Commit c2f78f0c authored by Daniel W. S. Almeida's avatar Daniel W. S. Almeida Committed by Mauro Carvalho Chehab

media: vidtv: psi: add a Network Information Table (NIT)

Add a Network Information Table (NIT) as specified in ETSI EN 300 468.

This table conveys information relating to the physical organization of
the multiplexes carried via a given network and the characteristics of
the network itself.

It is conveyed in the output of vidtv as packets with TS PID of 0x0010

[mchehab+huawei@kernel.org: removed an extra blank line]
Signed-off-by: default avatarDaniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
parent dd6dbe8d
......@@ -149,11 +149,11 @@ vidtv_psi.[ch]
Because the generator is implemented in a separate file, it can be
reused elsewhere in the media subsystem.
Currently vidtv supports working with 3 PSI tables: PAT, PMT and
SDT.
Currently vidtv supports working with 4 PSI tables: PAT, PMT,
SDT and NIT.
The specification for PAT and PMT can be found in *ISO 13818-1:
Systems*, while the specification for the SDT can be found in *ETSI
Systems*, while the specification for the SDT, NIT can be found in *ETSI
EN 300 468: Specification for Service Information (SI) in DVB
systems*.
......
......@@ -28,6 +28,8 @@
//#define MUX_BUF_MIN_SZ
#define TUNER_DEFAULT_ADDR 0x68
#define DEMOD_DEFAULT_ADDR 0x60
#define VIDTV_DEFAULT_NETWORK_ID 0x744
#define VIDTV_DEFAULT_NETWORK_NAME "LinuxTV.org"
/* LNBf fake parameters: ranges used by an Universal (extended) European LNBf */
#define LNB_CUT_FREQUENCY 11700000
......@@ -177,6 +179,8 @@ static int vidtv_start_streaming(struct vidtv_dvb *dvb)
mux_args.si_period_usecs = si_period_msec * 1000;
mux_args.pcr_pid = pcr_pid;
mux_args.transport_stream_id = VIDTV_DEFAULT_TS_ID;
mux_args.network_id = VIDTV_DEFAULT_NETWORK_ID,
mux_args.network_name = VIDTV_DEFAULT_NETWORK_NAME,
mux_args.priv = dvb;
dvb->streaming = true;
......
......@@ -246,10 +246,57 @@ vidtv_channel_pmt_match_sections(struct vidtv_channel *channels,
}
}
static struct vidtv_psi_desc_service_list_entry
*vidtv_channel_build_service_list(struct vidtv_psi_table_sdt_service *s)
{
struct vidtv_psi_desc_service_list_entry *curr_e = NULL;
struct vidtv_psi_desc_service_list_entry *head_e = NULL;
struct vidtv_psi_desc_service_list_entry *prev_e = NULL;
struct vidtv_psi_desc *desc = s->descriptor;
struct vidtv_psi_desc_service *s_desc;
while (s) {
while (desc) {
if (s->descriptor->type != SERVICE_DESCRIPTOR)
goto next_desc;
s_desc = (struct vidtv_psi_desc_service *)desc;
curr_e = kzalloc(sizeof(*curr_e), GFP_KERNEL);
curr_e->service_id = s->service_id;
curr_e->service_type = s_desc->service_type;
if (!head_e)
head_e = curr_e;
if (prev_e)
prev_e->next = curr_e;
prev_e = curr_e;
next_desc:
desc = desc->next;
}
s = s->next;
}
return head_e;
}
static void vidtv_channel_destroy_service_list(struct vidtv_psi_desc_service_list_entry *e)
{
struct vidtv_psi_desc_service_list_entry *tmp;
while (e) {
tmp = e;
e = e->next;
kfree(tmp);
}
}
void vidtv_channel_si_init(struct vidtv_mux *m)
{
struct vidtv_psi_table_pat_program *programs = NULL;
struct vidtv_psi_table_sdt_service *services = NULL;
struct vidtv_psi_desc_service_list_entry *service_list = NULL;
m->si.pat = vidtv_psi_pat_table_init(m->transport_stream_id);
......@@ -258,6 +305,15 @@ void vidtv_channel_si_init(struct vidtv_mux *m)
programs = vidtv_channel_pat_prog_cat_into_new(m);
services = vidtv_channel_sdt_serv_cat_into_new(m);
/* look for a service descriptor for every service */
service_list = vidtv_channel_build_service_list(services);
/* use these descriptors to build the NIT */
m->si.nit = vidtv_psi_nit_table_init(m->network_id,
m->transport_stream_id,
m->network_name,
service_list);
/* assemble all programs and assign to PAT */
vidtv_psi_pat_program_assign(m->si.pat, programs);
......@@ -269,6 +325,8 @@ void vidtv_channel_si_init(struct vidtv_mux *m)
vidtv_channel_pmt_match_sections(m->channels,
m->si.pmt_secs,
m->si.pat->programs);
vidtv_channel_destroy_service_list(service_list);
}
void vidtv_channel_si_destroy(struct vidtv_mux *m)
......@@ -283,6 +341,7 @@ void vidtv_channel_si_destroy(struct vidtv_mux *m)
kfree(m->si.pmt_secs);
vidtv_psi_sdt_table_destroy(m->si.sdt);
vidtv_psi_nit_table_destroy(m->si.nit);
}
void vidtv_channels_init(struct vidtv_mux *m)
......
......@@ -74,6 +74,8 @@ static void vidtv_mux_pid_ctx_init(struct vidtv_mux *m)
vidtv_mux_create_pid_ctx_once(m, VIDTV_PAT_PID);
/* push the SDT pid ctx */
vidtv_mux_create_pid_ctx_once(m, VIDTV_SDT_PID);
/* push the NIT pid ctx */
vidtv_mux_create_pid_ctx_once(m, VIDTV_NIT_PID);
/* add a ctx for all PMT sections */
while (p) {
......@@ -117,10 +119,12 @@ static u32 vidtv_mux_push_si(struct vidtv_mux *m)
struct vidtv_mux_pid_ctx *pat_ctx;
struct vidtv_mux_pid_ctx *pmt_ctx;
struct vidtv_mux_pid_ctx *sdt_ctx;
struct vidtv_mux_pid_ctx *nit_ctx;
struct vidtv_psi_pat_write_args pat_args = {};
struct vidtv_psi_pmt_write_args pmt_args = {};
struct vidtv_psi_sdt_write_args sdt_args = {};
struct vidtv_psi_nit_write_args nit_args = {};
u32 nbytes; /* the number of bytes written by this function */
u16 pmt_pid;
......@@ -128,6 +132,7 @@ static u32 vidtv_mux_push_si(struct vidtv_mux *m)
pat_ctx = vidtv_mux_get_pid_ctx(m, VIDTV_PAT_PID);
sdt_ctx = vidtv_mux_get_pid_ctx(m, VIDTV_SDT_PID);
nit_ctx = vidtv_mux_get_pid_ctx(m, VIDTV_NIT_PID);
pat_args.buf = m->mux_buf;
pat_args.offset = m->mux_buf_offset;
......@@ -169,6 +174,14 @@ static u32 vidtv_mux_push_si(struct vidtv_mux *m)
m->mux_buf_offset += vidtv_psi_sdt_write_into(sdt_args);
nit_args.buf = m->mux_buf;
nit_args.offset = m->mux_buf_offset;
nit_args.nit = m->si.nit;
nit_args.buf_sz = m->mux_buf_sz;
nit_args.continuity_counter = &nit_ctx->cc;
m->mux_buf_offset += vidtv_psi_nit_write_into(nit_args);
nbytes = m->mux_buf_offset - initial_offset;
m->num_streamed_si++;
......@@ -446,6 +459,8 @@ struct vidtv_mux *vidtv_mux_init(struct dvb_frontend *fe,
m->pcr_pid = args.pcr_pid;
m->transport_stream_id = args.transport_stream_id;
m->priv = args.priv;
m->network_id = args.network_id;
m->network_name = kstrdup(args.network_name, GFP_KERNEL);
m->timing.current_jiffies = get_jiffies_64();
if (args.channels)
......@@ -469,6 +484,7 @@ void vidtv_mux_destroy(struct vidtv_mux *m)
vidtv_mux_pid_ctx_destroy(m);
vidtv_channel_si_destroy(m);
vidtv_channels_destroy(m);
kfree(m->network_name);
vfree(m->mux_buf);
kfree(m);
}
......@@ -64,6 +64,7 @@ struct vidtv_mux_si {
struct vidtv_psi_table_pat *pat;
struct vidtv_psi_table_pmt **pmt_secs; /* the PMT sections */
struct vidtv_psi_table_sdt *sdt;
struct vidtv_psi_table_nit *nit;
};
/**
......@@ -99,6 +100,8 @@ struct vidtv_mux_pid_ctx {
* @pcr_pid: The TS PID used for the PSI packets. All channels will share the
* same PCR.
* @transport_stream_id: The transport stream ID
* @network_id: The network ID
* @network_name: The network name
* @priv: Private data.
*/
struct vidtv_mux {
......@@ -128,6 +131,8 @@ struct vidtv_mux {
u16 pcr_pid;
u16 transport_stream_id;
u16 network_id;
char *network_name;
void *priv;
};
......@@ -142,6 +147,8 @@ struct vidtv_mux {
* same PCR.
* @transport_stream_id: The transport stream ID
* @channels: an optional list of channels to use
* @network_id: The network ID
* @network_name: The network name
* @priv: Private data.
*/
struct vidtv_mux_init_args {
......@@ -153,6 +160,8 @@ struct vidtv_mux_init_args {
u16 pcr_pid;
u16 transport_stream_id;
struct vidtv_channel *channels;
u16 network_id;
char *network_name;
void *priv;
};
......
......@@ -6,10 +6,6 @@
* technically be broken into one or more sections, we do not do this here,
* hence 'table' and 'section' are interchangeable for vidtv.
*
* This code currently supports three tables: PAT, PMT and SDT. These are the
* bare minimum to get userspace to recognize our MPEG transport stream. It can
* be extended to support more PSI tables in the future.
*
* Copyright (C) 2020 Daniel W. S. Almeida
*/
......@@ -27,12 +23,16 @@
#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 MAX_SECTION_LEN 1021
#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 */
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 */
};
......@@ -90,6 +90,34 @@ struct vidtv_psi_desc_registration {
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_table_header - A header that is present for all PSI tables.
*/
......@@ -290,6 +318,13 @@ struct vidtv_psi_desc_registration
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,
......@@ -574,4 +609,79 @@ struct vidtv_psi_table_pmt *vidtv_psi_find_pmt_sec(struct vidtv_psi_table_pmt **
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);
#endif // VIDTV_PSI_H
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment