Resending.... since first time mail-delivery failed to linux-media Hi Hans, Mauro & list, I wants to add FM Radio RDS Alternate Frequency support in V4L2 and following is my proposal. What is Alternate Frequency? Alternative frequency (or AF) is an option that allows a receiver to re-tune to a different frequency that provides the same station, when the first signal becomes too weak (e.g. when moving out of range). This is often used in car stereo systems, enabled by Radio Data System(RDS). My Proposal: FM Transmitter: Add an extra control ID (CID) V4L2_CID_RDS_TX_AF like CID's for Radio_Text, PS_Name etc for Alternate Frequency set. With this CID driver will set the AF and starts transmitting in both the frequencies. FM Receiver: Solution 1: Add support for AF based Seek in ioctl "vidioc_s_hw_freq_seek" by adding AF_SEEK option in "struct v4l2_hw_freq_seek" so that whenever application receives signal strength low or a particular channel it will call the ioctl vidioc_s_hw_freq_seek with AF_SEEK option and driver will do AF seek and returns the seeked new frequency back to app. Solution 2: Whenever application receives signal strength low for a radio channel, it will call the ioctl .vidioc_g_frequency where driver will check the signal strength and if its low then do the AF switch and return the new frequency back to application Solution3: Let Application handle the AF switching, means application will get the available AF frequencies for a channel and whenever application receives signal strength low for the channel it will check the AF list and do the vidioc_s_frequency for each entries in list. -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
