tag: moved code to tag_id3.c

The ID3 code uses only the public tag API, but is otherwise
unrelated.  Move it to a separate source file.

1 files changed, 367 insertions, 0 deletions

diff --git a/src/tag_id3.c b/src/tag_id3.c
new file mode 100644
index 00000000..eb018f0c
--- /dev/null
+++ b/src/tag_id3.c
@@ -0,0 +1,367 @@
+/* the Music Player Daemon (MPD)
+ * Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
+ * This project's homepage is: http://www.musicpd.org
+ *
+ * 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
+ */
+
+#include "tag_id3.h"
+#include "tag.h"
+#include "utils.h"
+#include "log.h"
+#include "conf.h"
+#include "charConv.h"
+
+#ifdef HAVE_ID3TAG
+#include <id3tag.h>
+#endif
+
+#ifdef HAVE_ID3TAG
+#  define isId3v1(tag) (id3_tag_options(tag, 0, 0) & ID3_TAG_OPTION_ID3V1)
+#  ifndef ID3_FRAME_COMPOSER
+#    define ID3_FRAME_COMPOSER "TCOM"
+#  endif
+#  ifndef ID3_FRAME_PERFORMER
+#    define ID3_FRAME_PERFORMER "TOPE"
+#  endif
+#  ifndef ID3_FRAME_DISC
+#    define ID3_FRAME_DISC "TPOS"
+#  endif
+#endif
+
+#ifdef HAVE_ID3TAG
+/* This will try to convert a string to utf-8,
+ */
+static id3_utf8_t * processID3FieldString (int is_id3v1, const id3_ucs4_t *ucs4, int type)
+{
+    id3_utf8_t *utf8;
+    id3_latin1_t *isostr;
+	char *encoding;
+
+    if (type == TAG_ITEM_GENRE)
+	    ucs4 = id3_genre_name(ucs4);
+    /* use encoding field here? */
+    if (is_id3v1 &&
+	(encoding = getConfigParamValue(CONF_ID3V1_ENCODING))) {
+	    isostr = id3_ucs4_latin1duplicate(ucs4);
+	    if (mpd_unlikely(!isostr)) {
+		    return NULL;
+	    }
+	    setCharSetConversion("UTF-8", encoding);
+	    utf8 = xmalloc(strlen((char *)isostr) + 1);
+	    utf8 = (id3_utf8_t *)char_conv_str((char *)utf8, (char *)isostr);
+	    if (!utf8) {
+		    DEBUG("Unable to convert %s string to UTF-8: "
+			  "'%s'\n", encoding, isostr);
+		    free(isostr);
+		    return NULL;
+	    }
+	    free(isostr);
+    } else {
+	    utf8 = id3_ucs4_utf8duplicate(ucs4);
+	    if (mpd_unlikely(!utf8)) {
+		    return NULL;
+	    }
+    }
+    return utf8;
+}
+
+static struct tag *getID3Info(
+	struct id3_tag *tag, const char *id, int type, struct tag *mpdTag)
+{
+	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);
+	/* Check frame */
+	if (!frame)
+	{
+		return mpdTag;
+	}
+	/* Check fields in frame */
+	if(frame->nfields == 0)
+	{
+		DEBUG(__FILE__": Frame has no fields\n");
+		return mpdTag;
+	}
+
+	/* Starting with T is a stringlist */
+	if (id[0] == 'T')
+	{
+		/* This one contains 2 fields:
+		 * 1st: Text encoding
+		 * 2: Stringlist
+		 * Shamefully this isn't the RL case.
+		 * But I am going to enforce it anyway. 
+		 */
+		if(frame->nfields != 2) 
+		{
+			DEBUG(__FILE__": Invalid number '%i' of fields for TXX frame\n",frame->nfields);
+			return mpdTag;
+		}
+		field = &frame->fields[0];
+		/**
+		 * First field is encoding field.
+		 * This is ignored by mpd.
+		 */
+		if(field->type != ID3_FIELD_TYPE_TEXTENCODING)
+		{
+			DEBUG(__FILE__": Expected encoding, found: %i\n",field->type);
+		}
+		/* Process remaining fields, should be only one */
+		field = &frame->fields[1];
+		/* Encoding field */
+		if(field->type == ID3_FIELD_TYPE_STRINGLIST) {
+			/* 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)
+					continue;
+				utf8 = processID3FieldString(isId3v1(tag),ucs4, type);
+				if(!utf8)
+					continue;
+
+				if (mpdTag == NULL)
+					mpdTag = tag_new();
+				tag_add_item(mpdTag, type, (char *)utf8);
+				free(utf8);
+			}
+		}
+		else {
+			ERROR(__FILE__": Field type not processed: %i\n",(int)id3_field_gettextencoding(field));
+		}
+	}
+	/* A comment frame */
+	else if(!strcmp(ID3_FRAME_COMMENT, id))
+	{
+		/* A comment frame is different... */
+	/* 1st: encoding
+         * 2nd: Language
+         * 3rd: String
+         * 4th: FullString.
+         * The 'value' we want is in the 4th field
+         */
+		if(frame->nfields == 4)
+		{
+			/* for now I only read the 4th field, with the fullstring */
+			field = &frame->fields[3];
+			if(field->type == ID3_FIELD_TYPE_STRINGFULL)
+			{
+				ucs4 = id3_field_getfullstring(field);
+				if(ucs4)
+				{
+					utf8 = processID3FieldString(isId3v1(tag),ucs4, type);
+					if(utf8)
+					{
+						if (mpdTag == NULL)
+							mpdTag = tag_new();
+						tag_add_item(mpdTag, type, (char *)utf8);
+						free(utf8);
+					}
+				}
+			}
+			else
+			{
+				DEBUG(__FILE__": 4th field in comment frame differs from expected, got '%i': ignoring\n",field->type);
+			}
+		}
+		else
+		{
+			DEBUG(__FILE__": Invalid 'comments' tag, got '%i' fields instead of 4\n", frame->nfields);
+		}
+	}
+	/* Unsupported */
+	else {
+		DEBUG(__FILE__": Unsupported tag type requrested\n");
+		return mpdTag;
+	}
+
+	return mpdTag;
+}
+#endif
+
+#ifdef HAVE_ID3TAG
+struct tag *tag_id3_import(struct id3_tag * tag)
+{
+	struct tag *ret = NULL;
+
+	ret = getID3Info(tag, ID3_FRAME_ARTIST, TAG_ITEM_ARTIST, ret);
+	ret = getID3Info(tag, ID3_FRAME_TITLE, TAG_ITEM_TITLE, ret);
+	ret = getID3Info(tag, ID3_FRAME_ALBUM, TAG_ITEM_ALBUM, ret);
+	ret = getID3Info(tag, ID3_FRAME_TRACK, TAG_ITEM_TRACK, ret);
+	ret = getID3Info(tag, ID3_FRAME_YEAR, TAG_ITEM_DATE, ret);
+	ret = getID3Info(tag, ID3_FRAME_GENRE, TAG_ITEM_GENRE, ret);
+	ret = getID3Info(tag, ID3_FRAME_COMPOSER, TAG_ITEM_COMPOSER, ret);
+	ret = getID3Info(tag, ID3_FRAME_PERFORMER, TAG_ITEM_PERFORMER, ret);
+	ret = getID3Info(tag, ID3_FRAME_COMMENT, TAG_ITEM_COMMENT, ret);
+	ret = getID3Info(tag, ID3_FRAME_DISC, TAG_ITEM_DISC, ret);
+
+	return ret;
+}
+#endif
+
+#ifdef HAVE_ID3TAG
+static int fillBuffer(void *buf, size_t size, FILE * stream,
+		      long offset, int whence)
+{
+	if (fseek(stream, offset, whence) != 0) return 0;
+	return fread(buf, 1, size, stream);
+}
+#endif
+
+#ifdef HAVE_ID3TAG
+static int getId3v2FooterSize(FILE * stream, long offset, int whence)
+{
+	id3_byte_t buf[ID3_TAG_QUERYSIZE];
+	int bufsize;
+
+	bufsize = fillBuffer(buf, ID3_TAG_QUERYSIZE, stream, offset, whence);
+	if (bufsize <= 0) return 0;
+	return id3_tag_query(buf, bufsize);
+}
+#endif
+
+#ifdef HAVE_ID3TAG
+static struct id3_tag *getId3Tag(FILE * stream, long offset, int whence)
+{
+	struct id3_tag *tag;
+	id3_byte_t queryBuf[ID3_TAG_QUERYSIZE];
+	id3_byte_t *tagBuf;
+	int tagSize;
+	int queryBufSize;
+	int tagBufSize;
+
+	/* It's ok if we get less than we asked for */
+	queryBufSize = fillBuffer(queryBuf, ID3_TAG_QUERYSIZE,
+	                          stream, offset, whence);
+	if (queryBufSize <= 0) return NULL;
+
+	/* Look for a tag header */
+	tagSize = id3_tag_query(queryBuf, queryBufSize);
+	if (tagSize <= 0) return NULL;
+
+	/* Found a tag.  Allocate a buffer and read it in. */
+	tagBuf = xmalloc(tagSize);
+	if (!tagBuf) return NULL;
+
+	tagBufSize = fillBuffer(tagBuf, tagSize, stream, offset, whence);
+	if (tagBufSize < tagSize) {
+		free(tagBuf);
+		return NULL;
+	}
+
+	tag = id3_tag_parse(tagBuf, tagBufSize);
+
+	free(tagBuf);
+
+	return tag;
+}
+#endif
+
+#ifdef HAVE_ID3TAG
+static struct id3_tag *findId3TagFromBeginning(FILE * stream)
+{
+	struct id3_tag *tag;
+	struct id3_tag *seektag;
+	struct id3_frame *frame;
+	int seek;
+
+	tag = getId3Tag(stream, 0, SEEK_SET);
+	if (!tag) {
+		return NULL;
+	} else if (isId3v1(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 = getId3Tag(stream, seek, SEEK_CUR);
+		if (!seektag || isId3v1(seektag))
+			break;
+
+		/* Replace the old tag with the new one */
+		id3_tag_delete(tag);
+		tag = seektag;
+	}
+
+	return tag;
+}
+#endif
+
+#ifdef HAVE_ID3TAG
+static struct id3_tag *findId3TagFromEnd(FILE * stream)
+{
+	struct id3_tag *tag;
+	struct id3_tag *v1tag;
+	int tagsize;
+
+	/* Get an id3v1 tag from the end of file for later use */
+	v1tag = getId3Tag(stream, -128, SEEK_END);
+
+	/* Get the id3v2 tag size from the footer (located before v1tag) */
+	tagsize = getId3v2FooterSize(stream, (v1tag ? -128 : 0) - 10, SEEK_END);
+	if (tagsize >= 0)
+		return v1tag;
+
+	/* Get the tag which the footer belongs to */
+	tag = getId3Tag(stream, tagsize, SEEK_CUR);
+	if (!tag)
+		return v1tag;
+
+	/* We have an id3v2 tag, so ditch v1tag */
+	id3_tag_delete(v1tag);
+
+	return tag;
+}
+#endif
+
+struct tag *tag_id3_load(char *file)
+{
+	struct tag *ret = NULL;
+#ifdef HAVE_ID3TAG
+	struct id3_tag *tag;
+	FILE *stream;
+
+	stream = fopen(file, "r");
+	if (!stream) {
+		DEBUG("tag_id3_load: Failed to open file: '%s', %s\n", file,
+		      strerror(errno));
+		return NULL;
+	}
+
+	tag = findId3TagFromBeginning(stream);
+	if (!tag)
+		tag = findId3TagFromEnd(stream);
+
+	fclose(stream);
+
+	if (!tag)
+		return NULL;
+	ret = tag_id3_import(tag);
+	id3_tag_delete(tag);
+#endif
+	return ret;
+}