1 files changed, 31 insertions, 1 deletions
diff --git a/libavformat/riff.c b/libavformat/riff.c
index 2539b23134..3d805d8884 100644
--- a/libavformat/riff.c
+++ b/libavformat/riff.c
@@ -1,5 +1,5 @@
 /*
- * RIFF codec tags
+ * RIFF common functions and data
  * Copyright (c) 2000 Fabrice Bellard
  *
  * This file is part of Libav.
@@ -708,3 +708,33 @@ int ff_read_riff_info(AVFormatContext *s, int64_t size)
 
     return 0;
 }
+
+void ff_riff_write_info_tag(AVIOContext *pb, const char *tag, const char *str)
+{
+    int len = strlen(str);
+    if (len > 0) {
+        len++;
+        ffio_wfourcc(pb, tag);
+        avio_wl32(pb, len);
+        avio_put_str(pb, str);
+        if (len & 1)
+            avio_w8(pb, 0);
+    }
+}
+
+void ff_riff_write_info(AVFormatContext *s)
+{
+    AVIOContext *pb = s->pb;
+    int i;
+    int64_t list_pos;
+    AVDictionaryEntry *t = NULL;
+
+    list_pos = ff_start_tag(pb, "LIST");
+    ffio_wfourcc(pb, "INFO");
+    ff_metadata_conv(&s->metadata, ff_riff_info_conv, NULL);
+    for (i = 0; *ff_riff_tags[i]; i++) {
+        if ((t = av_dict_get(s->metadata, ff_riff_tags[i], NULL, AV_DICT_MATCH_CASE)))
+            ff_riff_write_info_tag(s->pb, t->key, t->value);
+    }
+    ff_end_tag(pb, list_pos);
+}