shaka-packager/packager/mpd/base/adaptation_set.cc

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// Copyright 2017 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/mpd/base/adaptation_set.h>
#include <cmath>
#include <absl/log/check.h>
#include <absl/log/log.h>
#include <absl/strings/numbers.h>
#include <absl/strings/str_format.h>
#include <packager/macros/classes.h>
#include <packager/macros/logging.h>
#include <packager/mpd/base/media_info.pb.h>
#include <packager/mpd/base/mpd_options.h>
#include <packager/mpd/base/mpd_utils.h>
#include <packager/mpd/base/representation.h>
#include <packager/mpd/base/xml/xml_node.h>
namespace shaka {
namespace {
AdaptationSet::Role MediaInfoTextTypeToRole(
MediaInfo::TextInfo::TextType type) {
switch (type) {
case MediaInfo::TextInfo::UNKNOWN:
LOG(WARNING) << "Unknown text type, assuming subtitle.";
return AdaptationSet::kRoleSubtitle;
case MediaInfo::TextInfo::CAPTION:
return AdaptationSet::kRoleCaption;
case MediaInfo::TextInfo::SUBTITLE:
return AdaptationSet::kRoleSubtitle;
default:
NOTIMPLEMENTED() << "Unknown MediaInfo TextType: " << type
<< " assuming subtitle.";
return AdaptationSet::kRoleSubtitle;
}
}
std::string RoleToText(AdaptationSet::Role role) {
// Using switch so that the compiler can detect whether there is a case that's
// not being handled.
switch (role) {
case AdaptationSet::kRoleCaption:
return "caption";
case AdaptationSet::kRoleSubtitle:
return "subtitle";
case AdaptationSet::kRoleMain:
return "main";
case AdaptationSet::kRoleAlternate:
return "alternate";
case AdaptationSet::kRoleSupplementary:
return "supplementary";
case AdaptationSet::kRoleCommentary:
return "commentary";
case AdaptationSet::kRoleDub:
return "dub";
case AdaptationSet::kRoleDescription:
return "description";
default:
return "unknown";
}
}
// Returns the picture aspect ratio string e.g. "16:9", "4:3".
// "Reducing the quotient to minimal form" does not work well in practice as
// there may be some rounding performed in the input, e.g. the resolution of
// 480p is 854:480 for 16:9 aspect ratio, can only be reduced to 427:240.
// The algorithm finds out the pair of integers, num and den, where num / den is
// the closest ratio to scaled_width / scaled_height, by looping den through
// common values.
std::string GetPictureAspectRatio(uint32_t width,
uint32_t height,
uint32_t pixel_width,
uint32_t pixel_height) {
const uint32_t scaled_width = pixel_width * width;
const uint32_t scaled_height = pixel_height * height;
const double par = static_cast<double>(scaled_width) / scaled_height;
// Typical aspect ratios have par_y less than or equal to 19:
// https://en.wikipedia.org/wiki/List_of_common_resolutions
const uint32_t kLargestPossibleParY = 19;
uint32_t par_num = 0;
uint32_t par_den = 0;
double min_error = 1.0;
for (uint32_t den = 1; den <= kLargestPossibleParY; ++den) {
uint32_t num = par * den + 0.5;
double error = fabs(par - static_cast<double>(num) / den);
if (error < min_error) {
min_error = error;
par_num = num;
par_den = den;
if (error == 0)
break;
}
}
VLOG(2) << "width*pix_width : height*pixel_height (" << scaled_width << ":"
<< scaled_height << ") reduced to " << par_num << ":" << par_den
<< " with error " << min_error << ".";
return absl::StrFormat("%d:%d", par_num, par_den);
}
// Adds an entry to picture_aspect_ratio if the size of picture_aspect_ratio is
// less than 2 and video_info has both pixel width and pixel height.
void AddPictureAspectRatio(const MediaInfo::VideoInfo& video_info,
std::set<std::string>* picture_aspect_ratio) {
// If there are more than one entries in picture_aspect_ratio, the @par
// attribute cannot be set, so skip.
if (picture_aspect_ratio->size() > 1)
return;
if (video_info.width() == 0 || video_info.height() == 0 ||
video_info.pixel_width() == 0 || video_info.pixel_height() == 0) {
// If there is even one Representation without a @sar attribute, @par cannot
// be calculated.
// Just populate the set with at least 2 bogus strings so that further call
// to this function will bail out immediately.
picture_aspect_ratio->insert("bogus");
picture_aspect_ratio->insert("entries");
return;
}
const std::string par = GetPictureAspectRatio(
video_info.width(), video_info.height(), video_info.pixel_width(),
video_info.pixel_height());
DVLOG(1) << "Setting par as: " << par
<< " for video with width: " << video_info.width()
<< " height: " << video_info.height()
<< " pixel_width: " << video_info.pixel_width() << " pixel_height; "
<< video_info.pixel_height();
picture_aspect_ratio->insert(par);
}
class RepresentationStateChangeListenerImpl
: public RepresentationStateChangeListener {
public:
// |adaptation_set| is not owned by this class.
RepresentationStateChangeListenerImpl(uint32_t representation_id,
AdaptationSet* adaptation_set)
: representation_id_(representation_id), adaptation_set_(adaptation_set) {
DCHECK(adaptation_set_);
}
~RepresentationStateChangeListenerImpl() override {}
// RepresentationStateChangeListener implementation.
void OnNewSegmentForRepresentation(int64_t start_time,
int64_t duration) override {
adaptation_set_->OnNewSegmentForRepresentation(representation_id_,
start_time, duration);
}
void OnSetFrameRateForRepresentation(int32_t frame_duration,
int32_t timescale) override {
adaptation_set_->OnSetFrameRateForRepresentation(representation_id_,
frame_duration, timescale);
}
private:
const uint32_t representation_id_;
AdaptationSet* const adaptation_set_;
DISALLOW_COPY_AND_ASSIGN(RepresentationStateChangeListenerImpl);
};
} // namespace
AdaptationSet::AdaptationSet(const std::string& language,
const MpdOptions& mpd_options,
uint32_t* counter)
: representation_counter_(counter),
language_(language),
mpd_options_(mpd_options),
segments_aligned_(kSegmentAlignmentUnknown),
force_set_segment_alignment_(false) {
DCHECK(counter);
}
AdaptationSet::~AdaptationSet() {}
Representation* AdaptationSet::AddRepresentation(const MediaInfo& media_info) {
const uint32_t representation_id = (*representation_counter_)++;
// Note that AdaptationSet outlive Representation, so this object
// will die before AdaptationSet.
std::unique_ptr<RepresentationStateChangeListener> listener(
new RepresentationStateChangeListenerImpl(representation_id, this));
std::unique_ptr<Representation> new_representation(new Representation(
media_info, mpd_options_, representation_id, std::move(listener)));
if (!new_representation->Init()) {
LOG(ERROR) << "Failed to initialize Representation.";
return NULL;
}
UpdateFromMediaInfo(media_info);
Representation* representation_ptr = new_representation.get();
representation_map_[representation_ptr->id()] = std::move(new_representation);
return representation_ptr;
}
Representation* AdaptationSet::CopyRepresentation(
const Representation& representation) {
// Note that AdaptationSet outlive Representation, so this object
// will die before AdaptationSet.
std::unique_ptr<RepresentationStateChangeListener> listener(
new RepresentationStateChangeListenerImpl(representation.id(), this));
std::unique_ptr<Representation> new_representation(
new Representation(representation, std::move(listener)));
UpdateFromMediaInfo(new_representation->GetMediaInfo());
Representation* representation_ptr = new_representation.get();
representation_map_[representation_ptr->id()] = std::move(new_representation);
return representation_ptr;
}
void AdaptationSet::AddContentProtectionElement(
const ContentProtectionElement& content_protection_element) {
content_protection_elements_.push_back(content_protection_element);
RemoveDuplicateAttributes(&content_protection_elements_.back());
}
void AdaptationSet::UpdateContentProtectionPssh(const std::string& drm_uuid,
const std::string& pssh) {
UpdateContentProtectionPsshHelper(drm_uuid, pssh,
&content_protection_elements_);
}
void AdaptationSet::AddAccessibility(const std::string& scheme,
const std::string& value) {
accessibilities_.push_back(Accessibility{scheme, value});
}
void AdaptationSet::AddRole(Role role) {
roles_.insert(role);
}
// Creates a copy of <AdaptationSet> xml element, iterate thru all the
// <Representation> (child) elements and add them to the copy.
// Set all the attributes first and then add the children elements so that flags
// can be passed to Representation to avoid setting redundant attributes. For
// example, if AdaptationSet@width is set, then Representation@width is
// redundant and should not be set.
std::optional<xml::XmlNode> AdaptationSet::GetXml() {
xml::AdaptationSetXmlNode adaptation_set;
bool suppress_representation_width = false;
bool suppress_representation_height = false;
bool suppress_representation_frame_rate = false;
if (id_ && !adaptation_set.SetId(id_.value()))
return std::nullopt;
if (!adaptation_set.SetStringAttribute("contentType", content_type_))
return std::nullopt;
if (!language_.empty() && language_ != "und" &&
!adaptation_set.SetStringAttribute("lang", language_)) {
return std::nullopt;
}
// Note that std::{set,map} are ordered, so the last element is the max value.
if (video_widths_.size() == 1) {
suppress_representation_width = true;
if (!adaptation_set.SetIntegerAttribute("width", *video_widths_.begin()))
return std::nullopt;
} else if (video_widths_.size() > 1) {
if (!adaptation_set.SetIntegerAttribute("maxWidth",
*video_widths_.rbegin())) {
return std::nullopt;
}
}
if (video_heights_.size() == 1) {
suppress_representation_height = true;
if (!adaptation_set.SetIntegerAttribute("height", *video_heights_.begin()))
return std::nullopt;
} else if (video_heights_.size() > 1) {
if (!adaptation_set.SetIntegerAttribute("maxHeight",
*video_heights_.rbegin())) {
return std::nullopt;
}
}
if (video_frame_rates_.size() == 1) {
suppress_representation_frame_rate = true;
if (!adaptation_set.SetStringAttribute(
"frameRate", video_frame_rates_.begin()->second)) {
return std::nullopt;
}
} else if (video_frame_rates_.size() > 1) {
if (!adaptation_set.SetStringAttribute(
"maxFrameRate", video_frame_rates_.rbegin()->second)) {
return std::nullopt;
}
}
// https://dashif.org/docs/DASH-IF-IOP-v4.3.pdf - 4.2.5.1
if (IsVideo() && transfer_characteristics_ > 0 &&
!adaptation_set.AddSupplementalProperty(
"urn:mpeg:mpegB:cicp:TransferCharacteristics",
std::to_string(transfer_characteristics_))) {
return std::nullopt;
}
// Note: must be checked before checking segments_aligned_ (below). So that
// segments_aligned_ is set before checking below.
if (mpd_options_.mpd_type == MpdType::kStatic) {
CheckStaticSegmentAlignment();
}
if (segments_aligned_ == kSegmentAlignmentTrue) {
if (!adaptation_set.SetStringAttribute(
mpd_options_.dash_profile == DashProfile::kOnDemand
? "subsegmentAlignment"
: "segmentAlignment",
"true")) {
return std::nullopt;
}
}
if (picture_aspect_ratio_.size() == 1 &&
!adaptation_set.SetStringAttribute("par",
*picture_aspect_ratio_.begin())) {
return std::nullopt;
}
if (!adaptation_set.AddContentProtectionElements(
content_protection_elements_)) {
return std::nullopt;
}
std::string trick_play_reference_ids;
for (const AdaptationSet* tp_adaptation_set : trick_play_references_) {
// Should be a whitespace-separated list, see DASH-IOP 3.2.9.
if (!trick_play_reference_ids.empty())
trick_play_reference_ids += ' ';
CHECK(tp_adaptation_set->has_id());
trick_play_reference_ids += std::to_string(tp_adaptation_set->id());
}
if (!trick_play_reference_ids.empty() &&
!adaptation_set.AddEssentialProperty(
"http://dashif.org/guidelines/trickmode", trick_play_reference_ids)) {
return std::nullopt;
}
std::string switching_ids;
for (const AdaptationSet* s_adaptation_set : switchable_adaptation_sets_) {
// Should be a comma-separated list, see DASH-IOP 3.8.
if (!switching_ids.empty())
switching_ids += ',';
CHECK(s_adaptation_set->has_id());
switching_ids += std::to_string(s_adaptation_set->id());
}
if (!switching_ids.empty() &&
!adaptation_set.AddSupplementalProperty(
"urn:mpeg:dash:adaptation-set-switching:2016", switching_ids)) {
return std::nullopt;
}
for (const AdaptationSet::Accessibility& accessibility : accessibilities_) {
if (!adaptation_set.AddAccessibilityElement(accessibility.scheme,
accessibility.value)) {
return std::nullopt;
}
}
for (AdaptationSet::Role role : roles_) {
if (!adaptation_set.AddRoleElement("urn:mpeg:dash:role:2011",
RoleToText(role))) {
return std::nullopt;
}
}
for (const auto& representation_pair : representation_map_) {
const auto& representation = representation_pair.second;
if (suppress_representation_width)
representation->SuppressOnce(Representation::kSuppressWidth);
if (suppress_representation_height)
representation->SuppressOnce(Representation::kSuppressHeight);
if (suppress_representation_frame_rate)
representation->SuppressOnce(Representation::kSuppressFrameRate);
auto child = representation->GetXml();
if (!child || !adaptation_set.AddChild(std::move(*child)))
return std::nullopt;
}
return adaptation_set;
}
void AdaptationSet::ForceSetSegmentAlignment(bool segment_alignment) {
segments_aligned_ =
segment_alignment ? kSegmentAlignmentTrue : kSegmentAlignmentFalse;
force_set_segment_alignment_ = true;
}
void AdaptationSet::AddAdaptationSetSwitching(
const AdaptationSet* adaptation_set) {
switchable_adaptation_sets_.push_back(adaptation_set);
}
// For dynamic MPD, storing all start_time and duration will out-of-memory
// because there's no way of knowing when it will end. Static MPD
// subsegmentAlignment check is *not* done here because it is possible that some
// Representations might not have been added yet (e.g. a thread is assigned per
// muxer so one might run faster than others). To be clear, for dynamic MPD, all
// Representations should be added before a segment is added.
void AdaptationSet::OnNewSegmentForRepresentation(uint32_t representation_id,
int64_t start_time,
int64_t duration) {
if (mpd_options_.mpd_type == MpdType::kDynamic) {
CheckDynamicSegmentAlignment(representation_id, start_time, duration);
} else {
representation_segment_start_times_[representation_id].push_back(
start_time);
}
}
void AdaptationSet::OnSetFrameRateForRepresentation(uint32_t representation_id,
int32_t frame_duration,
int32_t timescale) {
RecordFrameRate(frame_duration, timescale);
}
void AdaptationSet::AddTrickPlayReference(const AdaptationSet* adaptation_set) {
trick_play_references_.push_back(adaptation_set);
}
const std::list<Representation*> AdaptationSet::GetRepresentations() const {
std::list<Representation*> representations;
for (const auto& representation_pair : representation_map_) {
representations.push_back(representation_pair.second.get());
}
return representations;
}
bool AdaptationSet::IsVideo() const {
return content_type_ == "video";
}
void AdaptationSet::UpdateFromMediaInfo(const MediaInfo& media_info) {
// For videos, record the width, height, and the frame rate to calculate the
// max {width,height,framerate} required for DASH IOP.
if (media_info.has_video_info()) {
const MediaInfo::VideoInfo& video_info = media_info.video_info();
DCHECK(video_info.has_width());
DCHECK(video_info.has_height());
video_widths_.insert(video_info.width());
video_heights_.insert(video_info.height());
if (video_info.has_time_scale() && video_info.has_frame_duration())
RecordFrameRate(video_info.frame_duration(), video_info.time_scale());
AddPictureAspectRatio(video_info, &picture_aspect_ratio_);
}
if (media_info.has_video_info()) {
content_type_ = "video";
} else if (media_info.has_audio_info()) {
content_type_ = "audio";
} else if (media_info.has_text_info()) {
content_type_ = "text";
if (media_info.text_info().has_type() &&
(media_info.text_info().type() != MediaInfo::TextInfo::UNKNOWN)) {
roles_.insert(MediaInfoTextTypeToRole(media_info.text_info().type()));
}
}
}
// This implementation assumes that each representations' segments' are
// contiguous.
// Also assumes that all Representations are added before this is called.
// This checks whether the first elements of the lists in
// representation_segment_start_times_ are aligned.
// For example, suppose this method was just called with args rep_id=2
// start_time=1.
// 1 -> [1, 100, 200]
// 2 -> [1]
// The timestamps of the first elements match, so this flags
// segments_aligned_=true.
// Also since the first segment start times match, the first element of all the
// lists are removed, so the map of lists becomes:
// 1 -> [100, 200]
// 2 -> []
// Note that there could be false positives.
// e.g. just got rep_id=3 start_time=1 duration=300, and the duration of the
// whole AdaptationSet is 300.
// 1 -> [1, 100, 200]
// 2 -> [1, 90, 100]
// 3 -> [1]
// They are not aligned but this will be marked as aligned.
// But since this is unlikely to happen in the packager (and to save
// computation), this isn't handled at the moment.
void AdaptationSet::CheckDynamicSegmentAlignment(uint32_t representation_id,
int64_t start_time,
int64_t /* duration */) {
if (segments_aligned_ == kSegmentAlignmentFalse ||
force_set_segment_alignment_) {
return;
}
std::list<int64_t>& current_representation_start_times =
representation_segment_start_times_[representation_id];
current_representation_start_times.push_back(start_time);
// There's no way to detemine whether the segments are aligned if some
// representations do not have any segments.
if (representation_segment_start_times_.size() != representation_map_.size())
return;
DCHECK(!current_representation_start_times.empty());
const int64_t expected_start_time =
current_representation_start_times.front();
for (const auto& key_value : representation_segment_start_times_) {
const std::list<int64_t>& representation_start_time = key_value.second;
// If there are no entries in a list, then there is no way for the
// segment alignment status to change.
// Note that it can be empty because entries get deleted below.
if (representation_start_time.empty())
return;
if (expected_start_time != representation_start_time.front()) {
VLOG(1) << "Seeing Misaligned segments with different start_times: "
<< expected_start_time << " vs "
<< representation_start_time.front();
// Flag as false and clear the start times data, no need to keep it
// around.
segments_aligned_ = kSegmentAlignmentFalse;
representation_segment_start_times_.clear();
return;
}
}
segments_aligned_ = kSegmentAlignmentTrue;
for (auto& key_value : representation_segment_start_times_) {
std::list<int64_t>& representation_start_time = key_value.second;
representation_start_time.pop_front();
}
}
// Make sure all segements start times match for all Representations.
// This assumes that the segments are contiguous.
void AdaptationSet::CheckStaticSegmentAlignment() {
if (segments_aligned_ == kSegmentAlignmentFalse ||
force_set_segment_alignment_) {
return;
}
if (representation_segment_start_times_.empty())
return;
if (representation_segment_start_times_.size() == 1) {
segments_aligned_ = kSegmentAlignmentTrue;
return;
}
// This is not the most efficient implementation to compare the values
// because expected_time_line is compared against all other time lines, but
// probably the most readable.
const std::list<int64_t>& expected_time_line =
representation_segment_start_times_.begin()->second;
bool all_segment_time_line_same_length = true;
// Note that the first entry is skipped because it is expected_time_line.
RepresentationTimeline::const_iterator it =
representation_segment_start_times_.begin();
for (++it; it != representation_segment_start_times_.end(); ++it) {
const std::list<int64_t>& other_time_line = it->second;
if (expected_time_line.size() != other_time_line.size()) {
all_segment_time_line_same_length = false;
}
const std::list<int64_t>* longer_list = &other_time_line;
const std::list<int64_t>* shorter_list = &expected_time_line;
if (expected_time_line.size() > other_time_line.size()) {
shorter_list = &other_time_line;
longer_list = &expected_time_line;
}
if (!std::equal(shorter_list->begin(), shorter_list->end(),
longer_list->begin())) {
// Some segments are definitely unaligned.
segments_aligned_ = kSegmentAlignmentFalse;
representation_segment_start_times_.clear();
return;
}
}
// TODO(rkuroiwa): The right way to do this is to also check the durations.
// For example:
// (a) 3 4 5
// (b) 3 4 5 6
// could be true or false depending on the length of the third segment of (a).
// i.e. if length of the third segment is 2, then this is not aligned.
if (!all_segment_time_line_same_length) {
segments_aligned_ = kSegmentAlignmentUnknown;
return;
}
segments_aligned_ = kSegmentAlignmentTrue;
}
// Since all AdaptationSet cares about is the maxFrameRate, representation_id
// is not passed to this method.
void AdaptationSet::RecordFrameRate(int32_t frame_duration, int32_t timescale) {
if (frame_duration == 0) {
LOG(ERROR) << "Frame duration is 0 and cannot be set.";
return;
}
video_frame_rates_[static_cast<double>(timescale) / frame_duration] =
absl::StrFormat("%d/%d", timescale, frame_duration);
}
} // namespace shaka