The FFMPEG documentation for the flac encoder list levels of "compression_level (-f, -h, -hh, and -x) but those don't seem to be options for -compression_level which takes numeric arguments.
What are the corresponding numeric arguments and levels? Googling this, my paws are empty.
Thank you
Your question is unclear to me. Do you have any link to this "list levels of compression_level (-f, -h, -hh, and -x)"?
Ok, I got it. I got confused because you said "flac" when you meant "wavpack".
The "compression_level" is handled here:
https://github.com/FFmpeg/FFmpeg/blob/release/4.3/libavcodec/wavpackenc.c#L155
One of the things it does, it sets "s->decorr_filter" which is used to pick an element from "decorr_filters" table, which is defined here:
https://github.com/FFmpeg/FFmpeg/blob/release/4.3/libavcodec/wavpackenc.h#L640
as:
static const WavPackDecorrSpec * const decorr_filters[] = {
&fast_specs[0], &default_specs[0], &high_specs[0], &very_high_specs[0],
};From that, it would seem that:
- -f = 0
- wavpack default = 1
- -h = 2
- -hh = 3
and values above 4 probably correspond to "-x[n]" option.
Oh, and if you don't provide "-compression_level" then ffmpeg will default to s->decorr_filter = 0, which would be wavpack's "-f". Not sure if that's intentional (assuming I'm right in the first place).
FFmpeg just dropped libwavpack encoder (https://hydrogenaud.io/index.php?topic=120038.0)
There already was some investigation about corresponding compression values: https://hydrogenaud.io/index.php?topic=118278.msg976262#msg976262