141 lines
4.3 KiB
C++
141 lines
4.3 KiB
C++
// Copyright 2020 Google LLC. All rights reserved.
|
|
//
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file or at
|
|
// https://developers.google.com/open-source/licenses/bsd
|
|
|
|
#include "packager/media/formats/mp2t/es_parser_dvb.h"
|
|
|
|
#include "packager/media/base/bit_reader.h"
|
|
#include "packager/media/base/text_stream_info.h"
|
|
#include "packager/media/base/timestamp.h"
|
|
#include "packager/media/formats/mp2t/mp2t_common.h"
|
|
|
|
namespace shaka {
|
|
namespace media {
|
|
namespace mp2t {
|
|
|
|
namespace {
|
|
|
|
bool ParseSubtitlingDescriptor(
|
|
const uint8_t* descriptor,
|
|
size_t size,
|
|
std::unordered_map<uint16_t, std::string>* langs) {
|
|
// See ETSI EN 300 468 Section 6.2.41.
|
|
BitReader reader(descriptor, size);
|
|
size_t data_size;
|
|
RCHECK(reader.SkipBits(8)); // descriptor_tag
|
|
RCHECK(reader.ReadBits(8, &data_size));
|
|
RCHECK(data_size + 2 <= size);
|
|
for (size_t i = 0; i < data_size; i += 8) {
|
|
uint32_t lang_code;
|
|
uint16_t page;
|
|
RCHECK(reader.ReadBits(24, &lang_code));
|
|
RCHECK(reader.SkipBits(8)); // subtitling_type
|
|
RCHECK(reader.ReadBits(16, &page));
|
|
RCHECK(reader.SkipBits(16)); // ancillary_page_id
|
|
|
|
// The lang code is a ISO 639-2 code coded in Latin-1.
|
|
std::string lang(3, '\0');
|
|
lang[0] = (lang_code >> 16) & 0xff;
|
|
lang[1] = (lang_code >> 8) & 0xff;
|
|
lang[2] = (lang_code >> 0) & 0xff;
|
|
langs->emplace(page, std::move(lang));
|
|
}
|
|
return true;
|
|
}
|
|
|
|
} // namespace
|
|
|
|
EsParserDvb::EsParserDvb(uint32_t pid,
|
|
const NewStreamInfoCB& new_stream_info_cb,
|
|
const EmitTextSampleCB& emit_sample_cb,
|
|
const uint8_t* descriptor,
|
|
size_t descriptor_length)
|
|
: EsParser(pid),
|
|
new_stream_info_cb_(new_stream_info_cb),
|
|
emit_sample_cb_(emit_sample_cb) {
|
|
if (!ParseSubtitlingDescriptor(descriptor, descriptor_length, &languages_)) {
|
|
LOG(WARNING) << "Error parsing subtitling descriptor";
|
|
}
|
|
}
|
|
|
|
EsParserDvb::~EsParserDvb() {}
|
|
|
|
bool EsParserDvb::Parse(const uint8_t* buf,
|
|
int size,
|
|
int64_t pts,
|
|
int64_t dts) {
|
|
if (!sent_info_) {
|
|
sent_info_ = true;
|
|
std::shared_ptr<TextStreamInfo> info = std::make_shared<TextStreamInfo>(
|
|
pid(), kMpeg2Timescale, kInfiniteDuration, kCodecText,
|
|
/* codec_string= */ "", /* codec_config= */ "", /* width= */ 0,
|
|
/* height= */ 0, /* language= */ "");
|
|
for (const auto& pair : languages_) {
|
|
info->AddSubStream(pair.first, {pair.second});
|
|
}
|
|
|
|
new_stream_info_cb_(info);
|
|
}
|
|
|
|
// TODO: Handle buffering and multiple reads? All content so far has been
|
|
// a whole segment, so it may not be needed.
|
|
return ParseInternal(buf, size, pts);
|
|
}
|
|
|
|
bool EsParserDvb::Flush() {
|
|
for (auto& pair : parsers_) {
|
|
std::vector<std::shared_ptr<TextSample>> samples;
|
|
RCHECK(pair.second.Flush(&samples));
|
|
|
|
for (auto sample : samples) {
|
|
sample->set_sub_stream_index(pair.first);
|
|
emit_sample_cb_(sample);
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
void EsParserDvb::Reset() {
|
|
parsers_.clear();
|
|
}
|
|
|
|
bool EsParserDvb::ParseInternal(const uint8_t* data, size_t size, int64_t pts) {
|
|
// See EN 300 743 Table 3.
|
|
BitReader reader(data, size);
|
|
int data_identifier;
|
|
int subtitle_stream_id;
|
|
RCHECK(reader.ReadBits(8, &data_identifier));
|
|
RCHECK(reader.ReadBits(8, &subtitle_stream_id));
|
|
RCHECK(data_identifier == 0x20);
|
|
RCHECK(subtitle_stream_id == 0);
|
|
|
|
int temp;
|
|
while (reader.ReadBits(8, &temp) && temp == 0xf) {
|
|
DvbSubSegmentType segment_type;
|
|
uint16_t page_id;
|
|
size_t segment_length;
|
|
RCHECK(reader.ReadBits(8, &segment_type));
|
|
RCHECK(reader.ReadBits(16, &page_id));
|
|
RCHECK(reader.ReadBits(16, &segment_length));
|
|
RCHECK(reader.bits_available() > segment_length * 8);
|
|
|
|
const uint8_t* payload = data + (size - reader.bits_available() / 8);
|
|
std::vector<std::shared_ptr<TextSample>> samples;
|
|
RCHECK(parsers_[page_id].Parse(segment_type, pts, payload, segment_length,
|
|
&samples));
|
|
for (auto sample : samples) {
|
|
sample->set_sub_stream_index(page_id);
|
|
emit_sample_cb_(sample);
|
|
}
|
|
|
|
RCHECK(reader.SkipBytes(segment_length));
|
|
}
|
|
return temp == 0xff;
|
|
}
|
|
|
|
} // namespace mp2t
|
|
} // namespace media
|
|
} // namespace shaka
|