Signed-off-by: Konke Radlow <korad...@gmail.com>
---
lib/include/libv4l2rds.h | 35 +++++++-
lib/libv4l2rds/libv4l2rds.c | 190 ++++++++++++++++++++++++++++++++++++++++---
2 files changed, 208 insertions(+), 17 deletions(-)
diff --git a/lib/include/libv4l2rds.h b/lib/include/libv4l2rds.h
index 6a6c7f3..62b28bc 100644
--- a/lib/include/libv4l2rds.h
+++ b/lib/include/libv4l2rds.h
@@ -50,6 +50,9 @@ 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_EON_CNT 20 /* Maximal number of entries in the EON table (for
storing
+ * information about other radio stations, broadcasted
+ * by the current station) */
/* Define Constants for the possible types of RDS information
* used to address the relevant bit in the valid_fields bitmask */
@@ -69,7 +72,9 @@ extern "C" {
#define V4L2_RDS_LC 0x2000 /* Language Code */
#define V4L2_RDS_TMC_SG 0x4000 /* RDS-TMC single group */
#define V4L2_RDS_TMC_MG 0x8000 /* RDS-TMC multi group */
-#define V4L2_RDS_TMC_SYS 0x10000 /* RDS-TMC system information */
+#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 Constants for the state of the RDS decoding process
* used to address the relevant bit in the decode_information bitmask */
@@ -84,9 +89,10 @@ extern "C" {
#define V4L2_RDS_FLAG_STATIC_PTY 0x08
/* TMC related codes
- * used to extract TMC fields from RDS groups */
-#define V4L2_TMC_TUNING_INFO 0x08
-#define V4L2_TMC_SINGLE_GROUP 0x04
+ * used to extract TMC fields from RDS-TMC groups
+ * see ISO 14819-1:2003, Figure 2 - RDS-TMC single-grp full message structure
*/
+#define V4L2_TMC_TUNING_INFO 0x10 /* Bit 4 indicates Tuning Info / User
msg */
+#define V4L2_TMC_SINGLE_GROUP 0x08 /* Bit 3 indicates Single / Multi-group
msg */
/* struct to encapsulate one complete RDS group */
/* This structure is used internally to store data until a complete RDS
@@ -149,6 +155,26 @@ struct v4l2_rds_af_set {
uint32_t af[MAX_AF_CNT]; /* AFs defined in Hz */
};
+/* struct to encapsulate one entry in the EON table (Enhanced Other Network) */
+struct v4l2_rds_eon {
+ uint32_t valid_fields;
+ uint16_t pi;
+ uint8_t ps[9];
+ uint8_t pty;
+ bool ta;
+ bool tp;
+ uint16_t lsf; /* Linkage Set Number */
+ struct v4l2_rds_af_set af;
+};
+
+/* struct to encapsulate a table of EON information */
+struct v4l2_rds_eon_set {
+ uint8_t size; /* size of the table */
+ uint8_t index; /* current position in the table */
+ struct v4l2_rds_eon eon[MAX_EON_CNT]; /* Information about other
+ * radio channels */
+};
+
/* struct to encapsulate an additional data field in a TMC message */
struct v4l2_tmc_additional {
uint8_t label;
@@ -236,6 +262,7 @@ struct v4l2_rds {
struct v4l2_rds_statistics rds_statistics;
struct v4l2_rds_oda_set rds_oda; /* Open Data Services */
struct v4l2_rds_af_set rds_af; /* Alternative Frequencies */
+ struct v4l2_rds_eon_set rds_eon; /* EON information */
struct v4l2_rds_tmc tmc; /* TMC information */
};
diff --git a/lib/libv4l2rds/libv4l2rds.c b/lib/libv4l2rds/libv4l2rds.c
index 2918061..3a90a3b 100644
--- a/lib/libv4l2rds/libv4l2rds.c
+++ b/lib/libv4l2rds/libv4l2rds.c
@@ -92,6 +92,9 @@ enum rds_state {
RDS_C_RECEIVED,
};
+/* function declarations to prevent the need to move large code blocks */
+static uint32_t rds_decode_af(uint8_t af, bool is_vhf);
+
static inline uint8_t set_bit(uint8_t input, uint8_t bitmask, bool bitvalue)
{
return bitvalue ? input | bitmask : input & ~bitmask;
@@ -455,20 +458,11 @@ static bool rds_add_oda(struct rds_private_state
*priv_state, struct v4l2_rds_od
/* add a new AF to the list, if it doesn't exist yet */
static bool rds_add_af_to_list(struct v4l2_rds_af_set *af_set, uint8_t af,
bool is_vhf)
{
- uint32_t freq = 0;
-
- /* AF0 -> "Not to be used" */
- if (af == 0)
+ /* convert the frequency to Hz, skip on errors */
+ uint32_t freq = rds_decode_af(af, is_vhf);
+ if (freq == 0)
return false;
- /* calculate the AF values in HZ */
- if (is_vhf)
- freq = 87500000 + af * 100000;
- else if (freq <= 15)
- freq = 152000 + af * 9000;
- else
- freq = 531000 + af * 9000;
-
/* prevent buffer overflows */
if (af_set->size >= MAX_AF_CNT || af_set->size >= af_set->announced_af)
return false;
@@ -543,6 +537,42 @@ static bool rds_add_ps(struct rds_private_state
*priv_state, uint8_t pos, uint8_
return true;
}
+/* 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 EON table and returns
+ * the index of the new field */
+static uint8_t rds_add_eon_entry(struct rds_private_state *priv_state,
uint16_t pi) {
+ struct v4l2_rds *handle = &priv_state->handle;
+ uint8_t index = handle->rds_eon.index;
+ uint8_t size = handle->rds_eon.size;
+
+ /* check if there's an entry for the given PI key */
+ for (int i = 0; i < handle->rds_eon.size; i++) {
+ if (handle->rds_eon.eon[i].pi == pi) {
+ return i;
+ }
+ }
+ /* if the the maximum table size is reached, overwrite old
+ * entries, starting at the oldest one = 0 */
+ handle->rds_eon.eon[index].pi = pi;
+ handle->rds_eon.eon[index].valid_fields |= V4L2_RDS_PI;
+ handle->rds_eon.index = (index+1 < MAX_EON_CNT)? (index+1) : 0;
+ handle->rds_eon.size = (size+1 <= MAX_EON_CNT)? (size+1) : MAX_EON_CNT;
+ return index;
+}
+
+/* checks if an entry for the given PI already exists */
+static bool rds_check_eon_entry(struct rds_private_state *priv_state, uint16_t
pi) {
+ struct v4l2_rds *handle = &priv_state->handle;
+
+ /* check if there's an entry for the given PI key */
+ for (int i = 0; i <= handle->rds_eon.size; i++) {
+ if (handle->rds_eon.eon[i].pi == pi) {
+ return true;
+ }
+ }
+ return false;
+}
+
/* group of functions to decode successfully received RDS groups into
* easily accessible data fields
*
@@ -790,6 +820,29 @@ static uint32_t rds_decode_group3(struct rds_private_state
*priv_state)
return updated_fields;
}
+/* decodes the RDS radio frequency representation into Hz
+ * @af: 8-bit AF value as transmitted in RDS groups
+ * @is_vhf: boolean value defining which conversion table to use
+ * @return: frequency in Hz, 0 in case of wrong input values */
+static uint32_t rds_decode_af(uint8_t af, bool is_vhf) {
+ uint32_t freq = 0;
+
+ /* AF = 0 => "not to be used"
+ * AF >= 205 => special meanings */
+ if (af == 0 || af >= 205)
+ return 0;
+
+ /* calculate the AF values in HZ */
+ if (is_vhf)
+ freq = 87500000 + af * 100000;
+ else if (freq <= 15)
+ freq = 152000 + af * 9000;
+ else
+ freq = 531000 + af * 9000;
+
+ return freq;
+}
+
/* decodes the RDS date/time representation into a standard c representation
* that can be used with c-library functions */
static time_t rds_decode_mjd(const struct rds_private_state *priv_state)
@@ -880,7 +933,6 @@ static uint32_t rds_decode_group4(struct rds_private_state
*priv_state)
handle->time = rds_decode_mjd(priv_state);
updated_fields |= V4L2_RDS_TIME;
handle->valid_fields |= V4L2_RDS_TIME;
- printf("\nLIB: time_t: %ld", handle->time);
return updated_fields;
}
@@ -981,6 +1033,117 @@ static uint32_t rds_decode_group10(struct
rds_private_state *priv_state)
return updated_fields;
}
+/* group 14: EON (Enhanced Other Network) information */
+static uint32_t rds_decode_group14(struct rds_private_state* priv_state) {
+ struct v4l2_rds *handle = &priv_state->handle;
+ struct v4l2_rds_group *grp = &priv_state->rds_group;
+ uint32_t updated_fields = 0;
+ uint16_t pi_on;
+ uint16_t lsf_on;
+ uint8_t variant_code;
+ uint8_t eon_index;
+ uint8_t pty_on;
+ bool tp_on, ta_on;
+ bool new_a = false, new_b = false;
+
+ if (grp->group_version != 'A') {
+ return 0;
+ }
+
+ /* bits 0-3 of group b contain the variant code */
+ variant_code = grp->data_b_lsb & 0x0f;
+
+ /* group d contains the PI code of the ON (Other Network) */
+ pi_on = (grp->data_d_msb << 8) | grp->data_d_lsb;
+
+ /* bit 4 of group b contains the TP status of the ON*/
+ tp_on = grp->data_b_lsb & 0x10;
+ if (rds_check_eon_entry(priv_state, pi_on)) {
+ /* if there's an entry for this PI(ON) update the TP field */
+ eon_index = rds_add_eon_entry(priv_state, pi_on);
+ handle->rds_eon.eon[eon_index].tp = tp_on;
+ handle->rds_eon.eon[eon_index].valid_fields |= V4L2_RDS_TP;
+ updated_fields |= V4L2_RDS_EON;
+ }
+
+ /* perform group variant dependent decoding */
+ if ((variant_code >=5 && variant_code <=11) || variant_code >= 14) {
+ /* 5-9 = mapped FM frequencies -> unsupported
+ * 10-11 = unallocated
+ * 14 = PIN(ON) -> unsupported (unused RDS feature)
+ * 15 = reserved for broadcasters use */
+ return updated_fields;
+ }
+ /* PS Name */
+ else if (variant_code < 4) {
+ eon_index = rds_add_eon_entry(priv_state, pi_on);
+ handle->rds_eon.eon[eon_index].ps[variant_code*2] =
grp->data_c_msb;
+ handle->rds_eon.eon[eon_index].ps[variant_code*2+1] =
grp->data_c_lsb;
+ handle->rds_eon.eon[eon_index].valid_fields |= V4L2_RDS_PS;
+ updated_fields |= V4L2_RDS_EON;
+ }
+ /* Alternative frequencies */
+ else if (variant_code == 4) {
+ uint8_t c_msb = grp->data_c_msb;
+ uint8_t c_lsb = grp->data_c_lsb;
+ eon_index = rds_add_eon_entry(priv_state, pi_on);
+
+ /* 224..249: announcement of AF count (224=0, 249=25)*/
+ if (c_msb >= 224 && c_msb <= 249)
+ handle->rds_eon.eon[eon_index].af.announced_af = c_msb - 224;
+ /* check if the data represents an AF (for 1 =< val <= 204 the
+ * value represents an AF) */
+ if (c_msb < 205)
+ new_a =
rds_add_af_to_list(&handle->rds_eon.eon[eon_index].af,
+ grp->data_c_msb, true);
+ if (c_lsb < 205)
+ new_b =
rds_add_af_to_list(&handle->rds_eon.eon[eon_index].af,
+ grp->data_c_lsb, true);
+ /* check if one of the frequencies was previously unknown */
+ if (new_a || new_b) {
+ handle->rds_eon.eon[eon_index].valid_fields |=
V4L2_RDS_AF;
+ updated_fields |= V4L2_RDS_EON;
+ }
+ }
+ /* Linkage information */
+ else if (variant_code == 12) {
+ eon_index = rds_add_eon_entry(priv_state, pi_on);
+ /* group c contains the lsf code */
+ lsf_on = (grp->data_c_msb << 8) | grp->data_c_lsb;
+ /* check if the lsf code is already known */
+ new_a = (handle->rds_eon.eon[eon_index].lsf == lsf_on) ? false
: true;
+ if (new_a) {
+ handle->rds_eon.eon[eon_index].lsf = lsf_on;
+ handle->rds_eon.eon[eon_index].valid_fields |=
V4L2_RDS_LSF;
+ updated_fields |= V4L2_RDS_EON;
+ }
+ }
+ /* PTY(ON) and TA(ON) */
+ else if (variant_code == 13) {
+ eon_index = rds_add_eon_entry(priv_state, pi_on);
+ /* bits 15-10 of group c contain the PTY(ON) */
+ pty_on = grp->data_c_msb >> 3;
+ /* bit 0 of group c contains the TA code */
+ ta_on = grp->data_c_lsb & 0x01;
+ /* check if the data is new */
+ new_a = (handle->rds_eon.eon[eon_index].pty == pty_on) ? false
: true;
+ if (new_a) {
+ handle->rds_eon.eon[eon_index].pty = pty_on;
+ handle->rds_eon.eon[eon_index].valid_fields |=
V4L2_RDS_PTY;
+ }
+ new_b = (handle->rds_eon.eon[eon_index].ta == ta_on) ? false :
true;
+ handle->rds_eon.eon[eon_index].ta = ta_on;
+ handle->rds_eon.eon[eon_index].valid_fields |= V4L2_RDS_TA;
+ if (new_a || new_b)
+ updated_fields |= V4L2_RDS_EON;
+ }
+ /* set valid field for EON data, if EON table contains entries */
+ if (handle->rds_eon.size > 0)
+ handle->valid_fields |= V4L2_RDS_EON;
+
+ return updated_fields;
+}
+
typedef uint32_t (*decode_group_func)(struct rds_private_state *);
/* array of function pointers to contain all group specific decoding functions
*/
@@ -992,6 +1155,7 @@ static const decode_group_func decode_group[16] = {
[4] = rds_decode_group4,
[8] = rds_decode_group8,
[10] = rds_decode_group10,
+ [14] = rds_decode_group14
};
static uint32_t rds_decode_group(struct rds_private_state *priv_state)
--
1.7.10.4
--
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