VIVID_RDS_GEN_BLOCKS
use_alternates = (blk % VIVID_RDS_GEN_BLOCKS) & 1;
if (blk >= dev->radio_rx_rds_last_block + VIVID_RDS_GEN_BLOCKS)
dev->radio_rx_rds_last_block = blk - VIVID_RDS_GEN_BLOCKS + 1;
unsigned data_blk = dev->radio_rx_rds_last_block % VIVID_RDS_GEN_BLOCKS;
if (blk - VIVID_RDS_GEN_BLOCKS >= dev->radio_tx_rds_last_block)
dev->radio_tx_rds_last_block = blk - VIVID_RDS_GEN_BLOCKS + 1;
unsigned data_blk = dev->radio_tx_rds_last_block % VIVID_RDS_GEN_BLOCKS;
#define VIVID_RDS_NSEC_PER_BLK (u32)(5ull * NSEC_PER_SEC / VIVID_RDS_GEN_BLOCKS)
struct v4l2_rds_data data[VIVID_RDS_GEN_BLOCKS];