Move metadata API from lavf to lavu.

Rename it to AVDictionary, since it will be used as such.  Tags
documentation and metadata conversion API is lavf-specific, so remains
there.

1 files changed, 78 insertions, 0 deletions

diff --git a/libavutil/dict.h b/libavutil/dict.h
new file mode 100644
index 0000000000..bfd7f2682c
--- /dev/null
+++ b/libavutil/dict.h
@@ -0,0 +1,78 @@
+/*
+ *
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file Public dictionary API.
+ */
+
+#ifndef AVUTIL_DICT_H
+#define AVUTIL_DICT_H
+
+#define AV_DICT_MATCH_CASE      1
+#define AV_DICT_IGNORE_SUFFIX   2
+#define AV_DICT_DONT_STRDUP_KEY 4
+#define AV_DICT_DONT_STRDUP_VAL 8
+#define AV_DICT_DONT_OVERWRITE 16   ///< Don't overwrite existing entries.
+
+typedef struct {
+    char *key;
+    char *value;
+} AVDictionaryEntry;
+
+typedef struct AVDictionary AVDictionary;
+
+/**
+ * Get a dictionary entry with matching key.
+ *
+ * @param prev Set to the previous matching element to find the next.
+ *             If set to NULL the first matching element is returned.
+ * @param flags Allows case as well as suffix-insensitive comparisons.
+ * @return Found entry or NULL, changing key or value leads to undefined behavior.
+ */
+AVDictionaryEntry *
+av_dict_get(AVDictionary *m, const char *key, const AVDictionaryEntry *prev, int flags);
+
+/**
+ * Set the given entry in *pm, overwriting an existing entry.
+ *
+ * @param pm pointer to a pointer to a dictionary struct. If *pm is NULL
+ * a dictionary struct is allocated and put in *pm.
+ * @param key entry key to add to *pm (will be av_strduped depending on flags)
+ * @param value entry value to add to *pm (will be av_strduped depending on flags).
+ *        Passing a NULL value will cause an existing tag to be deleted.
+ * @return >= 0 on success otherwise an error code <0
+ */
+int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags);
+
+/**
+ * Copy entries from one AVDictionary struct into another.
+ * @param dst pointer to a pointer to a AVDictionary struct. If *dst is NULL,
+ *            this function will allocate a struct for you and put it in *dst
+ * @param src pointer to source AVDictionary struct
+ * @param flags flags to use when setting entries in *dst
+ * @note metadata is read using the AV_DICT_IGNORE_SUFFIX flag
+ */
+void av_dict_copy(AVDictionary **dst, AVDictionary *src, int flags);
+
+/**
+ * Free all the memory allocated for an AVDictionary struct.
+ */
+void av_dict_free(AVDictionary **m);
+
+#endif // AVUTIL_DICT_H