blob: 87be9c6b8685ba873f11689c791cf3c29d8e0034 [file] [log] [blame]
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "media/formats/mp2t/ts_section_pmt.h"
#include <map>
#include "base/logging.h"
#include "media/base/bit_reader.h"
#include "media/formats/mp2t/mp2t_common.h"
namespace media {
namespace mp2t {
TsSectionPmt::TsSectionPmt(const RegisterPesCb& register_pes_cb)
: register_pes_cb_(register_pes_cb) {
TsSectionPmt::~TsSectionPmt() {
bool TsSectionPmt::ParsePsiSection(BitReader* bit_reader) {
// Read up to |last_section_number|.
int table_id;
int section_syntax_indicator;
int dummy_zero;
int reserved;
int section_length;
int program_number;
int version_number;
int current_next_indicator;
int section_number;
int last_section_number;
RCHECK(bit_reader->ReadBits(8, &table_id));
RCHECK(bit_reader->ReadBits(1, &section_syntax_indicator));
RCHECK(bit_reader->ReadBits(1, &dummy_zero));
RCHECK(bit_reader->ReadBits(2, &reserved));
RCHECK(bit_reader->ReadBits(12, &section_length));
int section_start_marker = bit_reader->bits_available() / 8;
RCHECK(bit_reader->ReadBits(16, &program_number));
RCHECK(bit_reader->ReadBits(2, &reserved));
RCHECK(bit_reader->ReadBits(5, &version_number));
RCHECK(bit_reader->ReadBits(1, &current_next_indicator));
RCHECK(bit_reader->ReadBits(8, &section_number));
RCHECK(bit_reader->ReadBits(8, &last_section_number));
// Perform a few verifications:
// - table ID should be 2 for a PMT.
// - section_syntax_indicator should be one.
// - section length should not exceed 1021.
RCHECK(table_id == 0x2);
RCHECK(section_length <= 1021);
RCHECK(section_number == 0);
RCHECK(last_section_number == 0);
// TODO(damienv):
// Verify that there is no mismatch between the program number
// and the program number that was provided in a PAT for the current PMT.
// Read the end of the fixed length section.
int pcr_pid;
int program_info_length;
RCHECK(bit_reader->ReadBits(3, &reserved));
RCHECK(bit_reader->ReadBits(13, &pcr_pid));
RCHECK(bit_reader->ReadBits(4, &reserved));
RCHECK(bit_reader->ReadBits(12, &program_info_length));
RCHECK(program_info_length < 1024);
// Read the program info descriptor.
// TODO(damienv): check wether any of the descriptors could be useful.
// Defined in section 2.6 of ISO-13818.
RCHECK(bit_reader->SkipBits(8 * program_info_length));
// Read the ES description table.
// The end of the PID map if 4 bytes away from the end of the section
// (4 bytes = size of the CRC).
int pid_map_end_marker = section_start_marker - section_length + 4;
using PidMapValue = std::pair<int, Descriptors>;
std::map<int, PidMapValue> pid_map;
while (bit_reader->bits_available() > 8 * pid_map_end_marker) {
int stream_type;
int reserved;
int pid_es;
int es_info_length;
RCHECK(bit_reader->ReadBits(8, &stream_type));
RCHECK(bit_reader->ReadBits(3, &reserved));
RCHECK(bit_reader->ReadBits(13, &pid_es));
RCHECK(bit_reader->ReadBits(4, &reserved));
RCHECK(bit_reader->ReadBits(12, &es_info_length));
Descriptors descriptors;
RCHECK(descriptors.Read(bit_reader, es_info_length));
// Do not register the PID right away.
// Wait for the end of the section to be fully parsed
// to make sure there is no error.
PidMapValue stream_info(stream_type, descriptors);
pid_map.insert(std::make_pair(pid_es, stream_info));
// Read the CRC.
int crc32;
RCHECK(bit_reader->ReadBits(32, &crc32));
// Once the PMT has been proved to be correct, register the PIDs.
for (const auto& it : pid_map)
register_pes_cb_.Run(it.first, it.second.first, it.second.second);
return true;
void TsSectionPmt::ResetPsiSection() {
} // namespace mp2t
} // namespace media