From 196557a41abe7e63b84c6c9931b23e70bfd3abde Mon Sep 17 00:00:00 2001
From: Kendall Garner <17521368+kgarner7@users.noreply.github.com>
Date: Sat, 21 Sep 2024 20:46:14 +0000
Subject: [PATCH] fix(ui): show effective dB of track when playing (#3293)

* show effective db of track when playing

* tests
---
 ui/src/audioplayer/AudioTitle.js    |  6 ++--
 ui/src/audioplayer/Player.js        | 45 ++---------------------
 ui/src/common/QualityInfo.js        | 26 +++++++++-----
 ui/src/common/QualityInfo.test.js   | 55 ++++++++++++++++++++++++++++-
 ui/src/utils/calculateReplayGain.js | 31 ++++++++++++++++
 5 files changed, 110 insertions(+), 53 deletions(-)
 create mode 100644 ui/src/utils/calculateReplayGain.js

diff --git a/ui/src/audioplayer/AudioTitle.js b/ui/src/audioplayer/AudioTitle.js
index 89d046db6..7f25e8f49 100644
--- a/ui/src/audioplayer/AudioTitle.js
+++ b/ui/src/audioplayer/AudioTitle.js
@@ -18,8 +18,10 @@ const AudioTitle = React.memo(({ audioInfo, gainInfo, isMobile }) => {
   const qi = {
     suffix: song.suffix,
     bitRate: song.bitRate,
-    albumGain: song.rgAlbumGain,
-    trackGain: song.rgTrackGain,
+    rgAlbumGain: song.rgAlbumGain,
+    rgAlbumPeak: song.rgAlbumPeak,
+    rgTrackGain: song.rgTrackGain,
+    rgTrackPeak: song.rgTrackPeak,
   }
 
   return (
diff --git a/ui/src/audioplayer/Player.js b/ui/src/audioplayer/Player.js
index 174940aa2..6af8dd11f 100644
--- a/ui/src/audioplayer/Player.js
+++ b/ui/src/audioplayer/Player.js
@@ -23,16 +23,7 @@ import subsonic from '../subsonic'
 import locale from './locale'
 import { keyMap } from '../hotkeys'
 import keyHandlers from './keyHandlers'
-
-function calculateReplayGain(preAmp, gain, peak) {
-  if (gain === undefined || peak === undefined) {
-    return 1
-  }
-
-  // https://wiki.hydrogenaud.io/index.php?title=ReplayGain_1.0_specification&section=19
-  // Normalized to max gain
-  return Math.min(10 ** ((gain + preAmp) / 20), 1 / peak)
-}
+import { calculateGain } from '../utils/calculateReplayGain'
 
 const Player = () => {
   const theme = useCurrentTheme()
@@ -93,40 +84,10 @@ const Player = () => {
       const current = playerState.current || {}
       const song = current.song || {}
 
-      let numericGain
-
-      switch (gainInfo.gainMode) {
-        case 'album': {
-          numericGain = calculateReplayGain(
-            gainInfo.preAmp,
-            song.rgAlbumGain,
-            song.rgAlbumPeak,
-          )
-          break
-        }
-        case 'track': {
-          numericGain = calculateReplayGain(
-            gainInfo.preAmp,
-            song.rgTrackGain,
-            song.rgTrackPeak,
-          )
-          break
-        }
-        default: {
-          numericGain = 1
-        }
-      }
-
+      const numericGain = calculateGain(gainInfo, song)
       gainNode.gain.setValueAtTime(numericGain, context.currentTime)
     }
-  }, [
-    audioInstance,
-    context,
-    gainNode,
-    gainInfo.gainMode,
-    gainInfo.preAmp,
-    playerState,
-  ])
+  }, [audioInstance, context, gainNode, playerState, gainInfo])
 
   const defaultOptions = useMemo(
     () => ({
diff --git a/ui/src/common/QualityInfo.js b/ui/src/common/QualityInfo.js
index e663d3092..171f5e0f0 100644
--- a/ui/src/common/QualityInfo.js
+++ b/ui/src/common/QualityInfo.js
@@ -1,9 +1,10 @@
-import React from 'react'
+import React, { useMemo } from 'react'
 import PropTypes from 'prop-types'
 import Chip from '@material-ui/core/Chip'
 import config from '../config'
 import { makeStyles } from '@material-ui/core'
 import clsx from 'clsx'
+import { calculateGain } from '../utils/calculateReplayGain'
 
 const llFormats = new Set(config.losslessFormats.split(','))
 const placeholder = 'N/A'
@@ -21,7 +22,8 @@ const useStyle = makeStyles(
 
 export const QualityInfo = ({ record, size, gainMode, preAmp, className }) => {
   const classes = useStyle()
-  let { suffix, bitRate } = record
+  let { suffix, bitRate, rgAlbumGain, rgAlbumPeak, rgTrackGain, rgTrackPeak } =
+    record
   let info = placeholder
 
   if (suffix) {
@@ -32,18 +34,26 @@ export const QualityInfo = ({ record, size, gainMode, preAmp, className }) => {
     }
   }
 
-  if (gainMode !== 'none') {
-    info += ` (${
-      (gainMode === 'album' ? record.albumGain : record.trackGain) + preAmp
-    } dB)`
-  }
+  const extra = useMemo(() => {
+    if (gainMode !== 'none') {
+      const gainValue = calculateGain(
+        { gainMode, preAmp },
+        { rgAlbumGain, rgAlbumPeak, rgTrackGain, rgTrackPeak },
+      )
+      // convert normalized gain (after peak) back to dB
+      const toDb = (Math.log10(gainValue) * 20).toFixed(2)
+      return ` (${toDb} dB)`
+    }
+
+    return ''
+  }, [gainMode, preAmp, rgAlbumGain, rgAlbumPeak, rgTrackGain, rgTrackPeak])
 
   return (
     <Chip
       className={clsx(classes.chip, className)}
       variant="outlined"
       size={size}
-      label={info}
+      label={`${info}${extra}`}
     />
   )
 }
diff --git a/ui/src/common/QualityInfo.test.js b/ui/src/common/QualityInfo.test.js
index 735fe70b9..ae1874715 100644
--- a/ui/src/common/QualityInfo.test.js
+++ b/ui/src/common/QualityInfo.test.js
@@ -11,7 +11,14 @@ describe('<QualityInfo />', () => {
     expect(screen.getByText('FLAC')).toBeInTheDocument()
   })
   it('only render suffix and bitrate for lossy formats', () => {
-    const info = { suffix: 'MP3', bitRate: 320 }
+    const info = {
+      suffix: 'MP3',
+      bitRate: 320,
+      rgAlbumGain: -5,
+      rgAlbumPeak: 1,
+      rgTrackGain: 2.3,
+      rgTrackPeak: 0.5,
+    }
     render(<QualityInfo record={info} />)
     expect(screen.getByText('MP3 320')).toBeInTheDocument()
   })
@@ -24,4 +31,50 @@ describe('<QualityInfo />', () => {
     render(<QualityInfo />)
     expect(screen.getByText('N/A')).toBeInTheDocument()
   })
+  it('renders album gain info, no peak limit', () => {
+    render(
+      <QualityInfo
+        gainMode="album"
+        preAmp={0}
+        record={{
+          rgAlbumGain: -5,
+          rgAlbumPeak: 1,
+          rgTrackGain: -2,
+          rgTrackPeak: 0.2,
+        }}
+      />,
+    )
+    expect(screen.getByText('N/A (-5.00 dB)')).toBeInTheDocument()
+  })
+  it('renders track gain info, no peak limit capping, preAmp', () => {
+    render(
+      <QualityInfo
+        gainMode="track"
+        preAmp={-1}
+        record={{
+          rgAlbumGain: -5,
+          rgAlbumPeak: 1,
+          rgTrackGain: 2.3,
+          rgTrackPeak: 0.5,
+        }}
+      />,
+    )
+    expect(screen.getByText('N/A (1.30 dB)')).toBeInTheDocument()
+  })
+  it('renders gain info limited by peak', () => {
+    render(
+      <QualityInfo
+        gainMode="track"
+        preAmp={-1}
+        record={{
+          suffix: 'FLAC',
+          rgAlbumGain: -5,
+          rgAlbumPeak: 1,
+          rgTrackGain: 2.3,
+          rgTrackPeak: 1,
+        }}
+      />,
+    )
+    expect(screen.getByText('FLAC (0.00 dB)')).toBeInTheDocument()
+  })
 })
diff --git a/ui/src/utils/calculateReplayGain.js b/ui/src/utils/calculateReplayGain.js
new file mode 100644
index 000000000..0ce69fa4b
--- /dev/null
+++ b/ui/src/utils/calculateReplayGain.js
@@ -0,0 +1,31 @@
+const calculateReplayGain = (preAmp, gain, peak) => {
+  if (gain === undefined || peak === undefined) {
+    return 1
+  }
+
+  // https://wiki.hydrogenaud.io/index.php?title=ReplayGain_1.0_specification&section=19
+  // Normalized to max gain
+  return Math.min(10 ** ((gain + preAmp) / 20), 1 / peak)
+}
+
+export const calculateGain = (gainInfo, song) => {
+  switch (gainInfo.gainMode) {
+    case 'album': {
+      return calculateReplayGain(
+        gainInfo.preAmp,
+        song.rgAlbumGain,
+        song.rgAlbumPeak,
+      )
+    }
+    case 'track': {
+      return calculateReplayGain(
+        gainInfo.preAmp,
+        song.rgTrackGain,
+        song.rgTrackPeak,
+      )
+    }
+    default: {
+      return 1
+    }
+  }
+}