id3_field_finish(&frame->fields[i]); - - if (frame->encoded) - free(frame->encoded); - - free(frame); - } -} - -/* - * NAME: frame->addref() - * DESCRIPTION: add an external reference to a frame - */ -void id3_frame_addref(struct id3_frame *frame) -{ - assert(frame); - - ++frame->refcount; -} - -/* - * NAME: frame->delref() - * DESCRIPTION: remove an external reference to a frame - */ -void id3_frame_delref(struct id3_frame *frame) -{ - assert(frame && frame->refcount > 0); - - --frame->refcount; -} - -/* - * NAME: frame->field() - * DESCRIPTION: return a pointer to a field in a frame - */ -union id3_field *id3_frame_field(struct id3_frame const *frame, - unsigned int index) -{ - assert(frame); - - return (index < frame->nfields) ? &frame->fields[index] : 0; -} - -static -struct id3_frame *obsolete(char const *id, id3_byte_t const *data, - id3_length_t length) -{ - struct id3_frame *frame; - - frame = id3_frame_new(ID3_FRAME_OBSOLETE); - if (frame) { - if (id3_field_setframeid(&frame->fields[0], id) == -1 || - id3_field_setbinarydata(&frame->fields[1], data, length) == -1) - goto fail; - } - - if (0) { - fail: - if (frame) { - id3_frame_delete(frame); - frame = 0; - } - } - - return frame; -} - -static -struct id3_frame *unparseable(char const *id, id3_byte_t const **ptr, - id3_length_t length, int flags, - int group_id, int encryption_method, - id3_length_t decoded_length) -{ - struct id3_frame *frame = 0; - id3_byte_t *mem; - - mem = malloc(length ? length : 1); - if (mem == 0) - goto fail; - - frame = id3_frame_new(id); - if (frame == 0) - free(mem); - else { - memcpy(mem, *ptr, length); - - frame->flags = flags; - frame->group_id = group_id; - frame->encryption_method = encryption_method; - frame->encoded = mem; - frame->encoded_length = length; - frame->decoded_length = decoded_length; - } - - if (0) { - fail: - ; - } - - *ptr += length; - - return frame; -} - -static -int parse_data(struct id3_frame *frame, - id3_byte_t const *data, id3_length_t length) -{ - enum id3_field_textencoding encoding; - id3_byte_t const *end; - unsigned int i; - - encoding = ID3_FIELD_TEXTENCODING_ISO_8859_1; - - end = data + length; - - for (i = 0; i < frame->nfields; ++i) { - if (id3_field_parse(&frame->fields[i], &data, end - data, &encoding) == -1) - return -1; - } - - return 0; -} - -/* - * NAME: frame->parse() - * DESCRIPTION: parse raw frame data according to the specified ID3 tag version - */ -struct id3_frame *id3_frame_parse(id3_byte_t const **ptr, id3_length_t length, - unsigned int version) -{ - struct id3_frame *frame = 0; - id3_byte_t const *id, *end, *data; - id3_length_t size, decoded_length = 0; - int flags = 0, group_id = 0, encryption_method = 0; - struct id3_compat const *compat = 0; - id3_byte_t *mem = 0; - char xid[4]; - - id = *ptr; - end = *ptr + length; - - if (ID3_TAG_VERSION_MAJOR(version) < 4) { - switch (ID3_TAG_VERSION_MAJOR(version)) { - case 2: - if (length < 6) - goto fail; - - compat = id3_compat_lookup(id, 3); - - *ptr += 3; - size = id3_parse_uint(ptr, 3); - - if (size > end - *ptr) - goto fail; - - end = *ptr + size; - - break; - - case 3: - if (length < 10) - goto fail; - - compat = id3_compat_lookup(id, 4); - - *ptr += 4; - size = id3_parse_uint(ptr, 4); - flags = id3_parse_uint(ptr, 2); - - if (size > end - *ptr) - goto fail; - - end = *ptr + size; - - if (flags & (ID3_FRAME_FLAG_FORMATFLAGS & ~0x00e0)) { - frame = unparseable(id, ptr, end - *ptr, 0, 0, 0, 0); - goto done; - } - - flags = - ((flags >> 1) & ID3_FRAME_FLAG_STATUSFLAGS) | - ((flags >> 4) & (ID3_FRAME_FLAG_COMPRESSION | - ID3_FRAME_FLAG_ENCRYPTION)) | - ((flags << 1) & ID3_FRAME_FLAG_GROUPINGIDENTITY); - - if (flags & ID3_FRAME_FLAG_COMPRESSION) { - if (end - *ptr < 4) - goto fail; - - decoded_length = id3_parse_uint(ptr, 4); - } - - if (flags & ID3_FRAME_FLAG_ENCRYPTION) { - if (end - *ptr < 1) - goto fail; - - encryption_method = id3_parse_uint(ptr, 1); - } - - if (flags & ID3_FRAME_FLAG_GROUPINGIDENTITY) { - if (end - *ptr < 1) - goto fail; - - group_id = id3_parse_uint(ptr, 1); - } - - break; - - default: - goto fail; - } - - /* canonicalize frame ID for ID3v2.4 */ - - if (compat && compat->equiv) - id = compat->equiv; - else if (ID3_TAG_VERSION_MAJOR(version) == 2) { - xid[0] = 'Y'; - xid[1] = id[0]; - xid[2] = id[1]; - xid[3] = id[2]; - - id = xid; - - flags |= - ID3_FRAME_FLAG_TAGALTERPRESERVATION | - ID3_FRAME_FLAG_FILEALTERPRESERVATION; - } - } - else { /* ID3v2.4 */ - if (length < 10) - goto fail; - - *ptr += 4; - size = id3_parse_syncsafe(ptr, 4); - flags = id3_parse_uint(ptr, 2); - - if (size > end - *ptr) - goto fail; - - end = *ptr + size; - - if (flags & (ID3_FRAME_FLAG_FORMATFLAGS & ~ID3_FRAME_FLAG_KNOWNFLAGS)) { - frame = unparseable(id, ptr, end - *ptr, flags, 0, 0, 0); - goto done; - } - - if (flags & ID3_FRAME_FLAG_GROUPINGIDENTITY) { - if (end - *ptr < 1) - goto fail; - - group_id = id3_parse_uint(ptr, 1); - } - - if ((flags & ID3_FRAME_FLAG_COMPRESSION) && - !(flags & ID3_FRAME_FLAG_DATALENGTHINDICATOR)) - goto fail; - - if (flags & ID3_FRAME_FLAG_ENCRYPTION) { - if (end - *ptr < 1) - goto fail; - - encryption_method = id3_parse_uint(ptr, 1); - } - - if (flags & ID3_FRAME_FLAG_DATALENGTHINDICATOR) { - if (end - *ptr < 4) - goto fail; - - decoded_length = id3_parse_syncsafe(ptr, 4); - } - } - - data = *ptr; - *ptr = end; - - /* undo frame encodings */ - - if ((flags & ID3_FRAME_FLAG_UNSYNCHRONISATION) && end - data > 0) { - mem = malloc(end - data); - if (mem == 0) - goto fail; - - memcpy(mem, data, end - data); - - end = mem + id3_util_deunsynchronise(mem, end - data); - data = mem; - } - - if (flags & ID3_FRAME_FLAG_ENCRYPTION) { - frame = unparseable(id, &data, end - data, flags, - group_id, encryption_method, decoded_length); - goto done; - } - - if (flags & ID3_FRAME_FLAG_COMPRESSION) { - id3_byte_t *decomp; - - decomp = id3_util_decompress(data, end - data, decoded_length); - if (decomp == 0) - goto fail; - - if (mem) - free(mem); - - data = mem = decomp; - end = data + decoded_length; - } - - /* check for obsolescence */ - - if (compat && !compat->equiv) { - frame = obsolete(id, data, end - data); - goto done; - } - - /* generate the internal frame structure */ - - frame = id3_frame_new(id); - if (frame) { - frame->flags = flags; - frame->group_id = group_id; - - if (compat && compat->translate) { - if (compat->translate(frame, compat->id, data, end - data) == -1) - goto fail; - } - else { - if (parse_data(frame, data, end - data) == -1) - goto fail; - } - } - - if (0) { - fail: - if (frame) { - id3_frame_delete(frame); - frame = 0; - } - } - - done: - if (mem) - free(mem); - - return frame; -} - -static -id3_length_t render_data(id3_byte_t **ptr, - union id3_field *fields, unsigned int length) -{ - id3_length_t size = 0; - enum id3_field_textencoding encoding; - unsigned int i; - - encoding = ID3_FIELD_TEXTENCODING_ISO_8859_1; - - for (i = 0; i < length; ++i) - size += id3_field_render(&fields[i], ptr, &encoding, i < length - 1); - - return size; -} - -/* - * NAME: frame->render() - * DESCRIPTION: render a single, complete frame - */ -id3_length_t id3_frame_render(struct id3_frame const *frame, - id3_byte_t **ptr, int options) -{ - id3_length_t size = 0, decoded_length, datalen; - id3_byte_t *size_ptr = 0, *flags_ptr = 0, *data = 0; - int flags; - - assert(frame); - - if ((frame->flags & ID3_FRAME_FLAG_TAGALTERPRESERVATION) || - ((options & ID3_TAG_OPTION_FILEALTERED) && - (frame->flags & ID3_FRAME_FLAG_FILEALTERPRESERVATION))) - return 0; - - /* a frame must be at least 1 byte big, excluding the header */ - - decoded_length = render_data(0, frame->fields, frame->nfields); - if (decoded_length == 0 && frame->encoded == 0) - return 0; - - /* header */ - - size += id3_render_immediate(ptr, frame->id, 4); - - if (ptr) - size_ptr = *ptr; - - size += id3_render_syncsafe(ptr, 0, 4); - - if (ptr) - flags_ptr = *ptr; - - flags = frame->flags; - - size += id3_render_int(ptr, flags, 2); - - if (flags & (ID3_FRAME_FLAG_FORMATFLAGS & ~ID3_FRAME_FLAG_KNOWNFLAGS)) { - size += id3_render_binary(ptr, frame->encoded, frame->encoded_length); - if (size_ptr) - id3_render_syncsafe(&size_ptr, size - 10, 4); - - return size; - } - - flags &= ID3_FRAME_FLAG_KNOWNFLAGS; - - flags &= ~ID3_FRAME_FLAG_UNSYNCHRONISATION; - if (options & ID3_TAG_OPTION_UNSYNCHRONISATION) - flags |= ID3_FRAME_FLAG_UNSYNCHRONISATION; - - if (!(flags & ID3_FRAME_FLAG_ENCRYPTION)) { - flags &= ~ID3_FRAME_FLAG_COMPRESSION; - if (options & ID3_TAG_OPTION_COMPRESSION) - flags |= ID3_FRAME_FLAG_COMPRESSION | ID3_FRAME_FLAG_DATALENGTHINDICATOR; - } - - if (flags & ID3_FRAME_FLAG_GROUPINGIDENTITY) - size += id3_render_int(ptr, frame->group_id, 1); - if (flags & ID3_FRAME_FLAG_ENCRYPTION) - size += id3_render_int(ptr, frame->encryption_method, 1); - if (flags & ID3_FRAME_FLAG_DATALENGTHINDICATOR) { - if (flags & ID3_FRAME_FLAG_ENCRYPTION) - decoded_length = frame->decoded_length; - size += id3_render_syncsafe(ptr, decoded_length, 4); - } - - if (ptr) - data = *ptr; - - if (flags & ID3_FRAME_FLAG_ENCRYPTION) - datalen = id3_render_binary(ptr, frame->encoded, frame->encoded_length); - else { - if (ptr == 0) - datalen = decoded_length; - else { - datalen = render_data(ptr, frame->fields, frame->nfields); - - if (flags & ID3_FRAME_FLAG_COMPRESSION) { - id3_byte_t *comp; - id3_length_t complen; - - comp = id3_util_compress(data, datalen, &complen); - if (comp == 0) - flags &= ~ID3_FRAME_FLAG_COMPRESSION; - else { - *ptr = data; - datalen = id3_render_binary(ptr, comp, complen); - - free(comp); - } - } - } - } - - /* unsynchronisation */ - - if (flags & ID3_FRAME_FLAG_UNSYNCHRONISATION) { - if (data == 0) - datalen *= 2; - else { - id3_length_t newlen; - - newlen = id3_util_unsynchronise(data, datalen); - if (newlen == datalen) - flags &= ~ID3_FRAME_FLAG_UNSYNCHRONISATION; - else { - *ptr += newlen - datalen; - datalen = newlen; - } - } - } - - size += datalen; - - /* patch size and flags */ - - if (size_ptr) - id3_render_syncsafe(&size_ptr, size - 10, 4); - if (flags_ptr) - id3_render_int(&flags_ptr, flags, 2); - - return size; -} |