| Message ID | 59e7b78e35403e1157483794d5d7d796b46ed0c4.1367943797.git.koradlow@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue May 7 2013 18:24:22 Konke Radlow wrote: > Signed-off-by: Konke Radlow <koradlow@gmail.com> > --- > lib/include/libv4l2rds.h | 39 +++++++++++ > lib/libv4l2rds/libv4l2rds.c | 159 +++++++++++++++++++++++++++++++++++++++++-- > 2 files changed, 194 insertions(+), 4 deletions(-) > > diff --git a/lib/include/libv4l2rds.h b/lib/include/libv4l2rds.h > index 62b28bc..45dc2d1 100644 > --- a/lib/include/libv4l2rds.h > +++ b/lib/include/libv4l2rds.h > @@ -50,6 +50,10 @@ extern "C" { > * Additional data is limited to 112 bit, and the smallest > * optional tuple has a size of 4 bit (4 bit identifier + > * 0 bits of data) */ > +#define MAX_TMC_ALT_STATIONS 32 /* defined by ISO 14819-1:2003, 7.5.3.3 */ > +#define MAX_TMC_AF_CNT 4 /* limit for the numbers of AFs stored per alternative TMC > + * station. This value is not defined by the standard, but based on observation > + * of real-world RDS-TMC streams */ Could you clarify this a bit more? E.g. what is the maximum number of AFs you have seen in practice? > #define MAX_EON_CNT 20 /* Maximal number of entries in the EON table (for storing > * information about other radio stations, broadcasted > * by the current station) */ > @@ -75,6 +79,7 @@ extern "C" { > #define V4L2_RDS_TMC_SYS 0x10000 /* RDS-TMC system information */ > #define V4L2_RDS_EON 0x20000 /* Enhanced Other Network Info */ > #define V4L2_RDS_LSF 0x40000 /* Linkage information */ > +#define V4L2_RDS_TMC_TUNING 0x80000 /* RDS-TMC tuning information */ > > /* Define Constants for the state of the RDS decoding process > * used to address the relevant bit in the decode_information bitmask */ > @@ -175,6 +180,37 @@ struct v4l2_rds_eon_set { > * radio channels */ > }; > > +/* struct to encapsulate alternative frequencies (AFs) for RDS-TMC stations. > + * AFs listed in af[] can be used unconditionally. > + * AFs listed in mapped_af[n] should only be used if the current > + * tuner frequency matches the value in mapped_af_tuning[n] */ > +struct v4l2_tmc_alt_freq { > + uint8_t af_size; /* number of known AFs */ > + uint8_t af_index; > + uint8_t mapped_af_size; /* number of mapped AFs */ > + uint8_t mapped_af_index; > + uint32_t af[MAX_TMC_AF_CNT]; /* AFs defined in Hz */ > + uint32_t mapped_af[MAX_TMC_AF_CNT]; /* mapped AFs defined in Hz */ > + uint32_t mapped_af_tuning[MAX_TMC_AF_CNT]; /* mapped AFs defined in Hz */ > +}; > + > +/* struct to encapsulate information about stations carrying RDS-TMC services */ > +struct v4l2_tmc_station { > + uint16_t pi; > + uint8_t ltn; /* database-ID of ON */ > + uint8_t msg; /* msg parameters of ON */ > + uint8_t sid; /* service-ID of ON */ > + struct v4l2_tmc_alt_freq afi; > +}; > + > +/* struct to encapsulate tuning information for TMC */ > +struct v4l2_tmc_tuning { > + uint8_t station_cnt; /* number of announced alternative stations */ > + uint8_t index; > + struct v4l2_tmc_station station[MAX_TMC_ALT_STATIONS]; /* information > + * about other stations carrying the same RDS-TMC service */ > +}; > + > /* struct to encapsulate an additional data field in a TMC message */ > struct v4l2_tmc_additional { > uint8_t label; > @@ -225,6 +261,9 @@ struct v4l2_rds_tmc { > uint8_t t_d; /* delay time (only if mode = enhanced */ > uint8_t spn[9]; /* service provider name */ > struct v4l2_rds_tmc_msg tmc_msg; > + > + /* tuning information for alternative service providers */ > + struct v4l2_tmc_tuning tuning; > }; > > /* struct to encapsulate state and RDS information for current decoding process */ > diff --git a/lib/libv4l2rds/libv4l2rds.c b/lib/libv4l2rds/libv4l2rds.c > index 3a90a3b..3995c3d 100644 > --- a/lib/libv4l2rds/libv4l2rds.c > +++ b/lib/libv4l2rds/libv4l2rds.c > @@ -93,7 +93,9 @@ enum rds_state { > }; > > /* function declarations to prevent the need to move large code blocks */ > +static int rds_add_tmc_station(struct rds_private_state *priv_state, uint16_t pi); > static uint32_t rds_decode_af(uint8_t af, bool is_vhf); > +static bool rds_add_tmc_af(struct rds_private_state *priv_state); Same comment as previously: just have a separate patch that moves code around. > > static inline uint8_t set_bit(uint8_t input, uint8_t bitmask, bool bitvalue) > { > @@ -437,6 +439,59 @@ static uint32_t rds_decode_tmc_multi_group(struct rds_private_state *priv_state) > return V4L2_RDS_TMC_MG; > } > > +/* decode the RDS-TMC tuning information that is contained in type 8A groups > + * (variants 4 to 9) that announce the presence alternative transmitters > + * providing the same RDS-TMC service */ > +static uint32_t rds_decode_tmc_tuning(struct rds_private_state *priv_state) > +{ > + struct v4l2_rds_group *group = &priv_state->rds_group; > + struct v4l2_rds_tmc *tmc = &priv_state->handle.tmc; > + uint8_t variant_code = group->data_b_lsb & 0x0f; > + uint16_t pi_on = (group->data_d_msb << 8) | group->data_d_lsb; > + uint8_t index; > + > + /* variants 4 and 5 carry the service provider name */ > + if (variant_code >= 4 && variant_code <= 5) { > + int offset = 4 * (variant_code - 4); > + tmc->spn[0 + offset] = group->data_c_msb; > + tmc->spn[1 + offset] = group->data_c_lsb; > + tmc->spn[2 + offset] = group->data_d_msb; > + tmc->spn[3 + offset] = group->data_d_lsb; > + > + /* variant 6 provides specific frequencies for the same RDS-TMC service > + * on a network with a different PI code */ > + /* variant 7 provides mapped frequency pair information which should only > + * be used if the terminal is tuned to the tuning frequency */ > + } else if (variant_code == 6 || variant_code == 7) { > + rds_add_tmc_af(priv_state); > + > + /* variant 8 indicates up to 2 PI codes of adjacent networks carrying > + * the same RDS-TMC service on all transmitters of the network */ > + } else if (variant_code == 8) { > + uint16_t pi_on_2 = (group->data_c_msb << 8) | group->data_c_lsb; > + > + /* try to add both transmitted PI codes to the table */ > + rds_add_tmc_station(priv_state, pi_on); > + /* PI = 0 is used as a filler code */ > + if (pi_on_2 != 0) rds_add_tmc_station(priv_state, pi_on_2); Newline before rds_add_tmc_station(). > + > + /* variant 9 provides PI codes of other networks with different system > + * parameters */ > + } else if (variant_code == 9) { > + index = rds_add_tmc_station(priv_state, pi_on); > + > + /* bits 0 - 5 contain the service-ID of the ON */ > + tmc->tuning.station[index].sid = group->data_c_lsb & 0x3F; > + /* bits 6-10 contain the msg parameters of the ON */ > + tmc->tuning.station[index].msg = (group->data_c_msb & 0x03) << 2; > + tmc->tuning.station[index].msg |= (group->data_c_lsb >> 6) & 0x03; > + /* bits 11-15 contain the database-ID of the ON */ > + tmc->tuning.station[index].ltn = group->data_c_msb >> 2; > + } > + > + return V4L2_RDS_TMC_TUNING; > +} > + > static bool rds_add_oda(struct rds_private_state *priv_state, struct v4l2_rds_oda oda) > { > struct v4l2_rds *handle = &priv_state->handle; > @@ -516,6 +571,103 @@ static bool rds_add_af(struct rds_private_state *priv_state) > return updated_af; > } > > +/* checks if an entry for the given PI already exists and returns the index > + * of that entry if so. Else it adds a new entry to the TMC-Tuning table and returns > + * the index of the new field */ > +static int rds_add_tmc_station(struct rds_private_state *priv_state, uint16_t pi) > +{ > + struct v4l2_tmc_tuning *tuning = &priv_state->handle.tmc.tuning; > + uint8_t index = tuning->index; > + uint8_t size = tuning->station_cnt; > + > + /* check if there's an entry for the given PI key */ > + for (int i = 0; i < tuning->station_cnt; i++) { > + if (tuning->station[i].pi == pi) { > + return i; > + } > + } > + /* if the the maximum table size is reached, overwrite old > + * entries, starting at the oldest one = 0 */ > + tuning->station[index].pi = pi; > + tuning->index = (index+1 < MAX_TMC_ALT_STATIONS)? (index+1) : 0; Space before '?' > + tuning->station_cnt = (size+1 <= MAX_TMC_ALT_STATIONS)? (size+1) : MAX_TMC_ALT_STATIONS; Ditto. You do this elsewhere as well, please check :-) > + return index; > +} > + > +/* tries to add new AFs to the relevant entry in the list of RDS-TMC providers */ > +static bool rds_add_tmc_af(struct rds_private_state *priv_state) > +{ > + struct v4l2_rds_group *grp = &priv_state->rds_group; > + struct v4l2_tmc_alt_freq *afi; > + uint16_t pi_on = grp->data_d_msb << 8 | grp->data_d_lsb; > + uint8_t variant = grp->data_b_lsb & 0x0f; > + uint8_t station_index = rds_add_tmc_station(priv_state, pi_on); > + uint8_t af_index; > + uint8_t mapped_af_index; > + uint32_t freq_a = rds_decode_af(grp->data_c_msb, true); > + uint32_t freq_b = rds_decode_af(grp->data_c_lsb, true); > + > + afi = &priv_state->handle.tmc.tuning.station[station_index].afi; > + af_index = afi->af_index; > + mapped_af_index = afi->mapped_af_index; > + > + /* specific frequencies */ > + if (variant == 6) { > + /* compare the new AFs to the stored ones, reset them to 0 if the AFs are > + * already known */ > + for (int i = 0; i < afi->af_size; i++) { > + freq_a = (freq_a == afi->af[i])? 0 : freq_a; > + freq_b = (freq_b == afi->af[i])? 0 : freq_b; > + } > + /* return early if there is nothing to do */ > + if (freq_a == 0 && freq_b == 0) > + return false; > + > + /* add the new AFs if they were previously unknown */ > + if (freq_a != 0) { > + afi->af[af_index] = freq_a; > + af_index = (af_index+1 < MAX_TMC_AF_CNT)? af_index+1 : 0; > + afi->af_size++; > + } > + if (freq_b != 0) { > + afi->af[af_index] = freq_b; > + af_index = (af_index+1 < MAX_TMC_AF_CNT)? af_index+1 : 0; > + afi->af_size++; > + } > + /* update the information in the handle */ > + afi->af_index = af_index; > + if (afi->af_size >= MAX_TMC_AF_CNT) > + afi->af_size = MAX_TMC_AF_CNT; > + > + return true; > + } > + > + /* mapped frequency pair */ > + else if (variant == 7) { > + /* check the if there's already a frequency mapped to the new tuning > + * frequency, update the mapped frequency in this case */ > + for (int i = 0; i < afi->mapped_af_size; i++) { > + if (freq_a == afi->mapped_af_tuning[i]) > + afi->mapped_af[i] = freq_b; > + return true; > + } > + /* new pair is unknown, add it to the list */ > + if (freq_a != 0 && freq_b != 0) { > + mapped_af_index = (mapped_af_index+1 >= MAX_TMC_AF_CNT)? 0 : mapped_af_index + 1; > + afi->mapped_af[mapped_af_index] = freq_b; > + afi->mapped_af_tuning[mapped_af_index] = freq_a; > + afi->mapped_af_size++; > + } > + /* update the information in the handle */ > + afi->mapped_af_index = mapped_af_index; > + if (afi->mapped_af_size >= MAX_TMC_AF_CNT) > + afi->mapped_af_size = MAX_TMC_AF_CNT; > + > + return true; > + } > + return false; > +} > + > /* adds one char of the ps name to temporal storage, the value is validated > * if it is received twice in a row > * @pos: position of the char within the PS name (0..7) > @@ -968,13 +1120,12 @@ static uint32_t rds_decode_group8(struct rds_private_state *priv_state) > !(grp->data_b_lsb & V4L2_TMC_TUNING_INFO)) { > return rds_decode_tmc_multi_group(priv_state); > } > - /* -> tuning information message, defined for variants 4..9, submitted > - * in bits 0-3 of block 2 */ > + /* -> tuning information message, defined for variants 4..9, > + * submitted in bits 0-3 of block 2 */ > tuning_variant = grp->data_b_lsb & 0x0f; > if ((grp->data_b_lsb & V4L2_TMC_TUNING_INFO) && tuning_variant >= 4 && > tuning_variant <= 9) { > - /* TODO: Implement tuning information decoding */ > - return 0; > + return rds_decode_tmc_tuning(priv_state); > } > > return 0; > I suggest that we update V4L2_RDS_VERSION to 2. Unless I am mistaken we are now complete with regards to the RDS/TMC functionality and we can release the library officially. It would still be nice if rds-ctl could decode the TMC messages to human readable text, though... Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Hans, Thank you for your comments, they're very appreciated as always :) I will integrate the proposals and submit an updated version towards the end of this week. To my best knowledge I would say that the functionality of RDS/TMC as defined by the standards is completely implemented now. And I agree that human readable output for the TMC messages would be nice to have, but I'm quite busy with my thesis atm and will not make any promises ;) Cheers, Konke On Fri, May 10, 2013 at 12:46 PM, Hans Verkuil <hverkuil@xs4all.nl> wrote: > On Tue May 7 2013 18:24:22 Konke Radlow wrote: >> Signed-off-by: Konke Radlow <koradlow@gmail.com> >> --- >> lib/include/libv4l2rds.h | 39 +++++++++++ >> lib/libv4l2rds/libv4l2rds.c | 159 +++++++++++++++++++++++++++++++++++++++++-- >> 2 files changed, 194 insertions(+), 4 deletions(-) >> >> diff --git a/lib/include/libv4l2rds.h b/lib/include/libv4l2rds.h >> index 62b28bc..45dc2d1 100644 >> --- a/lib/include/libv4l2rds.h >> +++ b/lib/include/libv4l2rds.h >> @@ -50,6 +50,10 @@ extern "C" { >> * Additional data is limited to 112 bit, and the smallest >> * optional tuple has a size of 4 bit (4 bit identifier + >> * 0 bits of data) */ >> +#define MAX_TMC_ALT_STATIONS 32 /* defined by ISO 14819-1:2003, 7.5.3.3 */ >> +#define MAX_TMC_AF_CNT 4 /* limit for the numbers of AFs stored per alternative TMC >> + * station. This value is not defined by the standard, but based on observation >> + * of real-world RDS-TMC streams */ > > Could you clarify this a bit more? E.g. what is the maximum number of AFs you > have seen in practice? > >> #define MAX_EON_CNT 20 /* Maximal number of entries in the EON table (for storing >> * information about other radio stations, broadcasted >> * by the current station) */ >> @@ -75,6 +79,7 @@ extern "C" { >> #define V4L2_RDS_TMC_SYS 0x10000 /* RDS-TMC system information */ >> #define V4L2_RDS_EON 0x20000 /* Enhanced Other Network Info */ >> #define V4L2_RDS_LSF 0x40000 /* Linkage information */ >> +#define V4L2_RDS_TMC_TUNING 0x80000 /* RDS-TMC tuning information */ >> >> /* Define Constants for the state of the RDS decoding process >> * used to address the relevant bit in the decode_information bitmask */ >> @@ -175,6 +180,37 @@ struct v4l2_rds_eon_set { >> * radio channels */ >> }; >> >> +/* struct to encapsulate alternative frequencies (AFs) for RDS-TMC stations. >> + * AFs listed in af[] can be used unconditionally. >> + * AFs listed in mapped_af[n] should only be used if the current >> + * tuner frequency matches the value in mapped_af_tuning[n] */ >> +struct v4l2_tmc_alt_freq { >> + uint8_t af_size; /* number of known AFs */ >> + uint8_t af_index; >> + uint8_t mapped_af_size; /* number of mapped AFs */ >> + uint8_t mapped_af_index; >> + uint32_t af[MAX_TMC_AF_CNT]; /* AFs defined in Hz */ >> + uint32_t mapped_af[MAX_TMC_AF_CNT]; /* mapped AFs defined in Hz */ >> + uint32_t mapped_af_tuning[MAX_TMC_AF_CNT]; /* mapped AFs defined in Hz */ >> +}; >> + >> +/* struct to encapsulate information about stations carrying RDS-TMC services */ >> +struct v4l2_tmc_station { >> + uint16_t pi; >> + uint8_t ltn; /* database-ID of ON */ >> + uint8_t msg; /* msg parameters of ON */ >> + uint8_t sid; /* service-ID of ON */ >> + struct v4l2_tmc_alt_freq afi; >> +}; >> + >> +/* struct to encapsulate tuning information for TMC */ >> +struct v4l2_tmc_tuning { >> + uint8_t station_cnt; /* number of announced alternative stations */ >> + uint8_t index; >> + struct v4l2_tmc_station station[MAX_TMC_ALT_STATIONS]; /* information >> + * about other stations carrying the same RDS-TMC service */ >> +}; >> + >> /* struct to encapsulate an additional data field in a TMC message */ >> struct v4l2_tmc_additional { >> uint8_t label; >> @@ -225,6 +261,9 @@ struct v4l2_rds_tmc { >> uint8_t t_d; /* delay time (only if mode = enhanced */ >> uint8_t spn[9]; /* service provider name */ >> struct v4l2_rds_tmc_msg tmc_msg; >> + >> + /* tuning information for alternative service providers */ >> + struct v4l2_tmc_tuning tuning; >> }; >> >> /* struct to encapsulate state and RDS information for current decoding process */ >> diff --git a/lib/libv4l2rds/libv4l2rds.c b/lib/libv4l2rds/libv4l2rds.c >> index 3a90a3b..3995c3d 100644 >> --- a/lib/libv4l2rds/libv4l2rds.c >> +++ b/lib/libv4l2rds/libv4l2rds.c >> @@ -93,7 +93,9 @@ enum rds_state { >> }; >> >> /* function declarations to prevent the need to move large code blocks */ >> +static int rds_add_tmc_station(struct rds_private_state *priv_state, uint16_t pi); >> static uint32_t rds_decode_af(uint8_t af, bool is_vhf); >> +static bool rds_add_tmc_af(struct rds_private_state *priv_state); > > Same comment as previously: just have a separate patch that moves code around. > >> >> static inline uint8_t set_bit(uint8_t input, uint8_t bitmask, bool bitvalue) >> { >> @@ -437,6 +439,59 @@ static uint32_t rds_decode_tmc_multi_group(struct rds_private_state *priv_state) >> return V4L2_RDS_TMC_MG; >> } >> >> +/* decode the RDS-TMC tuning information that is contained in type 8A groups >> + * (variants 4 to 9) that announce the presence alternative transmitters >> + * providing the same RDS-TMC service */ >> +static uint32_t rds_decode_tmc_tuning(struct rds_private_state *priv_state) >> +{ >> + struct v4l2_rds_group *group = &priv_state->rds_group; >> + struct v4l2_rds_tmc *tmc = &priv_state->handle.tmc; >> + uint8_t variant_code = group->data_b_lsb & 0x0f; >> + uint16_t pi_on = (group->data_d_msb << 8) | group->data_d_lsb; >> + uint8_t index; >> + >> + /* variants 4 and 5 carry the service provider name */ >> + if (variant_code >= 4 && variant_code <= 5) { >> + int offset = 4 * (variant_code - 4); >> + tmc->spn[0 + offset] = group->data_c_msb; >> + tmc->spn[1 + offset] = group->data_c_lsb; >> + tmc->spn[2 + offset] = group->data_d_msb; >> + tmc->spn[3 + offset] = group->data_d_lsb; >> + >> + /* variant 6 provides specific frequencies for the same RDS-TMC service >> + * on a network with a different PI code */ >> + /* variant 7 provides mapped frequency pair information which should only >> + * be used if the terminal is tuned to the tuning frequency */ >> + } else if (variant_code == 6 || variant_code == 7) { >> + rds_add_tmc_af(priv_state); >> + >> + /* variant 8 indicates up to 2 PI codes of adjacent networks carrying >> + * the same RDS-TMC service on all transmitters of the network */ >> + } else if (variant_code == 8) { >> + uint16_t pi_on_2 = (group->data_c_msb << 8) | group->data_c_lsb; >> + >> + /* try to add both transmitted PI codes to the table */ >> + rds_add_tmc_station(priv_state, pi_on); >> + /* PI = 0 is used as a filler code */ >> + if (pi_on_2 != 0) rds_add_tmc_station(priv_state, pi_on_2); > > Newline before rds_add_tmc_station(). > >> + >> + /* variant 9 provides PI codes of other networks with different system >> + * parameters */ >> + } else if (variant_code == 9) { >> + index = rds_add_tmc_station(priv_state, pi_on); >> + >> + /* bits 0 - 5 contain the service-ID of the ON */ >> + tmc->tuning.station[index].sid = group->data_c_lsb & 0x3F; >> + /* bits 6-10 contain the msg parameters of the ON */ >> + tmc->tuning.station[index].msg = (group->data_c_msb & 0x03) << 2; >> + tmc->tuning.station[index].msg |= (group->data_c_lsb >> 6) & 0x03; >> + /* bits 11-15 contain the database-ID of the ON */ >> + tmc->tuning.station[index].ltn = group->data_c_msb >> 2; >> + } >> + >> + return V4L2_RDS_TMC_TUNING; >> +} >> + >> static bool rds_add_oda(struct rds_private_state *priv_state, struct v4l2_rds_oda oda) >> { >> struct v4l2_rds *handle = &priv_state->handle; >> @@ -516,6 +571,103 @@ static bool rds_add_af(struct rds_private_state *priv_state) >> return updated_af; >> } >> >> +/* checks if an entry for the given PI already exists and returns the index >> + * of that entry if so. Else it adds a new entry to the TMC-Tuning table and returns >> + * the index of the new field */ >> +static int rds_add_tmc_station(struct rds_private_state *priv_state, uint16_t pi) >> +{ >> + struct v4l2_tmc_tuning *tuning = &priv_state->handle.tmc.tuning; >> + uint8_t index = tuning->index; >> + uint8_t size = tuning->station_cnt; >> + >> + /* check if there's an entry for the given PI key */ >> + for (int i = 0; i < tuning->station_cnt; i++) { >> + if (tuning->station[i].pi == pi) { >> + return i; >> + } >> + } >> + /* if the the maximum table size is reached, overwrite old >> + * entries, starting at the oldest one = 0 */ >> + tuning->station[index].pi = pi; >> + tuning->index = (index+1 < MAX_TMC_ALT_STATIONS)? (index+1) : 0; > > Space before '?' > >> + tuning->station_cnt = (size+1 <= MAX_TMC_ALT_STATIONS)? (size+1) : MAX_TMC_ALT_STATIONS; > > Ditto. You do this elsewhere as well, please check :-) > >> + return index; >> +} >> + >> +/* tries to add new AFs to the relevant entry in the list of RDS-TMC providers */ >> +static bool rds_add_tmc_af(struct rds_private_state *priv_state) >> +{ >> + struct v4l2_rds_group *grp = &priv_state->rds_group; >> + struct v4l2_tmc_alt_freq *afi; >> + uint16_t pi_on = grp->data_d_msb << 8 | grp->data_d_lsb; >> + uint8_t variant = grp->data_b_lsb & 0x0f; >> + uint8_t station_index = rds_add_tmc_station(priv_state, pi_on); >> + uint8_t af_index; >> + uint8_t mapped_af_index; >> + uint32_t freq_a = rds_decode_af(grp->data_c_msb, true); >> + uint32_t freq_b = rds_decode_af(grp->data_c_lsb, true); >> + >> + afi = &priv_state->handle.tmc.tuning.station[station_index].afi; >> + af_index = afi->af_index; >> + mapped_af_index = afi->mapped_af_index; >> + >> + /* specific frequencies */ >> + if (variant == 6) { >> + /* compare the new AFs to the stored ones, reset them to 0 if the AFs are >> + * already known */ >> + for (int i = 0; i < afi->af_size; i++) { >> + freq_a = (freq_a == afi->af[i])? 0 : freq_a; >> + freq_b = (freq_b == afi->af[i])? 0 : freq_b; >> + } >> + /* return early if there is nothing to do */ >> + if (freq_a == 0 && freq_b == 0) >> + return false; >> + >> + /* add the new AFs if they were previously unknown */ >> + if (freq_a != 0) { >> + afi->af[af_index] = freq_a; >> + af_index = (af_index+1 < MAX_TMC_AF_CNT)? af_index+1 : 0; >> + afi->af_size++; >> + } >> + if (freq_b != 0) { >> + afi->af[af_index] = freq_b; >> + af_index = (af_index+1 < MAX_TMC_AF_CNT)? af_index+1 : 0; >> + afi->af_size++; >> + } >> + /* update the information in the handle */ >> + afi->af_index = af_index; >> + if (afi->af_size >= MAX_TMC_AF_CNT) >> + afi->af_size = MAX_TMC_AF_CNT; >> + >> + return true; >> + } >> + >> + /* mapped frequency pair */ >> + else if (variant == 7) { >> + /* check the if there's already a frequency mapped to the new tuning >> + * frequency, update the mapped frequency in this case */ >> + for (int i = 0; i < afi->mapped_af_size; i++) { >> + if (freq_a == afi->mapped_af_tuning[i]) >> + afi->mapped_af[i] = freq_b; >> + return true; >> + } >> + /* new pair is unknown, add it to the list */ >> + if (freq_a != 0 && freq_b != 0) { >> + mapped_af_index = (mapped_af_index+1 >= MAX_TMC_AF_CNT)? 0 : mapped_af_index + 1; >> + afi->mapped_af[mapped_af_index] = freq_b; >> + afi->mapped_af_tuning[mapped_af_index] = freq_a; >> + afi->mapped_af_size++; >> + } >> + /* update the information in the handle */ >> + afi->mapped_af_index = mapped_af_index; >> + if (afi->mapped_af_size >= MAX_TMC_AF_CNT) >> + afi->mapped_af_size = MAX_TMC_AF_CNT; >> + >> + return true; >> + } >> + return false; >> +} >> + >> /* adds one char of the ps name to temporal storage, the value is validated >> * if it is received twice in a row >> * @pos: position of the char within the PS name (0..7) >> @@ -968,13 +1120,12 @@ static uint32_t rds_decode_group8(struct rds_private_state *priv_state) >> !(grp->data_b_lsb & V4L2_TMC_TUNING_INFO)) { >> return rds_decode_tmc_multi_group(priv_state); >> } >> - /* -> tuning information message, defined for variants 4..9, submitted >> - * in bits 0-3 of block 2 */ >> + /* -> tuning information message, defined for variants 4..9, >> + * submitted in bits 0-3 of block 2 */ >> tuning_variant = grp->data_b_lsb & 0x0f; >> if ((grp->data_b_lsb & V4L2_TMC_TUNING_INFO) && tuning_variant >= 4 && >> tuning_variant <= 9) { >> - /* TODO: Implement tuning information decoding */ >> - return 0; >> + return rds_decode_tmc_tuning(priv_state); >> } >> >> return 0; >> > > I suggest that we update V4L2_RDS_VERSION to 2. > > Unless I am mistaken we are now complete with regards to the RDS/TMC > functionality and we can release the library officially. > > It would still be nice if rds-ctl could decode the TMC messages to human > readable text, though... > > Regards, > > Hans -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/lib/include/libv4l2rds.h b/lib/include/libv4l2rds.h index 62b28bc..45dc2d1 100644 --- a/lib/include/libv4l2rds.h +++ b/lib/include/libv4l2rds.h @@ -50,6 +50,10 @@ extern "C" { * Additional data is limited to 112 bit, and the smallest * optional tuple has a size of 4 bit (4 bit identifier + * 0 bits of data) */ +#define MAX_TMC_ALT_STATIONS 32 /* defined by ISO 14819-1:2003, 7.5.3.3 */ +#define MAX_TMC_AF_CNT 4 /* limit for the numbers of AFs stored per alternative TMC + * station. This value is not defined by the standard, but based on observation + * of real-world RDS-TMC streams */ #define MAX_EON_CNT 20 /* Maximal number of entries in the EON table (for storing * information about other radio stations, broadcasted * by the current station) */ @@ -75,6 +79,7 @@ extern "C" { #define V4L2_RDS_TMC_SYS 0x10000 /* RDS-TMC system information */ #define V4L2_RDS_EON 0x20000 /* Enhanced Other Network Info */ #define V4L2_RDS_LSF 0x40000 /* Linkage information */ +#define V4L2_RDS_TMC_TUNING 0x80000 /* RDS-TMC tuning information */ /* Define Constants for the state of the RDS decoding process * used to address the relevant bit in the decode_information bitmask */ @@ -175,6 +180,37 @@ struct v4l2_rds_eon_set { * radio channels */ }; +/* struct to encapsulate alternative frequencies (AFs) for RDS-TMC stations. + * AFs listed in af[] can be used unconditionally. + * AFs listed in mapped_af[n] should only be used if the current + * tuner frequency matches the value in mapped_af_tuning[n] */ +struct v4l2_tmc_alt_freq { + uint8_t af_size; /* number of known AFs */ + uint8_t af_index; + uint8_t mapped_af_size; /* number of mapped AFs */ + uint8_t mapped_af_index; + uint32_t af[MAX_TMC_AF_CNT]; /* AFs defined in Hz */ + uint32_t mapped_af[MAX_TMC_AF_CNT]; /* mapped AFs defined in Hz */ + uint32_t mapped_af_tuning[MAX_TMC_AF_CNT]; /* mapped AFs defined in Hz */ +}; + +/* struct to encapsulate information about stations carrying RDS-TMC services */ +struct v4l2_tmc_station { + uint16_t pi; + uint8_t ltn; /* database-ID of ON */ + uint8_t msg; /* msg parameters of ON */ + uint8_t sid; /* service-ID of ON */ + struct v4l2_tmc_alt_freq afi; +}; + +/* struct to encapsulate tuning information for TMC */ +struct v4l2_tmc_tuning { + uint8_t station_cnt; /* number of announced alternative stations */ + uint8_t index; + struct v4l2_tmc_station station[MAX_TMC_ALT_STATIONS]; /* information + * about other stations carrying the same RDS-TMC service */ +}; + /* struct to encapsulate an additional data field in a TMC message */ struct v4l2_tmc_additional { uint8_t label; @@ -225,6 +261,9 @@ struct v4l2_rds_tmc { uint8_t t_d; /* delay time (only if mode = enhanced */ uint8_t spn[9]; /* service provider name */ struct v4l2_rds_tmc_msg tmc_msg; + + /* tuning information for alternative service providers */ + struct v4l2_tmc_tuning tuning; }; /* struct to encapsulate state and RDS information for current decoding process */ diff --git a/lib/libv4l2rds/libv4l2rds.c b/lib/libv4l2rds/libv4l2rds.c index 3a90a3b..3995c3d 100644 --- a/lib/libv4l2rds/libv4l2rds.c +++ b/lib/libv4l2rds/libv4l2rds.c @@ -93,7 +93,9 @@ enum rds_state { }; /* function declarations to prevent the need to move large code blocks */ +static int rds_add_tmc_station(struct rds_private_state *priv_state, uint16_t pi); static uint32_t rds_decode_af(uint8_t af, bool is_vhf); +static bool rds_add_tmc_af(struct rds_private_state *priv_state); static inline uint8_t set_bit(uint8_t input, uint8_t bitmask, bool bitvalue) { @@ -437,6 +439,59 @@ static uint32_t rds_decode_tmc_multi_group(struct rds_private_state *priv_state) return V4L2_RDS_TMC_MG; } +/* decode the RDS-TMC tuning information that is contained in type 8A groups + * (variants 4 to 9) that announce the presence alternative transmitters + * providing the same RDS-TMC service */ +static uint32_t rds_decode_tmc_tuning(struct rds_private_state *priv_state) +{ + struct v4l2_rds_group *group = &priv_state->rds_group; + struct v4l2_rds_tmc *tmc = &priv_state->handle.tmc; + uint8_t variant_code = group->data_b_lsb & 0x0f; + uint16_t pi_on = (group->data_d_msb << 8) | group->data_d_lsb; + uint8_t index; + + /* variants 4 and 5 carry the service provider name */ + if (variant_code >= 4 && variant_code <= 5) { + int offset = 4 * (variant_code - 4); + tmc->spn[0 + offset] = group->data_c_msb; + tmc->spn[1 + offset] = group->data_c_lsb; + tmc->spn[2 + offset] = group->data_d_msb; + tmc->spn[3 + offset] = group->data_d_lsb; + + /* variant 6 provides specific frequencies for the same RDS-TMC service + * on a network with a different PI code */ + /* variant 7 provides mapped frequency pair information which should only + * be used if the terminal is tuned to the tuning frequency */ + } else if (variant_code == 6 || variant_code == 7) { + rds_add_tmc_af(priv_state); + + /* variant 8 indicates up to 2 PI codes of adjacent networks carrying + * the same RDS-TMC service on all transmitters of the network */ + } else if (variant_code == 8) { + uint16_t pi_on_2 = (group->data_c_msb << 8) | group->data_c_lsb; + + /* try to add both transmitted PI codes to the table */ + rds_add_tmc_station(priv_state, pi_on); + /* PI = 0 is used as a filler code */ + if (pi_on_2 != 0) rds_add_tmc_station(priv_state, pi_on_2); + + /* variant 9 provides PI codes of other networks with different system + * parameters */ + } else if (variant_code == 9) { + index = rds_add_tmc_station(priv_state, pi_on); + + /* bits 0 - 5 contain the service-ID of the ON */ + tmc->tuning.station[index].sid = group->data_c_lsb & 0x3F; + /* bits 6-10 contain the msg parameters of the ON */ + tmc->tuning.station[index].msg = (group->data_c_msb & 0x03) << 2; + tmc->tuning.station[index].msg |= (group->data_c_lsb >> 6) & 0x03; + /* bits 11-15 contain the database-ID of the ON */ + tmc->tuning.station[index].ltn = group->data_c_msb >> 2; + } + + return V4L2_RDS_TMC_TUNING; +} + static bool rds_add_oda(struct rds_private_state *priv_state, struct v4l2_rds_oda oda) { struct v4l2_rds *handle = &priv_state->handle; @@ -516,6 +571,103 @@ static bool rds_add_af(struct rds_private_state *priv_state) return updated_af; } +/* checks if an entry for the given PI already exists and returns the index + * of that entry if so. Else it adds a new entry to the TMC-Tuning table and returns + * the index of the new field */ +static int rds_add_tmc_station(struct rds_private_state *priv_state, uint16_t pi) +{ + struct v4l2_tmc_tuning *tuning = &priv_state->handle.tmc.tuning; + uint8_t index = tuning->index; + uint8_t size = tuning->station_cnt; + + /* check if there's an entry for the given PI key */ + for (int i = 0; i < tuning->station_cnt; i++) { + if (tuning->station[i].pi == pi) { + return i; + } + } + /* if the the maximum table size is reached, overwrite old + * entries, starting at the oldest one = 0 */ + tuning->station[index].pi = pi; + tuning->index = (index+1 < MAX_TMC_ALT_STATIONS)? (index+1) : 0; + tuning->station_cnt = (size+1 <= MAX_TMC_ALT_STATIONS)? (size+1) : MAX_TMC_ALT_STATIONS; + return index; +} + +/* tries to add new AFs to the relevant entry in the list of RDS-TMC providers */ +static bool rds_add_tmc_af(struct rds_private_state *priv_state) +{ + struct v4l2_rds_group *grp = &priv_state->rds_group; + struct v4l2_tmc_alt_freq *afi; + uint16_t pi_on = grp->data_d_msb << 8 | grp->data_d_lsb; + uint8_t variant = grp->data_b_lsb & 0x0f; + uint8_t station_index = rds_add_tmc_station(priv_state, pi_on); + uint8_t af_index; + uint8_t mapped_af_index; + uint32_t freq_a = rds_decode_af(grp->data_c_msb, true); + uint32_t freq_b = rds_decode_af(grp->data_c_lsb, true); + + afi = &priv_state->handle.tmc.tuning.station[station_index].afi; + af_index = afi->af_index; + mapped_af_index = afi->mapped_af_index; + + /* specific frequencies */ + if (variant == 6) { + /* compare the new AFs to the stored ones, reset them to 0 if the AFs are + * already known */ + for (int i = 0; i < afi->af_size; i++) { + freq_a = (freq_a == afi->af[i])? 0 : freq_a; + freq_b = (freq_b == afi->af[i])? 0 : freq_b; + } + /* return early if there is nothing to do */ + if (freq_a == 0 && freq_b == 0) + return false; + + /* add the new AFs if they were previously unknown */ + if (freq_a != 0) { + afi->af[af_index] = freq_a; + af_index = (af_index+1 < MAX_TMC_AF_CNT)? af_index+1 : 0; + afi->af_size++; + } + if (freq_b != 0) { + afi->af[af_index] = freq_b; + af_index = (af_index+1 < MAX_TMC_AF_CNT)? af_index+1 : 0; + afi->af_size++; + } + /* update the information in the handle */ + afi->af_index = af_index; + if (afi->af_size >= MAX_TMC_AF_CNT) + afi->af_size = MAX_TMC_AF_CNT; + + return true; + } + + /* mapped frequency pair */ + else if (variant == 7) { + /* check the if there's already a frequency mapped to the new tuning + * frequency, update the mapped frequency in this case */ + for (int i = 0; i < afi->mapped_af_size; i++) { + if (freq_a == afi->mapped_af_tuning[i]) + afi->mapped_af[i] = freq_b; + return true; + } + /* new pair is unknown, add it to the list */ + if (freq_a != 0 && freq_b != 0) { + mapped_af_index = (mapped_af_index+1 >= MAX_TMC_AF_CNT)? 0 : mapped_af_index + 1; + afi->mapped_af[mapped_af_index] = freq_b; + afi->mapped_af_tuning[mapped_af_index] = freq_a; + afi->mapped_af_size++; + } + /* update the information in the handle */ + afi->mapped_af_index = mapped_af_index; + if (afi->mapped_af_size >= MAX_TMC_AF_CNT) + afi->mapped_af_size = MAX_TMC_AF_CNT; + + return true; + } + return false; +} + /* adds one char of the ps name to temporal storage, the value is validated * if it is received twice in a row * @pos: position of the char within the PS name (0..7) @@ -968,13 +1120,12 @@ static uint32_t rds_decode_group8(struct rds_private_state *priv_state) !(grp->data_b_lsb & V4L2_TMC_TUNING_INFO)) { return rds_decode_tmc_multi_group(priv_state); } - /* -> tuning information message, defined for variants 4..9, submitted - * in bits 0-3 of block 2 */ + /* -> tuning information message, defined for variants 4..9, + * submitted in bits 0-3 of block 2 */ tuning_variant = grp->data_b_lsb & 0x0f; if ((grp->data_b_lsb & V4L2_TMC_TUNING_INFO) && tuning_variant >= 4 && tuning_variant <= 9) { - /* TODO: Implement tuning information decoding */ - return 0; + return rds_decode_tmc_tuning(priv_state); } return 0;
Signed-off-by: Konke Radlow <koradlow@gmail.com> --- lib/include/libv4l2rds.h | 39 +++++++++++ lib/libv4l2rds/libv4l2rds.c | 159 +++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 194 insertions(+), 4 deletions(-)