ReplayGain support + audio normalization (web player) (#1988)

* ReplayGain support

- extract ReplayGain tags from files, expose via native api
- use metadata to normalize audio in web player

* make pre-push happy

* remove unnecessary prints

* remove another unnecessary print

* add tooltips, see metadata

* address comments, use settings instead

* remove console.log

* use better language for gain modes

ui/src/personal/Personal.js

@@ -8,6 +8,7 @@ import { NotificationsToggle } from './NotificationsToggle'
 import { LastfmScrobbleToggle } from './LastfmScrobbleToggle'
 import { ListenBrainzScrobbleToggle } from './ListenBrainzScrobbleToggle'
 import config from '../config'
+import { ReplayGainToggle } from './ReplayGainToggle'
 
 const useStyles = makeStyles({
   root: { marginTop: '1em' },
@@ -24,6 +25,7 @@ const Personal = () => {
         <SelectTheme />
         <SelectLanguage />
         <SelectDefaultView />
+        {config.enableReplayGain && <ReplayGainToggle />}
         <NotificationsToggle />
         {config.lastFMEnabled && <LastfmScrobbleToggle />}
         {config.listenBrainzEnabled && <ListenBrainzScrobbleToggle />}

ui/src/personal/ReplayGainToggle.js

@@ -0,0 +1,44 @@
+import { NumberInput, SelectInput, useTranslate } from 'react-admin'
+import { useDispatch, useSelector } from 'react-redux'
+import { changeGain, changePreamp } from '../actions'
+
+export const ReplayGainToggle = (props) => {
+  const translate = useTranslate()
+  const dispatch = useDispatch()
+  const gainInfo = useSelector((state) => state.replayGain)
+
+  return (
+    <>
+      <SelectInput
+        {...props}
+        fullWidth
+        source="replayGain"
+        label={translate('menu.personal.options.replaygain')}
+        choices={[
+          { id: 'none', name: 'menu.personal.options.gain.none' },
+          { id: 'track', name: 'menu.personal.options.gain.album' },
+          { id: 'album', name: 'menu.personal.options.gain.track' },
+        ]}
+        defaultValue={gainInfo.gainMode}
+        onChange={(event) => {
+          dispatch(changeGain(event.target.value))
+        }}
+      />
+      <br />
+      {gainInfo.gainMode !== 'none' && (
+        <NumberInput
+          {...props}
+          source="preAmp"
+          label={translate('menu.personal.options.preAmp')}
+          defaultValue={gainInfo.preAmp}
+          step={0.5}
+          min={-15}
+          max={15}
+          onChange={(event) => {
+            dispatch(changePreamp(event.target.value))
+          }}
+        />
+      )}
+    </>
+  )
+}