ffmpeg.js Don't produce output file

I'm trying to use ffmpeg to get some information from an audio file (the lufs value), I don't actually want to transcode it. In the terminal I currently do this with:

ffmpeg -i /path.wav -af loudnorm=print_format=summary -f null - 2>&1 | grep -E 'Input Integrated'

When I tried this, I got a complaint about the -f null part saying there was no null codec, I replaced this with a real codec I don't actually want to transcode the file. I also then get an error saying loudnorm=print_format=summary: Invalid argument Is this not supported by ffmpeg.js?

Jun 01 '20 08:06 willm

You need to compile ffmpeg with the required filters. The prebuilt versions are very barebone.

Jun 01 '20 10:06 tpetry

thanks, I tried to recompile it by adding "loudnorm" to the COMMON_FILTERS in the makefile, but it still doesn't work. Is there a good resource for understanding which compiler options are needed for various things?

Jun 06 '20 09:06 willm

It seems like the loudnorm filter has https://github.com/jiixyj/libebur128 as a dependency. Do I somehow need to include that?

Jun 06 '20 10:06 willm