Function encode64

src/lib/libbrowser.js:104–127

(data)

            if (done) return;
            err(`warning: browser could not fully decode audio ${name}, trying slower base64 approach`);
            function encode64(data) {
              var BASE = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
              var PAD = '=';
              var ret = '';
              var leftchar = 0;
              var leftbits = 0;
              for (var i = 0; i < data.length; i++) {
                leftchar = (leftchar << 8) | data[i];
                leftbits += 8;
                while (leftbits >= 6) {
                  var curr = (leftchar >> (leftbits-6)) & 0x3f;
                  leftbits -= 6;
                  ret += BASE[curr];
                }
              }
              if (leftbits == 2) {
                ret += BASE[(leftchar&3) << 4];
                ret += PAD + PAD;
              } else if (leftbits == 4) {
                ret += BASE[(leftchar&0xf) << 2];
                ret += PAD;
              }
              return ret;
            }
            audio.src = 'data:audio/x-' + name.slice(-3) + ';base64,' + encode64(byteArray);
            finish(audio); // we don't wait for confirmation this worked - but it's worth trying
          };