EN 50067 "Specification of the radio data system (RDS) for +VHF/FM sound broadcasting in the frequency range from 87,5 to 108,0 MHz"

+ FM Transmitter Control Reference + + The FM Transmitter (FM_TX) class includes controls for common features of +FM transmissions capable devices. Currently this class include parameters for audio +compression, pilot tone generation, audio deviation limiter, RDS transmission and +tuning power features. + + + FM_TX Control IDs + + + + + + + + + + + ID + Type + Description + + + + + + V4L2_CID_FM_TX_CLASS + class + The FM_TX class +descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a +description of this control class. + + + V4L2_CID_RDS_ENABLED + boolean + + Enables or disables the RDS transmission feature. + + + V4L2_CID_RDS_PI + integer + + Sets the RDS Programme Identification field +for transmission. + + + V4L2_CID_RDS_PTY + integer + + Sets the RDS Programme Type field for transmission. +This coding of up to 31 pre-defined programme types. + + + V4L2_CID_RDS_PS_NAME + string + + Sets the Programme Service name (PS_NAME) for transmission. +It is intended for static display on a receiver. It is the primary aid to listeners in programme service +identification and selection. The use of PS to transmit text other than a single eight character name is not permitted. + + + V4L2_CID_RDS_RADIO_TEXT + string + + Sets the Radio Text info for transmission. It is a textual description of +what is being broadcasted. If broadcaster wishes to transmit longer PS names, programme-related information or any other +text, then RadioText should be used. + + + V4L2_CID_AUDIO_LIMITER_ENABLED + boolean + + Enables or disables the audio deviation limiter feature. +The limiter is useful when trying to maximize the audio volume, minimize receiver-generated +distortion and prevent overmodulation. + + + + V4L2_CID_AUDIO_LIMITER_RELEASE_TIME + integer + + Sets the audio deviation limiter feature release time. +The unit, step and range are driver-specific. + + + V4L2_CID_AUDIO_LIMITER_DEVIATION + integer + + Configures audio frequency deviation level in Hz. +The range and step are driver-specific. + + + V4L2_CID_AUDIO_COMPRESSION_ENABLED + boolean + + Enables or disables the audio compression feature. +This feature amplifies signals below the threshold by a fixed gain and compresses audio +signals above the threshold by the ratio of Threshold/(Gain + Threshold). + + + V4L2_CID_AUDIO_COMPRESSION_GAIN + integer + + Sets the gain for audio compression feature. It is +a dB value. The range and step are driver-specific. + + + V4L2_CID_AUDIO_COMPRESSION_THRESHOLD + integer + + Sets the threshold level for audio compression freature. +It is a dB value. The range and step are driver-specific. + + + V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME + integer + + Sets the attack time for audio compression feature. +It is a useconds value. The range and step are driver-specific. + + + V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME + integer + + Sets the release time for audio compression feature. +It is a useconds value. The range and step are driver-specific. + + + V4L2_CID_PILOT_TONE_ENABLED + boolean + + Enables or disables the pilot tone generation feature. + + + V4L2_CID_PILOT_TONE_DEVIATION + integer + + Configures pilot tone frequency deviation level. Unit is +in Hz. The range and step are driver-specific. + + + V4L2_CID_PILOT_TONE_FREQUENCY + integer + + Configures pilot tone frequency value. Unit is +in Hz. The range and step are driver-specific. + + + V4L2_CID_PREEMPHASIS + integer + + Configures the pre-emphasis value for broadcasting. +A pre-emphasis filter is applied to the broadcast to accentuate the high audio frequencies. +Depending on the region, a time constant of either 50 or 75 useconds is used. The enum v4l2_fm_tx_preemphasis +defines possible values for pre-emphasis. Here they are: + + + + + V4L2_FM_TX_PREEMPHASIS_DISABLED + No pre-emphasis is applied. + + + V4L2_FM_TX_PREEMPHASIS_50_uS + A pre-emphasis of 50 uS is used. + + + V4L2_FM_TX_PREEMPHASIS_75_uS + A pre-emphasis of 75 uS is used. + + + + + + + V4L2_CID_TUNE_POWER_LEVEL + integer + + Sets the output power level for signal transmission. +Unit is in dBuV. Range and step are driver-specific. + + + V4L2_CID_TUNE_ANTENNA_CAPACITOR + integer + + This selects the value of antenna tuning capacitor +manually or automatically if set to zero. Unit, range and step are driver-specific. + + + + +

+ +For more details about RDS specification, refer to + document, from CENELEC. +