dnxhdenc: mark CID 1260 encoder experimental

The MBAFF handling recently introduced on the decoder side shows that
the encoder does not support it correctly. Therefore, make the related
profile experimental.

Furthermore, current encoder logic treats it as unable to encode as
progressive, which isn't the case.

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/dnxhddata.c

@@ -1158,6 +1158,11 @@ int ff_dnxhd_find_cid(AVCodecContext *avctx, int bit_depth)
         if (cid->width == avctx->width && cid->height == avctx->height &&
             interlaced == !!(avctx->flags & AV_CODEC_FLAG_INTERLACED_DCT) &&
             !(cid->flags & DNXHD_444) && cid->bit_depth == bit_depth) {
+            if (avctx->strict_std_compliance > FF_COMPLIANCE_EXPERIMENTAL &&
+                cid->flags & DNXHD_MBAFF) {
+                av_log(avctx, AV_LOG_WARNING, "Profile selected is experimental\n");
+                continue;
+            }
             for (j = 0; j < FF_ARRAY_ELEMS(cid->bit_rates); j++) {
                 if (cid->bit_rates[j] == mbs)
                     return cid->cid;