Definition of a character set for DVB encoding. More...

#include <tsDVBCharTable.h>

Inheritance diagram for ts::DVBCharTable:

[legend]

Collaboration diagram for ts::DVBCharTable:

Public Member Functions
virtual	~DVBCharTable () override
	Virtual destructor.

virtual bool	canEncode (const UString &str, size_t start=0, size_t count=NPOS) const =0
	Check if a string can be encoded using the charset (ie all characters can be represented).

virtual bool	decode (UString &str, const uint8_t *data, size_t size) const =0
	Decode a string from the specified byte buffer.

UString	decoded (const uint8_t *data, size_t size) const
	Decode a string from the specified byte buffer and return a UString.

UString	decodedWithByteLength (const uint8_t *&data, size_t &size) const
	Decode a string (preceded by its one-byte length) from the specified byte buffer.

bool	decodeWithByteLength (UString &str, const uint8_t *&data, size_t &size) const
	Decode a string (preceded by its one-byte length) from the specified byte buffer.

virtual size_t	encode (uint8_t *&buffer, size_t &size, const UString &str, size_t start=0, size_t count=NPOS) const =0
	Encode a C++ Unicode string.

ByteBlock	encoded (const UString &str, size_t start=0, size_t count=NPOS) const
	Encode a C++ Unicode string as a ByteBlock.

ByteBlock	encodedWithByteLength (const UString &str, size_t start=0, size_t count=NPOS) const
	Encode a C++ Unicode string as a ByteBlock (preceded by its one-byte length).

virtual size_t	encodeTableCode (uint8_t *&buffer, size_t &size) const
	Encode the character set table code.

size_t	encodeWithByteLength (uint8_t *&buffer, size_t &size, const UString &str, size_t start=0, size_t count=NPOS) const
	Encode a C++ Unicode string preceded by its one-byte length.

UString	name () const
	Get the character set name.

uint32_t	tableCode () const
	Get the DVB table code for the character set.

virtual void	unregister () const override
	Unregister the character set from the repository of character sets.

Static Public Member Functions
static bool	DecodeTableCode (uint32_t &code, size_t &codeSize, const uint8_t *dvb, size_t dvbSize)
	This static function gets the character coding table at the beginning of a DVB string.

static UStringList	GetAllNames ()
	Find all registered character set names.

static const Charset *	GetCharset (const UString &name)
	Get a character set by name.

static const DVBCharTable *	GetTableFromLeadingCode (uint32_t code)
	Get a DVB character set by table code.

Static Public Attributes
static constexpr uint16_t	DVB_CODEPOINT_CRLF = 0xE08A
	Code point for DVB-encoded CR/LF in two-byte character sets.

static constexpr uint8_t	DVB_SINGLE_BYTE_CRLF = 0x8A
	DVB-encoded CR/LF in single-byte character sets.

Protected Member Functions
	DVBCharTable (const UChar *name, uint32_t tableCode)
	Protected constructor.

Detailed Description

Definition of a character set for DVB encoding.

It is important to understand the difference between DVBCharset and DVBCharTable.

Both classes are subclasses of Charset. So, they both have the capabilities to encode and decode binary strings in DVB representation. But this is the only similarity.

DVBCharset is the generic decoder and encoder for DVB strings. When decoding a DVB string, it recognizes the leading sequence and uses the appropriate character table (a DVBCharTable) to interpret the binary data. When encoding a string, DVBCharset selects the most appropriate DVB character table and encodes the string using that table, after inserting the appropriate leading sequence to indicate which character table was used.

DVBCharTable, on the other hand, is an abstract superclass for all DVB character tables. Each subclass of DVBCharTable implements one specific DVB character table (modified ISO 6937, ISO 8859-1, ISO 8859-2, etc.) When encoding or decoding strings, a subclass of DVBCharTable only decode or encode binary data for this specific DVB character table. No leading sequence or decoded or encoded.

Usage guidelines:

Use DVBCharset when you serialize or deserialize tables and descriptors.
Use DVBCharTable when you implement the body of DVBCharset.

See also: ETSI EN 300 468, Annex A.; DVBCharset

Constructor & Destructor Documentation

◆ DVBCharTable()

ts::DVBCharTable::DVBCharTable	(	const UChar *	name,
		uint32_t	tableCode
	)

protected

Protected constructor.

Parameters

[in]	name	charset name
[in]	tableCode	DVB table code

Member Function Documentation

◆ DecodeTableCode()

static bool ts::DVBCharTable::DecodeTableCode	(	uint32_t &	code,
		size_t &	codeSize,
		const uint8_t *	dvb,
		size_t	dvbSize
	)

static

This static function gets the character coding table at the beginning of a DVB string.

The character coding table is encoded on up to 3 bytes at the beginning of a DVB string. The following encodings are recognized, based on the first byte of the DVB string:

First byte >= 0x20: The first byte is a character. The default encoding is ISO-6937. We return zero as code.
First byte == 0x10: The next two bytes indicate an ISO-8859 encoding. We return 0x10xxyy as code.
First byte == 0x1F: The second byte is an encoding_type_id. This encoding is not supported here.
Other value: One byte encoding.

Parameters

[out]	code	Returned character coding table value. Zero when no code is present (use the default character table). 0xFFFFFFFF in case of invalid data.
[out]	codeSize	Size in bytes of character coding table in dvb.
[in]	dvb	Address of a DVB string.
[in]	dvbSize	Size in bytes of the DVB string.

Returns: True on success, false on error (truncated, unsupported format, etc.)

◆ tableCode()

uint32_t ts::DVBCharTable::tableCode ( ) const

inline

Get the DVB table code for the character set.

Returns: DVB table code.

◆ GetTableFromLeadingCode()

static const DVBCharTable * ts::DVBCharTable::GetTableFromLeadingCode ( uint32_t code )

static

Get a DVB character set by table code.

Parameters

[in] code Table code of the requested character set.

Returns: Address of the character or zero if not found.

◆ encodeTableCode()

virtual size_t ts::DVBCharTable::encodeTableCode	(	uint8_t *&	buffer,
		size_t &	size
	)		const

virtual

Encode the character set table code.

Stop either when the specified number of characters are serialized or when the buffer is full, whichever comes first.

Parameters

[in,out]	buffer	Address of the buffer. The address is updated to point after the encoded value.
[in,out]	size	Size of the buffer. Updated to remaining size.

Returns: The number of serialized byte.

◆ unregister()

virtual void ts::DVBCharTable::unregister ( ) const

overridevirtual

Unregister the character set from the repository of character sets.

This is done automatically when the object is destructed. Can be called earlier to make sure a character set is no longer referenced.

Reimplemented from ts::Charset.

◆ name()

UString ts::Charset::name ( ) const

inlineinherited

Get the character set name.

Returns: The name.

◆ GetCharset()

static const Charset * ts::Charset::GetCharset ( const UString & name )

staticinherited

Get a character set by name.

Parameters

[in] name Name of the requested character set.

Returns: Address of the character set or zero if not found.

◆ GetAllNames()

static UStringList ts::Charset::GetAllNames ( )

staticinherited

Find all registered character set names.

Returns: List of all registered names.

◆ decode()

virtual bool ts::Charset::decode	(	UString &	str,
		const uint8_t *	data,
		size_t	size
	)		const

pure virtualinherited

Decode a string from the specified byte buffer.

Parameters

[out]	str	Returned decoded string.
[in]	data	Address of an encoded string.
[in]	size	Size in bytes of the encoded string.

Returns: True on success, false on error (truncated, unsupported format, etc.)

Implemented in ts::ARIBCharset, ts::DumpCharset, ts::DVBCharset, ts::DVBCharTableSingleByte, ts::DVBCharTableUTF16, and ts::DVBCharTableUTF8.

◆ decoded()

UString ts::Charset::decoded	(	const uint8_t *	data,
		size_t	size
	)		const

inherited

Decode a string from the specified byte buffer and return a UString.

Errors (truncation, unsupported format, etc) are ignored.

Parameters

[in]	data	Address of an encoded string.
[in]	size	Size in bytes of the encoded string.

Returns: The decoded string.

◆ decodeWithByteLength()

bool ts::Charset::decodeWithByteLength	(	UString &	str,
		const uint8_t *&	data,
		size_t &	size
	)		const

inherited

Decode a string (preceded by its one-byte length) from the specified byte buffer.

Parameters

[out]	str	Returned decoded string.
[in,out]	data	Address of an encoded string. The address is updated to point after the decoded value.
[in,out]	size	Size of the buffer. Updated to remaining size.

Returns: True on success, false on error (truncated, unsupported format, etc.)

◆ decodedWithByteLength()

UString ts::Charset::decodedWithByteLength	(	const uint8_t *&	data,
		size_t &	size
	)		const

inherited

Decode a string (preceded by its one-byte length) from the specified byte buffer.

Errors (truncation, unsupported format, etc) are ignored.

Parameters

[in,out]	data	Address of an encoded string. The address is updated to point after the decoded value.
[in,out]	size	Size of the buffer. Updated to remaining size.

Returns: The decoded string.

◆ canEncode()

virtual bool ts::Charset::canEncode	(	const UString &	str,
		size_t	start = `0`,
		size_t	count = `NPOS`
	)		const

pure virtualinherited

Check if a string can be encoded using the charset (ie all characters can be represented).

Parameters

[in]	str	The string to encode.
[in]	start	Starting offset in str.
[in]	count	Maximum number of characters to encode.

Returns: True if all characters can be encoded.

Implemented in ts::ARIBCharset, ts::DumpCharset, ts::DVBCharset, ts::DVBCharTableSingleByte, ts::DVBCharTableUTF16, and ts::DVBCharTableUTF8.

◆ encode()

virtual size_t ts::Charset::encode	(	uint8_t *&	buffer,
		size_t &	size,
		const UString &	str,
		size_t	start = `0`,
		size_t	count = `NPOS`
	)		const

pure virtualinherited

Encode a C++ Unicode string.

Unrepresentable characters are skipped. Stop either when the specified number of characters are serialized or when the buffer is full, whichever comes first.

Parameters

[in,out]	buffer	Address of the buffer. The address is updated to point after the encoded value.
[in,out]	size	Size of the buffer. Updated to remaining size.
[in]	str	The string to encode.
[in]	start	Starting offset in str.
[in]	count	Maximum number of characters to encode.

Returns: The number of serialized characters (which is usually not the same as the number of written bytes).

Implemented in ts::ARIBCharset, ts::DumpCharset, ts::DVBCharset, ts::DVBCharTableSingleByte, ts::DVBCharTableUTF16, and ts::DVBCharTableUTF8.

◆ encodeWithByteLength()

size_t ts::Charset::encodeWithByteLength	(	uint8_t *&	buffer,
		size_t &	size,
		const UString &	str,
		size_t	start = `0`,
		size_t	count = `NPOS`
	)		const

inherited

Encode a C++ Unicode string preceded by its one-byte length.

Unrepresentable characters are skipped. Stop either when the specified number of characters are serialized or when the buffer is full, whichever comes first.

Parameters

[in,out]	buffer	Address of the buffer. The address is updated to point after the encoded value.
[in,out]	size	Size of the buffer. Updated to remaining size.
[in]	str	The string to encode.
[in]	start	Starting offset in str.
[in]	count	Maximum number of characters to encode.

Returns: The number of serialized characters (which is usually not the same as the number of written bytes).

◆ encoded()

ByteBlock ts::Charset::encoded	(	const UString &	str,
		size_t	start = `0`,
		size_t	count = `NPOS`
	)		const

inherited

Encode a C++ Unicode string as a ByteBlock.

Unrepresentable characters are skipped.

Parameters

[in]	str	The string to encode.
[in]	start	Starting offset in str.
[in]	count	Maximum number of characters to encode.

Returns: A ByteBlock containing the encoded string.

◆ encodedWithByteLength()

ByteBlock ts::Charset::encodedWithByteLength	(	const UString &	str,
		size_t	start = `0`,
		size_t	count = `NPOS`
	)		const

inherited

Encode a C++ Unicode string as a ByteBlock (preceded by its one-byte length).

Unrepresentable characters are skipped.

Parameters

[in]	str	The string to encode.
[in]	start	Starting offset in str.
[in]	count	Maximum number of characters to encode.

Returns: A ByteBlock containing the encoded string.

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

tsDVBCharTable.h

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ DVBCharTable()

Member Function Documentation

◆ DecodeTableCode()

◆ tableCode()

◆ GetTableFromLeadingCode()

◆ encodeTableCode()

◆ unregister()

◆ name()

◆ GetCharset()

◆ GetAllNames()

◆ decode()

◆ decoded()

◆ decodeWithByteLength()

◆ decodedWithByteLength()

◆ canEncode()

◆ encode()

◆ encodeWithByteLength()

◆ encoded()

◆ encodedWithByteLength()