Some codecs set this in the parser, but not the decoder
index = s->parser->parser_parse(s, avctx, (const uint8_t **) poutbuf,
poutbuf_size, buf, buf_size);
av_assert0(index > -0x20000000); // The API does not allow returning AVERROR codes
+#define FILL(name) if(s->name > 0 && avctx->name <= 0) avctx->name = s->name
+ if (avctx->codec_type == AVMEDIA_TYPE_VIDEO) {
+ FILL(field_order);
+ }
+
/* update the file pointer */
if (*poutbuf_size) {
/* fill the data for the current frame */