TEMPLATE_EssenceSubParser Class Reference

#include <esp_template.h>

Inheritance diagram for TEMPLATE_EssenceSubParser:

List of all members.

Public Member Functions
	TEMPLATE_EssenceSubParser ()
virtual EssenceSubParserPtr	NewParser (void) const
	Build a new parser of this type and return a pointer to it.
virtual StringList	HandledExtensions (void)
	Report the extensions of files this sub-parser is likely to handle.
virtual EssenceStreamDescriptorList	IdentifyEssence (FileHandle InFile)
	Examine the open file and return a list of essence descriptors.
virtual WrappingOptionList	IdentifyWrappingOptions (FileHandle InFile, EssenceStreamDescriptor &Descriptor)
	Examine the open file and return the wrapping options known by this parser.
virtual void	Use (UInt32 Stream, WrappingOptionPtr UseWrapping)
	Set a wrapping option for future Read and Write calls.
virtual bool	SetEditRate (Rational EditRate)
	Set a non-native edit rate.
virtual Rational	GetEditRate (void)
	Get the current edit rate.
virtual Rational	GetPreferredEditRate (void)
	Get the preferred edit rate (if one is known).
virtual UInt32	GetBytesPerEditUnit (UInt32 KAGSize=1)
	Get BytesPerEditUnit, if Constant.
virtual Position	GetCurrentPosition (void)
	Get the current position in SetEditRate() sized edit units.
virtual DataChunkPtr	Read (FileHandle InFile, UInt32 Stream, UInt64 Count=1)
	Read a number of wrapping items from the specified stream and return them in a data chunk.
virtual EssenceSubParserBase::ESP_EssenceSource *	GetEssenceSource (FileHandle InFile, UInt32 Stream, UInt64 Count=1)
	Build an EssenceSource to read a number of wrapping items from the specified stream.
virtual Length	Write (FileHandle InFile, UInt32 Stream, MXFFilePtr OutFile, UInt64 Count=1)
	Write a number of wrapping items from the specified stream to an MXF file.
virtual std::string	GetParserName (void) const
	Get a unique name for this sub-parser.
Protected Member Functions
bool	CalcWrappingSequence (Rational EditRate)
	Work out wrapping sequence.
MDObjectPtr	BuildDescriptor (FileHandle InFile, UInt64 Start=0)
	Read the essence information at the specified position in the source file and build an essence descriptor.
size_t	ReadInternal (FileHandle InFile, UInt32 Stream, UInt64 Count)
	Scan the essence to calculate how many bytes to transfer for the given edit unit count.
Protected Attributes
UInt32	SampleRate
	The sample rate of this essence.
Rational	UseEditRate
	The edit rate to use for wrapping this essence.
Position	DataStart
	Start of essence data within the file.
Length	DataSize
	Total size of the essence data within the file.
Position	CurrentPos
	Current position in the input file (in bytes).
size_t	CachedDataSize
	The size of the next data to be read, or (size_t)-1 if not known.
UInt64	CachedCount
	The number of wrapping units that CachedDataSize relates to.
int	SampleSize
	Size of each sample in bytes (if constant).
UInt32	ConstSamples
	Number of samples per edit unit (if constant, else zero).
int	SampleSequenceSize
	Size of SampleSequence if used.
UInt32 *	SampleSequence
	Array of counts of samples per edit unit for non integer relationships between edit rate and sample rate.
int	SequencePos
	Current position in the sequence (i.e. next entry to use).
MDObjectParent	CurrentDescriptor
	Pointer to the last essence descriptor we built.
Friends
class	TEMPLATE_EssenceSubParser::ESP_EssenceSource
Classes
class	ESP_EssenceSource
	Class for EssenceSource objects for parsing/sourcing <Type> essence. More...

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Constructor & Destructor Documentation

TEMPLATE_EssenceSubParser

(

)

[inline]

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Member Function Documentation

virtual EssenceSubParserPtr NewParser

(

void

)

const [inline, virtual]

Build a new parser of this type and return a pointer to it.

Implements EssenceSubParser.

virtual StringList HandledExtensions

(

void

)

[inline, virtual]

Report the extensions of files this sub-parser is likely to handle.

Reimplemented from EssenceSubParser.

EssenceStreamDescriptorList IdentifyEssence

(

FileHandle

InFile

)

[virtual]

Examine the open file and return a list of essence descriptors.

Note:

This call will modify properties SampleRate, DataStart and DataSize

Reimplemented from EssenceSubParser.

WrappingOptionList IdentifyWrappingOptions	(	FileHandle	InFile,
		EssenceStreamDescriptor &	Descriptor
	)			[virtual]

Examine the open file and return the wrapping options known by this parser.

Parameters:

	InFile	The open file to examine (if the descriptor does not contain enough info)
	Descriptor	An essence stream descriptor (as produced by function IdentifyEssence) of the essence stream requiring wrapping

Note:

The options should be returned in an order of preference as the caller is likely to use the first that it can support

Reimplemented from EssenceSubParser.

virtual void Use	(	UInt32	Stream,
		WrappingOptionPtr	UseWrapping
	)			[inline, virtual]

Set a wrapping option for future Read and Write calls.

Returns:

true if this EditRate is acceptable with this wrapping

virtual bool SetEditRate

(

Rational

EditRate

)

[inline, virtual]

Set a non-native edit rate.

Must be called after Use()

Returns:

true if this rate is acceptable

Reimplemented from EssenceSubParser.

virtual Rational GetEditRate

(

void

)

[inline, virtual]

Get the current edit rate.

Implements EssenceSubParser.

Rational GetPreferredEditRate

(

void

)

[virtual]

Get the preferred edit rate (if one is known).

Returns:

The prefered edit rate or 0/0 if note known

Reimplemented from EssenceSubParser.

virtual UInt32 GetBytesPerEditUnit

(

UInt32

KAGSize = 1

)

[inline, virtual]

Get BytesPerEditUnit, if Constant.

Reimplemented from EssenceSubParser.

Position GetCurrentPosition

(

void

)

[virtual]

Get the current position in SetEditRate() sized edit units.

Returns:

0 if position not known

Implements EssenceSubParser.

DataChunkPtr Read	(	FileHandle	InFile,
		UInt32	Stream,
		UInt64	Count = 1
	)			[virtual]

Read a number of wrapping items from the specified stream and return them in a data chunk.

If frame or line mapping is used the parameter Count is used to determine how many items are read. In frame wrapping it is in units of EditRate, as specified in the call to Use(), which may not be the frame rate of this essence

Note:

This is going to take a lot of memory in clip wrapping!

Implements EssenceSubParser.

virtual EssenceSubParserBase::ESP_EssenceSource* GetEssenceSource	(	FileHandle	InFile,
		UInt32	Stream,
		UInt64	Count = 1
	)			[inline, virtual]

Build an EssenceSource to read a number of wrapping items from the specified stream.

Implements EssenceSubParser.

Length Write	(	FileHandle	InFile,
		UInt32	Stream,
		MXFFilePtr	OutFile,
		UInt64	Count = 1
	)			[virtual]

Write a number of wrapping items from the specified stream to an MXF file.

If frame or line mapping is used the parameter Count is used to determine how many items are read. In frame wrapping it is in units of EditRate, as specified in the call to Use(), which may not be the frame rate of this essence stream

Note:

This is the only safe option for clip wrapping

Returns:

Count of bytes transferred

Implements EssenceSubParser.

virtual std::string GetParserName

(

void

)

const [inline, virtual]

Get a unique name for this sub-parser.

The name must be all lower case, and must be unique. The recommended name is the part of the filename of the parser header after "esp_" and before the ".h". If the parser has no name return "" (however this will prevent named wrapping option selection for this sub-parser)

Reimplemented from EssenceSubParser.

bool CalcWrappingSequence

(

Rational

EditRate

)

[protected]

Work out wrapping sequence.

Returns:

true if a sequence was found, otherwise false

MDObjectPtr BuildDescriptor	(	FileHandle	InFile,
		UInt64	Start = 0
	)			[protected]

Read the essence information at the specified position in the source file and build an essence descriptor.

Note:

This call will modify properties SampleRate, DataStart and DataSize

size_t ReadInternal	(	FileHandle	InFile,
		UInt32	Stream,
		UInt64	Count
	)			[protected]

Scan the essence to calculate how many bytes to transfer for the given edit unit count.

Note:

The file position pointer is left at the start of the chunk at the end of this function

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Friends And Related Function Documentation

friend class TEMPLATE_EssenceSubParser::ESP_EssenceSource [friend]

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Member Data Documentation

UInt32 SampleRate [protected]

The sample rate of this essence.

Rational UseEditRate [protected]

The edit rate to use for wrapping this essence.

Position DataStart [protected]

Start of essence data within the file.

Length DataSize [protected]

Total size of the essence data within the file.

Position CurrentPos [protected]

Current position in the input file (in bytes).

A value of 0 means the start of the data chunk, any other value is that position within the whole file. This means that a full rewind can be achieved by setting CurrentPos = 0

Note:

Other functions may move the file pointer between calls to our functions

size_t CachedDataSize [protected]

The size of the next data to be read, or (size_t)-1 if not known.

UInt64 CachedCount [protected]

The number of wrapping units that CachedDataSize relates to.

int SampleSize [protected]

Size of each sample in bytes (if constant).

UInt32 ConstSamples [protected]

Number of samples per edit unit (if constant, else zero).

int SampleSequenceSize [protected]

Size of SampleSequence if used.

UInt32* SampleSequence [protected]

Array of counts of samples per edit unit for non integer relationships between edit rate and sample rate.

int SequencePos [protected]

Current position in the sequence (i.e. next entry to use).

MDObjectParent CurrentDescriptor [protected]

Pointer to the last essence descriptor we built.

This is used as a quick-and-dirty check that we know how to process this source

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

• esp_template.h
• esp_template.cpp

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