/**
* Import a "Comment frame" (ID3v2.4.0 section 4.10). It
* contains 4 fields:
*
* - encoding
* - language
* - string
* - full string (we use this one)
*/
static void
tag_id3_import_comment(struct tag *dest, struct id3_tag *tag, const char *id,
enum tag_type type)
{
struct id3_frame const *frame;
id3_ucs4_t const *ucs4;
id3_utf8_t *utf8;
union id3_field const *field;
frame = id3_tag_findframe(tag, id, 0);
if (frame == NULL || frame->nfields != 4)
return;
/* for now I only read the 4th field, with the fullstring */
field = id3_frame_field(frame, 3);
if (field == NULL)
return;
ucs4 = id3_field_getfullstring(field);
if (ucs4 == NULL)
return;
utf8 = import_id3_string(tag_is_id3v1(tag), ucs4);
if (utf8 == NULL)
return;
tag_add_item(dest, type, (char *)utf8);
g_free(utf8);
}
static struct id3_tag *
tag_id3_find_from_beginning(FILE *stream)
{
struct id3_tag *tag;
struct id3_tag *seektag;
struct id3_frame *frame;
int seek;
tag = tag_id3_read(stream, 0, SEEK_SET);
if (!tag) {
return NULL;
} else if (tag_is_id3v1(tag)) {
/* id3v1 tags don't belong here */
id3_tag_delete(tag);
return NULL;
}
/* We have an id3v2 tag, so let's look for SEEK frames */
while ((frame = id3_tag_findframe(tag, "SEEK", 0))) {
/* Found a SEEK frame, get it's value */
seek = id3_field_getint(id3_frame_field(frame, 0));
if (seek < 0)
break;
/* Get the tag specified by the SEEK frame */
seektag = tag_id3_read(stream, seek, SEEK_CUR);
if (!seektag || tag_is_id3v1(seektag))
break;
/* Replace the old tag with the new one */
id3_tag_delete(tag);
tag = seektag;
}
return tag;
}
/**
* Import a "Text information frame" (ID3v2.4.0 section 4.2). It
* contains 2 fields:
*
* - encoding
* - string list
*/
static void
tag_id3_import_text(struct tag *dest, struct id3_tag *tag, const char *id,
enum tag_type type)
{
struct id3_frame const *frame;
id3_ucs4_t const *ucs4;
id3_utf8_t *utf8;
union id3_field const *field;
unsigned int nstrings, i;
frame = id3_tag_findframe(tag, id, 0);
if (frame == NULL || frame->nfields != 2)
return;
/* check the encoding field */
field = id3_frame_field(frame, 0);
if (field == NULL || field->type != ID3_FIELD_TYPE_TEXTENCODING)
return;
/* process the value(s) */
field = id3_frame_field(frame, 1);
if (field == NULL || field->type != ID3_FIELD_TYPE_STRINGLIST)
return;
/* Get the number of strings available */
nstrings = id3_field_getnstrings(field);
for (i = 0; i < nstrings; i++) {
ucs4 = id3_field_getstrings(field, i);
if (ucs4 == NULL)
continue;
if (type == TAG_GENRE)
ucs4 = id3_genre_name(ucs4);
utf8 = import_id3_string(tag_is_id3v1(tag), ucs4);
if (utf8 == NULL)
continue;
tag_add_item(dest, type, (char *)utf8);
g_free(utf8);
}
}
static int mp3_tagsize(const byte *data, size_t length)
{
if (tag_is_id3v1(data, length))
return 128;
if (tag_is_id3v2(data, length))
{
byte flags;
unsigned int size;
flags = data[5];
size = 10 + (data[6]<<21) + (data[7]<<14) + (data[8]<<7) + data[9];
if (flags & ID3_TAG_FLAG_FOOTERPRESENT)
size += 10;
for ( ; size < length && !data[size]; ++size)
; /* Consume padding */
return size;
}
return 0;
}
