LIBJXL
|
Files | |
file | cms_interface.h |
Interface to allow the injection of different color management systems (CMSes, also called color management modules, or CMMs) in JPEG XL. | |
file | codestream_header.h |
Definitions of structs and enums for the metadata from the JPEG XL codestream headers (signature, metadata, preview dimensions, ...), excluding color encoding which is in color_encoding.h. | |
file | color_encoding.h |
Color Encoding definitions used by JPEG XL. All CIE units are for the standard 1931 2 degree observer. | |
file | memory_manager.h |
Abstraction functions used by JPEG XL to allocate memory. | |
file | parallel_runner.h |
file | types.h |
Data types for the JPEG XL API, for both encoding and decoding. | |
Classes | |
struct | JxlColorProfile |
struct | JxlCmsInterface |
struct | JxlPreviewHeader |
struct | JxlIntrinsicSizeHeader |
struct | JxlAnimationHeader |
struct | JxlBasicInfo |
struct | JxlExtraChannelInfo |
struct | JxlHeaderExtensions |
struct | JxlBlendInfo |
struct | JxlLayerInfo |
struct | JxlFrameHeader |
struct | JxlColorEncoding |
struct | JxlMemoryManagerStruct |
struct | JxlPixelFormat |
Macros | |
#define | JXL_PARALLEL_RET_RUNNER_ERROR (-1) |
#define | JXL_BOOL int |
#define | JXL_TRUE 1 |
#define | JXL_FALSE 0 |
Typedefs | |
typedef void *(* | jpegxl_cms_init_func) (void *init_data, size_t num_threads, size_t pixels_per_thread, const JxlColorProfile *input_profile, const JxlColorProfile *output_profile, float intensity_target) |
typedef float *(* | jpegxl_cms_get_buffer_func) (void *user_data, size_t thread) |
typedef JXL_BOOL(* | jpegxl_cms_run_func) (void *user_data, size_t thread, const float *input_buffer, float *output_buffer, size_t num_pixels) |
typedef void(* | jpegxl_cms_destroy_func) (void *) |
typedef void *(* | jpegxl_alloc_func) (void *opaque, size_t size) |
typedef void(* | jpegxl_free_func) (void *opaque, void *address) |
typedef struct JxlMemoryManagerStruct | JxlMemoryManager |
typedef int | JxlParallelRetCode |
typedef JxlParallelRetCode(* | JxlParallelRunInit) (void *jpegxl_opaque, size_t num_threads) |
typedef void(* | JxlParallelRunFunction) (void *jpegxl_opaque, uint32_t value, size_t thread_id) |
typedef JxlParallelRetCode(* | JxlParallelRunner) (void *runner_opaque, void *jpegxl_opaque, JxlParallelRunInit init, JxlParallelRunFunction func, uint32_t start_range, uint32_t end_range) |
typedef char | JxlBoxType[4] |
Enumerations | |
enum | JxlOrientation { JXL_ORIENT_IDENTITY = 1 , JXL_ORIENT_FLIP_HORIZONTAL = 2 , JXL_ORIENT_ROTATE_180 = 3 , JXL_ORIENT_FLIP_VERTICAL = 4 , JXL_ORIENT_TRANSPOSE = 5 , JXL_ORIENT_ROTATE_90_CW = 6 , JXL_ORIENT_ANTI_TRANSPOSE = 7 , JXL_ORIENT_ROTATE_90_CCW = 8 } |
enum | JxlExtraChannelType { JXL_CHANNEL_ALPHA , JXL_CHANNEL_DEPTH , JXL_CHANNEL_SPOT_COLOR , JXL_CHANNEL_SELECTION_MASK , JXL_CHANNEL_BLACK , JXL_CHANNEL_CFA , JXL_CHANNEL_THERMAL , JXL_CHANNEL_RESERVED0 , JXL_CHANNEL_RESERVED1 , JXL_CHANNEL_RESERVED2 , JXL_CHANNEL_RESERVED3 , JXL_CHANNEL_RESERVED4 , JXL_CHANNEL_RESERVED5 , JXL_CHANNEL_RESERVED6 , JXL_CHANNEL_RESERVED7 , JXL_CHANNEL_UNKNOWN , JXL_CHANNEL_OPTIONAL } |
enum | JxlBlendMode { JXL_BLEND_REPLACE = 0 , JXL_BLEND_ADD = 1 , JXL_BLEND_BLEND = 2 , JXL_BLEND_MULADD = 3 , JXL_BLEND_MUL = 4 } |
enum | JxlColorSpace { JXL_COLOR_SPACE_RGB , JXL_COLOR_SPACE_GRAY , JXL_COLOR_SPACE_XYB , JXL_COLOR_SPACE_UNKNOWN } |
enum | JxlWhitePoint { JXL_WHITE_POINT_D65 = 1 , JXL_WHITE_POINT_CUSTOM = 2 , JXL_WHITE_POINT_E = 10 , JXL_WHITE_POINT_DCI = 11 } |
enum | JxlPrimaries { JXL_PRIMARIES_SRGB = 1 , JXL_PRIMARIES_CUSTOM = 2 , JXL_PRIMARIES_2100 = 9 , JXL_PRIMARIES_P3 = 11 } |
enum | JxlTransferFunction { JXL_TRANSFER_FUNCTION_709 = 1 , JXL_TRANSFER_FUNCTION_UNKNOWN = 2 , JXL_TRANSFER_FUNCTION_LINEAR = 8 , JXL_TRANSFER_FUNCTION_SRGB = 13 , JXL_TRANSFER_FUNCTION_PQ = 16 , JXL_TRANSFER_FUNCTION_DCI = 17 , JXL_TRANSFER_FUNCTION_HLG = 18 , JXL_TRANSFER_FUNCTION_GAMMA = 65535 } |
enum | JxlRenderingIntent { JXL_RENDERING_INTENT_PERCEPTUAL = 0 , JXL_RENDERING_INTENT_RELATIVE , JXL_RENDERING_INTENT_SATURATION , JXL_RENDERING_INTENT_ABSOLUTE } |
enum | JxlDataType { JXL_TYPE_FLOAT = 0 , JXL_TYPE_UINT8 = 2 , JXL_TYPE_UINT16 = 3 , JXL_TYPE_FLOAT16 = 5 } |
enum | JxlEndianness { JXL_NATIVE_ENDIAN = 0 , JXL_LITTLE_ENDIAN = 1 , JXL_BIG_ENDIAN = 2 } |
enum | JxlProgressiveDetail { kFrames = 0 , kDC = 1 , kLastPasses = 2 , kPasses = 3 , kDCProgressive = 4 , kDCGroups = 5 , kGroups = 6 } |
#define JXL_BOOL int |
#define JXL_FALSE 0 |
Portable false
replacement.
#define JXL_PARALLEL_RET_RUNNER_ERROR (-1) |
General error returned by the JxlParallelRunInit function to indicate an error.
#define JXL_TRUE 1 |
Portable true
replacement.
typedef void *(* jpegxl_alloc_func) (void *opaque, size_t size) |
Allocating function for a memory region of a given size.
Allocates a contiguous memory region of size size
bytes. The returned memory may not be aligned to a specific size or initialized at all.
opaque | custom memory manager handle provided by the caller. |
size | in bytes of the requested memory region. |
NULL
if the memory can not be allocated, typedef void(* jpegxl_cms_destroy_func) (void *) |
Performs the necessary clean-up and frees the memory allocated for user data.
typedef float *(* jpegxl_cms_get_buffer_func) (void *user_data, size_t thread) |
Returns a buffer that can be used by callers of the interface to store the input of the conversion or read its result, if they pass it as the input or output of the run
function.
user_data | the data returned by init . |
thread | the index of the thread for which to return a buffer. |
run
. typedef void *(* jpegxl_cms_init_func) (void *init_data, size_t num_threads, size_t pixels_per_thread, const JxlColorProfile *input_profile, const JxlColorProfile *output_profile, float intensity_target) |
Allocates and returns the data needed for num_threads
parallel transforms from the input
colorspace to output
, with up to pixels_per_thread
pixels to transform per call to JxlCmsInterface::run. init_data
comes directly from the JxlCmsInterface instance. Since run
only receives the data returned by init
, a reference to init_data
should be kept there if access to it is desired in run
. Likewise for JxlCmsInterface::destroy.
The ICC data in input
and output
is guaranteed to outlive the init
/ run
/ destroy
cycle.
init_data | JxlCmsInterface::init_data passed as-is. |
num_threads | the maximum number of threads from which JxlCmsInterface::run will be called. |
pixels_per_thread | the maximum number of pixels that each call to JxlCmsInterface::run will have to transform. |
input_profile | the input colorspace for the transform. |
output_profile | the colorspace to which JxlCmsInterface::run should convert the input data. |
intensity_target | for colorspaces where luminance is relative (essentially: not PQ), indicates the luminance at which (1, 1, 1) will be displayed. This is useful for conversions between PQ and a relative luminance colorspace, in either direction: intensity_target cd/m² in PQ should map to and from (1, 1, 1) in the relative one.It is also used for conversions to and from HLG, as it is scene-referred while other colorspaces are assumed to be display-referred. That is, conversions from HLG should apply the OOTF for a peak display luminance of intensity_target , and conversions to HLG should undo it. The OOTF is a gamma function applied to the luminance channel (https://www.itu.int/rec/R-REC-BT.2100-2-201807-I page 7), with the gamma value computed as 1.2 * 1.111^log2(intensity_target / 1000) (footnote 2 page 8 of the same document). |
NULL
in case of failure. This will be passed to the other functions as user_data
. typedef JXL_BOOL(* jpegxl_cms_run_func) (void *user_data, size_t thread, const float *input_buffer, float *output_buffer, size_t num_pixels) |
Executes one transform and returns true on success or false on error. It must be possible to call this from different threads with different values for thread
, all between 0 (inclusive) and the value of num_threads
passed to init
(exclusive). It is allowed to implement this by locking such that the transforms are essentially performed sequentially, if such a performance profile is acceptable. user_data
is the data returned by init
. The buffers each contain num_pixels
× num_channels
interleaved floating point (0..1) samples where num_channels
is the number of color channels of their respective color profiles. It is guaranteed that the only case in which they might overlap is if the output has fewer channels than the input, in which case the pointers may be identical. For CMYK data, 0 represents the maximum amount of ink while 1 represents no ink.
user_data | the data returned by init . |
thread | the index of the thread from which the function is being called. |
input_buffer | the buffer containing the pixel data to be transformed. |
output_buffer | the buffer receiving the transformed pixel data. |
num_pixels | the number of pixels to transform from input to output . |
typedef void(* jpegxl_free_func) (void *opaque, void *address) |
Deallocating function pointer type.
This function MUST do nothing if address
is NULL
.
opaque | custom memory manager handle provided by the caller. |
address | memory region pointer returned by jpegxl_alloc_func, or NULL . |
typedef char JxlBoxType[4] |
Data type holding the 4-character type name of an ISOBMFF box.
typedef struct JxlMemoryManagerStruct JxlMemoryManager |
Memory Manager struct. These functions, when provided by the caller, will be used to handle memory allocations.
typedef int JxlParallelRetCode |
API for running data operations in parallel in a multi-threaded environment. This module allows the JPEG XL caller to define their own way of creating and assigning threads.
The JxlParallelRunner function type defines a parallel data processing runner that may be implemented by the caller to allow the library to process in multiple threads. The multi-threaded processing in this library only requires to run the same function over each number of a range, possibly running each call in a different thread. The JPEG XL caller is responsible for implementing this logic using the thread APIs available in their system. For convenience, a C++ implementation based on std::thread is provided in jpegxl/parallel_runner_thread.h (part of the jpegxl_threads library).
Thread pools usually store small numbers of heterogeneous tasks in a queue. When tasks are identical or differ only by an integer input parameter, it is much faster to store just one function of an integer parameter and call it for each value. Conventional vector-of-tasks can be run in parallel using a lambda function adapter that simply calls task_funcs[task].
If no multi-threading is desired, a NULL
value of JxlParallelRunner will use an internal implementation without multi-threading. Return code used in the JxlParallel* functions as return value. A value of 0 means success and any other value means error. The special value JXL_PARALLEL_RET_RUNNER_ERROR can be used by the runner to indicate any other error.
typedef void(* JxlParallelRunFunction) (void *jpegxl_opaque, uint32_t value, size_t thread_id) |
Parallel run data processing callback. See JxlParallelRunner for details.
This function MUST be called once for every number in the range [start_range, end_range) (including start_range but not including end_range) passing this number as the value
. Calls for different value may be executed from different threads in parallel.
jpegxl_opaque | the jpegxl_opaque handle provided to JxlParallelRunner() must be passed here. |
value | the number in the range [start_range, end_range) of the call. |
thread_id | the thread number where this function is being called from. This must be lower than the num_threads value passed to JxlParallelRunInit. |
typedef JxlParallelRetCode(* JxlParallelRunInit) (void *jpegxl_opaque, size_t num_threads) |
Parallel run initialization callback. See JxlParallelRunner for details.
This function MUST be called by the JxlParallelRunner only once, on the same thread that called JxlParallelRunner, before any parallel execution. The purpose of this call is to provide the maximum number of threads that the JxlParallelRunner will use, which can be used by JPEG XL to allocate per-thread storage if needed.
jpegxl_opaque | the jpegxl_opaque handle provided to JxlParallelRunner() must be passed here. |
num_threads | the maximum number of threads. This value must be positive. |
typedef JxlParallelRetCode(* JxlParallelRunner) (void *runner_opaque, void *jpegxl_opaque, JxlParallelRunInit init, JxlParallelRunFunction func, uint32_t start_range, uint32_t end_range) |
JxlParallelRunner function type. A parallel runner implementation can be provided by a JPEG XL caller to allow running computations in multiple threads. This function must call the initialization function init
in the same thread that called it and then call the passed func
once for every number in the range [start_range, end_range) (including start_range but not including end_range) possibly from different multiple threads in parallel.
The JxlParallelRunner function does not need to be re-entrant. This means that the same JxlParallelRunner function with the same runner_opaque provided parameter will not be called from the library from either init
or func
in the same decoder or encoder instance. However, a single decoding or encoding instance may call the provided JxlParallelRunner multiple times for different parts of the decoding or encoding process.
init
call succeeded (returned 0) and no other error occurred in the runner code. init()
if non-zero. enum JxlBlendMode |
Frame blend modes. When decoding, if coalescing is enabled (default), this can be ignored.
enum JxlColorSpace |
Color space of the image data.
Enumerator | |
---|---|
JXL_COLOR_SPACE_RGB | Tristimulus RGB |
JXL_COLOR_SPACE_GRAY | Luminance based, the primaries in JxlColorEncoding must be ignored. This value implies that num_color_channels in JxlBasicInfo is 1, any other value implies num_color_channels is 3. |
JXL_COLOR_SPACE_XYB | XYB (opsin) color space |
JXL_COLOR_SPACE_UNKNOWN | None of the other table entries describe the color space appropriately |
enum JxlDataType |
Data type for the sample values per channel per pixel.
enum JxlEndianness |
Ordering of multi-byte data.
enum JxlExtraChannelType |
Given type of an extra channel.
enum JxlOrientation |
Image orientation metadata. Values 1..8 match the EXIF definitions. The name indicates the operation to perform to transform from the encoded image to the display image.
enum JxlPrimaries |
Built-in primaries for color encoding. When decoding, the primaries can be read from the JxlColorEncoding primaries_red_xy, primaries_green_xy and primaries_blue_xy fields regardless of the enum value. When encoding, the enum values except JXL_PRIMARIES_CUSTOM override the numerical fields. Some enum values match a subset of CICP (Rec. ITU-T H.273 | ISO/IEC 23091-2:2019(E)), however the white point and RGB primaries are separate enums here.
Enumerator | |
---|---|
JXL_PRIMARIES_SRGB | The CIE xy values of the red, green and blue primaries are: 0.639998686, 0.330010138; 0.300003784, 0.600003357; 0.150002046, 0.059997204 |
JXL_PRIMARIES_CUSTOM | Primaries must be read from the JxlColorEncoding primaries_red_xy, primaries_green_xy and primaries_blue_xy fields, or as ICC profile. This enum value is not an exact match of the corresponding CICP value. |
JXL_PRIMARIES_2100 | As specified in Rec. ITU-R BT.2100-1 |
JXL_PRIMARIES_P3 | As specified in SMPTE RP 431-2 |
enum JxlProgressiveDetail |
Types of progressive detail. Setting a progressive detail with value N implies all progressive details with smaller or equal value. Currently only the following level of progressive detail is implemented:
enum JxlRenderingIntent |
enum JxlTransferFunction |
Built-in transfer functions for color encoding. Enum values match a subset of CICP (Rec. ITU-T H.273 | ISO/IEC 23091-2:2019(E)) unless specified otherwise.
Enumerator | |
---|---|
JXL_TRANSFER_FUNCTION_709 | As specified in SMPTE RP 431-2 |
JXL_TRANSFER_FUNCTION_UNKNOWN | None of the other table entries describe the transfer function. |
JXL_TRANSFER_FUNCTION_LINEAR | The gamma exponent is 1 |
JXL_TRANSFER_FUNCTION_SRGB | As specified in IEC 61966-2-1 sRGB |
JXL_TRANSFER_FUNCTION_PQ | As specified in SMPTE ST 2084 |
JXL_TRANSFER_FUNCTION_DCI | As specified in SMPTE ST 428-1 |
JXL_TRANSFER_FUNCTION_HLG | As specified in Rec. ITU-R BT.2100-1 (HLG) |
JXL_TRANSFER_FUNCTION_GAMMA | Transfer function follows power law given by the gamma value in JxlColorEncoding. Not a CICP value. |
enum JxlWhitePoint |
Built-in whitepoints for color encoding. When decoding, the numerical xy whitepoint value can be read from the JxlColorEncoding white_point field regardless of the enum value. When encoding, enum values except JXL_WHITE_POINT_CUSTOM override the numerical fields. Some enum values match a subset of CICP (Rec. ITU-T H.273 | ISO/IEC 23091-2:2019(E)), however the white point and RGB primaries are separate enums here.
Enumerator | |
---|---|
JXL_WHITE_POINT_D65 | CIE Standard Illuminant D65: 0.3127, 0.3290 |
JXL_WHITE_POINT_CUSTOM | White point must be read from the JxlColorEncoding white_point field, or as ICC profile. This enum value is not an exact match of the corresponding CICP value. |
JXL_WHITE_POINT_E | CIE Standard Illuminant E (equal-energy): 1/3, 1/3 |
JXL_WHITE_POINT_DCI | DCI-P3 from SMPTE RP 431-2: 0.314, 0.351 |