From 1b9fe46733f8ae587ee592786a80a8b5b42a3ac7 Mon Sep 17 00:00:00 2001
From: Travis Ralston <travisr@matrix.org>
Date: Tue, 3 Aug 2021 13:51:11 -0600
Subject: [PATCH] Remove unnecessary rescaling of voice waveforms

Fixes https://github.com/vector-im/element-web/issues/18364
---
 src/audio/Playback.ts                              | 14 +++-----------
 .../views/audio_messages/LiveRecordingWaveform.tsx |  9 ++-------
 2 files changed, 5 insertions(+), 18 deletions(-)

diff --git a/src/audio/Playback.ts b/src/audio/Playback.ts
index 33d346629a..9dad828a79 100644
--- a/src/audio/Playback.ts
+++ b/src/audio/Playback.ts
@@ -38,17 +38,9 @@ function makePlaybackWaveform(input: number[]): number[] {
     // First, convert negative amplitudes to positive so we don't detect zero as "noisy".
     const noiseWaveform = input.map(v => Math.abs(v));
 
-    // Next, we'll resample the waveform using a smoothing approach so we can keep the same rough shape.
-    // We also rescale the waveform to be 0-1 for the remaining function logic.
-    const resampled = arrayRescale(arraySmoothingResample(noiseWaveform, PLAYBACK_WAVEFORM_SAMPLES), 0, 1);
-
-    // Then, we'll do a high and low pass filter to isolate actual speaking volumes within the rescaled
-    // waveform. Most speech happens below the 0.5 mark.
-    const filtered = resampled.map(v => clamp(v, 0.1, 0.5));
-
-    // Finally, we'll rescale the filtered waveform (0.1-0.5 becomes 0-1 again) so the user sees something
-    // sensible. This is what we return to keep our contract of "values between zero and one".
-    return arrayRescale(filtered, 0, 1);
+    // Then, we'll resample the waveform using a smoothing approach so we can keep the same rough shape.
+    // We also rescale the waveform to be 0-1 so we end up with a clamped waveform to rely upon.
+    return arrayRescale(arraySmoothingResample(noiseWaveform, PLAYBACK_WAVEFORM_SAMPLES), 0, 1);
 }
 
 export class Playback extends EventEmitter implements IDestroyable {
diff --git a/src/components/views/audio_messages/LiveRecordingWaveform.tsx b/src/components/views/audio_messages/LiveRecordingWaveform.tsx
index 9f981e8ca2..73e18626fe 100644
--- a/src/components/views/audio_messages/LiveRecordingWaveform.tsx
+++ b/src/components/views/audio_messages/LiveRecordingWaveform.tsx
@@ -18,7 +18,6 @@ import React from "react";
 import { IRecordingUpdate, RECORDING_PLAYBACK_SAMPLES, VoiceRecording } from "../../../audio/VoiceRecording";
 import { replaceableComponent } from "../../../utils/replaceableComponent";
 import { arrayFastResample, arraySeed } from "../../../utils/arrays";
-import { percentageOf } from "../../../utils/numbers";
 import Waveform from "./Waveform";
 import { MarkedExecution } from "../../../utils/MarkedExecution";
 
@@ -54,12 +53,8 @@ export default class LiveRecordingWaveform extends React.PureComponent<IProps, I
 
     componentDidMount() {
         this.props.recorder.liveData.onUpdate((update: IRecordingUpdate) => {
-            const bars = arrayFastResample(Array.from(update.waveform), RECORDING_PLAYBACK_SAMPLES);
-            // The incoming data is between zero and one, but typically even screaming into a
-            // microphone won't send you over 0.6, so we artificially adjust the gain for the
-            // waveform. This results in a slightly more cinematic/animated waveform for the
-            // user.
-            this.waveform = bars.map(b => percentageOf(b, 0, 0.50));
+            // The incoming data is between zero and one, so we don't need to clamp/rescale it.
+            this.waveform = arrayFastResample(Array.from(update.waveform), RECORDING_PLAYBACK_SAMPLES);
             this.scheduledUpdate.mark();
         });
     }