+/*
+ * Fast code for scanning text enclosed in braces. Functionally
+ * equivalent to this sscanf call:
+ *
+ * sscanf(in, "{\\an%*1u}%n", &len) >= 0 && len > 0
+ */
+static int scanbraces(const char* in) {
+ if (strncmp(in, "{\\an", 4) != 0) {
+ return 0;
+ }
+ if (!av_isdigit(in[4])) {
+ return 0;
+ }
+ if (in[5] != '}') {
+ return 0;
+ }
+ return 1;
+}
+