decoder/flac: use C++ compiler

src/decoder/FLACMetaData.cxx

@@ -0,0 +1,322 @@
+/*
+ * Copyright (C) 2003-2012 The Music Player Daemon Project
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "FLACMetaData.hxx"
+
+extern "C" {
+#include "XiphTags.h"
+#include "replay_gain_info.h"
+#include "tag.h"
+}
+
+#include "tag_handler.h"
+#include "tag_table.h"
+
+#include <glib.h>
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+static bool
+flac_find_float_comment(const FLAC__StreamMetadata *block,
+			const char *cmnt, float *fl)
+{
+	int offset;
+	size_t pos;
+	int len;
+	unsigned char tmp, *p;
+
+	offset = FLAC__metadata_object_vorbiscomment_find_entry_from(block, 0,
+								     cmnt);
+	if (offset < 0)
+		return false;
+
+	pos = strlen(cmnt) + 1; /* 1 is for '=' */
+	len = block->data.vorbis_comment.comments[offset].length - pos;
+	if (len <= 0)
+		return false;
+
+	p = &block->data.vorbis_comment.comments[offset].entry[pos];
+	tmp = p[len];
+	p[len] = '\0';
+	*fl = (float)atof((char *)p);
+	p[len] = tmp;
+
+	return true;
+}
+
+bool
+flac_parse_replay_gain(struct replay_gain_info *rgi,
+		       const FLAC__StreamMetadata *block)
+{
+	bool found = false;
+
+	replay_gain_info_init(rgi);
+
+	if (flac_find_float_comment(block, "replaygain_album_gain",
+				    &rgi->tuples[REPLAY_GAIN_ALBUM].gain))
+		found = true;
+	if (flac_find_float_comment(block, "replaygain_album_peak",
+				    &rgi->tuples[REPLAY_GAIN_ALBUM].peak))
+		found = true;
+	if (flac_find_float_comment(block, "replaygain_track_gain",
+				    &rgi->tuples[REPLAY_GAIN_TRACK].gain))
+		found = true;
+	if (flac_find_float_comment(block, "replaygain_track_peak",
+				    &rgi->tuples[REPLAY_GAIN_TRACK].peak))
+		found = true;
+
+	return found;
+}
+
+static bool
+flac_find_string_comment(const FLAC__StreamMetadata *block,
+			 const char *cmnt, char **str)
+{
+	int offset;
+	size_t pos;
+	int len;
+	const unsigned char *p;
+
+	*str = nullptr;
+	offset = FLAC__metadata_object_vorbiscomment_find_entry_from(block, 0,
+								     cmnt);
+	if (offset < 0)
+		return false;
+
+	pos = strlen(cmnt) + 1; /* 1 is for '=' */
+	len = block->data.vorbis_comment.comments[offset].length - pos;
+	if (len <= 0)
+		return false;
+
+	p = &block->data.vorbis_comment.comments[offset].entry[pos];
+	*str = g_strndup((const char *)p, len);
+
+	return true;
+}
+
+bool
+flac_parse_mixramp(char **mixramp_start, char **mixramp_end,
+		   const FLAC__StreamMetadata *block)
+{
+	bool found = false;
+
+	if (flac_find_string_comment(block, "mixramp_start", mixramp_start))
+		found = true;
+	if (flac_find_string_comment(block, "mixramp_end", mixramp_end))
+		found = true;
+
+	return found;
+}
+
+/**
+ * Checks if the specified name matches the entry's name, and if yes,
+ * returns the comment value (not null-temrinated).
+ */
+static const char *
+flac_comment_value(const FLAC__StreamMetadata_VorbisComment_Entry *entry,
+		   const char *name, const char *char_tnum, size_t *length_r)
+{
+	size_t name_length = strlen(name);
+	size_t char_tnum_length = 0;
+	const char *comment = (const char*)entry->entry;
+
+	if (entry->length <= name_length ||
+	    g_ascii_strncasecmp(comment, name, name_length) != 0)
+		return nullptr;
+
+	if (char_tnum != nullptr) {
+		char_tnum_length = strlen(char_tnum);
+		if (entry->length > name_length + char_tnum_length + 2 &&
+		    comment[name_length] == '[' &&
+		    g_ascii_strncasecmp(comment + name_length + 1,
+					char_tnum, char_tnum_length) == 0 &&
+		    comment[name_length + char_tnum_length + 1] == ']')
+			name_length = name_length + char_tnum_length + 2;
+		else if (entry->length > name_length + char_tnum_length &&
+			 g_ascii_strncasecmp(comment + name_length,
+					     char_tnum, char_tnum_length) == 0)
+			name_length = name_length + char_tnum_length;
+	}
+
+	if (comment[name_length] == '=') {
+		*length_r = entry->length - name_length - 1;
+		return comment + name_length + 1;
+	}
+
+	return nullptr;
+}
+
+/**
+ * Check if the comment's name equals the passed name, and if so, copy
+ * the comment value into the tag.
+ */
+static bool
+flac_copy_comment(const FLAC__StreamMetadata_VorbisComment_Entry *entry,
+		  const char *name, enum tag_type tag_type,
+		  const char *char_tnum,
+		  const struct tag_handler *handler, void *handler_ctx)
+{
+	const char *value;
+	size_t value_length;
+
+	value = flac_comment_value(entry, name, char_tnum, &value_length);
+	if (value != nullptr) {
+		char *p = g_strndup(value, value_length);
+		tag_handler_invoke_tag(handler, handler_ctx, tag_type, p);
+		g_free(p);
+		return true;
+	}
+
+	return false;
+}
+
+static void
+flac_scan_comment(const char *char_tnum,
+		  const FLAC__StreamMetadata_VorbisComment_Entry *entry,
+		  const struct tag_handler *handler, void *handler_ctx)
+{
+	if (handler->pair != nullptr) {
+		char *name = g_strdup((const char*)entry->entry);
+		char *value = strchr(name, '=');
+
+		if (value != nullptr && value > name) {
+			*value++ = 0;
+			tag_handler_invoke_pair(handler, handler_ctx,
+						name, value);
+		}
+
+		g_free(name);
+	}
+
+	for (const struct tag_table *i = xiph_tags; i->name != nullptr; ++i)
+		if (flac_copy_comment(entry, i->name, i->type, char_tnum,
+				      handler, handler_ctx))
+			return;
+
+	for (unsigned i = 0; i < TAG_NUM_OF_ITEM_TYPES; ++i)
+		if (flac_copy_comment(entry,
+				      tag_item_names[i], (enum tag_type)i,
+				      char_tnum,
+				      handler, handler_ctx))
+			return;
+}
+
+static void
+flac_scan_comments(const char *char_tnum,
+		   const FLAC__StreamMetadata_VorbisComment *comment,
+		   const struct tag_handler *handler, void *handler_ctx)
+{
+	for (unsigned i = 0; i < comment->num_comments; ++i)
+		flac_scan_comment(char_tnum, &comment->comments[i],
+				  handler, handler_ctx);
+}
+
+void
+flac_scan_metadata(const char *track,
+		   const FLAC__StreamMetadata *block,
+		   const struct tag_handler *handler, void *handler_ctx)
+{
+	switch (block->type) {
+	case FLAC__METADATA_TYPE_VORBIS_COMMENT:
+		flac_scan_comments(track, &block->data.vorbis_comment,
+				   handler, handler_ctx);
+		break;
+
+	case FLAC__METADATA_TYPE_STREAMINFO:
+		if (block->data.stream_info.sample_rate > 0)
+			tag_handler_invoke_duration(handler, handler_ctx,
+						    flac_duration(&block->data.stream_info));
+		break;
+
+	default:
+		break;
+	}
+}
+
+void
+flac_vorbis_comments_to_tag(struct tag *tag, const char *char_tnum,
+			    const FLAC__StreamMetadata_VorbisComment *comment)
+{
+	flac_scan_comments(char_tnum, comment,
+			   &add_tag_handler, tag);
+}
+
+bool
+flac_scan_file2(const char *file, const char *char_tnum,
+		const struct tag_handler *handler, void *handler_ctx)
+{
+	FLAC__Metadata_SimpleIterator *it;
+	FLAC__StreamMetadata *block = nullptr;
+
+	it = FLAC__metadata_simple_iterator_new();
+	if (!FLAC__metadata_simple_iterator_init(it, file, 1, 0)) {
+		const char *err;
+		FLAC_API FLAC__Metadata_SimpleIteratorStatus s;
+
+		s = FLAC__metadata_simple_iterator_status(it);
+
+		switch (s) { /* slightly more human-friendly messages: */
+		case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ILLEGAL_INPUT:
+			err = "illegal input";
+			break;
+		case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_ERROR_OPENING_FILE:
+			err = "error opening file";
+			break;
+		case FLAC__METADATA_SIMPLE_ITERATOR_STATUS_NOT_A_FLAC_FILE:
+			err = "not a FLAC file";
+			break;
+		default:
+			err = FLAC__Metadata_SimpleIteratorStatusString[s];
+		}
+		g_debug("Reading '%s' metadata gave the following error: %s\n",
+			file, err);
+		FLAC__metadata_simple_iterator_delete(it);
+		return false;
+	}
+
+	do {
+		block = FLAC__metadata_simple_iterator_get_block(it);
+		if (!block)
+			break;
+
+		flac_scan_metadata(char_tnum, block, handler, handler_ctx);
+		FLAC__metadata_object_delete(block);
+	} while (FLAC__metadata_simple_iterator_next(it));
+
+	FLAC__metadata_simple_iterator_delete(it);
+
+	return true;
+}
+
+struct tag *
+flac_tag_load(const char *file, const char *char_tnum)
+{
+	struct tag *tag = tag_new();
+
+	if (!flac_scan_file2(file, char_tnum, &add_tag_handler, tag) ||
+	    tag_is_empty(tag)) {
+		tag_free(tag);
+		tag = nullptr;
+	}
+
+	return tag;
+}