Instances of me can encode two ASCII characters into a "line 21" closed-captioning waveform. Conversely, my CNTV2Line21Captioner::DecodeLine class method can decode a "line 21" waveform to the two characters it contains. More...

#include <ntv2line21captioner.h>

Inheritance diagram for CNTV2Line21Captioner:

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Collaboration diagram for CNTV2Line21Captioner:

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Public Member Functions
	CNTV2Line21Captioner ()
	720 pixels x 2 bytes per pixel More...

virtual	~CNTV2Line21Captioner ()
	My default destructor. More...

virtual UByte *	EncodeLine (const UByte inByte1, const UByte inByte2)
	Encodes the two given characters as an EIA-608-compliant "line 21" waveform into my private line data buffer. Client applications will probably want to copy this waveform data into their own host frame buffer for eventual transmission to an SDI output. Returns the starting address of my private line buffer. More...

Public Member Functions inherited from CNTV2CaptionLogConfig
	CNTV2CaptionLogConfig (const std::string inLogLabel=std::string())
	Default constructor. More...

virtual	~CNTV2CaptionLogConfig ()

virtual NTV2CaptionLogMask	SetLogMask (const NTV2CaptionLogMask inLogMask)
	Specifies what, if any, debug information I will write to my log stream. More...

virtual NTV2CaptionLogMask	GetLogMask (void) const
	Answers with my current caption logging bit mask. More...

virtual bool	TestLogMask (const NTV2CaptionLogMask inLogMask, const bool inExact=false) const
	Answers true if the given log mask bits are set in my current log mask. More...

virtual void	SetLogLabel (const std::string &inNewLabel)
	Specifies my logging label. More...

virtual void	AppendToLogLabel (const std::string &inString)
	Appends the given string to my current log label. More...

virtual const std::string &	GetLogLabel (void) const
	Answers with my current logging label. More...

virtual void	SetLogStream (std::ostream &inOutputStream)

virtual std::ostream &	LogIf (const NTV2CaptionLogMask inLogMask) const

virtual std::ostream &	Log (void) const

Static Public Member Functions
static bool	DecodeLine (const UByte *pLineData, UByte &outChar1, UByte &outChar2)
	Decodes the supplied line of 8-bit uncompressed ('2vuy') data and, if successful, returns the two 8-bit characters. More...

static bool	DecodeLine (const std::vector< uint8_t > &inLineData, std::vector< uint8_t > &outData)
	Decodes the supplied line of 8-bit uncompressed ('2vuy') data and, if successful, returns the 8-bit decoded data. More...

static const UByte *	FindFirstDataBit_NTSC (const void *pInVideoLine)
	Searches for a valid captioning clock run-in in the given 8-bit uncompressed ('2vuy') line. More...

static std::vector< uint8_t >::size_type	FindFirstDataBit_NTSC (const std::vector< uint8_t > &in2VUYLine)
	Searches for a valid captioning clock run-in in the given 8-bit uncompressed ('2vuy') line. More...

Static Public Member Functions inherited from CNTV2CaptionLogConfig
static std::ostream &	DumpMemory (const void *pInStartAddress, const size_t inByteCount, std::ostream &inOutputStream=std::cout, const size_t inRadix=16, const size_t inBytesPerGroup=4, const size_t inGroupsPerLine=8, const size_t inAddressRadix=16, const bool inShowAscii=true, const size_t inAddrOffset=0)
	Dumps a contiguous chunk of memory in hex, octal, decimal, with or without ascii, to the given output stream. More...

static std::string	HexDump32Bytes (const void *pInStartAddress, const size_t inByteCount, const size_t inLimitBytes=32)

static std::ostream &	DumpYBytes_2vuy (const UByte *pInVideoLine, std::ostream &inOutputStream, const unsigned inFromPixel=0, const unsigned inToPixel=719, const bool inShowRuler=true, const unsigned inHiliteRangeFrom=9999, const unsigned inHiliteRangeTo=9999)
	Dumps the luma values in hexadecimal from the given line of '2vuy' video to the given output stream. More...

static std::ostream &	DumpYBytes_2vuy (const std::vector< uint8_t > &inVideoLine, std::ostream &inOutputStream, const size_t inFromPixel=0, const size_t inToPixel=719, const bool inShowRuler=true, const size_t inHiliteRangeFrom=9999, const size_t inHiliteRangeTo=9999)
	Dumps the luma values in hexadecimal from the given line of '2vuy' video to the given output stream. More...

static std::string	GetSeverityLabel (const unsigned inSeverity)

Static Public Attributes
static const UWord	CC_LINE_WIDTH_PIXELS = 720

static const UWord	ENCODE_LINE_LENGTH_BYTES = CC_LINE_WIDTH_PIXELS * 2
	Standard-Definition only – assume fixed line width of 720 pixels. More...

Additional Inherited Members
Protected Attributes inherited from CNTV2CaptionLogConfig
NTV2CaptionLogMask	mLogMask
	Determines what messages are logged. More...

std::string	mLogLabel
	My debug label. More...

void *	mpLabelLock
	Protects my debug label from simultaneous access by more than one thread. More...

Detailed Description

Instances of me can encode two ASCII characters into a "line 21" closed-captioning waveform. Conversely, my CNTV2Line21Captioner::DecodeLine class method can decode a "line 21" waveform to the two characters it contains.

In either use case, I assume a 720-pixel line (e.g. Standard Definition "NTSC"), and the closed captioning is represented by an EIA-608 waveform. I do not handle other forms of closed captioning transmission (e.g., EIA-708, digital ancillary packets, etc.).

Note: This implementation only handles conversion to/from 8-bit uncompressed ('2vuy') video.; This implementation makes a simplifying assumption that all captioning bits are 27 pixels wide. The actual bit duration should be (H / 32), which for NTSC video is 858 pixels / 32 = 26.8125 pixels per bit. This difference should be within the tolerance of most captioning receivers. (In PAL, the line width is 864 pixels, which is exactly 27.0 pixels per bit.)

Definition at line 34 of file ntv2line21captioner.h.

Constructor & Destructor Documentation

◆ CNTV2Line21Captioner()

CNTV2Line21Captioner::CNTV2Line21Captioner ( )

720 pixels x 2 bytes per pixel

My default constructor.

◆ ~CNTV2Line21Captioner()

virtual CNTV2Line21Captioner::~CNTV2Line21Captioner ( )

virtual

My default destructor.

Member Function Documentation

◆ DecodeLine() [1/2]

static bool CNTV2Line21Captioner::DecodeLine	(	const std::vector< uint8_t > &	inLineData,
		std::vector< uint8_t > &	outData
	)

static

Decodes the supplied line of 8-bit uncompressed ('2vuy') data and, if successful, returns the 8-bit decoded data.

Parameters

[in]	inLineData	A line of 8-bit uncompressed '2vuy' data that contains the "line 21" waveform data to be decoded.
[out]	outData	Receives the data bytes (including parity) decoded from the line.

Returns: True if the given line appears to contain valid data; otherwise, false.

Note: Character analysis, including parity checks, are the caller's responsibility. However, this method WILL make a reasonable attempt to discover whether captioning data is present or not.

◆ DecodeLine() [2/2]

static bool CNTV2Line21Captioner::DecodeLine	(	const UByte *	pLineData,
		UByte &	outChar1,
		UByte &	outChar2
	)

static

Decodes the supplied line of 8-bit uncompressed ('2vuy') data and, if successful, returns the two 8-bit characters.

Parameters

[in]	pLineData	Specifies a valid, non-NULL pointer to the first byte in a frame buffer that contains the "line 21" waveform data to be decoded.
[out]	outChar1	Receives the first caption data byte decoded from the line.
[out]	outChar2	Receives the second caption data byte decoded from the line.

Returns: True if the given line appears to contain valid caption data; otherwise, false.

Note: Character analysis, including parity checks, are the caller's responsibility. However, this method WILL make a reasonable attempt to discover whether captioning data is present or not.

◆ EncodeLine()

virtual UByte* CNTV2Line21Captioner::EncodeLine	(	const UByte	inByte1,
		const UByte	inByte2
	)

virtual

Encodes the two given characters as an EIA-608-compliant "line 21" waveform into my private line data buffer. Client applications will probably want to copy this waveform data into their own host frame buffer for eventual transmission to an SDI output. Returns the starting address of my private line buffer.

Parameters

[in]	inByte1	The first character to be encoded. The data byte MUST include parity.
[in]	inByte2	The second character to be encoded. The data byte MUST include parity.

Returns: A pointer to the first byte of my private buffer, which contains the encoded "line 21" waveform.

Note: My private line data buffer has a single line containing 720 pixels of '2vuy' (8-bit YCbCr) SD video data.

◆ FindFirstDataBit_NTSC() [1/2]

static std::vector<uint8_t>::size_type CNTV2Line21Captioner::FindFirstDataBit_NTSC ( const std::vector< uint8_t > & in2VUYLine )

static

Searches for a valid captioning clock run-in in the given 8-bit uncompressed ('2vuy') line.

Parameters

[in] in2VUYLine A buffer containing the line of 8-bit '2vuy' video to be searched.

Returns: in2VUYLine.max_size() if unsuccessful; otherwise an index/offset to the middle of the first data bit (i.e. the one following the last '1' start bit).

◆ FindFirstDataBit_NTSC() [2/2]

static const UByte* CNTV2Line21Captioner::FindFirstDataBit_NTSC ( const void * pInVideoLine )

static

Searches for a valid captioning clock run-in in the given 8-bit uncompressed ('2vuy') line.

Parameters

[in] pInVideoLine A valid pointer to a buffer containing the line of 8-bit '2vuy' video to be searched. Must be at least 1440 bytes in length.

Returns: NULL if unsuccessful; otherwise a pointer to the middle of the first data bit (i.e. the one following the last '1' start bit).

Member Data Documentation

◆ CC_LINE_WIDTH_PIXELS

const UWord CNTV2Line21Captioner::CC_LINE_WIDTH_PIXELS = 720

static

Definition at line 82 of file ntv2line21captioner.h.

◆ ENCODE_LINE_LENGTH_BYTES

const UWord CNTV2Line21Captioner::ENCODE_LINE_LENGTH_BYTES = CC_LINE_WIDTH_PIXELS * 2

static

Standard-Definition only – assume fixed line width of 720 pixels.

Definition at line 83 of file ntv2line21captioner.h.

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

/home/tcbuilder/buildAgent/work/df8e8cce5bebfd58/libajacc/includes/ntv2line21captioner.h

Public Member Functions

Static Public Member Functions

Static Public Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ CNTV2Line21Captioner()

◆ ~CNTV2Line21Captioner()

Member Function Documentation

◆ DecodeLine() [1/2]

◆ DecodeLine() [2/2]

◆ EncodeLine()

◆ FindFirstDataBit_NTSC() [1/2]

◆ FindFirstDataBit_NTSC() [2/2]

Member Data Documentation

◆ CC_LINE_WIDTH_PIXELS

◆ ENCODE_LINE_LENGTH_BYTES