feat: send audio with waveform (#2309)

* added generateWaveform

* docs updated

* added usage example

* ESLint fix

* fixed: undefined returned on waveform generation failure

* fix: ESLint

src/util/Injected.js

@@ -390,6 +390,9 @@ exports.LoadUtils = () => {
 
         if (forceVoice && mediaData.type === 'audio') {
             mediaData.type = 'ptt';
+            const waveform = mediaObject.contentInfo.waveform;
+            mediaData.waveform =
+                waveform ?? await window.WWebJS.generateWaveform(file);
         }
 
         if (forceGif && mediaData.type === 'video') {
@@ -632,6 +635,42 @@ exports.LoadUtils = () => {
         return result;
     };
 
+    /**
+     * Referenced from and modified:
+     * @see https://github.com/wppconnect-team/wa-js/commit/290ebfefe6021b3d17f7fdfdda5545bb0473b26f
+     */
+    window.WWebJS.generateWaveform = async (audioFile) => {
+        try {
+            const audioData = await audioFile.arrayBuffer();
+            const audioContext = new AudioContext();
+            const audioBuffer = await audioContext.decodeAudioData(audioData);
+
+            const rawData = audioBuffer.getChannelData(0);
+            const samples = 64;
+            const blockSize = Math.floor(rawData.length / samples);
+            const filteredData = [];
+            for (let i = 0; i < samples; i++) {
+                const blockStart = blockSize * i;
+                let sum = 0;
+                for (let j = 0; j < blockSize; j++) {
+                    sum = sum + Math.abs(rawData[blockStart + j]);
+                }
+                filteredData.push(sum / blockSize);
+            }
+
+            const multiplier = Math.pow(Math.max(...filteredData), -1);
+            const normalizedData = filteredData.map((n) => n * multiplier);
+
+            const waveform = new Uint8Array(
+                normalizedData.map((n) => Math.floor(100 * n))
+            );
+
+            return waveform;
+        } catch (e) {
+            return undefined;
+        }
+    };
+
     window.WWebJS.sendClearChat = async (chatId) => {
         let chat = window.Store.Chat.get(chatId);
         if (chat !== undefined) {