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[152.78.162.254]) by mx.google.com with ESMTPSA id i4sm3759854wix.10.2013.05.07.09.24.38 for (version=TLSv1.2 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 07 May 2013 09:24:38 -0700 (PDT) From: Konke Radlow To: linux-media@vger.kernel.org Cc: hverkuil@xs4all.nl, hdegoede@redhat.com Subject: [RFC PATCH 1/4] libv4l2rds: added support to decode RDS-EON information Date: Tue, 7 May 2013 17:24:20 +0100 Message-Id: <43cedfcd3ab893d4efbf97587ee0fe6640ee3d39.1367943797.git.koradlow@gmail.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1367943863-28803-1-git-send-email-koradlow@gmail.com> References: <1367943863-28803-1-git-send-email-koradlow@gmail.com> Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Signed-off-by: Konke Radlow --- 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)