I am working on a Node.js application where I need to convert audio data, received in chunks, into a WAV format. The audio data consists of an array of strings, with each string representing a chunk of audio data. The conversion works fine for most chunks, but I encounter distortion specifically for chunks that start with “data:audio/webm;codecs=opus;base64”. I am using a function that handles the conversion, but the output for these chunks is not as expected, resulting in distorted audio.

I have tried using the provided function to convert the audio data to WAV format. For chunks that do not start with “data:audio/webm;codecs=opus;base64”, the conversion works correctly, producing clear audio output. However, for chunks that start with “data:audio/webm;codecs=opus;base64”, the resulting audio is distorted. I have attempted to handle these chunks differently in the conversion function by decoding the base64 data and writing it to a WAV file using the ‘wav’ module in Node.js. However, this approach has not resolved the distortion issue.

async sendAudioDataToWAVConverter(audioData, streamSid){
        return new Promise((resolve, reject) => {
            const outputPath = `./audio_files/${streamSid}/output_${Date.now()}.wav`
            const writer = new wav.FileWriter(outputPath, {
                channels: 1,
                sampleRate: 8000,
                bitDepth: 16,
            });
            writer.on('error', (err) => {
                console.error('WAV FileWriter Error: ', err);
                reject(err);
            })
            audioData.forEach((item) => {
                if (item.event === 'media' && item.media && item.media.payload) {
                    const audioDataa = Buffer.from(item.media.payload, 'base64');
                    writer.write(audioDataa);
                } else if(item.startsWith('data:audio/webm;codecs=opus;base64,')){
                    const base64Data = item.split(';base64,')[1];
                    const audioDataa = Buffer.from(base64Data, 'base64');
                    fs.writeFileSync('./audio.wav', audioDataa)
                    writer.write(audioDataa);
                } else{
                    const audioDataa = Buffer.from(item, 'base64');
                    writer.write(audioDataa);
                }
            })
            writer.end(() => {
                resolve(outputPath);
            });
        });
    },