Revert some changes in cc2e091 causing crash.
Revert some changes in cc2e091 causing crash.

For now, filters that depend on audio being processed before video are
incompatible with parallel processing.

zzhhui/mlt,wideioltd/mlt,wideioltd/mlt,zzhhui/mlt,j-b-m/mlt,xzhavilla/mlt,j-b-m/mlt,zzhhui/mlt,mltframework/mlt,mltframework/mlt,anba8005/mlt,xzhavilla/mlt,zzhhui/mlt,j-b-m/mlt,anba8005/mlt,xzhavilla/mlt,wideioltd/mlt,anba8005/mlt,anba8005/mlt,wideioltd/mlt,zzhhui/mlt,siddharudh/mlt,zzhhui/mlt,mltframework/mlt,anba8005/mlt,j-b-m/mlt,xzhavilla/mlt,mltframework/mlt,j-b-m/mlt,wideioltd/mlt,siddharudh/mlt,siddharudh/mlt,j-b-m/mlt,xzhavilla/mlt,zzhhui/mlt,j-b-m/mlt,xzhavilla/mlt,wideioltd/mlt,siddharudh/mlt,siddharudh/mlt,wideioltd/mlt,anba8005/mlt,anba8005/mlt,wideioltd/mlt,zzhhui/mlt,zzhhui/mlt,j-b-m/mlt,xzhavilla/mlt,siddharudh/mlt,anba8005/mlt,siddharudh/mlt,j-b-m/mlt,xzhavilla/mlt,wideioltd/mlt,anba8005/mlt,mltframework/mlt,mltframework/mlt,xzhavilla/mlt,mltframework/mlt,siddharudh/mlt,siddharudh/mlt,mltframework/mlt,mltframework/mlt,mltframework/mlt,j-b-m/mlt