Update src/modules/avformat/producer_avformat.c
Update src/modules/avformat/producer_avformat.c

Better way to detect the availability of PIX_FMT_YUVA444P.
xzhavilla/mlt,gmarco/mlt-orig,siddharudh/mlt,xzhavilla/mlt,xzhavilla/mlt,wideioltd/mlt,siddharudh/mlt,j-b-m/mlt,xzhavilla/mlt,xzhavilla/mlt,gmarco/mlt-orig,zzhhui/mlt,mltframework/mlt,gmarco/mlt-orig,xzhavilla/mlt,zzhhui/mlt,j-b-m/mlt,zzhhui/mlt,zzhhui/mlt,mltframework/mlt,anba8005/mlt,j-b-m/mlt,j-b-m/mlt,mltframework/mlt,xzhavilla/mlt,zzhhui/mlt,gmarco/mlt-orig,gmarco/mlt-orig,j-b-m/mlt,j-b-m/mlt,siddharudh/mlt,siddharudh/mlt,j-b-m/mlt,wideioltd/mlt,siddharudh/mlt,anba8005/mlt,siddharudh/mlt,j-b-m/mlt,j-b-m/mlt,siddharudh/mlt,zzhhui/mlt,gmarco/mlt-orig,wideioltd/mlt,wideioltd/mlt,xzhavilla/mlt,mltframework/mlt,gmarco/mlt-orig,wideioltd/mlt,mltframework/mlt,anba8005/mlt,mltframework/mlt,siddharudh/mlt,anba8005/mlt,gmarco/mlt-orig,zzhhui/mlt,wideioltd/mlt,zzhhui/mlt,j-b-m/mlt,mltframework/mlt,mltframework/mlt,wideioltd/mlt,anba8005/mlt,wideioltd/mlt,anba8005/mlt,anba8005/mlt,gmarco/mlt-orig,siddharudh/mlt,anba8005/mlt,xzhavilla/mlt,mltframework/mlt,anba8005/mlt,zzhhui/mlt,wideioltd/mlt,mltframework/mlt