根据source code，

private String digest(CharSequence rawPassword, byte[] salt) {
    byte[] derived = SCrypt.generate(Utf8.encode(rawPassword), salt, this.cpuCost, this.memoryCost,
            this.parallelization, this.keyLength);
    String params = Long.toString(
            ((int) (Math.log(this.cpuCost) / Math.log(2)) << 16L) | this.memoryCost << 8 | this.parallelization,
            16);
    StringBuilder sb = new StringBuilder((salt.length + derived.length) * 2);
    sb.append("$").append(params).append('$');
    sb.append(encodePart(salt)).append('$');
    sb.append(encodePart(derived));
    return sb.toString();
}

字符串
参数、salt和hash使用$分隔符彼此相邻，因此中间的值是编码的salt。