Implementation of TagParser::AbstractTrack for the MP4 container. More...

#include <mp4track.h>

Inheritance diagram for TagParser::Mp4Track:

Collaboration diagram for TagParser::Mp4Track:

Public Member Functions
	Mp4Track (Mp4Atom &trakAtom)
	Constructs a new track for the specified trakAtom.

	~Mp4Track () override
	Destroys the track.

TrackType	type () const override
	Returns the type of the track if known; otherwise returns TrackType::Unspecified.

Mp4Atom &	trakAtom ()
	Returns the trak atom for the current instance.

const std::vector< std::uint32_t > &	sampleSizes () const
	Returns the sample size table for the track.

unsigned int	chunkOffsetSize () const
	Returns the size of a single chunk offset denotation within the stco atom.

std::uint32_t	chunkCount () const
	Returns the number of chunks denoted by the stco atom.

std::uint32_t	sampleToChunkEntryCount () const
	Returns the number of "sample to chunk" entries within the stsc atom.

const Mpeg4ElementaryStreamInfo *	mpeg4ElementaryStreamInfo () const
	Returns information about the MPEG-4 elementary stream.

const AvcConfiguration *	avcConfiguration () const
	Returns the AVC configuration.

const Av1Configuration *	av1Configuration () const
	Returns the AV1 configuration.

std::vector< std::uint64_t >	readChunkOffsets (bool parseFragments, Diagnostics &diag)
	Reads the chunk offsets from the stco atom and fragments if parseFragments is true.

std::vector< std::tuple< std::uint32_t, std::uint32_t, std::uint32_t > >	readSampleToChunkTable (Diagnostics &diag)
	Reads the sample to chunk table.

std::vector< std::uint64_t >	readChunkSizes (TagParser::Diagnostics &diag)
	Reads the chunk sizes from the stsz (sample sizes) and stsc (samples per chunk) atom.

void	bufferTrackAtoms (Diagnostics &diag)
	Buffers all atoms required by the makeTrack() method.

std::uint64_t	requiredSize (Diagnostics &diag) const
	Returns the number of bytes written when calling makeTrack().

void	makeTrack (Diagnostics &diag)
	Makes the track entry ("trak"-atom) for the track.

void	makeTrackHeader (Diagnostics &diag)
	Makes the track header (tkhd atom) for the track.

void	makeMedia (Diagnostics &diag)
	Makes the media information (mdia atom) for the track.

void	makeMediaInfo (Diagnostics &diag)
	Makes a media information (minf atom) for the track.

void	makeSampleTable (Diagnostics &diag)
	Makes the sample table (stbl atom) for the track.

void	updateChunkOffsets (const std::vector< std::int64_t > &oldMdatOffsets, const std::vector< std::int64_t > &newMdatOffsets)
	Updates the chunk offsets of the track.

void	updateChunkOffsets (const std::vector< std::uint64_t > &chunkOffsets)
	Updates the chunk offsets of the track.

void	updateChunkOffset (std::uint32_t chunkIndex, std::uint64_t offset)
	Updates a particular chunk offset.

Public Member Functions inherited from TagParser::AbstractTrack
virtual	~AbstractTrack ()
	Destroys the track.

std::istream &	inputStream ()
	Returns the associated input stream.

void	setInputStream (std::istream &stream)
	Assigns another input stream.

std::ostream &	outputStream ()
	Returns the associated output stream.

void	setOutputStream (std::ostream &stream)
	Assigns another output stream.

CppUtilities::BinaryReader &	reader ()
	Returns a binary reader for the associated stream.

CppUtilities::BinaryWriter &	writer ()
	Returns a binary writer for the associated stream.

std::uint64_t	startOffset () const
	Returns the start offset of the track in the associated stream.

TrackFlags	flags () const
	Returns flags (various boolean properties) of this track.

MediaFormat	format () const
	Returns the format of the track if known; otherwise returns MediaFormat::Unknown.

double	version () const
	Returns the version/level of the track if known; otherwise returns 0.

std::string_view	formatName () const
	Returns the format of the track as C-style string if known; otherwise returns the format abbreviation or an empty string.

std::string_view	formatAbbreviation () const
	Returns the a more or less common abbreviation for the format of the track if known; otherwise returns an empty string.

const std::string &	formatId () const
	Returns the format/codec ID.

MediaType	mediaType () const
	Returns the media type if known; otherwise returns MediaType::Other.

std::string_view	mediaTypeName () const
	Returns the string representation of the media type of the track.

std::uint64_t	size () const
	Returns the size in bytes if known; otherwise returns 0.

void	setSize (std::uint64_t size)
	Sets the size in bytes.

std::uint32_t	trackNumber () const
	Returns the track number if known; otherwise returns 0.

void	setTrackNumber (std::uint32_t trackNumber)
	Sets the track number.

std::uint64_t	id () const
	Returns the track ID if known; otherwise returns 0.

void	setId (std::uint64_t id)
	Sets the track ID.

const std::string	name () const
	Returns the track name if known; otherwise returns an empty string.

void	setName (std::string_view name)
	Sets the name.

const CppUtilities::TimeSpan &	duration () const
	Returns the duration if known; otherwise returns a TimeSpan of zero ticks.

double	bitrate () const
	Returns the average bitrate in kbit/s if known; otherwise returns zero.

double	maxBitrate () const
	Returns the maximum bitrate in kbit/s if known; otherwise returns zero.

const CppUtilities::DateTime &	creationTime () const
	Returns the creation time if known; otherwise returns a DateTime of zero ticks.

const CppUtilities::DateTime &	modificationTime () const
	Returns the time of the last modification if known; otherwise returns a DateTime of zero ticks.

const Locale &	locale () const
	Returns the locale of the track if known; otherwise returns an empty locale.

void	setLocale (const Locale &locale)
	Sets the locale of the track.

std::uint32_t	samplingFrequency () const
	Returns the number of samples per second if known; otherwise returns 0.

std::uint32_t	extensionSamplingFrequency () const
	Returns the number of samples per second if known; otherwise returns 0.

std::uint16_t	bitsPerSample () const
	Returns the number of bits per sample; otherwise returns 0.

std::uint16_t	channelCount () const
	Returns the number of channels if known; otherwise returns 0.

std::uint8_t	channelConfig () const
	Returns the channel configuration.

std::string_view	channelConfigString () const
	Returns a string with the channel configuration if available; otherwise returns nullptr.

std::uint8_t	extensionChannelConfig () const
	Returns the extension channel configuration if available; otherwise returns nullptr.

std::string_view	extensionChannelConfigString () const
	Returns a string with the extension channel configuration if available; otherwise returns nullptr.

std::uint64_t	sampleCount () const
	Returns the number of samples/frames if known; otherwise returns 0.

int	quality () const
	Returns the quality if known; otherwise returns 0.

const Size &	pixelSize () const
	Returns the size of the encoded video frames if known; otherwise returns a zero size.

const Size &	displaySize () const
	Returns the size of the video frames to display if known; otherwise returns a zero size.

const Size &	resolution () const
	Returns the resolution if known; otherwise returns a zero size.

const std::string &	compressorName () const
	Returns the compressor name if known; otherwise returns an empty string.

void	setCompressorName (std::string_view compressorName)
	Returns the compressor name if known; otherwise returns an empty string.

std::uint16_t	depth () const
	Returns the bit depth if known; otherwise returns 0.

std::uint32_t	fps () const
	Returns the number of frames per second if known; otherwise returns 0.

std::string_view	chromaFormat () const
	Returns the chroma subsampling format if known; otherwise returns nullptr.

const AspectRatio &	pixelAspectRatio () const
	Returns the pixel aspect ratio (PAR).

bool	isInterlaced () const
	Returns true if the video is interlaced; otherwise returns false.

std::uint32_t	timeScale () const
	Returns the time scale if known; otherwise returns 0.

bool	isEnabled () const
	Returns true if the track is marked as enabled; otherwise returns false.

void	setEnabled (bool enabled)
	Sets whether the track is enabled.

bool	isDefault () const
	Returns true if the track is marked as default; otherwise returns false.

void	setDefault (bool isDefault)
	Sets whether the track is a default track.

bool	isForced () const
	Returns true if the track is marked as forced; otherwise returns false.

void	setForced (bool forced)
	Sets whether the track is forced.

bool	hasLacing () const
	Returns true if the track has lacing; otherwise returns false.

bool	isEncrypted () const
	Returns true if the track is marked as encrypted; otherwise returns false.

std::uint32_t	colorSpace () const
	Returns the color space if known; otherwise returns 0.

const Margin &	cropping () const
	Returns the cropping if known; otherwise returns zero margins.

std::string	label () const
	Returns a label for the track.

std::string	description () const
	Returns a description about the track.

std::string	shortDescription () const
	Returns a short description about the track.

void	parseHeader (Diagnostics &diag, AbortableProgressFeedback &progress)
	Parses technical information about the track from the header.

bool	isHeaderValid () const
	Returns an indication whether the track header is valid.

Static Public Member Functions
static std::unique_ptr< Mpeg4ElementaryStreamInfo >	parseMpeg4ElementaryStreamInfo (CppUtilities::BinaryReader &reader, Mp4Atom *esDescAtom, Diagnostics &diag)
	Reads the MPEG-4 elementary stream descriptor for the track.

static std::unique_ptr< Mpeg4AudioSpecificConfig >	parseAudioSpecificConfig (std::istream &stream, std::uint64_t startOffset, std::uint64_t size, Diagnostics &diag)
	Parses the audio specific configuration for the track.

static std::unique_ptr< Mpeg4VideoSpecificConfig >	parseVideoSpecificConfig (CppUtilities::BinaryReader &reader, std::uint64_t startOffset, std::uint64_t size, Diagnostics &diag)
	Parses the video specific configuration for the track.

static void	addInfo (const AvcConfiguration &avcConfig, AbstractTrack &track)
	Adds the information from the specified avcConfig to the specified track.

static void	addInfo (const Av1Configuration &av1Config, AbstractTrack &track)
	Adds the information from the specified av1Config to the specified track.

Protected Member Functions
void	internalParseHeader (Diagnostics &diag, AbortableProgressFeedback &progress) override
	This method is internally called to parse header information.

Protected Member Functions inherited from TagParser::AbstractTrack
	AbstractTrack (std::istream &inputStream, std::ostream &outputStream, std::uint64_t startOffset)
	Constructs a new track.

	AbstractTrack (std::iostream &stream, std::uint64_t startOffset)
	Constructs a new track.

Additional Inherited Members
Protected Attributes inherited from TagParser::AbstractTrack
std::istream *	m_istream

std::ostream *	m_ostream

CppUtilities::BinaryReader	m_reader

CppUtilities::BinaryWriter	m_writer

std::uint64_t	m_startOffset

TrackFlags	m_flags

MediaFormat	m_format

std::string	m_formatId

std::string	m_formatName

MediaType	m_mediaType

double	m_version

std::uint64_t	m_size

std::uint32_t	m_trackNumber

std::uint64_t	m_id

std::string	m_name

CppUtilities::TimeSpan	m_duration

double	m_bitrate

double	m_maxBitrate

CppUtilities::DateTime	m_creationTime

CppUtilities::DateTime	m_modificationTime

Locale	m_locale

std::uint32_t	m_samplingFrequency

std::uint32_t	m_extensionSamplingFrequency

std::uint16_t	m_bitsPerSample

std::uint32_t	m_bytesPerSecond

std::uint16_t	m_channelCount

std::uint8_t	m_channelConfig

std::uint8_t	m_extensionChannelConfig

std::uint16_t	m_chunkSize

std::uint64_t	m_sampleCount

int	m_quality

Size	m_pixelSize

Size	m_displaySize

Size	m_resolution

std::string	m_compressorName

std::uint16_t	m_depth

std::uint32_t	m_fps

std::string_view	m_chromaFormat

AspectRatio	m_pixelAspectRatio

std::uint32_t	m_timeScale

std::uint32_t	m_colorSpace

Margin	m_cropping

FieldOrder	m_fieldOrder

StereoMode	m_stereoMode

AlphaMode	m_alphaMode

DisplayUnit	m_displayUnit

AspectRatioType	m_aspectRatioType

std::unique_ptr< AbstractTrackPrivate >	m_p

Detailed Description

Implementation of TagParser::AbstractTrack for the MP4 container.

Definition at line 119 of file mp4track.h.

Constructor & Destructor Documentation

◆ Mp4Track()

TagParser::Mp4Track::Mp4Track ( Mp4Atom & trakAtom )

Constructs a new track for the specified trakAtom.

"trak"-atoms are stored in the top-level atom "move". Each "trak"-atom holds header information for one track in the MP4 file.

Definition at line 150 of file mp4track.cpp.

◆ ~Mp4Track()

TagParser::Mp4Track::~Mp4Track ( )

override

Destroys the track.

Definition at line 180 of file mp4track.cpp.

Member Function Documentation

◆ addInfo() [1/2]

void TagParser::Mp4Track::addInfo	(	const Av1Configuration &	av1Config,
		AbstractTrack &	track
	)

static

Adds the information from the specified av1Config to the specified track.

Todo:: Provide implementation

Definition at line 1106 of file mp4track.cpp.

◆ addInfo() [2/2]

void TagParser::Mp4Track::addInfo	(	const AvcConfiguration &	avcConfig,
		AbstractTrack &	track
	)

static

Adds the information from the specified avcConfig to the specified track.

Definition at line 1072 of file mp4track.cpp.

◆ av1Configuration()

const Av1Configuration * TagParser::Mp4Track::av1Configuration ( ) const

inline

Returns the AV1 configuration.

Remarks

The track must be parsed before this information becomes available.
The track keeps ownership over the returned object.

Definition at line 280 of file mp4track.h.

◆ avcConfiguration()

const AvcConfiguration * TagParser::Mp4Track::avcConfiguration ( ) const

inline

Returns the AVC configuration.

Remarks

The track must be parsed before this information becomes available.
The track keeps ownership over the returned object.

Definition at line 269 of file mp4track.h.

◆ bufferTrackAtoms()

void TagParser::Mp4Track::bufferTrackAtoms ( Diagnostics & diag )

Buffers all atoms required by the makeTrack() method.

This allows to invoke makeTrack() also when the input stream is going to be modified (eg. to apply changed tags without rewriting the file).

Definition at line 1119 of file mp4track.cpp.

◆ chunkCount()

std::uint32_t TagParser::Mp4Track::chunkCount ( ) const

inline

Returns the number of chunks denoted by the stco atom.

Definition at line 238 of file mp4track.h.

◆ chunkOffsetSize()

unsigned int TagParser::Mp4Track::chunkOffsetSize ( ) const

inline

Returns the size of a single chunk offset denotation within the stco atom.

Valid values are 4 and 8 bytes.

Definition at line 230 of file mp4track.h.

◆ internalParseHeader()

void TagParser::Mp4Track::internalParseHeader	(	Diagnostics &	diag,
		AbortableProgressFeedback &	progress
	)

overrideprotectedvirtual

This method is internally called to parse header information.

It needs to be implemented when subclassing this class.

Exceptions

Throws	std::ios_base::failure when an IO error occurs.
Throws	TagParser::Failure or a derived exception when a parsing error occurs.

Implements TagParser::AbstractTrack.

Definition at line 1526 of file mp4track.cpp.

◆ makeMedia()

void TagParser::Mp4Track::makeMedia ( Diagnostics & diag )

Makes the media information (mdia atom) for the track.

The data is written to the assigned output stream at the current position.

Definition at line 1311 of file mp4track.cpp.

◆ makeMediaInfo()

void TagParser::Mp4Track::makeMediaInfo ( Diagnostics & diag )

Makes a media information (minf atom) for the track.

The data is written to the assigned output stream at the current position.

Definition at line 1411 of file mp4track.cpp.

◆ makeSampleTable()

void TagParser::Mp4Track::makeSampleTable ( Diagnostics & diag )

Makes the sample table (stbl atom) for the track.

The data is written to the assigned output stream at the current position.

Remarks: Not fully implemented yet.

Definition at line 1466 of file mp4track.cpp.

◆ makeTrack()

void TagParser::Mp4Track::makeTrack ( Diagnostics & diag )

Makes the track entry ("trak"-atom) for the track.

The data is written to the assigned output stream at the current position. Note that this method uses the assigned input stream to copy some parts from the source file. Hence the input stream must still be valid when calling this method. To avoid this limitation call bufferTrackAtoms() before invalidating the input stream.

Definition at line 1194 of file mp4track.cpp.

◆ makeTrackHeader()

void TagParser::Mp4Track::makeTrackHeader ( Diagnostics & diag )

Makes the track header (tkhd atom) for the track.

The data is written to the assigned output stream at the current position.

Definition at line 1223 of file mp4track.cpp.

◆ mpeg4ElementaryStreamInfo()

const Mpeg4ElementaryStreamInfo * TagParser::Mp4Track::mpeg4ElementaryStreamInfo ( ) const

inline

Returns information about the MPEG-4 elementary stream.

Remarks

The track must be parsed before this information becomes available.
The information is only available, if the track has an MPEG-4 elementary stream descriptor atom.
The track keeps ownership over the returned object.

Definition at line 258 of file mp4track.h.

◆ parseAudioSpecificConfig()

unique_ptr< Mpeg4AudioSpecificConfig > TagParser::Mp4Track::parseAudioSpecificConfig	(	std::istream &	stream,
		std::uint64_t	startOffset,
		std::uint64_t	size,
		Diagnostics &	diag
	)

static

Parses the audio specific configuration for the track.

See also: mpeg4ElementaryStreamInfo()

Definition at line 705 of file mp4track.cpp.

◆ parseMpeg4ElementaryStreamInfo()

std::unique_ptr< Mpeg4ElementaryStreamInfo > TagParser::Mp4Track::parseMpeg4ElementaryStreamInfo	(	CppUtilities::BinaryReader &	reader,
		Mp4Atom *	esDescAtom,
		Diagnostics &	diag
	)

static

Reads the MPEG-4 elementary stream descriptor for the track.

See also: mpeg4ElementaryStreamInfo()

Definition at line 613 of file mp4track.cpp.

◆ parseVideoSpecificConfig()

std::unique_ptr< Mpeg4VideoSpecificConfig > TagParser::Mp4Track::parseVideoSpecificConfig	(	CppUtilities::BinaryReader &	reader,
		std::uint64_t	startOffset,
		std::uint64_t	size,
		Diagnostics &	diag
	)

static

Parses the video specific configuration for the track.

See also: mpeg4ElementaryStreamInfo()

Definition at line 870 of file mp4track.cpp.

◆ readChunkOffsets()

std::vector< std::uint64_t > TagParser::Mp4Track::readChunkOffsets	(	bool	parseFragments,
		Diagnostics &	diag
	)

Reads the chunk offsets from the stco atom and fragments if parseFragments is true.

Returns: Returns the chunk offset table for the track.

Exceptions

Throws	InvalidDataException when there is no stream assigned. the header has been considered as invalid when parsing the header information. the determined chunk offset size is invalid.
Throws	std::ios_base::failure when an IO error occurs.

See also: readChunkSizes();

Definition at line 199 of file mp4track.cpp.

◆ readChunkSizes()

vector< std::uint64_t > TagParser::Mp4Track::readChunkSizes ( TagParser::Diagnostics & diag )

Reads the chunk sizes from the stsz (sample sizes) and stsc (samples per chunk) atom.

Returns: Returns the chunk sizes for the track.

Exceptions

Throws	InvalidDataException when there is no stream assigned. the header has been considered as invalid when parsing the header information. the determined chunk offset size is invalid.
Throws	std::ios_base::failure when an IO error occurs.

See also: readChunkOffsets();

Definition at line 563 of file mp4track.cpp.

◆ readSampleToChunkTable()

vector< tuple< std::uint32_t, std::uint32_t, std::uint32_t > > TagParser::Mp4Track::readSampleToChunkTable ( Diagnostics & diag )

Reads the sample to chunk table.

Returns: Returns a vector with the table entries wrapped using the tuple container. The first value is an integer that gives the first chunk that share the same samples count and sample description index. The second value is sample count and the third value is the sample description index.

Remarks: The table is not validated.

Definition at line 514 of file mp4track.cpp.

◆ requiredSize()

std::uint64_t TagParser::Mp4Track::requiredSize ( Diagnostics & diag ) const

Returns the number of bytes written when calling makeTrack().

Definition at line 1142 of file mp4track.cpp.

◆ sampleSizes()

const std::vector< std::uint32_t > & TagParser::Mp4Track::sampleSizes ( ) const

inline

Returns the sample size table for the track.

Remarks: If the table contains only one size this is the constant sample size.; The table is empty if the track denotes 64-bit sample sizes.

See also: sampleSizes64()

Definition at line 220 of file mp4track.h.

◆ sampleToChunkEntryCount()

std::uint32_t TagParser::Mp4Track::sampleToChunkEntryCount ( ) const

inline

Returns the number of "sample to chunk" entries within the stsc atom.

Definition at line 246 of file mp4track.h.

◆ trakAtom()

Mp4Atom & TagParser::Mp4Track::trakAtom ( )

inline

Returns the trak atom for the current instance.

Definition at line 208 of file mp4track.h.

◆ type()

TrackType TagParser::Mp4Track::type ( ) const

overridevirtual

Returns the type of the track if known; otherwise returns TrackType::Unspecified.

Reimplemented from TagParser::AbstractTrack.

Definition at line 184 of file mp4track.cpp.

◆ updateChunkOffset()

void TagParser::Mp4Track::updateChunkOffset	(	std::uint32_t	chunkIndex,
		std::uint64_t	offset
	)

Updates a particular chunk offset.

Parameters

chunkIndex	Specifies the index of the chunk offset to be updated.
offset	Specifies the new chunk offset. If the "stco" atom is used the value must fit into a 32-bit unsigned int.

Remarks: This method seems to be obsolete.

Exceptions

Throws

InvalidDataException when

there is no stream assigned.
the header has been considered as invalid when parsing the header information.
chunkIndex is not less than chunkCount().
there is no atom holding these offsets.
the ID of the atom holding these offsets is not "stco" or "co64".

Definition at line 1051 of file mp4track.cpp.

◆ updateChunkOffsets() [1/2]

void TagParser::Mp4Track::updateChunkOffsets	(	const std::vector< std::int64_t > &	oldMdatOffsets,
		const std::vector< std::int64_t > &	newMdatOffsets
	)

Updates the chunk offsets of the track.

This is necessary when the "mdat"-atom (which contains the actual chunk data) is moved.

Parameters

oldMdatOffsets	Specifies a vector holding the old offsets of the "mdat"-atoms.
newMdatOffsets	Specifies a vector holding the new offsets of the "mdat"-atoms.

Exceptions

Throws	InvalidDataException when there is no stream assigned. the header has been considered as invalid when parsing the header information. oldMdatOffsets holds not the same number of offsets as newMdatOffsets. there is no atom holding these offsets. the ID of the atom holding these offsets is not "stco" or "co64"
Throws	std::ios_base::failure when an IO error occurs.

Remarks: This method needs to be fixed.

Definition at line 946 of file mp4track.cpp.

◆ updateChunkOffsets() [2/2]

void TagParser::Mp4Track::updateChunkOffsets ( const std::vector< std::uint64_t > & chunkOffsets )

Updates the chunk offsets of the track.

This is necessary when the "mdat"-atom (which contains the actual chunk data) is moved.

Parameters

chunkOffsets Specifies the new chunk offset table. If the "stco" atom is used the values must fit into an 32-bit unsigned int.

Exceptions

Throws

InvalidDataException when

there is no stream assigned.
the header has been considered as invalid when parsing the header information.
the size of chunkOffsets does not match chunkCount().
there is no atom holding these offsets.
the ID of the atom holding these offsets is not "stco" or "co64".

Definition at line 1013 of file mp4track.cpp.

The documentation for this class was generated from the following files:

mp4/mp4track.h
mp4/mp4track.cpp

Public Member Functions

Static Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Mp4Track()

◆ ~Mp4Track()

Member Function Documentation

◆ addInfo() [1/2]

◆ addInfo() [2/2]

◆ av1Configuration()

◆ avcConfiguration()

◆ bufferTrackAtoms()

◆ chunkCount()

◆ chunkOffsetSize()

◆ internalParseHeader()

◆ makeMedia()

◆ makeMediaInfo()

◆ makeSampleTable()

◆ makeTrack()

◆ makeTrackHeader()

◆ mpeg4ElementaryStreamInfo()

◆ parseAudioSpecificConfig()

◆ parseMpeg4ElementaryStreamInfo()

◆ parseVideoSpecificConfig()

◆ readChunkOffsets()

◆ readChunkSizes()

◆ readSampleToChunkTable()

◆ requiredSize()

◆ sampleSizes()

◆ sampleToChunkEntryCount()

◆ trakAtom()

◆ type()

◆ updateChunkOffset()

◆ updateChunkOffsets() [1/2]

◆ updateChunkOffsets() [2/2]