[FFmpeg-user] second pass combined with volume detect

jacky renaux.jacky at orange.fr
Thu Dec 12 13:10:25 CET 2013

I am doing encoding from vob to flv (avc/aac) 2 passes
using a git static built on 21013 dec 6
my command line are
ffmpeg -i input_file -vcodec x264 -b:v value -r:v value -vf 0.9375 -g 
value -an pass 1 -y output.flv
ffmpeg -i input_file -vcodec x264 -b:v value -r:v value -vf 0.9375 -g 
value -acodec aac -strict -2 -ab value -ar value -ac value pass 2 -y 

then I have to restart 2 ffmpeg runs one to figure out what is the sound 
level , and then correct it
my command lines are
ffmpeg -f lavfi -i movie=input_file,volumedetect -f null -y logfile
calculated_volume = from the logfile
ffmpeg -i input_file -vcodec copy -acodec aac -strict -2 -ab value -ar 
value -ac 1 -af calculated_volume -y output_file

would it be possible during the second passe to include a volumedetect ?

I am presently doing so using -f lavfi -i 
amovie=<inputaudiofile>,volumedetect -f null
there are some "collission" betwen -f options
i do not succeed to mix both , what would be the correct syntax


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