int bits_left = get_bits_left(gb);
static inline void bit_copy(PutBitContext *pb, GetBitContext *gb, int bits_left){    while (bits_left >= 16) {        put_bits(pb, 16, get_bits(gb, 16));        bits_left -= 16;    }    if (bits_left > 0) {        put_bits(pb, bits_left, get_bits(gb, bits_left));    }}