demonstrate use of grouped rvq in soundstream

soundstream = SoundStream(

    codebook_size = 1024,

    rq_num_quantizers = 8,

    rq_groups = 2,                # this paper proposes using multi-headed residual vector quantization - https://arxiv.org/abs/2305.02765

    attn_window_size = 128,       # local attention receptive field at bottleneck

    attn_depth = 2                # 2 local attention transformer blocks - the soundstream folks were not experts with attention, so i took the liberty to add some. encodec went with lstms, but attention should be better

)