+ av_log(s, AV_LOG_TRACE, "avs_is_field_based: %d\n", avs_is_field_based(avs->vi));
+ av_log(s, AV_LOG_TRACE, "avs_is_parity_known: %d\n", avs_is_parity_known(avs->vi));
+
+ /* The following typically only works when assumetff (-bff) and
+ * assumefieldbased is used in-script. Additional
+ * logic using GetParity() could deliver more accurate results
+ * but also decodes a frame which we want to avoid. */
+ st->codecpar->field_order = AV_FIELD_UNKNOWN;
+ if (avs_is_field_based(avs->vi)) {
+ if (avs_is_tff(avs->vi)) {
+ st->codecpar->field_order = AV_FIELD_TT;
+ }
+ else if (avs_is_bff(avs->vi)) {
+ st->codecpar->field_order = AV_FIELD_BB;
+ }
+ }
+