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- /*
- * NIT table parser and generator
- * Copyright (C) 2010-2011 Unix Solutions Ltd.
- *
- * Released under MIT license.
- * See LICENSE-MIT.txt for license terms.
- */
- #include <stdio.h>
- #include <unistd.h>
- #include <netdb.h>
- #include <stdlib.h>
- #include <string.h>
-
- #include "tsfuncs.h"
-
- struct ts_nit *ts_nit_alloc() {
- struct ts_nit *nit = calloc(1, sizeof(struct ts_nit));
- nit->section_header = ts_section_data_alloc();
- nit->streams_max = 128;
- nit->streams = calloc(nit->streams_max, sizeof(struct ts_nit_stream *));
- return nit;
- }
-
- static void ts_nit_streams_data_free(struct ts_nit *nit) {
- int i;
- for (i=0;i<nit->streams_num;i++) {
- if (nit->streams[i]) {
- FREE(nit->streams[i]->descriptor_data);
- FREE(nit->streams[i]);
- }
- }
- }
-
- void ts_nit_clear(struct ts_nit *nit) {
- if (!nit)
- return;
- // save
- struct ts_section_header *section_header = nit->section_header;
- struct ts_nit_stream **streams = nit->streams;
- int streams_max = nit->streams_max;
- // free
- FREE(nit->network_info);
- ts_nit_streams_data_free(nit);
- // clear
- ts_section_data_clear(section_header);
- memset(nit, 0, sizeof(struct ts_nit));
- // restore
- nit->section_header = section_header;
- nit->streams = streams;
- nit->streams_max = streams_max;
- }
-
- void ts_nit_free(struct ts_nit **pnit) {
- struct ts_nit *nit = *pnit;
- if (nit) {
- ts_section_data_free(&nit->section_header);
- FREE(nit->network_info);
- ts_nit_streams_data_free(nit);
- FREE(nit->streams);
- FREE(*pnit);
- }
- }
-
- struct ts_nit *ts_nit_push_packet(struct ts_nit *nit, uint8_t *ts_packet) {
- struct ts_header ts_header;
- memset(&ts_header, 0, sizeof(struct ts_header));
-
- if (ts_packet_header_parse(ts_packet, &ts_header)) {
- // NIT should be with PID 0x10
- if (ts_header.pid != 0x10)
- goto OUT;
- // Received PUSI packet before table END, clear the table to start gathering new one
- if (ts_header.pusi && nit->ts_header.pusi)
- ts_nit_clear(nit);
- if (!nit->ts_header.pusi)
- nit->ts_header = ts_header;
- }
-
- if (ts_header.pusi) {
- struct ts_section_header section_header;
- memset(§ion_header, 0, sizeof(struct ts_section_header));
-
- uint8_t *section_data = ts_section_header_parse(ts_packet, &nit->ts_header, §ion_header);
- if (!section_data)
- goto OUT;
- // table_id should be 0x40 (network_information_section - actual_network)
- if (section_header.table_id != 0x40) {
- memset(&nit->ts_header, 0, sizeof(struct ts_header));
- goto OUT;
- }
-
- // Set correct section_header
- ts_section_header_parse(ts_packet, &nit->ts_header, nit->section_header);
- }
-
- if (!nit->initialized) {
- ts_section_add_packet(nit->section_header, &ts_header, ts_packet);
- if (nit->section_header->initialized) {
- if (!ts_nit_parse(nit))
- goto ERROR;
- }
- }
-
- OUT:
- return nit;
-
- ERROR:
- ts_nit_clear(nit);
- return nit;
- }
-
-
- int ts_nit_parse(struct ts_nit *nit) {
- uint8_t *section_data = nit->section_header->data;
-
- /* Table data (2 bytes) */
- nit->reserved1 = (section_data[0] &~ 0x0F) >> 4; // xxxx1111
- nit->network_info_size = ((section_data[0] &~ 0xF0) << 8) | section_data[1]; // 1111xxxx xxxxxxxx
-
- /* Handle streams */
- uint8_t *stream_data = section_data + 2 + nit->network_info_size; // +2 is to compensate for reserved1 and network_info_size
-
- nit->network_info = NULL;
- if (nit->network_info_size) {
- nit->network_info = malloc(nit->network_info_size);
- if (nit->network_info) {
- memcpy(nit->network_info, stream_data - nit->network_info_size, nit->network_info_size);
- }
- }
-
- // Before the table there are two more fields
- nit->reserved2 = (stream_data[0] &~ 0x0F) >> 4; // xxxx1111
- nit->ts_loop_size = ((stream_data[0] &~ 0xF0) << 8) | stream_data[1]; // 1111xxxx xxxxxxxx
-
- stream_data += 2;
- int stream_len = nit->ts_loop_size;
-
- while (stream_len > 0) {
- if (nit->streams_num == nit->streams_max) {
- ts_LOGf("!!! Too many streams in NIT, max %d\n", nit->streams_max);
- break;
- }
-
- struct ts_nit_stream *sinfo = calloc(1, sizeof(struct ts_nit_stream));
-
- sinfo->transport_stream_id = (stream_data[0] << 8) | stream_data[1];
- sinfo->original_network_id = (stream_data[2] << 8) | stream_data[3];
-
- sinfo->reserved1 = (stream_data[4] &~ 0x0F) >> 4; // xxxx1111
- sinfo->descriptor_size = ((stream_data[4] &~ 0xF0) << 8) | stream_data[5]; // 1111xxxx xxxxxxxx
-
- sinfo->descriptor_data = NULL;
- if (sinfo->descriptor_size > 0) {
- sinfo->descriptor_data = malloc(sinfo->descriptor_size);
- memcpy(sinfo->descriptor_data, &stream_data[6], sinfo->descriptor_size);
- }
- nit->streams[nit->streams_num] = sinfo;
- nit->streams_num++;
-
- stream_data += 6 + sinfo->descriptor_size;
- stream_len -= 6 + sinfo->descriptor_size;
- }
-
- if (!ts_crc32_section_check(nit->section_header, "NIT"))
- return 0;
-
- nit->initialized = 1;
- return 1;
- }
-
- void ts_nit_generate(struct ts_nit *nit, uint8_t **ts_packets, int *num_packets) {
- uint8_t *secdata = ts_section_data_alloc_section();
- ts_section_header_generate(secdata, nit->section_header, 0);
- int curpos = 8; // Compensate for the section header, frist data byte is at offset 8
-
- secdata[curpos + 0] = nit->reserved1 << 4; // xxxx1111
- secdata[curpos + 0] |= nit->network_info_size >> 8; // 1111xxxx xxxxxxxx
- secdata[curpos + 1] = nit->network_info_size &~ 0xff00;
- curpos += 2; // For the fields above
-
- if (nit->network_info_size) {
- memcpy(secdata + curpos, nit->network_info, nit->network_info_size);
- curpos += nit->network_info_size;
- }
-
- // Before the table there are two more fields
- secdata[curpos + 0] = nit->reserved2 << 4; // xxxx1111
- secdata[curpos + 0] |= nit->ts_loop_size >> 8; // 1111xxxx xxxxxxxx
- secdata[curpos + 1] = nit->ts_loop_size &~ 0xff00;
- curpos += 2; // For the fields above
-
- int i;
- for(i=0;i<nit->streams_num;i++) {
- struct ts_nit_stream *stream = nit->streams[i];
-
- secdata[curpos + 0] = stream->transport_stream_id >> 8; // xxxxxxxx xxxxxxxx
- secdata[curpos + 1] = stream->transport_stream_id &~ 0xff00;
-
- secdata[curpos + 2] = stream->original_network_id >> 8; // xxxxxxxx xxxxxxxx
- secdata[curpos + 3] = stream->original_network_id &~ 0xff00;
-
- secdata[curpos + 4] = stream->reserved1 << 4; // xxxx1111
- secdata[curpos + 4] |= stream->descriptor_size >> 8; // 1111xxxx xxxxxxxx
-
- secdata[curpos + 5] = stream->descriptor_size &~ 0xff00;
-
- curpos += 6; // Compensate for the above
-
- if (stream->descriptor_size > 0) {
- memcpy(secdata + curpos, stream->descriptor_data, stream->descriptor_size);
- curpos += stream->descriptor_size;
- }
- }
- nit->section_header->CRC = ts_section_data_calculate_crc(secdata, curpos);
- curpos += 4; // CRC
-
- ts_section_data_gen_ts_packets(&nit->ts_header, secdata, curpos, nit->section_header->pointer_field, ts_packets, num_packets);
-
- FREE(secdata);
- }
-
- struct ts_nit *ts_nit_copy(struct ts_nit *nit) {
- struct ts_nit *newnit = ts_nit_alloc();
- int i;
- for (i=0;i<nit->section_header->num_packets; i++) {
- newnit = ts_nit_push_packet(newnit, nit->section_header->packet_data + (i * TS_PACKET_SIZE));
- }
- if (newnit->initialized) {
- return newnit;
- } else {
- ts_LOGf("Error copying nit!\n");
- ts_nit_free(&newnit);
- return NULL;
- }
- }
-
- void ts_nit_check_generator(struct ts_nit *nit) {
- struct ts_nit *nit1 = ts_nit_alloc();
- int i;
- for (i=0;i<nit->section_header->num_packets;i++) {
- nit1 = ts_nit_push_packet(nit1, nit->section_header->packet_data + (i * TS_PACKET_SIZE));
- }
- ts_compare_data("NIT (tspacket->struct)",
- nit1->section_header->packet_data,
- nit->section_header->packet_data,
- nit->section_header->num_packets * TS_PACKET_SIZE);
- ts_nit_free(&nit1);
-
- uint8_t *ts_packets;
- int num_packets;
- ts_nit_generate(nit, &ts_packets, &num_packets);
- if (num_packets != nit->section_header->num_packets) {
- ts_LOGf("ERROR: num_packets:%d != sec->num_packets:%d\n", num_packets, nit->section_header->num_packets);
- }
- ts_compare_data("NIT (struct->tspacket)", nit->section_header->packet_data, ts_packets, num_packets * TS_PACKET_SIZE);
- free(ts_packets);
- }
-
- void ts_nit_dump(struct ts_nit *nit) {
- struct ts_section_header *sec = nit->section_header;
- int i;
-
- ts_section_dump(sec);
-
- ts_LOGf(" * NIT data\n");
- ts_LOGf(" * PID : 0x%04x (%d)\n", nit->ts_header.pid, nit->ts_header.pid);
- ts_LOGf(" * reserved1 : 0x%02x\n", nit->reserved1);
- ts_LOGf(" * network_len : 0x%02x (%d)\n", nit->network_info_size, nit->network_info_size);
- ts_LOGf(" * reserved2 : 0x%02x\n", nit->reserved1);
- ts_LOGf(" * ts_loop_len : %d\n", nit->ts_loop_size);
- ts_LOGf(" * num_streams : %d\n", nit->streams_num);
-
- if (nit->network_info_size > 0) {
- ts_LOGf(" * Network info:\n");
- ts_LOGf(" * network info size: %d\n", nit->network_info_size);
- ts_descriptor_dump(nit->network_info, nit->network_info_size);
- }
-
- for(i=0;i<nit->streams_num;i++) {
- struct ts_nit_stream *stream = nit->streams[i];
- ts_LOGf(" - [%02d/%02d] | TS_id: 0x%04x (%d) ORG_net_id: 0x%04x (%d) Reserved: 0x%0x Desc_size: %d\n",
- i+1, nit->streams_num,
- stream->transport_stream_id, stream->transport_stream_id,
- stream->original_network_id, stream->original_network_id,
- stream->reserved1,
- stream->descriptor_size);
- if (stream->descriptor_data) {
- ts_descriptor_dump(stream->descriptor_data, stream->descriptor_size);
- }
- }
-
- ts_nit_check_generator(nit);
- }
-
- int ts_nit_is_same(struct ts_nit *nit1, struct ts_nit *nit2) {
- if (nit1 == nit2) return 1; // Same
- if (nit1 && nit2)
- return ts_section_is_same(nit1->section_header, nit2->section_header);
- else
- return 0;
- }
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