avformat/utils: add ff_parse_creation_time_metadata

Signed-off-by: Marton Balint <cus@passwd.hu>

libavformat/internal.h

@@ -554,4 +554,15 @@ int ffio_open2_wrapper(struct AVFormatContext *s, AVIOContext **pb, const char *
  */
 void ff_format_io_close(AVFormatContext *s, AVIOContext **pb);
 
+/**
+ * Parse creation_time in AVFormatContext metadata if exists and warn if the
+ * parsing fails.
+ *
+ * @param s AVFormatContext
+ * @param timestamp parsed timestamp in microseconds, only set on successful parsing
+ * @param return_seconds set this to get the number of seconds in timestamp instead of microseconds
+ * @return 1 if OK, 0 if the metadata was not present, AVERROR(EINVAL) on parse error
+ */
+int ff_parse_creation_time_metadata(AVFormatContext *s, int64_t *timestamp, int return_seconds);
+
 #endif /* AVFORMAT_INTERNAL_H */

libavformat/utils.c

@@ -4751,3 +4751,20 @@ void ff_format_io_close(AVFormatContext *s, AVIOContext **pb)
         s->io_close(s, *pb);
     *pb = NULL;
 }
+
+int ff_parse_creation_time_metadata(AVFormatContext *s, int64_t *timestamp, int return_seconds)
+{
+    AVDictionaryEntry *entry;
+    int64_t parsed_timestamp;
+    int ret;
+    if ((entry = av_dict_get(s->metadata, "creation_time", NULL, 0))) {
+        if ((ret = av_parse_time(&parsed_timestamp, entry->value, 0)) >= 0) {
+            *timestamp = return_seconds ? parsed_timestamp / 1000000 : parsed_timestamp;
+            return 1;
+        } else {
+            av_log(s, AV_LOG_WARNING, "Failed to parse creation_time %s\n", entry->value);
+            return ret;
+        }
+    }
+    return 0;
+}