mp3 is too much noisy about lamejs

[shanewho]

I've used this library to encode MP3's at high quality, it works very well. I was getting noise at first, one of the main problems I ran into was working with 8, 16, 24, etc bit audio samples and converting between them. 8 bit audio gives you 256 possible values, 16 bit audio is 65,536, so much higher quality. This is just a guess, but I think the issue might be here:

var out = new Int8Array(samples.length/2);

You are converting mp3buf's return to 8 bit and may be getting distortion in the conversion. Here is the code I use (note this is stereo, not mono, so you might have to change):

function lameEncode(l, r, sampleRate, progress) {
        var liblame = new lamejs();
        var mp3Encoder = new liblame.Mp3Encoder(2, sampleRate, 128);

        var blockSize = 1152;
        var blocks = [];
        var mp3Buffer;

        var length = l.length;
        for (var i = 0; i < length; i += blockSize) {
            progress((i/length)*100);
            var lc = l.subarray(i, i + blockSize);
            var rc = r.subarray(i, i + blockSize);
            mp3Buffer = mp3Encoder.encodeBuffer(lc, rc);
            if (mp3Buffer.length > 0) blocks.push(mp3Buffer);
        }
        mp3Buffer = mp3Encoder.flush();   
        if (mp3Buffer.length > 0) blocks.push(mp3Buffer);
        progress(100);
        return new Blob(blocks, {type: 'audio/mpeg'});
    }

[Dewsworld]

Still couldn't find my luck! Also see that mp3Buf is also of type Int8Array

Update: I found the problem. I was mixing singed and unsigned int. I changed
samples = new Uint16Array(audioData, wav.dataOffset, wav.dataLen / 2);
to
samples = new Int16Array(audioData, wav.dataOffset, wav.dataLen / 2);

I think that resolve the issue as closed.