- /* prepend only to the first type 5 NAL unit of an IDR picture */
- if (ctx->first_idr && (unit_type == 5 || unit_type == 7 || unit_type == 8)) {
+ if (unit_type == 7 || unit_type == 8)
+ ctx->idr_sps_pps_seen = 1;
+
+ /* if this is a new IDR picture following an IDR picture, reset the idr flag.
+ * Just check first_mb_in_slice to be 0 as this is the simplest solution.
+ * This could be checking idr_pic_id instead, but would complexify the parsing. */
+ if (!ctx->new_idr && unit_type == 5 && (buf[1] & 0x80))
+ ctx->new_idr = 1;
+
+ /* prepend only to the first type 5 NAL unit of an IDR picture, if no sps/pps are already present */
+ if (ctx->new_idr && unit_type == 5 && !ctx->idr_sps_pps_seen) {