ssdfb_bitstream_append
ssdfb_bitstream_append(s, 0, 1);
ssdfb_bitstream_append(s, cmd, 0x80);
ssdfb_bitstream_append(s, 1, 1);
ssdfb_bitstream_append(s, *data++, 0x80);
static void ssdfb_bitstream_append(struct bs_state *, uint8_t, uint8_t);