[FFmpeg-user] ebur128 filter metadata - adding to a stream

[Gregory King]

Hi,

I’m trying to add ebur128 metering metadata to my stream's audio, for the purpose of testing I have tried:
	
	ffmpeg -i test.mp4 -filter_complex ebur128=metadata=1 -vcodec copy -acodec libfdk_aac -f nut - | ffprobe -show_frames - | more

But it doesn't seem to add the metadata.  Running a very similar command in ffbrobe using -lavfi I can see the frame metadata:

ffprobe 2>/dev/null -f lavfi amovie=test.mp4,ebur128=metadata=1 -show_frames -show_format

Looking something like:

	TAG:lavfi.r128.M=-37.871
	TAG:lavfi.r128.S=-34.617
	TAG:lavfi.r128.I=-34.174
	TAG:lavfi.r128.LRA=7.260
	TAG:lavfi.r128.LRA.low=-38.470
	TAG:lavfi.r128.LRA.high=-31.210


Why is it that I can’t see the same metadata in the streams created by ffmpeg using my original ffmpeg command?  For context, I will be trying to add the metadata to a live stream as it is sent so I can consume the metering data in an application receiving the stream.

Thanks,
Greg