Flag filter based on resampler manifests

[oxygen-dioxide]

Many resamplers are unable to parse flags correctly when there are moresampler-specific flags, because most resamplers only use single-character flags, but moresampler uses multi-character flags, such as "Mt", "Me", "Mb". To solve this issue, we can pass only the supported flags (specified in resampler manifest) into the resampler.

This filter uses the abbr of flags to check if it is supported, because a flag char could function differently on different resamplers. It is off by default to avoid breaking existing ustx files. To enable this filter, add this line into the resampler manifest:

expression_filter: true

Full resampler manifest example (tn_fnds.yaml):

expression_filter: True
expressions:
  amp:
    abbr: amp
    default_value: 0
    flag: A
    is_flag: true
    max: 100
    min: -100
    name: Amplitude Modulation
    type: Numerical
  bre:
    abbr: bre
    default_value: 0
    flag: B
    is_flag: true
    max: 100
    min: 50
    name: Breath
    type: Numerical
  bri:
    abbr: bri
    default_value: 0
    flag: O
    is_flag: true
    max: 100
    min: 0
    name: Brightness
    type: Numerical
  fstr:
    abbr: fstr
    is_flag: true
    name: Force Stretch
    options:
    - ''
    - e
    - Me
    type: Options
  gen:
    abbr: gen
    default_value: 0
    flag: g
    is_flag: true
    max: 100
    min: -100
    name: Gender
    type: Numerical
  pit:
    abbr: pit
    default_value: 0
    flag: t
    is_flag: true
    max: 1200
    min: -1200
    name: Pitch deviation (flag)
    type: Numerical