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

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// Copyright 2014 Google Inc. 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/mpd_builder.h"
#include <libxml/tree.h>
#include <libxml/xmlstring.h>
#include <cmath>
#include <iterator>
#include <list>
#include <memory>
#include <string>
#include "packager/base/base64.h"
#include "packager/base/bind.h"
#include "packager/base/files/file_path.h"
#include "packager/base/logging.h"
#include "packager/base/strings/string_number_conversions.h"
#include "packager/base/strings/stringprintf.h"
#include "packager/base/synchronization/lock.h"
#include "packager/base/time/default_clock.h"
#include "packager/base/time/time.h"
#include "packager/media/base/language_utils.h"
#include "packager/media/file/file.h"
#include "packager/mpd/base/content_protection_element.h"
#include "packager/mpd/base/mpd_utils.h"
#include "packager/mpd/base/xml/xml_node.h"
#include "packager/version/version.h"
namespace shaka {
using base::FilePath;
using xml::XmlNode;
using xml::RepresentationXmlNode;
using xml::AdaptationSetXmlNode;
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:
NOTREACHED() << "Unknown MediaInfo TextType: " << type
<< " assuming subtitle.";
return AdaptationSet::kRoleSubtitle;
}
}
std::string GetMimeType(const std::string& prefix,
MediaInfo::ContainerType container_type) {
switch (container_type) {
case MediaInfo::CONTAINER_MP4:
return prefix + "/mp4";
case MediaInfo::CONTAINER_MPEG2_TS:
// NOTE: DASH MPD spec uses lowercase but RFC3555 says uppercase.
return prefix + "/MP2T";
case MediaInfo::CONTAINER_WEBM:
return prefix + "/webm";
default:
break;
}
// Unsupported container types should be rejected/handled by the caller.
LOG(ERROR) << "Unrecognized container type: " << container_type;
return std::string();
}
void AddMpdNameSpaceInfo(XmlNode* mpd) {
DCHECK(mpd);
static const char kXmlNamespace[] = "urn:mpeg:dash:schema:mpd:2011";
static const char kXmlNamespaceXsi[] =
"http://www.w3.org/2001/XMLSchema-instance";
static const char kXmlNamespaceXlink[] = "http://www.w3.org/1999/xlink";
static const char kDashSchemaMpd2011[] =
"urn:mpeg:dash:schema:mpd:2011 DASH-MPD.xsd";
static const char kCencNamespace[] = "urn:mpeg:cenc:2013";
mpd->SetStringAttribute("xmlns", kXmlNamespace);
mpd->SetStringAttribute("xmlns:xsi", kXmlNamespaceXsi);
mpd->SetStringAttribute("xmlns:xlink", kXmlNamespaceXlink);
mpd->SetStringAttribute("xsi:schemaLocation", kDashSchemaMpd2011);
mpd->SetStringAttribute("xmlns:cenc", kCencNamespace);
}
bool IsPeriodNode(xmlNodePtr node) {
DCHECK(node);
int kEqual = 0;
return xmlStrcmp(node->name, reinterpret_cast<const xmlChar*>("Period")) ==
kEqual;
}
// Find the first <Period> element. This does not recurse down the tree,
// only checks direct children. Returns the pointer to Period element on
// success, otherwise returns false.
// As noted here, we must traverse.
// http://www.xmlsoft.org/tutorial/ar01s04.html
xmlNodePtr FindPeriodNode(XmlNode* xml_node) {
for (xmlNodePtr node = xml_node->GetRawPtr()->xmlChildrenNode; node != NULL;
node = node->next) {
if (IsPeriodNode(node))
return node;
}
return NULL;
}
bool Positive(double d) {
return d > 0.0;
}
// Return current time in XML DateTime format. The value is in UTC, so the
// string ends with a 'Z'.
std::string XmlDateTimeNowWithOffset(
int32_t offset_seconds,
base::Clock* clock) {
base::Time time = clock->Now();
time += base::TimeDelta::FromSeconds(offset_seconds);
base::Time::Exploded time_exploded;
time.UTCExplode(&time_exploded);
return base::StringPrintf("%4d-%02d-%02dT%02d:%02d:%02dZ", time_exploded.year,
time_exploded.month, time_exploded.day_of_month,
time_exploded.hour, time_exploded.minute,
time_exploded.second);
}
void SetIfPositive(const char* attr_name, double value, XmlNode* mpd) {
if (Positive(value)) {
mpd->SetStringAttribute(attr_name, SecondsToXmlDuration(value));
}
}
uint32_t GetTimeScale(const MediaInfo& media_info) {
if (media_info.has_reference_time_scale()) {
return media_info.reference_time_scale();
}
if (media_info.has_video_info()) {
return media_info.video_info().time_scale();
}
if (media_info.has_audio_info()) {
return media_info.audio_info().time_scale();
}
LOG(WARNING) << "No timescale specified, using 1 as timescale.";
return 1;
}
uint64_t LastSegmentStartTime(const SegmentInfo& segment_info) {
return segment_info.start_time + segment_info.duration * segment_info.repeat;
}
// This is equal to |segment_info| end time
uint64_t LastSegmentEndTime(const SegmentInfo& segment_info) {
return segment_info.start_time +
segment_info.duration * (segment_info.repeat + 1);
}
uint64_t LatestSegmentStartTime(const std::list<SegmentInfo>& segments) {
DCHECK(!segments.empty());
const SegmentInfo& latest_segment = segments.back();
return LastSegmentStartTime(latest_segment);
}
// Given |timeshift_limit|, finds out the number of segments that are no longer
// valid and should be removed from |segment_info|.
int SearchTimedOutRepeatIndex(uint64_t timeshift_limit,
const SegmentInfo& segment_info) {
DCHECK_LE(timeshift_limit, LastSegmentEndTime(segment_info));
if (timeshift_limit < segment_info.start_time)
return 0;
return (timeshift_limit - segment_info.start_time) / segment_info.duration;
}
// Overload this function to support different types of |output|.
// Note that this could be done by call MpdBuilder::ToString() and use the
// result to write to a file, it requires an extra copy.
bool WriteXmlCharArrayToOutput(xmlChar* doc,
int doc_size,
std::string* output) {
DCHECK(doc);
DCHECK(output);
output->assign(doc, doc + doc_size);
return true;
}
bool WriteXmlCharArrayToOutput(xmlChar* doc,
int doc_size,
media::File* output) {
DCHECK(doc);
DCHECK(output);
if (output->Write(doc, doc_size) < doc_size)
return false;
return output->Flush();
}
std::string MakePathRelative(const std::string& path,
const std::string& mpd_dir) {
return (path.find(mpd_dir) == 0) ? path.substr(mpd_dir.size()) : path;
}
// Check whether the video info has width and height.
// DASH IOP also requires several other fields for video representations, namely
// width, height, framerate, and sar.
bool HasRequiredVideoFields(const MediaInfo_VideoInfo& video_info) {
if (!video_info.has_height() || !video_info.has_width()) {
LOG(ERROR)
<< "Width and height are required fields for generating a valid MPD.";
return false;
}
// These fields are not required for a valid MPD, but required for DASH IOP
// compliant MPD. MpdBuilder can keep generating MPDs without these fields.
LOG_IF(WARNING, !video_info.has_time_scale())
<< "Video info does not contain timescale required for "
"calculating framerate. @frameRate is required for DASH IOP.";
LOG_IF(WARNING, !video_info.has_frame_duration())
<< "Video info does not contain frame duration required "
"for calculating framerate. @frameRate is required for DASH IOP.";
LOG_IF(WARNING, !video_info.has_pixel_width())
<< "Video info does not contain pixel_width to calculate the sample "
"aspect ratio required for DASH IOP.";
LOG_IF(WARNING, !video_info.has_pixel_height())
<< "Video info does not contain pixel_height to calculate the sample "
"aspect ratio required for DASH IOP.";
return true;
}
// 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 base::IntToString(par_num) + ":" + base::IntToString(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);
}
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";
default:
break;
}
NOTREACHED();
return "";
}
// Spooky static initialization/cleanup of libxml.
class LibXmlInitializer {
public:
LibXmlInitializer() : initialized_(false) {
base::AutoLock lock(lock_);
if (!initialized_) {
xmlInitParser();
initialized_ = true;
}
}
~LibXmlInitializer() {
base::AutoLock lock(lock_);
if (initialized_) {
xmlCleanupParser();
initialized_ = false;
}
}
private:
base::Lock lock_;
bool initialized_;
DISALLOW_COPY_AND_ASSIGN(LibXmlInitializer);
};
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(uint64_t start_time,
uint64_t duration) override {
adaptation_set_->OnNewSegmentForRepresentation(representation_id_,
start_time, duration);
}
void OnSetFrameRateForRepresentation(uint32_t frame_duration,
uint32_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
MpdBuilder::MpdBuilder(const MpdOptions& mpd_options)
: mpd_options_(mpd_options), clock_(new base::DefaultClock()) {}
MpdBuilder::~MpdBuilder() {}
void MpdBuilder::AddBaseUrl(const std::string& base_url) {
base_urls_.push_back(base_url);
}
AdaptationSet* MpdBuilder::AddAdaptationSet(const std::string& lang) {
std::unique_ptr<AdaptationSet> adaptation_set(
new AdaptationSet(adaptation_set_counter_.GetNext(), lang, mpd_options_,
&representation_counter_));
DCHECK(adaptation_set);
if (!lang.empty() && lang == mpd_options_.default_language) {
adaptation_set->AddRole(AdaptationSet::kRoleMain);
}
adaptation_sets_.push_back(std::move(adaptation_set));
return adaptation_sets_.back().get();
}
bool MpdBuilder::WriteMpdToFile(media::File* output_file) {
DCHECK(output_file);
return WriteMpdToOutput(output_file);
}
bool MpdBuilder::ToString(std::string* output) {
DCHECK(output);
return WriteMpdToOutput(output);
}
template <typename OutputType>
bool MpdBuilder::WriteMpdToOutput(OutputType* output) {
static LibXmlInitializer lib_xml_initializer;
xml::scoped_xml_ptr<xmlDoc> doc(GenerateMpd());
if (!doc.get())
return false;
static const int kNiceFormat = 1;
int doc_str_size = 0;
xmlChar* doc_str = NULL;
xmlDocDumpFormatMemoryEnc(doc.get(), &doc_str, &doc_str_size, "UTF-8",
kNiceFormat);
bool result = WriteXmlCharArrayToOutput(doc_str, doc_str_size, output);
xmlFree(doc_str);
// Cleanup, free the doc.
doc.reset();
return result;
}
xmlDocPtr MpdBuilder::GenerateMpd() {
// Setup nodes.
static const char kXmlVersion[] = "1.0";
xml::scoped_xml_ptr<xmlDoc> doc(xmlNewDoc(BAD_CAST kXmlVersion));
XmlNode mpd("MPD");
// Iterate thru AdaptationSets and add them to one big Period element.
XmlNode period("Period");
// Always set id=0 for now. Since this class can only generate one Period
// at the moment, just use a constant.
// Required for 'dynamic' MPDs.
period.SetId(0);
for (const std::unique_ptr<AdaptationSet>& adaptation_set :
adaptation_sets_) {
xml::scoped_xml_ptr<xmlNode> child(adaptation_set->GetXml());
if (!child.get() || !period.AddChild(std::move(child)))
return NULL;
}
// Add baseurls to MPD.
std::list<std::string>::const_iterator base_urls_it = base_urls_.begin();
for (; base_urls_it != base_urls_.end(); ++base_urls_it) {
XmlNode base_url("BaseURL");
base_url.SetContent(*base_urls_it);
if (!mpd.AddChild(base_url.PassScopedPtr()))
return NULL;
}
// TODO(kqyang): Should we set @start unconditionally to 0?
if (mpd_options_.mpd_type == MpdType::kDynamic) {
// This is the only Period and it is a regular period.
period.SetStringAttribute("start", "PT0S");
}
if (!mpd.AddChild(period.PassScopedPtr()))
return NULL;
AddMpdNameSpaceInfo(&mpd);
static const char kOnDemandProfile[] =
"urn:mpeg:dash:profile:isoff-on-demand:2011";
static const char kLiveProfile[] =
"urn:mpeg:dash:profile:isoff-live:2011";
switch (mpd_options_.dash_profile) {
case DashProfile::kOnDemand:
mpd.SetStringAttribute("profiles", kOnDemandProfile);
break;
case DashProfile::kLive:
mpd.SetStringAttribute("profiles", kLiveProfile);
break;
default:
NOTREACHED() << "Unknown DASH profile: "
<< static_cast<int>(mpd_options_.dash_profile);
break;
}
AddCommonMpdInfo(&mpd);
switch (mpd_options_.mpd_type) {
case MpdType::kStatic:
AddStaticMpdInfo(&mpd);
break;
case MpdType::kDynamic:
AddDynamicMpdInfo(&mpd);
break;
default:
NOTREACHED() << "Unknown MPD type: "
<< static_cast<int>(mpd_options_.mpd_type);
break;
}
DCHECK(doc);
const std::string version = GetPackagerVersion();
if (!version.empty()) {
std::string version_string =
base::StringPrintf("Generated with %s version %s",
GetPackagerProjectUrl().c_str(), version.c_str());
xml::scoped_xml_ptr<xmlNode> comment(
xmlNewDocComment(doc.get(), BAD_CAST version_string.c_str()));
xmlDocSetRootElement(doc.get(), comment.get());
xmlAddSibling(comment.release(), mpd.Release());
} else {
xmlDocSetRootElement(doc.get(), mpd.Release());
}
return doc.release();
}
void MpdBuilder::AddCommonMpdInfo(XmlNode* mpd_node) {
if (Positive(mpd_options_.min_buffer_time)) {
mpd_node->SetStringAttribute(
"minBufferTime", SecondsToXmlDuration(mpd_options_.min_buffer_time));
} else {
LOG(ERROR) << "minBufferTime value not specified.";
// TODO(tinskip): Propagate error.
}
}
void MpdBuilder::AddStaticMpdInfo(XmlNode* mpd_node) {
DCHECK(mpd_node);
DCHECK_EQ(MpdType::kStatic, mpd_options_.mpd_type);
static const char kStaticMpdType[] = "static";
mpd_node->SetStringAttribute("type", kStaticMpdType);
mpd_node->SetStringAttribute(
"mediaPresentationDuration",
SecondsToXmlDuration(GetStaticMpdDuration(mpd_node)));
}
void MpdBuilder::AddDynamicMpdInfo(XmlNode* mpd_node) {
DCHECK(mpd_node);
DCHECK_EQ(MpdType::kDynamic, mpd_options_.mpd_type);
static const char kDynamicMpdType[] = "dynamic";
mpd_node->SetStringAttribute("type", kDynamicMpdType);
// No offset from NOW.
mpd_node->SetStringAttribute("publishTime",
XmlDateTimeNowWithOffset(0, clock_.get()));
// 'availabilityStartTime' is required for dynamic profile. Calculate if
// not already calculated.
if (availability_start_time_.empty()) {
double earliest_presentation_time;
if (GetEarliestTimestamp(&earliest_presentation_time)) {
availability_start_time_ =
XmlDateTimeNowWithOffset(mpd_options_.availability_time_offset -
std::ceil(earliest_presentation_time),
clock_.get());
} else {
LOG(ERROR) << "Could not determine the earliest segment presentation "
"time for availabilityStartTime calculation.";
// TODO(tinskip). Propagate an error.
}
}
if (!availability_start_time_.empty())
mpd_node->SetStringAttribute("availabilityStartTime",
availability_start_time_);
if (Positive(mpd_options_.minimum_update_period)) {
mpd_node->SetStringAttribute(
"minimumUpdatePeriod",
SecondsToXmlDuration(mpd_options_.minimum_update_period));
} else {
LOG(WARNING) << "The profile is dynamic but no minimumUpdatePeriod "
"specified.";
}
SetIfPositive("timeShiftBufferDepth", mpd_options_.time_shift_buffer_depth,
mpd_node);
SetIfPositive("suggestedPresentationDelay",
mpd_options_.suggested_presentation_delay, mpd_node);
}
float MpdBuilder::GetStaticMpdDuration(XmlNode* mpd_node) {
DCHECK(mpd_node);
DCHECK_EQ(MpdType::kStatic, mpd_options_.mpd_type);
xmlNodePtr period_node = FindPeriodNode(mpd_node);
DCHECK(period_node) << "Period element must be a child of mpd_node.";
DCHECK(IsPeriodNode(period_node));
// TODO(kqyang): Verify if this works for static + live profile.
// Attribute mediaPresentationDuration must be present for 'static' MPD. So
// setting "PT0S" is required even if none of the representaions have duration
// attribute.
float max_duration = 0.0f;
for (xmlNodePtr adaptation_set = xmlFirstElementChild(period_node);
adaptation_set; adaptation_set = xmlNextElementSibling(adaptation_set)) {
for (xmlNodePtr representation = xmlFirstElementChild(adaptation_set);
representation;
representation = xmlNextElementSibling(representation)) {
float duration = 0.0f;
if (GetDurationAttribute(representation, &duration)) {
max_duration = max_duration > duration ? max_duration : duration;
// 'duration' attribute is there only to help generate MPD, not
// necessary for MPD, remove the attribute.
xmlUnsetProp(representation, BAD_CAST "duration");
}
}
}
return max_duration;
}
bool MpdBuilder::GetEarliestTimestamp(double* timestamp_seconds) {
DCHECK(timestamp_seconds);
double earliest_timestamp(-1);
for (const std::unique_ptr<AdaptationSet>& adaptation_set :
adaptation_sets_) {
double timestamp;
if (adaptation_set->GetEarliestTimestamp(&timestamp) &&
((earliest_timestamp < 0) || (timestamp < earliest_timestamp))) {
earliest_timestamp = timestamp;
}
}
if (earliest_timestamp < 0)
return false;
*timestamp_seconds = earliest_timestamp;
return true;
}
void MpdBuilder::MakePathsRelativeToMpd(const std::string& mpd_path,
MediaInfo* media_info) {
DCHECK(media_info);
const std::string kFileProtocol("file://");
std::string mpd_file_path = (mpd_path.find(kFileProtocol) == 0)
? mpd_path.substr(kFileProtocol.size())
: mpd_path;
if (!mpd_file_path.empty()) {
std::string mpd_dir(FilePath::FromUTF8Unsafe(mpd_file_path)
.DirName().AsEndingWithSeparator().AsUTF8Unsafe());
if (!mpd_dir.empty()) {
if (media_info->has_media_file_name()) {
media_info->set_media_file_name(
MakePathRelative(media_info->media_file_name(), mpd_dir));
}
if (media_info->has_init_segment_name()) {
media_info->set_init_segment_name(
MakePathRelative(media_info->init_segment_name(), mpd_dir));
}
if (media_info->has_segment_template()) {
media_info->set_segment_template(
MakePathRelative(media_info->segment_template(), mpd_dir));
}
}
}
}
AdaptationSet::AdaptationSet(uint32_t adaptation_set_id,
const std::string& lang,
const MpdOptions& mpd_options,
base::AtomicSequenceNumber* counter)
: representation_counter_(counter),
id_(adaptation_set_id),
lang_(lang),
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_->GetNext();
// 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> representation(new Representation(
media_info, mpd_options_, representation_id, std::move(listener)));
if (!representation->Init()) {
LOG(ERROR) << "Failed to initialize Representation.";
return NULL;
}
// 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()));
}
}
representations_.push_back(std::move(representation));
return representations_.back().get();
}
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::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.
xml::scoped_xml_ptr<xmlNode> AdaptationSet::GetXml() {
AdaptationSetXmlNode adaptation_set;
bool suppress_representation_width = false;
bool suppress_representation_height = false;
bool suppress_representation_frame_rate = false;
adaptation_set.SetId(id_);
adaptation_set.SetStringAttribute("contentType", content_type_);
if (!lang_.empty() && lang_ != "und") {
adaptation_set.SetStringAttribute("lang", LanguageToShortestForm(lang_));
}
// Note that std::{set,map} are ordered, so the last element is the max value.
if (video_widths_.size() == 1) {
suppress_representation_width = true;
adaptation_set.SetIntegerAttribute("width", *video_widths_.begin());
} else if (video_widths_.size() > 1) {
adaptation_set.SetIntegerAttribute("maxWidth", *video_widths_.rbegin());
}
if (video_heights_.size() == 1) {
suppress_representation_height = true;
adaptation_set.SetIntegerAttribute("height", *video_heights_.begin());
} else if (video_heights_.size() > 1) {
adaptation_set.SetIntegerAttribute("maxHeight", *video_heights_.rbegin());
}
if (video_frame_rates_.size() == 1) {
suppress_representation_frame_rate = true;
adaptation_set.SetStringAttribute("frameRate",
video_frame_rates_.begin()->second);
} else if (video_frame_rates_.size() > 1) {
adaptation_set.SetStringAttribute("maxFrameRate",
video_frame_rates_.rbegin()->second);
}
// Note: must be checked before checking segments_aligned_ (below). So that
// segments_aligned_ is set before checking below.
if (mpd_options_.dash_profile == DashProfile::kOnDemand) {
CheckVodSegmentAlignment();
}
if (segments_aligned_ == kSegmentAlignmentTrue) {
adaptation_set.SetStringAttribute(
mpd_options_.dash_profile == DashProfile::kOnDemand
? "subsegmentAlignment"
: "segmentAlignment",
"true");
}
if (picture_aspect_ratio_.size() == 1)
adaptation_set.SetStringAttribute("par", *picture_aspect_ratio_.begin());
if (!adaptation_set.AddContentProtectionElements(
content_protection_elements_)) {
return xml::scoped_xml_ptr<xmlNode>();
}
if (!trick_play_reference_ids_.empty()) {
std::string id_string;
for (uint32_t id : trick_play_reference_ids_) {
id_string += std::to_string(id) + ",";
}
DCHECK(!id_string.empty());
id_string.resize(id_string.size() - 1);
adaptation_set.AddEssentialProperty(
"http://dashif.org/guidelines/trickmode", id_string);
}
std::string switching_ids;
for (uint32_t id : adaptation_set_switching_ids_) {
if (!switching_ids.empty())
switching_ids += ',';
switching_ids += base::UintToString(id);
}
if (!switching_ids.empty()) {
adaptation_set.AddSupplementalProperty(
"urn:mpeg:dash:adaptation-set-switching:2016", switching_ids);
}
for (AdaptationSet::Role role : roles_)
adaptation_set.AddRoleElement("urn:mpeg:dash:role:2011", RoleToText(role));
for (const std::unique_ptr<Representation>& representation :
representations_) {
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);
xml::scoped_xml_ptr<xmlNode> child(representation->GetXml());
if (!child || !adaptation_set.AddChild(std::move(child)))
return xml::scoped_xml_ptr<xmlNode>();
}
return adaptation_set.PassScopedPtr();
}
void AdaptationSet::ForceSetSegmentAlignment(bool segment_alignment) {
segments_aligned_ =
segment_alignment ? kSegmentAlignmentTrue : kSegmentAlignmentFalse;
force_set_segment_alignment_ = true;
}
void AdaptationSet::AddAdaptationSetSwitching(uint32_t adaptation_set_id) {
adaptation_set_switching_ids_.push_back(adaptation_set_id);
}
// Check segmentAlignment for Live here. Storing all start_time and duration
// will out-of-memory because there's no way of knowing when it will end.
// VOD 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 Live, all Representations should be added before a
// segment is added.
void AdaptationSet::OnNewSegmentForRepresentation(uint32_t representation_id,
uint64_t start_time,
uint64_t duration) {
if (mpd_options_.dash_profile == DashProfile::kLive) {
CheckLiveSegmentAlignment(representation_id, start_time, duration);
} else {
representation_segment_start_times_[representation_id].push_back(
start_time);
}
}
void AdaptationSet::OnSetFrameRateForRepresentation(
uint32_t representation_id,
uint32_t frame_duration,
uint32_t timescale) {
RecordFrameRate(frame_duration, timescale);
}
void AdaptationSet::AddTrickPlayReferenceId(uint32_t id) {
trick_play_reference_ids_.insert(id);
}
bool AdaptationSet::GetEarliestTimestamp(double* timestamp_seconds) {
DCHECK(timestamp_seconds);
double earliest_timestamp(-1);
for (const std::unique_ptr<Representation>& representation :
representations_) {
double timestamp;
if (representation->GetEarliestTimestamp(&timestamp) &&
((earliest_timestamp < 0) || (timestamp < earliest_timestamp))) {
earliest_timestamp = timestamp;
}
}
if (earliest_timestamp < 0)
return false;
*timestamp_seconds = earliest_timestamp;
return true;
}
// 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::CheckLiveSegmentAlignment(uint32_t representation_id,
uint64_t start_time,
uint64_t /* duration */) {
if (segments_aligned_ == kSegmentAlignmentFalse ||
force_set_segment_alignment_) {
return;
}
std::list<uint64_t>& representation_start_times =
representation_segment_start_times_[representation_id];
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() != representations_.size())
return;
DCHECK(!representation_start_times.empty());
const uint64_t expected_start_time = representation_start_times.front();
for (RepresentationTimeline::const_iterator it =
representation_segment_start_times_.begin();
it != representation_segment_start_times_.end(); ++it) {
// 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 (it->second.empty())
return;
if (expected_start_time != it->second.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 (RepresentationTimeline::iterator it =
representation_segment_start_times_.begin();
it != representation_segment_start_times_.end(); ++it) {
it->second.pop_front();
}
}
// Make sure all segements start times match for all Representations.
// This assumes that the segments are contiguous.
void AdaptationSet::CheckVodSegmentAlignment() {
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<uint64_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<uint64_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<uint64_t>* longer_list = &other_time_line;
const std::list<uint64_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(uint32_t frame_duration,
uint32_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] =
base::IntToString(timescale) + "/" + base::IntToString(frame_duration);
}
Representation::Representation(
const MediaInfo& media_info,
const MpdOptions& mpd_options,
uint32_t id,
std::unique_ptr<RepresentationStateChangeListener> state_change_listener)
: media_info_(media_info),
id_(id),
bandwidth_estimator_(BandwidthEstimator::kUseAllBlocks),
mpd_options_(mpd_options),
start_number_(1),
state_change_listener_(std::move(state_change_listener)),
output_suppression_flags_(0) {}
Representation::~Representation() {}
bool Representation::Init() {
if (!AtLeastOneTrue(media_info_.has_video_info(),
media_info_.has_audio_info(),
media_info_.has_text_info())) {
// This is an error. Segment information can be in AdaptationSet, Period, or
// MPD but the interface does not provide a way to set them.
// See 5.3.9.1 ISO 23009-1:2012 for segment info.
LOG(ERROR) << "Representation needs one of video, audio, or text.";
return false;
}
if (MoreThanOneTrue(media_info_.has_video_info(),
media_info_.has_audio_info(),
media_info_.has_text_info())) {
LOG(ERROR) << "Only one of VideoInfo, AudioInfo, or TextInfo can be set.";
return false;
}
if (media_info_.container_type() == MediaInfo::CONTAINER_UNKNOWN) {
LOG(ERROR) << "'container_type' in MediaInfo cannot be CONTAINER_UNKNOWN.";
return false;
}
if (media_info_.has_video_info()) {
mime_type_ = GetVideoMimeType();
if (!HasRequiredVideoFields(media_info_.video_info())) {
LOG(ERROR) << "Missing required fields to create a video Representation.";
return false;
}
} else if (media_info_.has_audio_info()) {
mime_type_ = GetAudioMimeType();
} else if (media_info_.has_text_info()) {
mime_type_ = GetTextMimeType();
}
if (mime_type_.empty())
return false;
codecs_ = GetCodecs(media_info_);
return true;
}
void Representation::AddContentProtectionElement(
const ContentProtectionElement& content_protection_element) {
content_protection_elements_.push_back(content_protection_element);
RemoveDuplicateAttributes(&content_protection_elements_.back());
}
void Representation::UpdateContentProtectionPssh(const std::string& drm_uuid,
const std::string& pssh) {
UpdateContentProtectionPsshHelper(drm_uuid, pssh,
&content_protection_elements_);
}
void Representation::AddNewSegment(uint64_t start_time,
uint64_t duration,
uint64_t size) {
if (start_time == 0 && duration == 0) {
LOG(WARNING) << "Got segment with start_time and duration == 0. Ignoring.";
return;
}
if (state_change_listener_)
state_change_listener_->OnNewSegmentForRepresentation(start_time, duration);
if (IsContiguous(start_time, duration, size)) {
++segment_infos_.back().repeat;
} else {
SegmentInfo s = {start_time, duration, /* Not repeat. */ 0};
segment_infos_.push_back(s);
}
bandwidth_estimator_.AddBlock(
size, static_cast<double>(duration) / media_info_.reference_time_scale());
SlideWindow();
DCHECK_GE(segment_infos_.size(), 1u);
}
void Representation::SetSampleDuration(uint32_t sample_duration) {
if (media_info_.has_video_info()) {
media_info_.mutable_video_info()->set_frame_duration(sample_duration);
if (state_change_listener_) {
state_change_listener_->OnSetFrameRateForRepresentation(
sample_duration, media_info_.video_info().time_scale());
}
}
}
// Uses info in |media_info_| and |content_protection_elements_| to create a
// "Representation" node.
// MPD schema has strict ordering. The following must be done in order.
// AddVideoInfo() (possibly adds FramePacking elements), AddAudioInfo() (Adds
// AudioChannelConfig elements), AddContentProtectionElements*(), and
// AddVODOnlyInfo() (Adds segment info).
xml::scoped_xml_ptr<xmlNode> Representation::GetXml() {
if (!HasRequiredMediaInfoFields()) {
LOG(ERROR) << "MediaInfo missing required fields.";
return xml::scoped_xml_ptr<xmlNode>();
}
const uint64_t bandwidth = media_info_.has_bandwidth()
? media_info_.bandwidth()
: bandwidth_estimator_.Estimate();
DCHECK(!(HasVODOnlyFields(media_info_) && HasLiveOnlyFields(media_info_)));
RepresentationXmlNode representation;
// Mandatory fields for Representation.
representation.SetId(id_);
representation.SetIntegerAttribute("bandwidth", bandwidth);
if (!codecs_.empty())
representation.SetStringAttribute("codecs", codecs_);
representation.SetStringAttribute("mimeType", mime_type_);
const bool has_video_info = media_info_.has_video_info();
const bool has_audio_info = media_info_.has_audio_info();
if (has_video_info &&
!representation.AddVideoInfo(
media_info_.video_info(),
!(output_suppression_flags_ & kSuppressWidth),
!(output_suppression_flags_ & kSuppressHeight),
!(output_suppression_flags_ & kSuppressFrameRate))) {
LOG(ERROR) << "Failed to add video info to Representation XML.";
return xml::scoped_xml_ptr<xmlNode>();
}
if (has_audio_info &&
!representation.AddAudioInfo(media_info_.audio_info())) {
LOG(ERROR) << "Failed to add audio info to Representation XML.";
return xml::scoped_xml_ptr<xmlNode>();
}
if (!representation.AddContentProtectionElements(
content_protection_elements_)) {
return xml::scoped_xml_ptr<xmlNode>();
}
// Set media duration for static mpd.
if (mpd_options_.mpd_type == MpdType::kStatic &&
media_info_.has_media_duration_seconds()) {
// Adding 'duration' attribute, so that this information can be used when
// generating one MPD file. This should be removed from the final MPD.
representation.SetFloatingPointAttribute(
"duration", media_info_.media_duration_seconds());
}
if (HasVODOnlyFields(media_info_) &&
!representation.AddVODOnlyInfo(media_info_)) {
LOG(ERROR) << "Failed to add VOD segment info.";
return xml::scoped_xml_ptr<xmlNode>();
}
if (HasLiveOnlyFields(media_info_) &&
!representation.AddLiveOnlyInfo(media_info_, segment_infos_,
start_number_)) {
LOG(ERROR) << "Failed to add Live info.";
return xml::scoped_xml_ptr<xmlNode>();
}
// TODO(rkuroiwa): It is likely that all representations have the exact same
// SegmentTemplate. Optimize and propagate the tag up to AdaptationSet level.
output_suppression_flags_ = 0;
return representation.PassScopedPtr();
}
void Representation::SuppressOnce(SuppressFlag flag) {
output_suppression_flags_ |= flag;
}
bool Representation::HasRequiredMediaInfoFields() {
if (HasVODOnlyFields(media_info_) && HasLiveOnlyFields(media_info_)) {
LOG(ERROR) << "MediaInfo cannot have both VOD and Live fields.";
return false;
}
if (!media_info_.has_container_type()) {
LOG(ERROR) << "MediaInfo missing required field: container_type.";
return false;
}
if (HasVODOnlyFields(media_info_) && !media_info_.has_bandwidth()) {
LOG(ERROR) << "Missing 'bandwidth' field. MediaInfo requires bandwidth for "
"static profile for generating a valid MPD.";
return false;
}
VLOG_IF(3, HasLiveOnlyFields(media_info_) && !media_info_.has_bandwidth())
<< "MediaInfo missing field 'bandwidth'. Using estimated from "
"segment size.";
return true;
}
bool Representation::IsContiguous(uint64_t start_time,
uint64_t duration,
uint64_t size) const {
if (segment_infos_.empty())
return false;
// Contiguous segment.
const SegmentInfo& previous = segment_infos_.back();
const uint64_t previous_segment_end_time =
previous.start_time + previous.duration * (previous.repeat + 1);
if (previous_segment_end_time == start_time &&
segment_infos_.back().duration == duration) {
return true;
}
// No out of order segments.
const uint64_t previous_segment_start_time =
previous.start_time + previous.duration * previous.repeat;
if (previous_segment_start_time >= start_time) {
LOG(ERROR) << "Segments should not be out of order segment. Adding segment "
"with start_time == "
<< start_time << " but the previous segment starts at "
<< previous_segment_start_time << ".";
return false;
}
// A gap since previous.
const uint64_t kRoundingErrorGrace = 5;
if (previous_segment_end_time + kRoundingErrorGrace < start_time) {
LOG(WARNING) << "Found a gap of size "
<< (start_time - previous_segment_end_time)
<< " > kRoundingErrorGrace (" << kRoundingErrorGrace
<< "). The new segment starts at " << start_time
<< " but the previous segment ends at "
<< previous_segment_end_time << ".";
return false;
}
// No overlapping segments.
if (start_time < previous_segment_end_time - kRoundingErrorGrace) {
LOG(WARNING)
<< "Segments should not be overlapping. The new segment starts at "
<< start_time << " but the previous segment ends at "
<< previous_segment_end_time << ".";
return false;
}
// Within rounding error grace but technically not contiguous in terms of MPD.
return false;
}
void Representation::SlideWindow() {
DCHECK(!segment_infos_.empty());
if (mpd_options_.time_shift_buffer_depth <= 0.0 ||
mpd_options_.mpd_type == MpdType::kStatic)
return;
const uint32_t time_scale = GetTimeScale(media_info_);
DCHECK_GT(time_scale, 0u);
uint64_t time_shift_buffer_depth =
static_cast<uint64_t>(mpd_options_.time_shift_buffer_depth * time_scale);
// The start time of the latest segment is considered the current_play_time,
// and this should guarantee that the latest segment will stay in the list.
const uint64_t current_play_time = LatestSegmentStartTime(segment_infos_);
if (current_play_time <= time_shift_buffer_depth)
return;
const uint64_t timeshift_limit = current_play_time - time_shift_buffer_depth;
// First remove all the SegmentInfos that are completely out of range, by
// looking at the very last segment's end time.
std::list<SegmentInfo>::iterator first = segment_infos_.begin();
std::list<SegmentInfo>::iterator last = first;
size_t num_segments_removed = 0;
for (; last != segment_infos_.end(); ++last) {
const uint64_t last_segment_end_time = LastSegmentEndTime(*last);
if (timeshift_limit < last_segment_end_time)
break;
num_segments_removed += last->repeat + 1;
}
segment_infos_.erase(first, last);
start_number_ += num_segments_removed;
// Now some segment in the first SegmentInfo should be left in the list.
SegmentInfo* first_segment_info = &segment_infos_.front();
DCHECK_LE(timeshift_limit, LastSegmentEndTime(*first_segment_info));
// Identify which segments should still be in the SegmentInfo.
const int repeat_index =
SearchTimedOutRepeatIndex(timeshift_limit, *first_segment_info);
CHECK_GE(repeat_index, 0);
if (repeat_index == 0)
return;
first_segment_info->start_time = first_segment_info->start_time +
first_segment_info->duration * repeat_index;
first_segment_info->repeat = first_segment_info->repeat - repeat_index;
start_number_ += repeat_index;
}
std::string Representation::GetVideoMimeType() const {
return GetMimeType("video", media_info_.container_type());
}
std::string Representation::GetAudioMimeType() const {
return GetMimeType("audio", media_info_.container_type());
}
std::string Representation::GetTextMimeType() const {
CHECK(media_info_.has_text_info());
if (media_info_.text_info().format() == "ttml") {
switch (media_info_.container_type()) {
case MediaInfo::CONTAINER_TEXT:
return "application/ttml+xml";
case MediaInfo::CONTAINER_MP4:
return "application/mp4";
default:
LOG(ERROR) << "Failed to determine MIME type for TTML container: "
<< media_info_.container_type();
return "";
}
}
if (media_info_.text_info().format() == "vtt") {
if (media_info_.container_type() == MediaInfo::CONTAINER_TEXT) {
return "text/vtt";
} else if (media_info_.container_type() == MediaInfo::CONTAINER_MP4) {
return "application/mp4";
}
LOG(ERROR) << "Failed to determine MIME type for VTT container: "
<< media_info_.container_type();
return "";
}
LOG(ERROR) << "Cannot determine MIME type for format: "
<< media_info_.text_info().format()
<< " container: " << media_info_.container_type();
return "";
}
bool Representation::GetEarliestTimestamp(double* timestamp_seconds) {
DCHECK(timestamp_seconds);
if (segment_infos_.empty())
return false;
*timestamp_seconds = static_cast<double>(segment_infos_.begin()->start_time) /
GetTimeScale(media_info_);
return true;
}
} // namespace shaka
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