Print all metadata values for frames with key lavfi.signalstats.YDIF with values between 0 and 1

signalstats,metadata=print:key=lavfi.signalstats.YDIF:value=0:function=expr:expr='between(VALUE1,0,1)'

Print silencedetect output to file 'metadata.txt'.

silencedetect,ametadata=mode=print:file=metadata.txt

Direct all metadata to a pipe with file descriptor 4.

metadata=mode=print:file='pipe\:4'