Signed-off-by: Konke Radlow <koradlow@xxxxxxxxx>
---
lib/include/libv4l2rds.h | 65 +++++++++
lib/libv4l2rds/libv4l2rds.c | 309 ++++++++++++++++++++++++++++++++++++++++++-
utils/rds-ctl/rds-ctl.cpp | 31 ++++-
3 files changed, 402 insertions(+), 3 deletions(-)
diff --git a/lib/include/libv4l2rds.h b/lib/include/libv4l2rds.h
index d8baf15..3ec7735 100644
--- a/lib/include/libv4l2rds.h
+++ b/lib/include/libv4l2rds.h
@@ -46,6 +46,10 @@ extern "C" {
* AF Method B does not impose a limit on the number of AFs
* but it is not fully supported at the moment and will
* not receive more than 25 AFs */
+#define MAX_TMC_ADDITIONAL 28 /* 28 is the maximal possible number of fields.
+ * 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 Constants for the possible types of RDS information
* used to address the relevant bit in the valid_fields bitmask */
@@ -63,6 +67,9 @@ extern "C" {
#define V4L2_RDS_AF 0x800 /* AF (alternative freq) available */
#define V4L2_RDS_ECC 0x1000 /* Extended County Code */
#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 Constants for the state of the RDS decoding process
* used to address the relevant bit in the decode_information bitmask */
@@ -76,6 +83,11 @@ extern "C" {
#define V4L2_RDS_FLAG_COMPRESSED 0x04
#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
+
/* struct to encapsulate one complete RDS group */
/* This structure is used internally to store data until a complete RDS
* group was received and group id dependent decoding can be done.
@@ -137,6 +149,58 @@ struct v4l2_rds_af_set {
uint32_t af[MAX_AF_CNT]; /* AFs defined in Hz */
};
+/* struct to encapsulate an additional data field in a TMC message */
+struct v4l2_tmc_additional {
+ uint8_t label;
+ uint16_t data;
+};
+
+/* struct to encapsulate an arbitrary number of additional data fields
+ * belonging to one TMC message */
+struct v4l2_tmc_additional_set {
+ uint8_t size;
+ struct v4l2_tmc_additional fields[MAX_TMC_ADDITIONAL];
+};
+
+/* struct to encapsulate a decoded TMC message with optional additional
+ * data field (in case of a multi-group TMC message) */
+struct v4l2_rds_tmc_msg {
+ uint8_t length; /* length of multi-group message (0..4) */
+ uint8_t sid; /* service identifier at time of reception */
+ uint8_t extent;
+ uint8_t dp; /* duration and persistence */
+ uint16_t event; /* TMC event code */
+ uint16_t location; /* TMC event location */
+ bool follow_diversion; /* indicates if the driver is adviced to
+ * follow the diversion */
+ bool neg_direction; /* indicates negative / positive direction */
+
+ /* decoded additional information (only available in multi-group
+ * messages) */
+ struct v4l2_tmc_additional_set additional;
+};
+
+/* struct to encapsulate all TMC related information, including TMC System
+ * Information, TMC Tuning information and a buffer for the last decoded
+ * TMC messages */
+struct v4l2_rds_tmc {
+ uint8_t ltn; /* location_table_number */
+ bool afi; /* alternative frequency indicator */
+ bool enhanced_mode; /* mode of transmission,
+ * if false -> basic => gaps between tmc groups
+ * gap defines timing behavior
+ * if true -> enhanced => t_a, t_w and t_d
+ * define timing behavior of tmc groups */
+ uint8_t mgs; /* message geographical scope */
+ uint8_t sid; /* service identifier (unique ID on national level) */
+ uint8_t gap; /* Gap parameters */
+ uint8_t t_a; /* activity time (only if mode = enhanced) */
+ uint8_t t_w; /* window time (only if mode = enhanced */
+ uint8_t t_d; /* delay time (only if mode = enhanced */
+ uint8_t spn[9]; /* service provider name */
+ struct v4l2_rds_tmc_msg tmc_msg;
+};
+
/* struct to encapsulate state and RDS information for current decoding process */
/* This is the structure that will be used by external applications, to
* communicate with the library and get access to RDS data */
@@ -172,6 +236,7 @@ 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_tmc tmc; /* TMC information */
};
/* v4l2_rds_init() - initializes a new decoding process
diff --git a/lib/libv4l2rds/libv4l2rds.c b/lib/libv4l2rds/libv4l2rds.c
index 783db22..2918061 100644
--- a/lib/libv4l2rds/libv4l2rds.c
+++ b/lib/libv4l2rds/libv4l2rds.c
@@ -63,6 +63,23 @@ struct rds_private_state {
uint8_t utc_minute;
uint8_t utc_offset;
+ /* TMC decoding buffers, to store data before it can be verified,
+ * and before all parts of a multi-group message have been received */
+ uint8_t continuity_id; /* continuity index of current TMC multigroup */
+ uint8_t grp_seq_id; /* group sequence identifier */
+ bool optional_tmc[112]; /* buffer for up to 112 bits of optional
+ * additional data in multi-group
+ * messages (112 is the maximal possible length
+ * specified by the standard) */
+
+ /* TMC groups are only accepted if the same data was received twice,
+ * these structs are used as receive buffers to validate TMC groups */
+ struct v4l2_rds_group prev_tmc_group;
+ struct v4l2_rds_group prev_tmc_sys_group;
+ struct v4l2_rds_tmc_msg new_tmc_msg;
+
+ /* buffers for rds data, before group type specific decoding can
+ * be done */
struct v4l2_rds_group rds_group;
struct v4l2_rds_data rds_data_raw[4];
};
@@ -179,6 +196,244 @@ static void rds_decode_d(struct rds_private_state *priv_state, struct v4l2_rds_d
grp->data_d_lsb = rds_data->lsb;
}
+/* compare two rds-groups for equality */
+/* used for decoding RDS-TMC, which has the requirement that the same group
+ * is at least received twice before it is accepted */
+static bool rds_compare_group(const struct v4l2_rds_group *a,
+ const struct v4l2_rds_group *b)
+{
+ if (a->pi != b->pi)
+ return false;
+ if (a->group_version != b->group_version)
+ return false;
+ if (a->group_id != b->group_id)
+ return false;
+
+ if (a->data_b_lsb != b->data_b_lsb)
+ return false;
+ if (a->data_c_lsb != b->data_c_lsb || a->data_c_msb != b->data_c_msb)
+ return false;
+ if (a->data_d_lsb != b->data_d_lsb || a->data_d_msb != b->data_d_msb)
+ return false;
+ /* all values are equal */
+ return true;
+}
+
+/* decode additional information of a TMC message into handy representation */
+/* the additional information of TMC messages is submitted in (up to) 4 blocks of
+ * 28 bits each, which are to be treated as a consecutive bit-array. This data
+ * is represented by the optional_tmc array in the private handle, where each
+ * value represents 1 bit. Each additional information set is defined by a 4-bit
+ * label, and an associated data field for which the length is known */
+void rds_tmc_decode_additional(struct rds_private_state *priv_state)
+{
+ struct v4l2_rds_tmc_msg *msg = &priv_state->handle.tmc.tmc_msg;
+ struct v4l2_tmc_additional *fields = &msg->additional.fields[0];
+ const uint8_t label_len = 4; /* fixed length of a label */
+ uint8_t len; /* length of next data field to be extracted */
+ uint8_t label; /* buffer for extracted label */
+ uint16_t data; /* buffer for extracted data */
+ uint8_t array_idx = 0; /* index for optional_tmc array */
+ uint8_t *field_idx = &msg->additional.size; /* index for
+ * additional field array */
+ /* LUT for the length of additional data blocks as defined in
+ * ISO 14819-1 sect. 5.5.1 */
+ static const uint8_t additional_lut[16] = {
+ 3, 3, 5, 5, 5, 8, 8, 8, 8, 11, 16, 16, 16, 16, 0, 0
+ };
+
+ /* reset the additional information from previous messages */
+ *field_idx = 0;
+ memset(fields, 0, sizeof(*fields));
+
+ /* decode the optional TMC data */
+ while (array_idx < (msg->length * 28)) {
+ /* extract the next label */
+ label = 0;
+ for (int i = 0; i < label_len; i++) {
+ if (priv_state->optional_tmc[array_idx++])
+ label |= 1 << (label_len - 1 - i);
+ }
+
+ /* extract the associated data block */
+ data = 0;
+ len = additional_lut[label]; /* length of data block */
+ for (int i = 0; i < len; i++) {
+ if (priv_state->optional_tmc[array_idx++])
+ data |= 1 << (len - 1 - i);
+ }
+
+ /* if the label is not "reserved for future use", or both
+ * fields are 0, store the extracted additional information */
+ if (label == 15)
+ continue;
+ if (label == 0 && data == 0)
+ continue;
+ fields[*field_idx].label = label;
+ fields[*field_idx].data = data;
+ *field_idx += 1;
+ }
+}
+
+/* decode the TMC system information that is contained in type 3A groups
+ * that announce the presence of TMC */
+static uint32_t rds_decode_tmc_system(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;
+
+ /* check if the same group was received twice. If not, store new
+ * group and return early */
+ if (!rds_compare_group(&priv_state->prev_tmc_sys_group, &priv_state->rds_group)) {
+ priv_state->prev_tmc_sys_group = priv_state->rds_group;
+ return 0;
+ }
+ /* bits 14-15 of block 3 contain the variant code */
+ variant_code = priv_state->rds_group.data_c_msb >> 6;
+ switch (variant_code) {
+ case 0x00:
+ /* bits 11-16 of block 3 contain the LTN */
+ tmc->ltn = (((group->data_c_msb & 0x0f) << 2)) |
+ (group->data_c_lsb >> 6);
+ /* bit 5 of block 3 contains the AFI */
+ tmc->afi = group->data_c_lsb & 0x20;
+ /* bit 4 of block 3 contains the Mode */
+ tmc->enhanced_mode = group->data_c_lsb & 0x10;
+ /* bits 0-3 of block 3 contain the MGS */
+ tmc->mgs = group->data_c_lsb & 0x0f;
+ break;
+ case 0x01:
+ /* bits 12-13 of block 3 contain the Gap parameters */
+ tmc->gap = (group->data_c_msb & 0x30) >> 4;
+ /* bits 11-16 of block 3 contain the SID */
+ tmc->sid = (((group->data_c_msb & 0x0f) << 2)) |
+ (group->data_c_lsb >> 6);
+ /* timing information is only valid in enhanced mode */
+ if (!tmc->enhanced_mode)
+ break;
+ /* bits 4-5 of block 3 contain the activity time */
+ tmc->t_a = (group->data_c_lsb & 0x30) >> 4;
+ /* bits 2-3 of block 3 contain the window time */
+ tmc->t_w = (group->data_c_lsb & 0x0c) >> 2;
+ /* bits 0-1 of block 3 contain the delay time */
+ tmc->t_d = group->data_c_lsb & 0x03;
+ break;
+ }
+ return V4L2_RDS_TMC_SYS;
+}
+
+/* decode a single group TMC message */
+static uint32_t rds_decode_tmc_single_group(struct rds_private_state *priv_state)
+{
+ struct v4l2_rds_group *grp = &priv_state->rds_group;
+ struct v4l2_rds_tmc_msg msg;
+
+ /* bits 0-2 of group 2 contain the duration value */
+ msg.dp = grp->data_b_lsb & 0x07;
+ /* bit 15 of block 3 indicates follow diversion advice */
+ msg.follow_diversion = grp->data_c_msb & 0x80;
+ /* bit 14 of block 3 indicates the direction */
+ msg.neg_direction = grp->data_c_msb & 0x40;
+ /* bits 11-13 of block 3 contain the extend of the event */
+ msg.extent = (grp->data_c_msb & 0x38) >> 3;
+ /* bits 0-10 of block 3 contain the event */
+ msg.event = ((grp->data_c_msb & 0x07) << 8) | grp->data_c_lsb;
+ /* bits 0-15 of block 4 contain the location */
+ msg.location = (grp->data_d_msb << 8) | grp->data_c_lsb;
+
+ /* decoding done, store the new message */
+ priv_state->handle.tmc.tmc_msg = msg;
+ priv_state->handle.valid_fields |= V4L2_RDS_TMC_SG;
+ priv_state->handle.valid_fields &= ~V4L2_RDS_TMC_MG;
+
+ return V4L2_RDS_TMC_SG;
+}
+
+/* decode a multi group TMC message and decode the additional fields once
+ * a complete group was decoded */
+static uint32_t rds_decode_tmc_multi_group(struct rds_private_state *priv_state)
+{
+ struct v4l2_rds_group *grp = &priv_state->rds_group;
+ struct v4l2_rds_tmc_msg *msg = &priv_state->new_tmc_msg;
+ bool message_completed = false;
+ uint8_t grp_seq_id;
+ uint64_t buffer;
+
+ /* bits 12-13 of block 3 contain the group sequence id, for all
+ * multi groups except the first group */
+ grp_seq_id = (grp->data_c_msb & 0x30) >> 4;
+
+ /* beginning of a new multigroup ? */
+ /* bit 15 of block 3 is the first group indicator */
+ if (grp->data_c_msb & 0x80) {
+ /* begine decoding of new message */
+ memset(msg, 0, sizeof(msg));
+ memset(priv_state->optional_tmc, 0, 112*sizeof(bool));
+ /* bits 0-3 of block 2 contain continuity index */
+ priv_state->continuity_id = grp->data_b_lsb & 0x07;
+ /* bit 15 of block 3 indicates follow diversion advice */
+ msg->follow_diversion = grp->data_c_msb & 0x80;
+ /* bit 14 of block 3 indicates the direction */
+ msg->neg_direction = grp->data_c_msb & 0x40;
+ /* bits 11-13 of block 3 contain the extend of the event */
+ msg->extent = (grp->data_c_msb & 0x38) >> 3;
+ /* bits 0-10 of block 3 contain the event */
+ msg->event = ((grp->data_c_msb & 0x07) << 8) | grp->data_c_lsb;
+ /* bits 0-15 of block 4 contain the location */
+ msg->location = (grp->data_d_msb << 8) | grp->data_c_lsb;
+ }
+ /* second group of multigroup ? */
+ /* bit 14 of block 3 ist the second group indicator, and the
+ * group continuity id has to match */
+ else if (grp->data_c_msb & 0x40 &&
+ (grp->data_b_lsb & 0x07) == priv_state->continuity_id) {
+ priv_state->grp_seq_id = grp_seq_id;
+ /* store group for later decoding by transforming the bit values
+ * into boolean values and storing them in an array, to ease
+ * further handling */
+ msg->length = 1;
+ buffer = grp->data_c_msb << 24 | grp->data_c_lsb << 16 |
+ grp->data_d_msb << 8 | grp->data_d_lsb;
+ /* the buffer contains 28 bits of additional information */
+ for (int i = 27; i >= 0; i--) {
+ if (buffer & (1 << i))
+ priv_state->optional_tmc[27-i] = true;
+ }
+ if (grp_seq_id == 0)
+ message_completed = true;
+ }
+ /* subsequent groups of multigroup ? */
+ /* group continuity id has to match, and group sequence number has
+ * to be smaller by one than the group sequence id */
+ else if ((grp->data_b_lsb & 0x07) == priv_state->continuity_id &&
+ (grp_seq_id == priv_state->grp_seq_id-1)) {
+ priv_state->grp_seq_id = grp_seq_id;
+ /* store group for later decoding */
+ msg->length += 1;
+ buffer = grp->data_c_msb << 24 | grp->data_c_lsb << 16|
+ grp->data_d_msb << 8 | grp->data_d_lsb;
+ /* the buffer contains 28 bits of additional information */
+ for (int i = 27; i >= 0; i--) {
+ if (buffer & (1 << i))
+ priv_state->optional_tmc[msg->length*28 + 27 - i] = true;
+ }
+ if (grp_seq_id == 0)
+ message_completed = true;
+ }
+
+ /* complete message received -> decode additional fields and store
+ * the new message */
+ if (message_completed) {
+ priv_state->handle.tmc.tmc_msg = *msg;
+ rds_tmc_decode_additional(priv_state);
+ priv_state->handle.valid_fields |= V4L2_RDS_TMC_MG;
+ priv_state->handle.valid_fields &= ~V4L2_RDS_TMC_SG;
+ }
+
+ return V4L2_RDS_TMC_MG;
+}
+
static bool rds_add_oda(struct rds_private_state *priv_state, struct v4l2_rds_oda oda)
{
struct v4l2_rds *handle = &priv_state->handle;
@@ -526,6 +781,12 @@ static uint32_t rds_decode_group3(struct rds_private_state *priv_state)
handle->decode_information |= V4L2_RDS_ODA;
updated_fields |= V4L2_RDS_ODA;
}
+
+ /* if it's a TMC announcement decode the contained information */
+ if (new_oda.aid == 0xcd46 || new_oda.aid == 0xcd47) {
+ rds_decode_tmc_system(priv_state);
+ }
+
return updated_fields;
}
@@ -623,6 +884,50 @@ static uint32_t rds_decode_group4(struct rds_private_state *priv_state)
return updated_fields;
}
+/* group 8A: TMC */
+static uint32_t rds_decode_group8(struct rds_private_state *priv_state)
+{
+ struct v4l2_rds_group *grp = &priv_state->rds_group;
+ uint8_t tuning_variant;
+
+ /* TMC uses version A exclusively */
+ if (grp->group_version != 'A')
+ return 0;
+
+ /* check if the same group was received twice, store new rds group
+ * and return early if the old group doesn't match the new one */
+ if (!rds_compare_group(&priv_state->prev_tmc_group, &priv_state->rds_group)) {
+ priv_state->prev_tmc_group = priv_state->rds_group;
+ return 0;
+ }
+ /* modify the old group, to prevent that the same TMC message is decoded
+ * again in the next iteration (the default number of repetitions for
+ * RDS-TMC groups is 3) */
+ priv_state->prev_tmc_group.group_version = 0;
+
+ /* handle the new TMC data depending on the message type */
+ /* -> single group message */
+ if ((grp->data_b_lsb & V4L2_TMC_SINGLE_GROUP) &&
+ !(grp->data_b_lsb & V4L2_TMC_TUNING_INFO)) {
+ return rds_decode_tmc_single_group(priv_state);
+ }
+ /* -> multi group message */
+ if (!(grp->data_b_lsb & V4L2_TMC_SINGLE_GROUP) &&
+ !(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_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 0;
+}
+
/* group 10: Program Type Name */
static uint32_t rds_decode_group10(struct rds_private_state *priv_state)
{
@@ -685,6 +990,7 @@ static const decode_group_func decode_group[16] = {
[2] = rds_decode_group2,
[3] = rds_decode_group3,
[4] = rds_decode_group4,
+ [8] = rds_decode_group8,
[10] = rds_decode_group10,
};
@@ -956,8 +1262,7 @@ const char *v4l2_rds_get_coverage_str(const struct v4l2_rds *handle)
return coverage_lut[coverage];
}
-const struct v4l2_rds_group *v4l2_rds_get_group
- (const struct v4l2_rds *handle)
+const struct v4l2_rds_group *v4l2_rds_get_group(const struct v4l2_rds *handle)
{
struct rds_private_state *priv_state = (struct rds_private_state *) handle;
return &priv_state->rds_group;
diff --git a/utils/rds-ctl/rds-ctl.cpp b/utils/rds-ctl/rds-ctl.cpp
index c872aed..6906431 100644
--- a/utils/rds-ctl/rds-ctl.cpp
+++ b/utils/rds-ctl/rds-ctl.cpp
@@ -76,6 +76,7 @@ enum Option {
OptOpenFile,
OptPrintBlock,
OptSilent,
+ OptTMC,
OptTunerIndex,
OptVerbose,
OptWaitLimit,
@@ -110,6 +111,7 @@ static struct option long_options[] = {
{"print-block", no_argument, 0, OptPrintBlock},
{"read-rds", no_argument, 0, OptReadRds},
{"set-freq", required_argument, 0, OptSetFreq},
+ {"tmc", no_argument, 0, OptTMC},
{"tuner-index", required_argument, 0, OptTunerIndex},
{"verbose", no_argument, 0, OptVerbose},
{"wait-limit", required_argument, 0, OptWaitLimit},
@@ -170,6 +172,8 @@ static void usage_rds(void)
" --print-block\n"
" prints all valid RDS fields, whenever a value is updated\n"
" instead of printing only updated values\n"
+ " --tmc\n"
+ " enables decoding of TMC (Traffic Message Channel) data\n"
" --verbose\n"
" turn on verbose mode - every received RDS group\n"
" will be printed\n"
@@ -491,7 +495,30 @@ static void print_decoder_info(uint8_t di)
printf("Not Compressed");
}
-static void print_rds_statistics(struct v4l2_rds_statistics *statistics)
+static void print_rds_tmc(const struct v4l2_rds *handle, uint32_t updated_fields)
+{
+ const struct v4l2_rds_tmc_msg *msg = &handle->tmc.tmc_msg;
+ const struct v4l2_tmc_additional_set *set = &msg->additional;
+
+ if (updated_fields & V4L2_RDS_TMC_SG) {
+ printf("\nTMC Single-grp: location: %04x, event: %04x, extent: %02x "
+ "duration: %02x", msg->location, msg->event,
+ msg->extent, msg->dp);
+ return;
+ }
+ if (updated_fields & V4L2_RDS_TMC_MG) {
+ printf("\nTMC Multi-grp: length: %02d, location: %04x, event: %04x,\n"
+ " extent: %02x duration: %02x", msg->length, msg->location, msg->event,
+ msg->extent, msg->dp);
+ for (int i = 0; i < set->size; i++) {
+ printf("\n additional[%02d]: label: %02d, value: %04x",
+ i, set->fields[i].label, set->fields[i].data);
+ }
+ return;
+ }
+}
+
+static void print_rds_statistics(const struct v4l2_rds_statistics *statistics)
{
printf("\n\nRDS Statistics: \n");
printf("received blocks / received groups: %u / %u\n",
@@ -583,6 +610,8 @@ static void print_rds_data(const struct v4l2_rds *handle, uint32_t updated_field
print_rds_af(&handle->rds_af);
if (params.options[OptPrintBlock])
printf("\n");
+ if (params.options[OptTMC])
+ print_rds_tmc(handle, updated_fields);
}
static void read_rds(struct v4l2_rds *handle, const int fd, const int wait_limit)
--
1.7.10.4
--
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