vrs::ImageContentBlockSpec Class Reference

Specification of an image content block. More...

#include <RecordFormat.h>

Public Member Functions
	ImageContentBlockSpec (const ImageContentBlockSpec &)=default
	ImageContentBlockSpec (const ImageContentBlockSpec &imageSpec, double keyFrameTimestamp, uint32_t keyFrameIndex)
	ImageContentBlockSpec (ImageFormat imageFormat, PixelFormat pixelFormat, uint32_t width=0, uint32_t height=0, uint32_t stride=0, uint32_t stride2=0, string codecName={}, uint8_t codecQuality=kQualityUndefined, double keyFrameTimestamp=kInvalidTimestamp, uint32_t keyFrameIndex=0)
	Specify-everything constructor.
	ImageContentBlockSpec (ImageFormat imageFormat, uint32_t width=0, uint32_t height=0)
	Image formats with encoding (png, jpeg, etc).
	ImageContentBlockSpec (PixelFormat pixelFormat, uint32_t width, uint32_t height, uint32_t stride=0, uint32_t stride2=0)
	Raw pixels image formats.
	ImageContentBlockSpec (string codecName, uint8_t codecQuality, PixelFormat pixelFormat, uint32_t width, uint32_t height, uint32_t stride=0, uint32_t stride2=0)
	Video image with codec.
	ImageContentBlockSpec (const string &formatStr)
	Constructor used for factory construction.
void	set (ContentParser &parser)
	When constructing from a string.
void	clear ()
	Clear/reset object to default values.
ImageContentBlockSpec	core () const
	Return base of format (no codec quality nor key frame info)
string	asString () const
size_t	getBlockSize () const
size_t	getRawImageSize () const
ImageContentBlockSpec &	operator= (const ImageContentBlockSpec &)=default
	Default copy assignment.
bool	operator== (const ImageContentBlockSpec &rhs) const
	Compare two image block spec strictly, field by field.
bool	operator!= (const ImageContentBlockSpec &rhs) const
ImageFormat	getImageFormat () const
	Get image format.
string	getImageFormatAsString () const
	Get Image format as string.
PixelFormat	getPixelFormat () const
	Get Pixel format.
string	getPixelFormatAsString () const
	Get pixel format presented as a readable string, from which it can be reconstructed.
uint32_t	getWidth () const
	Get image width, or 0 if unknown/unspecified.
uint32_t	getHeight () const
	Get image height, or 0 if unknown/unspecified.
uint32_t	getStride () const
	Get image stride (number of bytes between rows) for the first plane.
uint32_t	getRawStride () const
uint32_t	getRawStride2 () const
uint32_t	getDefaultStride () const
	Get default stride for plane 0 when stride isn't specified (minimum stride value)
uint32_t	getDefaultStride2 () const
	Get default stride for planes N > 0, when stride2 isn't specified (minimum stride2 value)
uint32_t	getPlaneCount () const
	Get the number of planes for this pixel format.
uint32_t	getPlaneStride (uint32_t planeIndex) const
uint32_t	getPlaneHeight (uint32_t planeIndex) const
uint8_t	getChannelCountPerPixel () const
size_t	getBytesPerPixel () const
const string &	getCodecName () const
uint8_t	getCodecQuality () const
double	getKeyFrameTimestamp () const
	Get timestamp of the key frame of the group of frames this video frame belongs to.
uint32_t	getKeyFrameIndex () const
bool	sanityCheckStrides () const

Static Public Member Functions
static bool	isQualityValid (uint8_t quality)
	Validate that a quality value is valid.
static uint8_t	getChannelCountPerPixel (PixelFormat pixel)
	Get the number channels of a pixel. See getChannelCountPerPixel()
static size_t	getBytesPerPixel (PixelFormat pixel)
	Get the size of a pixel, in bytes. See getBytesPerPixel()
static string	getPixelFormatAsString (PixelFormat pixelFormat)
	Get pixel format presented as a readable string, from which it can be reconstructed.
static uint32_t	getPlaneCount (PixelFormat pixelFormat)
	Get the number of planes for this pixel format.

Static Public Attributes
static constexpr uint8_t	kQualityUndefined = 255
static constexpr double	kInvalidTimestamp = -1E-308

Detailed Description

Specification of an image content block.

Constructor & Destructor Documentation

ImageContentBlockSpec()

vrs::ImageContentBlockSpec::ImageContentBlockSpec	(	PixelFormat	pixelFormat,
		uint32_t	width,
		uint32_t	height,
		uint32_t	stride = 0,
		uint32_t	stride2 = 0
	)

Raw pixels image formats.

Parameters

stride	number of bytes between lines, if not width * sizeof(pixelFormat)
stride2	stride for planes after the first plane

Member Function Documentation

asString()

string vrs::ImageContentBlockSpec::asString

(

)

const

Convert to string, to store on disk & reconstruct later using factory constructor.

getBlockSize()

size_t vrs::ImageContentBlockSpec::getBlockSize

(

)

const

Get the number of bytes for this content block, or ContentBlock::kSizeUnknown. For RAW images, that's the combined size of all the planes, though there is usually only 1.

getBytesPerPixel()

size_t vrs::ImageContentBlockSpec::getBytesPerPixel ( ) const

inline

Get the size of a pixel format, in bytes. Compliant pixel formats use a fixed number of bytes per pixel, and pixels follow each other without overlap. Some bits might be unused, such as when using two bytes to store 10 bits. Pixel formats that don't work that way will return ContentBlock::kSizeUnknown

getChannelCountPerPixel()

uint8_t vrs::ImageContentBlockSpec::getChannelCountPerPixel ( ) const

inline

Get the number of channels of this format. Every pixel format has a channel count, but it does not tell how the pixel data is arranged in the image buffer (might not be contiguous). In other words, this should not be used to make assumptions on memory layout in any way. A value of 1 means the image is grayscale, or some form of 1 dimensional value, such as depth.

getCodecName()

const string & vrs::ImageContentBlockSpec::getCodecName ( ) const

inline

Get name of the video codec used to encode the image, if any. Only used for ImageFormat::VIDEO

getCodecQuality()

uint8_t vrs::ImageContentBlockSpec::getCodecQuality ( ) const

inline

Get codec quality setting used to encode the image, if any. 0 means codec-default, 100 means lossless Only used for ImageFormat::VIDEO

getKeyFrameIndex()

uint32_t vrs::ImageContentBlockSpec::getKeyFrameIndex ( ) const

inline

Get index of the frame in the group of frames this video frame belongs to. Key frames and only key frames (i-frames) have have an index of 0. The first p-frame after an i-frame has a key frame index of 1, and so on.

getPlaneHeight()

uint32_t vrs::ImageContentBlockSpec::getPlaneHeight

(

uint32_t

planeIndex

)

const

Get the number of lines in a specific plane. Returns 0 if plane index is invalid.

getPlaneStride()

uint32_t vrs::ImageContentBlockSpec::getPlaneStride

(

uint32_t

planeIndex

)

const

Get the number of bytes of each line for a specific plane. Returns 0 if plane index is invalid.

getRawImageSize()

size_t vrs::ImageContentBlockSpec::getRawImageSize

(

)

const

Get the number of bytes for this content block, or ContentBlock::kSizeUnknown. Use pixel format, dimensions and stride, and compute the size as if the image format is RAW.

getRawStride()

uint32_t vrs::ImageContentBlockSpec::getRawStride ( ) const

inline

Get the raw stride parameter. Return 0 if no stride value was explicitly provided.

sanityCheckStrides()

bool vrs::ImageContentBlockSpec::sanityCheckStrides

(

)

const

Verify that stride and stride2 values are reasonable.

Returns

True if everything is ok, otherwise, log a warning and return false.

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

• vrs/RecordFormat.h
• vrs/RecordFormat.cpp