libdvbv5 1.22.1
Library to work with Digital TV devices on Linux
Files | Data Structures | Typedefs | Functions
Digital TV frontend scan

Files

file  dvb-scan.h
 Provides interfaces to scan programs inside MPEG-TS digital TV streams.
 

Data Structures

struct  dvb_v5_descriptors_program
 Associates PMT with PAT tables. More...
 
struct  dvb_v5_descriptors
 Contains the descriptors needed to scan the Service ID and other relevant info at a MPEG-TS Digital TV stream. More...
 
struct  dvb_table_filter
 Describes the PES filters used by DVB scan. More...
 

Typedefs

typedef int() check_frontend_t(void *args, struct dvb_v5_fe_parms *parms)
 Callback for the application to show the frontend status. More...
 

Functions

struct dvb_v5_descriptorsdvb_dev_scan (struct dvb_open_descriptor *open_dev, struct dvb_entry *entry, check_frontend_t *check_frontend, void *args, unsigned other_nit, unsigned timeout_multiply)
 Scans a DVB dvb_add_scaned_transponder. More...
 
void dvb_table_filter_free (struct dvb_table_filter *sect)
 deallocates all data associated with a table filter More...
 
int dvb_read_section (struct dvb_v5_fe_parms *parms, int dmx_fd, unsigned char tid, uint16_t pid, void **table, unsigned timeout)
 read MPEG-TS tables that comes from a DTV card More...
 
int dvb_read_section_with_id (struct dvb_v5_fe_parms *parms, int dmx_fd, unsigned char tid, uint16_t pid, int ts_id, void **table, unsigned timeout)
 read MPEG-TS tables that comes from a DTV card with an specific table section ID More...
 
int dvb_read_sections (struct dvb_v5_fe_parms *parms, int dmx_fd, struct dvb_table_filter *sect, unsigned timeout)
 read MPEG-TS tables that comes from a DTV card More...
 
struct dvb_v5_descriptorsdvb_scan_alloc_handler_table (uint32_t delivery_system)
 allocates a struct dvb_v5_descriptors More...
 
void dvb_scan_free_handler_table (struct dvb_v5_descriptors *dvb_scan_handler)
 frees a struct dvb_v5_descriptors More...
 
struct dvb_v5_descriptorsdvb_get_ts_tables (struct dvb_v5_fe_parms *parms, int dmx_fd, uint32_t delivery_system, unsigned other_nit, unsigned timeout_multiply)
 Scans a DVB stream, looking for the tables needed to identify the programs inside a MPEG-TS. More...
 
void dvb_free_ts_tables (struct dvb_v5_descriptors *dvb_desc)
 frees a struct dvb_v5_descriptors More...
 
struct dvb_v5_descriptorsdvb_scan_transponder (struct dvb_v5_fe_parms *parms, struct dvb_entry *entry, int dmx_fd, check_frontend_t *check_frontend, void *args, unsigned other_nit, unsigned timeout_multiply)
 Scans a DVB dvb_add_scaned_transponder. More...
 
void dvb_add_scaned_transponders (struct dvb_v5_fe_parms *parms, struct dvb_v5_descriptors *dvb_scan_handler, struct dvb_entry *first_entry, struct dvb_entry *entry)
 Add new transponders to a dvb_file. More...
 

Detailed Description

Typedef Documentation

◆ check_frontend_t

typedef int() check_frontend_t(void *args, struct dvb_v5_fe_parms *parms)

Callback for the application to show the frontend status.

Parameters
argsa pointer, opaque to libdvbv5, to be used by the application if needed.
parmspointer to struct dvb_v5_fe_parms created when the frontend is opened

Definition at line 293 of file dvb-scan.h.

Function Documentation

◆ dvb_add_scaned_transponders()

void dvb_add_scaned_transponders ( struct dvb_v5_fe_parms parms,
struct dvb_v5_descriptors dvb_scan_handler,
struct dvb_entry first_entry,
struct dvb_entry entry 
)

Add new transponders to a dvb_file.

Parameters
parmspointer to struct dvb_v5_fe_parms created when the frontend is opened
dvb_scan_handlerpointer to a struct dvb_v5_descriptors containing scaned MPEG-TS
first_entryfirst entry of a DVB file struct
entrycurrent entry on a DVB file struct

When the NIT table is parsed, some new transponders could be described inside. This function adds new entries to a dvb_file struct, pointing to those new transponders. It is used inside the scan loop, as shown at the dvb_scan_transponder(), to add new channels.

Example:

for (entry = dvb_file->first_entry; entry != NULL; entry = entry->next) {
struct dvb_v5_descriptors *dvb_scan_handler = NULL;
dvb_scan_handler = dvb_scan_transponder(parms, entry, dmx_fd,
&check_frontend, args,
args->other_nit,
args->timeout_multiply);
if (parms->abort) {
dvb_scan_free_handler_table(dvb_scan_handler);
break;
}
if (dvb_scan_handler) {
dvb_store_channel(&dvb_file_new, parms, dvb_scan_handler,
args->get_detected, args->get_nit);
dvb_scan_free_handler_table(dvb_scan_handler);
dvb_add_scaned_transponders(parms, dvb_scan_handler,
dvb_scan_free_handler_table(dvb_scan_handler);
}
}
int dvb_store_channel(struct dvb_file **dvb_file, struct dvb_v5_fe_parms *parms, struct dvb_v5_descriptors *dvb_desc, int get_detected, int get_nit)
stored a new scanned channel into a dvb_file struct
struct dvb_v5_descriptors * dvb_scan_transponder(struct dvb_v5_fe_parms *parms, struct dvb_entry *entry, int dmx_fd, check_frontend_t *check_frontend, void *args, unsigned other_nit, unsigned timeout_multiply)
Scans a DVB dvb_add_scaned_transponder.
void dvb_add_scaned_transponders(struct dvb_v5_fe_parms *parms, struct dvb_v5_descriptors *dvb_scan_handler, struct dvb_entry *first_entry, struct dvb_entry *entry)
Add new transponders to a dvb_file.
void dvb_scan_free_handler_table(struct dvb_v5_descriptors *dvb_scan_handler)
frees a struct dvb_v5_descriptors
struct dvb_entry * next
Definition: dvb-file.h:107
Describes an entire DVB file opened.
Definition: dvb-file.h:135
struct dvb_entry * first_entry
Definition: dvb-file.h:138
Contains the descriptors needed to scan the Service ID and other relevant info at a MPEG-TS Digital T...
Definition: dvb-scan.h:87
struct dvb_entry * entry
Definition: dvb-scan.h:90
Examples
dvbv5-scan.c.

◆ dvb_dev_scan()

struct dvb_v5_descriptors * dvb_dev_scan ( struct dvb_open_descriptor open_dev,
struct dvb_entry entry,
check_frontend_t check_frontend,
void *  args,
unsigned  other_nit,
unsigned  timeout_multiply 
)

Scans a DVB dvb_add_scaned_transponder.

Parameters
entryDVB file entry that corresponds to a transponder to be tuned
open_devPoints to the struct dvb_open_descriptor
check_frontenda pointer to a function that will show the frontend status while tuning into a transponder
argsa pointer, opaque to libdvbv5, that will be used when calling check_frontend. It should contain any parameters that could be needed by check_frontend.
other_nitUse alternate table IDs for NIT and other tables
timeout_multiplyImproves the timeout for each table reception, by

This is the function that applications should use when doing a transponders scan. It does everything needed to fill the entries with DVB programs (virtual channels) and detect the PIDs associated with them.

This is the dvb_device variant of dvb_scan_transponder().

Examples
dvbv5-scan.c.

◆ dvb_free_ts_tables()

void dvb_free_ts_tables ( struct dvb_v5_descriptors dvb_desc)

frees a struct dvb_v5_descriptors

Parameters
dvb_descpointed to the structure to be freed.

This function recursively frees everything that is allocated by dvb_get_ts_tables() and stored at dvb_desc, including dvb_desc itself.

◆ dvb_get_ts_tables()

struct dvb_v5_descriptors * dvb_get_ts_tables ( struct dvb_v5_fe_parms parms,
int  dmx_fd,
uint32_t  delivery_system,
unsigned  other_nit,
unsigned  timeout_multiply 
)

Scans a DVB stream, looking for the tables needed to identify the programs inside a MPEG-TS.

Parameters
parmspointer to struct dvb_v5_fe_parms created when the frontend is opened
dmx_fdan opened demux file descriptor
delivery_systemdelivery system to be scanned
other_nituse alternate table IDs for NIT and other tables
timeout_multiplyimproves the timeout for each table reception by using a value that will multiply the wait time.

Given an opened frontend and demux, this function seeks for all programs available at the transport stream, and parses the following tables: PAT, PMT, NIT, SDT (and VCT, if the delivery system is ATSC).

On sucess, it returns a pointer to a struct dvb_v5_descriptors, that can either be used to tune into a service or to be stored inside a file.

◆ dvb_read_section()

int dvb_read_section ( struct dvb_v5_fe_parms parms,
int  dmx_fd,
unsigned char  tid,
uint16_t  pid,
void **  table,
unsigned  timeout 
)

read MPEG-TS tables that comes from a DTV card

Parameters
parmspointer to struct dvb_v5_fe_parms created when the frontend is opened
dmx_fdan opened demux file descriptor
tidTable ID
pidProgram ID
tablepointer to a pointer for the table struct to be filled
timeoutLimit, in seconds, to read a MPEG-TS table

This function is used to read the DVB tables by specifying a table ID and a program ID. The libdvbv5 should have a parser for the descriptors of the table type that should be parsed. The table will be automatically allocated on success. The function will read on the specified demux and return when reading is done or an error has occurred. If table is not NULL after the call, it has to be freed with the apropriate free table function (even if an error has occurred).

If the application wants to abort the read operation, it can change the value of parms->p.abort to 1.

Returns 0 on success or a negative error code.

Example usage:

struct dvb_table_pat *pat;
(void **) &pat, 5 );
if (r < 0)
dvb_logerr("error reading PAT table");
else {
// do something with pat
}
if (pat)
#define DVB_TABLE_PAT_PID
PAT Program ID.
Definition: pat.h:56
#define DVB_TABLE_PAT
PAT table ID.
Definition: pat.h:55
void dvb_table_pat_free(struct dvb_table_pat *table)
Frees all data allocated by the PAT table parser.
int dvb_read_section(struct dvb_v5_fe_parms *parms, int dmx_fd, unsigned char tid, uint16_t pid, void **table, unsigned timeout)
read MPEG-TS tables that comes from a DTV card
MPEG-TS PAT table.
Definition: pat.h:108

◆ dvb_read_section_with_id()

int dvb_read_section_with_id ( struct dvb_v5_fe_parms parms,
int  dmx_fd,
unsigned char  tid,
uint16_t  pid,
int  ts_id,
void **  table,
unsigned  timeout 
)

read MPEG-TS tables that comes from a DTV card with an specific table section ID

Parameters
parmspointer to struct dvb_v5_fe_parms created when the frontend is opened
dmx_fdan opened demux file descriptor
tidTable ID
pidProgram ID
ts_idTable section ID (for multisession filtering). If no specific table section is needed, -1 should be used
tablepointer to a pointer for the table struct to be filled
timeoutlimit, in seconds, to read a MPEG-TS table

This is a variant of dvb_read_section() that also seeks for an specific table section ID given by ts_id.

◆ dvb_read_sections()

int dvb_read_sections ( struct dvb_v5_fe_parms parms,
int  dmx_fd,
struct dvb_table_filter sect,
unsigned  timeout 
)

read MPEG-TS tables that comes from a DTV card

Parameters
parmspointer to struct dvb_v5_fe_parms created when the frontend is opened
dmx_fdan opened demux file descriptor
sectsection filter pointer
timeoutlimit, in seconds, to read a MPEG-TS table

This is a variant of dvb_read_section() that uses a struct dvb_table_filter to specify the filter to use.

◆ dvb_scan_alloc_handler_table()

struct dvb_v5_descriptors * dvb_scan_alloc_handler_table ( uint32_t  delivery_system)

allocates a struct dvb_v5_descriptors

Parameters
delivery_systemDelivery system to be used on the table

At success, returns a pointer. NULL otherwise.

◆ dvb_scan_free_handler_table()

void dvb_scan_free_handler_table ( struct dvb_v5_descriptors dvb_scan_handler)

frees a struct dvb_v5_descriptors

Parameters
dvb_scan_handlerpointer to the struct to be freed.
Examples
dvbv5-scan.c.

◆ dvb_scan_transponder()

struct dvb_v5_descriptors * dvb_scan_transponder ( struct dvb_v5_fe_parms parms,
struct dvb_entry entry,
int  dmx_fd,
check_frontend_t check_frontend,
void *  args,
unsigned  other_nit,
unsigned  timeout_multiply 
)

Scans a DVB dvb_add_scaned_transponder.

Parameters
parmspointer to struct dvb_v5_fe_parms created when the frontend is opened
entryDVB file entry that corresponds to a transponder to be tuned
dmx_fdan opened demux file descriptor
check_frontenda pointer to a function that will show the frontend status while tuning into a transponder
argsa pointer, opaque to libdvbv5, that will be used when calling check_frontend. It should contain any parameters that could be needed by check_frontend.
other_nitUse alternate table IDs for NIT and other tables
timeout_multiplyImproves the timeout for each table reception, by

This is the function that applications should use when doing a transponders scan. It does everything needed to fill the entries with DVB programs (virtual channels) and detect the PIDs associated with them.

A typical usage is to after open a channel file, open a dmx_fd and open a frontend. Then, seek for the MPEG tables on all the transponder frequencies with:

for (entry = dvb_file->first_entry; entry != NULL; entry = entry->next) {
struct dvb_v5_descriptors *dvb_scan_handler = NULL;
dvb_scan_handler = dvb_scan_transponder(parms, entry, dmx_fd,
&check_frontend, args,
args->other_nit,
args->timeout_multiply);
if (parms->abort) {
dvb_scan_free_handler_table(dvb_scan_handler);
break;
}
if (dvb_scan_handler) {
dvb_store_channel(&dvb_file_new, parms, dvb_scan_handler,
args->get_detected, args->get_nit);
dvb_scan_free_handler_table(dvb_scan_handler);
}
}

◆ dvb_table_filter_free()

void dvb_table_filter_free ( struct dvb_table_filter sect)

deallocates all data associated with a table filter

Parameters
secttable filter pointer