/* SPDX-License-Identifier: GPL-2.0 */
/*
* This file contains the logic to work with MPEG Program-Specific Information.
* These are defined both in ISO/IEC 13818-1 (systems) and ETSI EN 300 468.
* PSI is carried in the form of table structures, and although each table might
* technically be broken into one or more sections, we do not do this here,
* hence 'table' and 'section' are interchangeable for vidtv.
*
* Copyright (C) 2020 Daniel W. S. Almeida
*/
#ifndef VIDTV_PSI_H
#define VIDTV_PSI_H
#include <linux/types.h>
/*
* all section lengths start immediately after the 'section_length' field
* see ISO/IEC 13818-1 : 2000 and ETSI EN 300 468 V 1.10.1 for
* reference
*/
#define PAT_LEN_UNTIL_LAST_SECTION_NUMBER 5
#define PMT_LEN_UNTIL_PROGRAM_INFO_LENGTH 9
#define SDT_LEN_UNTIL_RESERVED_FOR_FUTURE_USE 8
#define NIT_LEN_UNTIL_NETWORK_DESCRIPTOR_LEN 7
#define EIT_LEN_UNTIL_LAST_TABLE_ID 11
#define MAX_SECTION_LEN 1021
#define EIT_MAX_SECTION_LEN 4093 /* see ETSI 300 468 v.1.10.1 p. 26 */
#define VIDTV_PAT_PID 0 /* mandated by the specs */
#define VIDTV_SDT_PID 0x0011 /* mandated by the specs */
#define VIDTV_NIT_PID 0x0010 /* mandated by the specs */
#define VIDTV_EIT_PID 0x0012 /*mandated by the specs */
enum vidtv_psi_descriptors {
REGISTRATION_DESCRIPTOR = 0x05, /* See ISO/IEC 13818-1 section 2.6.8 */
NETWORK_NAME_DESCRIPTOR = 0x40, /* See ETSI EN 300 468 section 6.2.27 */
SERVICE_LIST_DESCRIPTOR = 0x41, /* See ETSI EN 300 468 section 6.2.35 */
SERVICE_DESCRIPTOR = 0x48, /* See ETSI EN 300 468 section 6.2.33 */
SHORT_EVENT_DESCRIPTOR = 0x4d, /* See ETSI EN 300 468 section 6.2.37 */
};
enum vidtv_psi_stream_types {
STREAM_PRIVATE_DATA = 0x06, /* see ISO/IEC 13818-1 2000 p. 48 */
};
/*
* struct vidtv_psi_desc - A generic PSI descriptor type.
* The descriptor length is an 8-bit field specifying the total number of bytes of the data portion
* of the descriptor following the byte defining the value of this field.
*/
struct vidtv_psi_desc {
struct vidtv_psi_desc *next;
u8 type;
u8 length;
u8 data[];
} __packed;
/*
* struct vidtv_psi_desc_service - Service descriptor.
* See ETSI EN 300 468 section 6.2.33.
*/
struct vidtv_psi_desc_service {
struct vidtv_psi_desc *next;
u8 type;
u8 length;
u8 service_type;
u8 provider_name_len;
char *provider_name;
u8 service_name_len;
char *service_name;
} __packed;
/*
* struct vidtv_psi_desc_registration - A registration descriptor.
* See ISO/IEC 13818-1 section 2.6.8
*/
struct vidtv_psi_desc_registration {
struct vidtv_psi_desc *next;
u8 type;
u8 length;
/*
* The format_identifier is a 32-bit value obtained from a Registration
* Authority as designated by ISO/IEC JTC 1/SC 29.
*/
__be32 format_id;
/*
* The meaning of additional_identification_info bytes, if any, are
* defined by the assignee of that format_identifier, and once defined
* they shall not change.
*/
u8 additional_identification_info[];
} __packed;
/*
* struct vidtv_psi_desc_network_name - A network name descriptor
* see ETSI EN 300 468 v1.15.1 section 6.2.27
*/
struct vidtv_psi_desc_network_name {
struct vidtv_psi_desc *next;
u8 type;
u8 length;
char *network_name;
} __packed;
struct vidtv_psi_desc_service_list_entry {
__be16 service_id;
u8 service_type;
struct vidtv_psi_desc_service_list_entry *next;
} __packed;
/*
* struct vidtv_psi_desc_service_list - A service list descriptor
* see ETSI EN 300 468 v1.15.1 section 6.2.35
*/
struct vidtv_psi_desc_service_list {
struct vidtv_psi_desc *next;
u8 type;
u8 length;
struct vidtv_psi_desc_service_list_entry *service_list;
} __packed;
/*
* struct vidtv_psi_desc_short_event - A short event descriptor
* see ETSI EN 300 468 v1.15.1 section 6.2.37
*/
struct vidtv_psi_desc_short_event {
struct vidtv_psi_desc *next;
u8 type;
u8 length;
char *iso_language_code;
u8 event_name_len;
char *event_name;
u8 text_len;
char *text;
} __packed;
struct vidtv_psi_desc_short_event
*vidtv_psi_short_event_desc_init(struct vidtv_psi_desc *head,
char *iso_language_code,
char *event_name,
char *text);
/*
* struct vidtv_psi_table_header - A header that is present for all PSI tables.
*/
struct vidtv_psi_table_header {
u8 table_id;
__be16 bitfield; /* syntax: 1, zero: 1, one: 2, section_length: 13 */
__be16 id; /* TS ID */
u8 current_next:1;
u8 version:5;
u8 one2:2;
u8 section_id; /* section_number */
u8 last_section; /* last_section_number */
} __packed;
/*
* struct vidtv_psi_table_pat_program - A single program in the PAT
* See ISO/IEC 13818-1 : 2000 p.43
*/
struct vidtv_psi_table_pat_program {
__be16 service_id;
__be16 bitfield; /* reserved: 3, program_map_pid/network_pid: 13 */
struct vidtv_psi_table_pat_program *next;
} __packed;
/*
* struct vidtv_psi_table_pat - The Program Allocation Table (PAT)
* See ISO/IEC 13818-1 : 2000 p.43
*/
struct vidtv_psi_table_pat {
struct vidtv_psi_table_header header;
u16 num_pat;
u16 num_pmt;
struct vidtv_psi_table_pat_program *program;
} __packed;
/*
* struct vidtv_psi_table_sdt_service - Represents a service in the SDT.
* see ETSI EN 300 468 v1.15.1 section 5.2.3.
*/
struct vidtv_psi_table_sdt_service {
__be16 service_id;
u8 EIT_present_following:1;
u8 EIT_schedule:1;
u8 reserved:6;
__be16 bitfield; /* running_status: 3, free_ca:1, desc_loop_len:12 */
struct vidtv_psi_desc *descriptor;
struct vidtv_psi_table_sdt_service *next;
} __packed;
/*
* struct vidtv_psi_table_sdt - Represents the Service Description Table
* see ETSI EN 300 468 v1.15.1 section 5.2.3.
*/
struct vidtv_psi_table_sdt {
struct vidtv_psi_table_header header;
__be16 network_id; /* original_network_id */
u8 reserved;
struct vidtv_psi_table_sdt_service *service;
} __packed;
/*
* enum service_running_status - Status of a SDT service.
* see ETSI EN 300 468 v1.15.1 section 5.2.3 table 6.
*/
enum service_running_status {
RUNNING = 0x4,
};
/*
* enum service_type - The type of a SDT service.
* see ETSI EN 300 468 v1.15.1 section 6.2.33, table 81.
*/
enum service_type {
/* see ETSI EN 300 468 v1.15.1 p. 77 */
DIGITAL_TELEVISION_SERVICE = 0x1,
DIGITAL_RADIO_SOUND_SERVICE = 0X2,
};
/*
* struct vidtv_psi_table_pmt_stream - A single stream in the PMT.
* See ISO/IEC 13818-1 : 2000 p.46.
*/
struct vidtv_psi_table_pmt_stream {
u8 type;
__be16 bitfield; /* reserved: 3, elementary_pid: 13 */
__be16 bitfield2; /*reserved: 4, zero: 2, desc_length: 10 */
struct vidtv_psi_desc *descriptor;
struct vidtv_psi_table_pmt_stream *next;
} __packed;
/*
* struct vidtv_psi_table_pmt - The Program Map Table (PMT).
* See ISO/IEC 13818-1 : 2000 p.46.
*/
struct vidtv_psi_table_pmt {
struct vidtv_psi_table_header header;
__be16 bitfield; /* reserved:3, pcr_pid: 13 */
__be16 bitfield2; /* reserved: 4, zero: 2, desc_len: 10 */
struct vidtv_psi_desc *descriptor;
struct vidtv_psi_table_pmt_stream *stream;
} __packed;
/**
* struct psi_write_args - Arguments for the PSI packetizer.
* @dest_buf: The buffer to write into.
* @from: PSI data to be copied.
* @len: How much to write.
* @dest_offset: where to start writing in the dest_buffer.
* @pid: TS packet ID.
* @new_psi_section: Set when starting a table section.
* @continuity_counter: Incremented on every new packet.
* @is_crc: Set when writing the CRC at the end.
* @dest_buf_sz: The size of the dest_buffer
* @crc: a pointer to store the crc for this chunk
*/
struct psi_write_args {
void *dest_buf;
void *from;
size_t len;
u32 dest_offset;
u16 pid;
bool new_psi_section;
u8 *continuity_counter;
bool is_crc;
u32 dest_buf_sz;
u32 *crc;
};
/**
* struct desc_write_args - Arguments in order to write a descriptor.
* @dest_buf: The buffer to write into.
* @dest_offset: where to start writing in the dest_buffer.
* @desc: A pointer to the descriptor
* @pid: TS packet ID.
* @continuity_counter: Incremented on every new packet.
* @dest_buf_sz: The size of the dest_buffer
* @crc: a pointer to store the crc for this chunk
*/
struct desc_write_args {
void *dest_buf;
u32 dest_offset;
struct vidtv_psi_desc *desc;
u16 pid;
u8 *continuity_counter;
u32 dest_buf_sz;
u32 *crc;
};
/**
* struct crc32_write_args - Arguments in order to write the CRC at the end of
* the PSI tables.
* @dest_buf: The buffer to write into.
* @dest_offset: where to start writing in the dest_buffer.
* @crc: the CRC value to write
* @pid: TS packet ID.
* @continuity_counter: Incremented on every new packet.
* @dest_buf_sz: The size of the dest_buffer
*/
struct crc32_write_args {
void *dest_buf;
u32 dest_offset;
__be32 crc;
u16 pid;
u8 *continuity_counter;
u32 dest_buf_sz;
};
/**
* struct header_write_args - Arguments in order to write the common table
* header
* @dest_buf: The buffer to write into.
* @dest_offset: where to start writing in the dest_buffer.
* @h: a pointer to the header.
* @pid: TS packet ID.
* @continuity_counter: Incremented on every new packet.
* @dest_buf_sz: The size of the dest_buffer
* @crc: a pointer to store the crc for this chunk
*/
struct header_write_args {
void *dest_buf;
u32 dest_offset;
struct vidtv_psi_table_header *h;
u16 pid;
u8 *continuity_counter;
u32 dest_buf_sz;
u32 *crc;
};
struct vidtv_psi_desc_service *vidtv_psi_service_desc_init(struct vidtv_psi_desc *head,
enum service_type service_type,
char *service_name,
char *provider_name);
struct vidtv_psi_desc_registration
*vidtv_psi_registration_desc_init(struct vidtv_psi_desc *head,
__be32 format_id,
u8 *additional_ident_info,
u32 additional_info_len);
struct vidtv_psi_desc_network_name
*vidtv_psi_network_name_desc_init(struct vidtv_psi_desc *head, char *network_name);
struct vidtv_psi_desc_service_list
*vidtv_psi_service_list_desc_init(struct vidtv_psi_desc *head,
struct vidtv_psi_desc_service_list_entry *entry);
struct vidtv_psi_table_pat_program
*vidtv_psi_pat_program_init(struct vidtv_psi_table_pat_program *head,
u16 service_id,
u16 program_map_pid);
struct vidtv_psi_table_pmt_stream*
vidtv_psi_pmt_stream_init(struct vidtv_psi_table_pmt_stream *head,
enum vidtv_psi_stream_types stream_type,
u16 es_pid);
struct vidtv_psi_table_pat *vidtv_psi_pat_table_init(u16 transport_stream_id);
struct vidtv_psi_table_pmt *vidtv_psi_pmt_table_init(u16 program_number,
u16 pcr_pid);
struct vidtv_psi_table_sdt *vidtv_psi_sdt_table_init(u16 network_id,
u16 transport_stream_id);
struct vidtv_psi_table_sdt_service*
vidtv_psi_sdt_service_init(struct vidtv_psi_table_sdt_service *head,
u16 service_id,
bool eit_schedule,
bool eit_present_following);
void
vidtv_psi_desc_destroy(struct vidtv_psi_desc *desc);
void
vidtv_psi_pat_program_destroy(struct vidtv_psi_table_pat_program *p);
void
vidtv_psi_pat_table_destroy(struct vidtv_psi_table_pat *p);
void
vidtv_psi_pmt_stream_destroy(struct vidtv_psi_table_pmt_stream *s);
void
vidtv_psi_pmt_table_destroy(struct vidtv_psi_table_pmt *pmt);
void
vidtv_psi_sdt_table_destroy(struct vidtv_psi_table_sdt *sdt);
void
vidtv_psi_sdt_service_destroy(struct vidtv_psi_table_sdt_service *service);
/**
* vidtv_psi_sdt_service_assign - Assigns the service loop to the SDT.
* @sdt: The SDT to assign to.
* @service: The service loop (one or more services)
*
* This will free the previous service loop in the table.
* This will assign ownership of the service loop to the table, i.e. the table
* will free this service loop when a call to its destroy function is made.
*/
void
vidtv_psi_sdt_service_assign(struct vidtv_psi_table_sdt *sdt,
struct vidtv_psi_table_sdt_service *service);
/**
* vidtv_psi_desc_assign - Assigns a descriptor loop at some point
* @to: Where to assign this descriptor loop to
* @desc: The descriptor loop that will be assigned.
*
* This will free the loop in 'to', if any.
*/
void vidtv_psi_desc_assign(struct vidtv_psi_desc **to,
struct vidtv_psi_desc *desc);
/**
* vidtv_pmt_desc_assign - Assigns a descriptor loop at some point in a PMT section.
* @pmt: The PMT section that will contain the descriptor loop
* @to: Where in the PMT to assign this descriptor loop to
* @desc: The descriptor loop that will be assigned.
*
* This will free the loop in 'to', if any.
* This will assign ownership of the loop to the table, i.e. the table
* will free this loop when a call to its destroy function is made.
*/
void vidtv_pmt_desc_assign(struct vidtv_psi_table_pmt *pmt,
struct vidtv_psi_desc **to,
struct vidtv_psi_desc *desc);
/**
* vidtv_sdt_desc_assign - Assigns a descriptor loop at some point in a SDT.
* @sdt: The SDT that will contain the descriptor loop
* @to: Where in the PMT to assign this descriptor loop to
* @desc: The descriptor loop that will be assigned.
*
* This will free the loop in 'to', if any.
* This will assign ownership of the loop to the table, i.e. the table
* will free this loop when a call to its destroy function is made.
*/
void vidtv_sdt_desc_assign(struct vidtv_psi_table_sdt *sdt,
struct vidtv_psi_desc **to,
struct vidtv_psi_desc *desc);
/**
* vidtv_psi_pat_program_assign - Assigns the program loop to the PAT.
* @pat: The PAT to assign to.
* @p: The program loop (one or more programs)
*
* This will free the previous program loop in the table.
* This will assign ownership of the program loop to the table, i.e. the table
* will free this program loop when a call to its destroy function is made.
*/
void vidtv_psi_pat_program_assign(struct vidtv_psi_table_pat *pat,
struct vidtv_psi_table_pat_program *p);
/**
* vidtv_psi_pmt_stream_assign - Assigns the stream loop to the PAT.
* @pmt: The PMT to assign to.
* @s: The stream loop (one or more streams)
*
* This will free the previous stream loop in the table.
* This will assign ownership of the stream loop to the table, i.e. the table
* will free this stream loop when a call to its destroy function is made.
*/
void vidtv_psi_pmt_stream_assign(struct vidtv_psi_table_pmt *pmt,
struct vidtv_psi_table_pmt_stream *s);
struct vidtv_psi_desc *vidtv_psi_desc_clone(struct vidtv_psi_desc *desc);
/**
* vidtv_psi_pmt_create_sec_for_each_pat_entry - Create a PMT section for each
* program found in the PAT
* @pat: The PAT to look for programs.
* @pcr_pid: packet ID for the PCR to be used for the program described in this
* PMT section
*/
struct vidtv_psi_table_pmt**
vidtv_psi_pmt_create_sec_for_each_pat_entry(struct vidtv_psi_table_pat *pat, u16 pcr_pid);
/**
* vidtv_psi_pmt_get_pid - Get the TS PID for a PMT section.
* @section: The PMT section whose PID we want to retrieve.
* @pat: The PAT table to look into.
*
* Returns: the TS PID for 'section'
*/
u16 vidtv_psi_pmt_get_pid(struct vidtv_psi_table_pmt *section,
struct vidtv_psi_table_pat *pat);
/**
* vidtv_psi_pat_table_update_sec_len - Recompute and update the PAT section length.
* @pat: The PAT whose length is to be updated.
*
* This will traverse the table and accumulate the length of its components,
* which is then used to replace the 'section_length' field.
*
* If section_length > MAX_SECTION_LEN, the operation fails.
*/
void vidtv_psi_pat_table_update_sec_len(struct vidtv_psi_table_pat *pat);
/**
* vidtv_psi_pmt_table_update_sec_len - Recompute and update the PMT section length.
* @pmt: The PMT whose length is to be updated.
*
* This will traverse the table and accumulate the length of its components,
* which is then used to replace the 'section_length' field.
*
* If section_length > MAX_SECTION_LEN, the operation fails.
*/
void vidtv_psi_pmt_table_update_sec_len(struct vidtv_psi_table_pmt *pmt);
/**
* vidtv_psi_sdt_table_update_sec_len - Recompute and update the SDT section length.
* @sdt: The SDT whose length is to be updated.
*
* This will traverse the table and accumulate the length of its components,
* which is then used to replace the 'section_length' field.
*
* If section_length > MAX_SECTION_LEN, the operation fails.
*/
void vidtv_psi_sdt_table_update_sec_len(struct vidtv_psi_table_sdt *sdt);
/**
* struct vidtv_psi_pat_write_args - Arguments for writing a PAT table
* @buf: The destination buffer.
* @offset: The offset into the destination buffer.
* @pat: A pointer to the PAT.
* @buf_sz: The size of the destination buffer.
* @continuity_counter: A pointer to the CC. Incremented on every new packet.
*
*/
struct vidtv_psi_pat_write_args {
char *buf;
u32 offset;
struct vidtv_psi_table_pat *pat;
u32 buf_sz;
u8 *continuity_counter;
};
/**
* vidtv_psi_pat_write_into - Write PAT as MPEG-TS packets into a buffer.
* @args: An instance of struct vidtv_psi_pat_write_args
*
* This function writes the MPEG TS packets for a PAT table into a buffer.
* Calling code will usually generate the PAT via a call to its init function
* and thus is responsible for freeing it.
*
* Return: The number of bytes written into the buffer. This is NOT
* equal to the size of the PAT, since more space is needed for TS headers during TS
* encapsulation.
*/
u32 vidtv_psi_pat_write_into(struct vidtv_psi_pat_write_args *args);
/**
* struct vidtv_psi_sdt_write_args - Arguments for writing a SDT table
* @buf: The destination buffer.
* @offset: The offset into the destination buffer.
* @sdt: A pointer to the SDT.
* @buf_sz: The size of the destination buffer.
* @continuity_counter: A pointer to the CC. Incremented on every new packet.
*
*/
struct vidtv_psi_sdt_write_args {
char *buf;
u32 offset;
struct vidtv_psi_table_sdt *sdt;
u32 buf_sz;
u8 *continuity_counter;
};
/**
* vidtv_psi_sdt_write_into - Write SDT as MPEG-TS packets into a buffer.
* @args: an instance of struct vidtv_psi_sdt_write_args
*
* This function writes the MPEG TS packets for a SDT table into a buffer.
* Calling code will usually generate the SDT via a call to its init function
* and thus is responsible for freeing it.
*
* Return: The number of bytes written into the buffer. This is NOT
* equal to the size of the SDT, since more space is needed for TS headers during TS
* encapsulation.
*/
u32 vidtv_psi_sdt_write_into(struct vidtv_psi_sdt_write_args *args);
/**
* struct vidtv_psi_pmt_write_args - Arguments for writing a PMT section
* @buf: The destination buffer.
* @offset: The offset into the destination buffer.
* @pmt: A pointer to the PMT.
* @pid: Program ID
* @buf_sz: The size of the destination buffer.
* @continuity_counter: A pointer to the CC. Incremented on every new packet.
* @pcr_pid: The TS PID used for the PSI packets. All channels will share the
* same PCR.
*/
struct vidtv_psi_pmt_write_args {
char *buf;
u32 offset;
struct vidtv_psi_table_pmt *pmt;
u16 pid;
u32 buf_sz;
u8 *continuity_counter;
u16 pcr_pid;
};
/**
* vidtv_psi_pmt_write_into - Write PMT as MPEG-TS packets into a buffer.
* @args: an instance of struct vidtv_psi_pmt_write_args
*
* This function writes the MPEG TS packets for a PMT section into a buffer.
* Calling code will usually generate the PMT section via a call to its init function
* and thus is responsible for freeing it.
*
* Return: The number of bytes written into the buffer. This is NOT
* equal to the size of the PMT section, since more space is needed for TS headers
* during TS encapsulation.
*/
u32 vidtv_psi_pmt_write_into(struct vidtv_psi_pmt_write_args *args);
/**
* vidtv_psi_find_pmt_sec - Finds the PMT section for 'program_num'
* @pmt_sections: The sections to look into.
* @nsections: The number of sections.
* @program_num: The 'program_num' from PAT pointing to a PMT section.
*
* Return: A pointer to the PMT, if found, or NULL.
*/
struct vidtv_psi_table_pmt *vidtv_psi_find_pmt_sec(struct vidtv_psi_table_pmt **pmt_sections,
u16 nsections,
u16 program_num);
u16 vidtv_psi_get_pat_program_pid(struct vidtv_psi_table_pat_program *p);
u16 vidtv_psi_pmt_stream_get_elem_pid(struct vidtv_psi_table_pmt_stream *s);
/**
* struct vidtv_psi_table_transport - A entry in the TS loop for the NIT and/or other tables.
* See ETSI 300 468 section 5.2.1
* @transport_id: The TS ID being described
* @network_id: The network_id that contains the TS ID
* @bitfield: Contains the descriptor loop length
* @descriptor: A descriptor loop
* @next: Pointer to the next entry
*
*/
struct vidtv_psi_table_transport {
__be16 transport_id;
__be16 network_id;
__be16 bitfield; /* desc_len: 12, reserved: 4 */
struct vidtv_psi_desc *descriptor;
struct vidtv_psi_table_transport *next;
} __packed;
/**
* struct vidtv_psi_table_nit - A Network Information Table (NIT). See ETSI 300
* 468 section 5.2.1
* @header: A PSI table header
* @bitfield: Contains the network descriptor length
* @descriptor: A descriptor loop describing the network
* @bitfield2: Contains the transport stream loop length
* @transport: The transport stream loop
*
*/
struct vidtv_psi_table_nit {
struct vidtv_psi_table_header header;
__be16 bitfield; /* network_desc_len: 12, reserved:4 */
struct vidtv_psi_desc *descriptor;
__be16 bitfield2; /* ts_loop_len: 12, reserved: 4 */
struct vidtv_psi_table_transport *transport;
} __packed;
struct vidtv_psi_table_nit
*vidtv_psi_nit_table_init(u16 network_id,
u16 transport_stream_id,
char *network_name,
struct vidtv_psi_desc_service_list_entry *service_list);
/**
* struct vidtv_psi_nit_write_args - Arguments for writing a NIT section
* @buf: The destination buffer.
* @offset: The offset into the destination buffer.
* @nit: A pointer to the NIT
* @buf_sz: The size of the destination buffer.
* @continuity_counter: A pointer to the CC. Incremented on every new packet.
*
*/
struct vidtv_psi_nit_write_args {
char *buf;
u32 offset;
struct vidtv_psi_table_nit *nit;
u32 buf_sz;
u8 *continuity_counter;
};
/**
* vidtv_psi_nit_write_into - Write NIT as MPEG-TS packets into a buffer.
* @args: an instance of struct vidtv_psi_nit_write_args
*
* This function writes the MPEG TS packets for a NIT table into a buffer.
* Calling code will usually generate the NIT via a call to its init function
* and thus is responsible for freeing it.
*
* Return: The number of bytes written into the buffer. This is NOT
* equal to the size of the NIT, since more space is needed for TS headers during TS
* encapsulation.
*/
u32 vidtv_psi_nit_write_into(struct vidtv_psi_nit_write_args *args);
void vidtv_psi_nit_table_destroy(struct vidtv_psi_table_nit *nit);
/*
* struct vidtv_psi_desc_short_event - A short event descriptor
* see ETSI EN 300 468 v1.15.1 section 6.2.37
*/
struct vidtv_psi_table_eit_event {
__be16 event_id;
u8 start_time[5];
u8 duration[3];
__be16 bitfield; /* desc_length: 12, free_CA_mode: 1, running_status: 1 */
struct vidtv_psi_desc *descriptor;
struct vidtv_psi_table_eit_event *next;
} __packed;
/*
* struct vidtv_psi_table_eit - A Event Information Table (EIT)
* See ETSI 300 468 section 5.2.4
*/
struct vidtv_psi_table_eit {
struct vidtv_psi_table_header header;
__be16 transport_id;
__be16 network_id;
u8 last_segment;
u8 last_table_id;
struct vidtv_psi_table_eit_event *event;
} __packed;
struct vidtv_psi_table_eit
*vidtv_psi_eit_table_init(u16 network_id,
u16 transport_stream_id,
__be16 service_id);
/**
* struct vidtv_psi_eit_write_args - Arguments for writing an EIT section
* @buf: The destination buffer.
* @offset: The offset into the destination buffer.
* @eit: A pointer to the EIT
* @buf_sz: The size of the destination buffer.
* @continuity_counter: A pointer to the CC. Incremented on every new packet.
*
*/
struct vidtv_psi_eit_write_args {
char *buf;
u32 offset;
struct vidtv_psi_table_eit *eit;
u32 buf_sz;
u8 *continuity_counter;
};
/**
* vidtv_psi_eit_write_into - Write EIT as MPEG-TS packets into a buffer.
* @args: an instance of struct vidtv_psi_nit_write_args
*
* This function writes the MPEG TS packets for a EIT table into a buffer.
* Calling code will usually generate the EIT via a call to its init function
* and thus is responsible for freeing it.
*
* Return: The number of bytes written into the buffer. This is NOT
* equal to the size of the EIT, since more space is needed for TS headers during TS
* encapsulation.
*/
u32 vidtv_psi_eit_write_into(struct vidtv_psi_eit_write_args *args);
void vidtv_psi_eit_table_destroy(struct vidtv_psi_table_eit *eit);
/**
* vidtv_psi_eit_table_update_sec_len - Recompute and update the EIT section length.
* @eit: The EIT whose length is to be updated.
*
* This will traverse the table and accumulate the length of its components,
* which is then used to replace the 'section_length' field.
*
* If section_length > EIT_MAX_SECTION_LEN, the operation fails.
*/
void vidtv_psi_eit_table_update_sec_len(struct vidtv_psi_table_eit *eit);
/**
* vidtv_psi_eit_event_assign - Assigns the event loop to the EIT.
* @eit: The EIT to assign to.
* @e: The event loop
*
* This will free the previous event loop in the table.
* This will assign ownership of the stream loop to the table, i.e. the table
* will free this stream loop when a call to its destroy function is made.
*/
void vidtv_psi_eit_event_assign(struct vidtv_psi_table_eit *eit,
struct vidtv_psi_table_eit_event *e);
struct vidtv_psi_table_eit_event
*vidtv_psi_eit_event_init(struct vidtv_psi_table_eit_event *head, u16 event_id);
void vidtv_psi_eit_event_destroy(struct vidtv_psi_table_eit_event *e);
#endif // VIDTV_PSI_H
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