[FFmpeg-user] Question Falcc for mathmatically lossless

[Jim Shupert]

friends,
I wish to know more about flac audio encoding in ffmpeg , i am just 
starting.

I see by the documentation :
FLAC (Free Lossless Audio Codec) Encoder

compression_level
Sets the compression level, which chooses defaults for many other 
options if they are not set explicitly.
Valid values are from 0 to 12, 5 is the default.

My question is:  what should the compression level be for mathematically 
lossless


thank you