From d35747a40c7dea12de95f78a4f283a45ef687597 Mon Sep 17 00:00:00 2001 From: Warren Dukes Date: Mon, 23 Feb 2004 23:41:20 +0000 Subject: import from SF CVS git-svn-id: https://svn.musicpd.org/mpd/trunk@1 09075e82-0dd4-0310-85a5-a0d7c8717e4f --- src/libid3tag/frame.c | 626 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 626 insertions(+) create mode 100644 src/libid3tag/frame.c (limited to 'src/libid3tag/frame.c') diff --git a/src/libid3tag/frame.c b/src/libid3tag/frame.c new file mode 100644 index 000000000..aafd54e27 --- /dev/null +++ b/src/libid3tag/frame.c @@ -0,0 +1,626 @@ +/* + * 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: frame.c,v 1.1 2003/08/14 03:57:13 shank Exp $ + */ + +# ifdef HAVE_CONFIG_H +# include "config.h" +# endif + +# include "global.h" + +# include +# include + +# ifdef HAVE_ASSERT_H +# include +# 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; +} -- cgit v1.2.3