mozilla-central/third_party/jpeg-xl/lib/include/jxl/encode.h

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/* Copyright (c) the JPEG XL Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style
* license that can be found in the LICENSE file.
*/
/** @addtogroup libjxl_encoder
* @{
* @file encode.h
* @brief Encoding API for JPEG XL.
*/
#ifndef JXL_ENCODE_H_
#define JXL_ENCODE_H_
#include <jxl/cms_interface.h>
#include <jxl/codestream_header.h>
#include <jxl/color_encoding.h>
#include <jxl/jxl_export.h>
#include <jxl/memory_manager.h>
#include <jxl/parallel_runner.h>
#include <jxl/stats.h>
#include <jxl/types.h>
#include <jxl/version.h> // TODO(eustas): remove before v1.0
#include <stddef.h>
#include <stdint.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* Encoder library version.
*
* @return the encoder library version as an integer:
* MAJOR_VERSION * 1000000 + MINOR_VERSION * 1000 + PATCH_VERSION. For example,
* version 1.2.3 would return 1002003.
*/
JXL_EXPORT uint32_t JxlEncoderVersion(void);
/**
* Opaque structure that holds the JPEG XL encoder.
*
* Allocated and initialized with @ref JxlEncoderCreate().
* Cleaned up and deallocated with @ref JxlEncoderDestroy().
*/
typedef struct JxlEncoderStruct JxlEncoder;
/**
* Settings and metadata for a single image frame. This includes encoder options
* for a frame such as compression quality and speed.
*
* Allocated and initialized with @ref JxlEncoderFrameSettingsCreate().
* Cleaned up and deallocated when the encoder is destroyed with
* @ref JxlEncoderDestroy().
*/
typedef struct JxlEncoderFrameSettingsStruct JxlEncoderFrameSettings;
/**
* Return value for multiple encoder functions.
*/
typedef enum {
/** Function call finished successfully, or encoding is finished and there is
* nothing more to be done.
*/
JXL_ENC_SUCCESS = 0,
/** An error occurred, for example out of memory.
*/
JXL_ENC_ERROR = 1,
/** The encoder needs more output buffer to continue encoding.
*/
JXL_ENC_NEED_MORE_OUTPUT = 2,
} JxlEncoderStatus;
/**
* Error conditions:
* API usage errors have the 0x80 bit set to 1
* Other errors have the 0x80 bit set to 0
*/
typedef enum {
/** No error
*/
JXL_ENC_ERR_OK = 0,
/** Generic encoder error due to unspecified cause
*/
JXL_ENC_ERR_GENERIC = 1,
/** Out of memory
* TODO(jon): actually catch this and return this error
*/
JXL_ENC_ERR_OOM = 2,
/** JPEG bitstream reconstruction data could not be
* represented (e.g. too much tail data)
*/
JXL_ENC_ERR_JBRD = 3,
/** Input is invalid (e.g. corrupt JPEG file or ICC profile)
*/
JXL_ENC_ERR_BAD_INPUT = 4,
/** The encoder doesn't (yet) support this. Either no version of libjxl
* supports this, and the API is used incorrectly, or the libjxl version
* should have been checked before trying to do this.
*/
JXL_ENC_ERR_NOT_SUPPORTED = 0x80,
/** The encoder API is used in an incorrect way.
* In this case, a debug build of libjxl should output a specific error
* message. (if not, please open an issue about it)
*/
JXL_ENC_ERR_API_USAGE = 0x81,
} JxlEncoderError;
/**
* Id of encoder options for a frame. This includes options such as setting
* encoding effort/speed or overriding the use of certain coding tools, for this
* frame. This does not include non-frame related encoder options such as for
* boxes.
*/
typedef enum {
/** Sets encoder effort/speed level without affecting decoding speed. Valid
* values are, from faster to slower speed: 1:lightning 2:thunder 3:falcon
* 4:cheetah 5:hare 6:wombat 7:squirrel 8:kitten 9:tortoise 10:glacier.
* Default: squirrel (7).
*/
JXL_ENC_FRAME_SETTING_EFFORT = 0,
/** Sets the decoding speed tier for the provided options. Minimum is 0
* (slowest to decode, best quality/density), and maximum is 4 (fastest to
* decode, at the cost of some quality/density). Default is 0.
*/
JXL_ENC_FRAME_SETTING_DECODING_SPEED = 1,
/** Sets resampling option. If enabled, the image is downsampled before
* compression, and upsampled to original size in the decoder. Integer option,
* use -1 for the default behavior (resampling only applied for low quality),
* 1 for no downsampling (1x1), 2 for 2x2 downsampling, 4 for 4x4
* downsampling, 8 for 8x8 downsampling.
*/
JXL_ENC_FRAME_SETTING_RESAMPLING = 2,
/** Similar to ::JXL_ENC_FRAME_SETTING_RESAMPLING, but for extra channels.
* Integer option, use -1 for the default behavior (depends on encoder
* implementation), 1 for no downsampling (1x1), 2 for 2x2 downsampling, 4 for
* 4x4 downsampling, 8 for 8x8 downsampling.
*/
JXL_ENC_FRAME_SETTING_EXTRA_CHANNEL_RESAMPLING = 3,
/** Indicates the frame added with @ref JxlEncoderAddImageFrame is already
* downsampled by the downsampling factor set with @ref
* JXL_ENC_FRAME_SETTING_RESAMPLING. The input frame must then be given in the
* downsampled resolution, not the full image resolution. The downsampled
* resolution is given by ceil(xsize / resampling), ceil(ysize / resampling)
* with xsize and ysize the dimensions given in the basic info, and resampling
* the factor set with ::JXL_ENC_FRAME_SETTING_RESAMPLING.
* Use 0 to disable, 1 to enable. Default value is 0.
*/
JXL_ENC_FRAME_SETTING_ALREADY_DOWNSAMPLED = 4,
/** Adds noise to the image emulating photographic film noise, the higher the
* given number, the grainier the image will be. As an example, a value of 100
* gives low noise whereas a value of 3200 gives a lot of noise. The default
* value is 0.
*/
JXL_ENC_FRAME_SETTING_PHOTON_NOISE = 5,
/** Enables adaptive noise generation. This setting is not recommended for
* use, please use ::JXL_ENC_FRAME_SETTING_PHOTON_NOISE instead. Use -1 for
* the default (encoder chooses), 0 to disable, 1 to enable.
*/
JXL_ENC_FRAME_SETTING_NOISE = 6,
/** Enables or disables dots generation. Use -1 for the default (encoder
* chooses), 0 to disable, 1 to enable.
*/
JXL_ENC_FRAME_SETTING_DOTS = 7,
/** Enables or disables patches generation. Use -1 for the default (encoder
* chooses), 0 to disable, 1 to enable.
*/
JXL_ENC_FRAME_SETTING_PATCHES = 8,
/** Edge preserving filter level, -1 to 3. Use -1 for the default (encoder
* chooses), 0 to 3 to set a strength.
*/
JXL_ENC_FRAME_SETTING_EPF = 9,
/** Enables or disables the gaborish filter. Use -1 for the default (encoder
* chooses), 0 to disable, 1 to enable.
*/
JXL_ENC_FRAME_SETTING_GABORISH = 10,
/** Enables modular encoding. Use -1 for default (encoder
* chooses), 0 to enforce VarDCT mode (e.g. for photographic images), 1 to
* enforce modular mode (e.g. for lossless images).
*/
JXL_ENC_FRAME_SETTING_MODULAR = 11,
/** Enables or disables preserving color of invisible pixels. Use -1 for the
* default (1 if lossless, 0 if lossy), 0 to disable, 1 to enable.
*/
JXL_ENC_FRAME_SETTING_KEEP_INVISIBLE = 12,
/** Determines the order in which 256x256 regions are stored in the codestream
* for progressive rendering. Use -1 for the encoder
* default, 0 for scanline order, 1 for center-first order.
*/
JXL_ENC_FRAME_SETTING_GROUP_ORDER = 13,
/** Determines the horizontal position of center for the center-first group
* order. Use -1 to automatically use the middle of the image, 0..xsize to
* specifically set it.
*/
JXL_ENC_FRAME_SETTING_GROUP_ORDER_CENTER_X = 14,
/** Determines the center for the center-first group order. Use -1 to
* automatically use the middle of the image, 0..ysize to specifically set it.
*/
JXL_ENC_FRAME_SETTING_GROUP_ORDER_CENTER_Y = 15,
/** Enables or disables progressive encoding for modular mode. Use -1 for the
* encoder default, 0 to disable, 1 to enable.
*/
JXL_ENC_FRAME_SETTING_RESPONSIVE = 16,
/** Set the progressive mode for the AC coefficients of VarDCT, using spectral
* progression from the DCT coefficients. Use -1 for the encoder default, 0 to
* disable, 1 to enable.
*/
JXL_ENC_FRAME_SETTING_PROGRESSIVE_AC = 17,
/** Set the progressive mode for the AC coefficients of VarDCT, using
* quantization of the least significant bits. Use -1 for the encoder default,
* 0 to disable, 1 to enable.
*/
JXL_ENC_FRAME_SETTING_QPROGRESSIVE_AC = 18,
/** Set the progressive mode using lower-resolution DC images for VarDCT. Use
* -1 for the encoder default, 0 to disable, 1 to have an extra 64x64 lower
* resolution pass, 2 to have a 512x512 and 64x64 lower resolution pass.
*/
JXL_ENC_FRAME_SETTING_PROGRESSIVE_DC = 19,
/** Use Global channel palette if the amount of colors is smaller than this
* percentage of range. Use 0-100 to set an explicit percentage, -1 to use the
* encoder default. Used for modular encoding.
*/
JXL_ENC_FRAME_SETTING_CHANNEL_COLORS_GLOBAL_PERCENT = 20,
/** Use Local (per-group) channel palette if the amount of colors is smaller
* than this percentage of range. Use 0-100 to set an explicit percentage, -1
* to use the encoder default. Used for modular encoding.
*/
JXL_ENC_FRAME_SETTING_CHANNEL_COLORS_GROUP_PERCENT = 21,
/** Use color palette if amount of colors is smaller than or equal to this
* amount, or -1 to use the encoder default. Used for modular encoding.
*/
JXL_ENC_FRAME_SETTING_PALETTE_COLORS = 22,
/** Enables or disables delta palette. Use -1 for the default (encoder
* chooses), 0 to disable, 1 to enable. Used in modular mode.
*/
JXL_ENC_FRAME_SETTING_LOSSY_PALETTE = 23,
/** Color transform for internal encoding: -1 = default, 0=XYB, 1=none (RGB),
* 2=YCbCr. The XYB setting performs the forward XYB transform. None and
* YCbCr both perform no transform, but YCbCr is used to indicate that the
* encoded data losslessly represents YCbCr values.
*/
JXL_ENC_FRAME_SETTING_COLOR_TRANSFORM = 24,
/** Reversible color transform for modular encoding: -1=default, 0-41=RCT
* index, e.g. index 0 = none, index 6 = YCoCg.
* If this option is set to a non-default value, the RCT will be globally
* applied to the whole frame.
* The default behavior is to try several RCTs locally per modular group,
* depending on the speed and distance setting.
*/
JXL_ENC_FRAME_SETTING_MODULAR_COLOR_SPACE = 25,
/** Group size for modular encoding: -1=default, 0=128, 1=256, 2=512, 3=1024.
*/
JXL_ENC_FRAME_SETTING_MODULAR_GROUP_SIZE = 26,
/** Predictor for modular encoding. -1 = default, 0=zero, 1=left, 2=top,
* 3=avg0, 4=select, 5=gradient, 6=weighted, 7=topright, 8=topleft,
* 9=leftleft, 10=avg1, 11=avg2, 12=avg3, 13=toptop predictive average 14=mix
* 5 and 6, 15=mix everything.
*/
JXL_ENC_FRAME_SETTING_MODULAR_PREDICTOR = 27,
/** Fraction of pixels used to learn MA trees as a percentage. -1 = default,
* 0 = no MA and fast decode, 50 = default value, 100 = all, values above
* 100 are also permitted. Higher values use more encoder memory.
*/
JXL_ENC_FRAME_SETTING_MODULAR_MA_TREE_LEARNING_PERCENT = 28,
/** Number of extra (previous-channel) MA tree properties to use. -1 =
* default, 0-11 = valid values. Recommended values are in the range 0 to 3,
* or 0 to amount of channels minus 1 (including all extra channels, and
* excluding color channels when using VarDCT mode). Higher value gives slower
* encoding and slower decoding.
*/
JXL_ENC_FRAME_SETTING_MODULAR_NB_PREV_CHANNELS = 29,
/** Enable or disable CFL (chroma-from-luma) for lossless JPEG recompression.
* -1 = default, 0 = disable CFL, 1 = enable CFL.
*/
JXL_ENC_FRAME_SETTING_JPEG_RECON_CFL = 30,
/** Prepare the frame for indexing in the frame index box.
* 0 = ignore this frame (same as not setting a value),
* 1 = index this frame within the Frame Index Box.
* If any frames are indexed, the first frame needs to
* be indexed, too. If the first frame is not indexed, and
* a later frame is attempted to be indexed, ::JXL_ENC_ERROR will occur.
* If non-keyframes, i.e., frames with cropping, blending or patches are
* attempted to be indexed, ::JXL_ENC_ERROR will occur.
*/
JXL_ENC_FRAME_INDEX_BOX = 31,
/** Sets brotli encode effort for use in JPEG recompression and
* compressed metadata boxes (brob). Can be -1 (default) or 0 (fastest) to 11
* (slowest). Default is based on the general encode effort in case of JPEG
* recompression, and 4 for brob boxes.
*/
JXL_ENC_FRAME_SETTING_BROTLI_EFFORT = 32,
/** Enables or disables brotli compression of metadata boxes derived from
* a JPEG frame when using @ref JxlEncoderAddJPEGFrame. This has no effect on
* boxes added using @ref JxlEncoderAddBox. -1 = default, 0 = disable
* compression, 1 = enable compression.
*/
JXL_ENC_FRAME_SETTING_JPEG_COMPRESS_BOXES = 33,
/** Control what kind of buffering is used, when using chunked image frames.
* -1 = default (let the encoder decide)
* 0 = buffers everything, basically the same as non-streamed code path
(mainly for testing)
* 1 = buffers everything for images that are smaller than 2048 x 2048, and
* uses streaming input and output for larger images
* 2 = uses streaming input and output for all images that are larger than
* one group, i.e. 256 x 256 pixels by default
* 3 = currently same as 2
*
* When using streaming input and output the encoder minimizes memory usage at
* the cost of compression density. Also note that images produced with
* streaming mode might not be progressively decodeable.
*/
JXL_ENC_FRAME_SETTING_BUFFERING = 34,
/** Keep or discard Exif metadata boxes derived from a JPEG frame when using
* @ref JxlEncoderAddJPEGFrame. This has no effect on boxes added using
* @ref JxlEncoderAddBox. When @ref JxlEncoderStoreJPEGMetadata is set to 1,
* this option cannot be set to 0. Even when Exif metadata is discarded, the
* orientation will still be applied. 0 = discard Exif metadata, 1 = keep Exif
* metadata (default).
*/
JXL_ENC_FRAME_SETTING_JPEG_KEEP_EXIF = 35,
/** Keep or discard XMP metadata boxes derived from a JPEG frame when using
* @ref JxlEncoderAddJPEGFrame. This has no effect on boxes added using
* @ref JxlEncoderAddBox. When @ref JxlEncoderStoreJPEGMetadata is set to 1,
* this option cannot be set to 0. 0 = discard XMP metadata, 1 = keep XMP
* metadata (default).
*/
JXL_ENC_FRAME_SETTING_JPEG_KEEP_XMP = 36,
/** Keep or discard JUMBF metadata boxes derived from a JPEG frame when using
* @ref JxlEncoderAddJPEGFrame. This has no effect on boxes added using
* @ref JxlEncoderAddBox. 0 = discard JUMBF metadata, 1 = keep JUMBF metadata
* (default).
*/
JXL_ENC_FRAME_SETTING_JPEG_KEEP_JUMBF = 37,
/** If this mode is disabled, the encoder will not make any image quality
* decisions that are computed based on the full image, but stored only once
* (e.g. the X quant multiplier in the frame header). Used mainly for testing
* equivalence of streaming and non-streaming code.
* 0 = disabled, 1 = enabled (default)
*/
JXL_ENC_FRAME_SETTING_USE_FULL_IMAGE_HEURISTICS = 38,
/** Disable perceptual optimizations. 0 = optimizations enabled (default), 1 =
* optimizations disabled.
*/
JXL_ENC_FRAME_SETTING_DISABLE_PERCEPTUAL_HEURISTICS = 39,
/** Enum value not to be used as an option. This value is added to force the
* C compiler to have the enum to take a known size.
*/
JXL_ENC_FRAME_SETTING_FILL_ENUM = 65535,
} JxlEncoderFrameSettingId;
/**
* Creates an instance of @ref JxlEncoder and initializes it.
*
* @p memory_manager will be used for all the library dynamic allocations made
* from this instance. The parameter may be NULL, in which case the default
* allocator will be used. See jpegxl/memory_manager.h for details.
*
* @param memory_manager custom allocator function. It may be NULL. The memory
* manager will be copied internally.
* @return @c NULL if the instance can not be allocated or initialized
* @return pointer to initialized @ref JxlEncoder otherwise
*/
JXL_EXPORT JxlEncoder* JxlEncoderCreate(const JxlMemoryManager* memory_manager);
/**
* Re-initializes a @ref JxlEncoder instance, so it can be re-used for encoding
* another image. All state and settings are reset as if the object was
* newly created with @ref JxlEncoderCreate, but the memory manager is kept.
*
* @param enc instance to be re-initialized.
*/
JXL_EXPORT void JxlEncoderReset(JxlEncoder* enc);
/**
* Deinitializes and frees a @ref JxlEncoder instance.
*
* @param enc instance to be cleaned up and deallocated.
*/
JXL_EXPORT void JxlEncoderDestroy(JxlEncoder* enc);
/**
* Sets the color management system (CMS) that will be used for color conversion
* (if applicable) during encoding. May only be set before starting encoding. If
* left unset, the default CMS implementation will be used.
*
* @param enc encoder object.
* @param cms structure representing a CMS implementation. See @ref
* JxlCmsInterface for more details.
*/
JXL_EXPORT void JxlEncoderSetCms(JxlEncoder* enc, JxlCmsInterface cms);
/**
* Set the parallel runner for multithreading. May only be set before starting
* encoding.
*
* @param enc encoder object.
* @param parallel_runner function pointer to runner for multithreading. It may
* be NULL to use the default, single-threaded, runner. A multithreaded
* runner should be set to reach fast performance.
* @param parallel_runner_opaque opaque pointer for parallel_runner.
* @return ::JXL_ENC_SUCCESS if the runner was set, ::JXL_ENC_ERROR
* otherwise (the previous runner remains set).
*/
JXL_EXPORT JxlEncoderStatus
JxlEncoderSetParallelRunner(JxlEncoder* enc, JxlParallelRunner parallel_runner,
void* parallel_runner_opaque);
/**
* Get the (last) error code in case ::JXL_ENC_ERROR was returned.
*
* @param enc encoder object.
* @return the @ref JxlEncoderError that caused the (last) ::JXL_ENC_ERROR to
* be returned.
*/
JXL_EXPORT JxlEncoderError JxlEncoderGetError(JxlEncoder* enc);
/**
* Encodes a JPEG XL file using the available bytes. @p *avail_out indicates how
* many output bytes are available, and @p *next_out points to the input bytes.
* *avail_out will be decremented by the amount of bytes that have been
* processed by the encoder and *next_out will be incremented by the same
* amount, so *next_out will now point at the amount of *avail_out unprocessed
* bytes.
*
* The returned status indicates whether the encoder needs more output bytes.
* When the return value is not ::JXL_ENC_ERROR or ::JXL_ENC_SUCCESS, the
* encoding requires more @ref JxlEncoderProcessOutput calls to continue.
*
* The caller must guarantee that *avail_out >= 32 when calling
* @ref JxlEncoderProcessOutput; otherwise, ::JXL_ENC_NEED_MORE_OUTPUT will
* be returned. It is guaranteed that, if *avail_out >= 32, at least one byte of
* output will be written.
*
* This encodes the frames and/or boxes added so far. If the last frame or last
* box has been added, @ref JxlEncoderCloseInput, @ref JxlEncoderCloseFrames
* and/or @ref JxlEncoderCloseBoxes must be called before the next
* @ref JxlEncoderProcessOutput call, or the codestream won't be encoded
* correctly.
*
* @param enc encoder object.
* @param next_out pointer to next bytes to write to.
* @param avail_out amount of bytes available starting from *next_out.
* @return ::JXL_ENC_SUCCESS when encoding finished and all events handled.
* @return ::JXL_ENC_ERROR when encoding failed, e.g. invalid input.
* @return ::JXL_ENC_NEED_MORE_OUTPUT more output buffer is necessary.
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderProcessOutput(JxlEncoder* enc,
uint8_t** next_out,
size_t* avail_out);
/**
* Sets the frame information for this frame to the encoder. This includes
* animation information such as frame duration to store in the frame header.
* The frame header fields represent the frame as passed to the encoder, but not
* necessarily the exact values as they will be encoded file format: the encoder
* could change crop and blending options of a frame for more efficient encoding
* or introduce additional internal frames. Animation duration and time code
* information is not altered since those are immutable metadata of the frame.
*
* It is not required to use this function, however if have_animation is set
* to true in the basic info, then this function should be used to set the
* time duration of this individual frame. By default individual frames have a
* time duration of 0, making them form a composite still. See @ref
* JxlFrameHeader for more information.
*
* This information is stored in the @ref JxlEncoderFrameSettings and so is used
* for any frame encoded with these @ref JxlEncoderFrameSettings. It is ok to
* change between @ref JxlEncoderAddImageFrame calls, each added image frame
* will have the frame header that was set in the options at the time of calling
* @ref JxlEncoderAddImageFrame.
*
* The is_last and name_length fields of the @ref JxlFrameHeader are ignored,
* use
* @ref JxlEncoderCloseFrames to indicate last frame, and @ref
* JxlEncoderSetFrameName to indicate the name and its length instead.
* Calling this function will clear any name that was previously set with @ref
* JxlEncoderSetFrameName.
*
* @param frame_settings set of options and metadata for this frame. Also
* includes reference to the encoder object.
* @param frame_header frame header data to set. Object owned by the caller and
* does not need to be kept in memory, its information is copied internally.
* @return ::JXL_ENC_SUCCESS on success, ::JXL_ENC_ERROR on error
*/
JXL_EXPORT JxlEncoderStatus
JxlEncoderSetFrameHeader(JxlEncoderFrameSettings* frame_settings,
const JxlFrameHeader* frame_header);
/**
* Sets blend info of an extra channel. The blend info of extra channels is set
* separately from that of the color channels, the color channels are set with
* @ref JxlEncoderSetFrameHeader.
*
* @param frame_settings set of options and metadata for this frame. Also
* includes reference to the encoder object.
* @param index index of the extra channel to use.
* @param blend_info blend info to set for the extra channel
* @return ::JXL_ENC_SUCCESS on success, ::JXL_ENC_ERROR on error
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderSetExtraChannelBlendInfo(
JxlEncoderFrameSettings* frame_settings, size_t index,
const JxlBlendInfo* blend_info);
/**
* Sets the name of the animation frame. This function is optional, frames are
* not required to have a name. This setting is a part of the frame header, and
* the same principles as for @ref JxlEncoderSetFrameHeader apply. The
* name_length field of @ref JxlFrameHeader is ignored by the encoder, this
* function determines the name length instead as the length in bytes of the C
* string.
*
* The maximum possible name length is 1071 bytes (excluding terminating null
* character).
*
* Calling @ref JxlEncoderSetFrameHeader clears any name that was
* previously set.
*
* @param frame_settings set of options and metadata for this frame. Also
* includes reference to the encoder object.
* @param frame_name name of the next frame to be encoded, as a UTF-8 encoded C
* string (zero terminated). Owned by the caller, and copied internally.
* @return ::JXL_ENC_SUCCESS on success, ::JXL_ENC_ERROR on error
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderSetFrameName(
JxlEncoderFrameSettings* frame_settings, const char* frame_name);
/**
* Sets the bit depth of the input buffer.
*
* For float pixel formats, only the default @ref
JXL_BIT_DEPTH_FROM_PIXEL_FORMAT
* setting is allowed, while for unsigned pixel formats,
* ::JXL_BIT_DEPTH_FROM_CODESTREAM setting is also allowed. See the comment
on
* @ref JxlEncoderAddImageFrame for the effects of the bit depth setting.
* @param frame_settings set of options and metadata for this frame. Also
* includes reference to the encoder object.
* @param bit_depth the bit depth setting of the pixel input
* @return ::JXL_ENC_SUCCESS on success, ::JXL_ENC_ERROR on error
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderSetFrameBitDepth(
JxlEncoderFrameSettings* frame_settings, const JxlBitDepth* bit_depth);
/**
* Sets the buffer to read JPEG encoded bytes from for the next frame to encode.
*
* If @ref JxlEncoderSetBasicInfo has not yet been called, calling
* @ref JxlEncoderAddJPEGFrame will implicitly call it with the parameters of
* the added JPEG frame.
*
* If @ref JxlEncoderSetColorEncoding or @ref JxlEncoderSetICCProfile has not
* yet been called, calling @ref JxlEncoderAddJPEGFrame will implicitly call it
* with the parameters of the added JPEG frame.
*
* If the encoder is set to store JPEG reconstruction metadata using @ref
* JxlEncoderStoreJPEGMetadata and a single JPEG frame is added, it will be
* possible to losslessly reconstruct the JPEG codestream.
*
* If this is the last frame, @ref JxlEncoderCloseInput or @ref
* JxlEncoderCloseFrames must be called before the next
* @ref JxlEncoderProcessOutput call.
*
* Note, this can only be used to add JPEG frames for lossless compression. To
* encode with lossy compression, the JPEG must be decoded manually and a pixel
* buffer added using JxlEncoderAddImageFrame.
*
* @param frame_settings set of options and metadata for this frame. Also
* includes reference to the encoder object.
* @param buffer bytes to read JPEG from. Owned by the caller and its contents
* are copied internally.
* @param size size of buffer in bytes.
* @return ::JXL_ENC_SUCCESS on success, ::JXL_ENC_ERROR on error
*/
JXL_EXPORT JxlEncoderStatus
JxlEncoderAddJPEGFrame(const JxlEncoderFrameSettings* frame_settings,
const uint8_t* buffer, size_t size);
/**
* Sets the buffer to read pixels from for the next image to encode. Must call
* @ref JxlEncoderSetBasicInfo before @ref JxlEncoderAddImageFrame.
*
* Currently only some data types for pixel formats are supported:
* - ::JXL_TYPE_UINT8, with range 0..255
* - ::JXL_TYPE_UINT16, with range 0..65535
* - ::JXL_TYPE_FLOAT16, with nominal range 0..1
* - ::JXL_TYPE_FLOAT, with nominal range 0..1
*
* Note: the sample data type in pixel_format is allowed to be different from
* what is described in the @ref JxlBasicInfo. The type in pixel_format,
* together with an optional @ref JxlBitDepth parameter set by @ref
* JxlEncoderSetFrameBitDepth describes the format of the uncompressed pixel
* buffer. The bits_per_sample and exponent_bits_per_sample in the @ref
* JxlBasicInfo describes what will actually be encoded in the JPEG XL
* codestream. For example, to encode a 12-bit image, you would set
* bits_per_sample to 12, while the input frame buffer can be in the following
* formats:
* - if pixel format is in ::JXL_TYPE_UINT16 with default bit depth setting
* (i.e. ::JXL_BIT_DEPTH_FROM_PIXEL_FORMAT), input sample values are
* rescaled to 16-bit, i.e. multiplied by 65535/4095;
* - if pixel format is in ::JXL_TYPE_UINT16 with @ref
* JXL_BIT_DEPTH_FROM_CODESTREAM bit depth setting, input sample values are
* provided unscaled;
* - if pixel format is in ::JXL_TYPE_FLOAT, input sample values are
* rescaled to 0..1, i.e. multiplied by 1.f/4095.f. While it is allowed, it is
* obviously not recommended to use a pixel_format with lower precision than
* what is specified in the @ref JxlBasicInfo.
*
* We support interleaved channels as described by the @ref JxlPixelFormat
* "JxlPixelFormat":
* - single-channel data, e.g. grayscale
* - single-channel + alpha
* - trichromatic, e.g. RGB
* - trichromatic + alpha
*
* Extra channels not handled here need to be set by @ref
* JxlEncoderSetExtraChannelBuffer.
* If the image has alpha, and alpha is not passed here, it will implicitly be
* set to all-opaque (an alpha value of 1.0 everywhere).
*
* The pixels are assumed to be encoded in the original profile that is set with
* @ref JxlEncoderSetColorEncoding or @ref JxlEncoderSetICCProfile. If none of
* these functions were used, the pixels are assumed to be nonlinear sRGB for
* integer data types (::JXL_TYPE_UINT8, ::JXL_TYPE_UINT16), and linear
* sRGB for floating point data types (::JXL_TYPE_FLOAT16, @ref
* JXL_TYPE_FLOAT).
*
* Sample values in floating-point pixel formats are allowed to be outside the
* nominal range, e.g. to represent out-of-sRGB-gamut colors in the
* uses_original_profile=false case. They are however not allowed to be NaN or
* +-infinity.
*
* If this is the last frame, @ref JxlEncoderCloseInput or @ref
* JxlEncoderCloseFrames must be called before the next
* @ref JxlEncoderProcessOutput call.
*
* @param frame_settings set of options and metadata for this frame. Also
* includes reference to the encoder object.
* @param pixel_format format for pixels. Object owned by the caller and its
* contents are copied internally.
* @param buffer buffer type to input the pixel data from. Owned by the caller
* and its contents are copied internally.
* @param size size of buffer in bytes. This size should match what is implied
* by the frame dimensions and the pixel format.
* @return ::JXL_ENC_SUCCESS on success, ::JXL_ENC_ERROR on error
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderAddImageFrame(
const JxlEncoderFrameSettings* frame_settings,
const JxlPixelFormat* pixel_format, const void* buffer, size_t size);
/**
* The @ref JxlEncoderOutputProcessor structure provides an interface for the
* encoder's output processing. Users of the library, who want to do streaming
* encoding, should implement the required callbacks for buffering, writing,
* seeking (if supported), and setting a finalized position during the encoding
* process.
*
* At a high level, the processor can be in one of two states:
* - With an active buffer: This indicates that a buffer has been acquired using
* `get_buffer` and encoded data can be written to it.
* - Without an active buffer: In this state, no data can be written. A new
* buffer must be acquired after releasing any previously active buffer.
*
* The library will not acquire more than one buffer at a given time.
*
* The state of the processor includes `position` and `finalized position`,
* which have the following meaning.
*
* - position: Represents the current position, in bytes, within the output
* stream where the encoded data will be written next. This position moves
* forward with each `release_buffer` call as data is written, and can also be
* adjusted through the optional seek callback, if provided. At this position
* the next write will occur.
*
* - finalized position: A position in the output stream that ensures all bytes
* before this point are finalized and won't be changed by later writes.
*
* All fields but `seek` are required, `seek` is optional and can be NULL.
*/
struct JxlEncoderOutputProcessor {
/**
* Required.
* An opaque pointer that the client can use to store custom data.
* This data will be passed to the associated callback functions.
*/
void* opaque;
/**
* Required.
* Acquires a buffer at the current position into which the library will write
* the output data.
*
* If the `size` argument points to 0 and the returned value is NULL, this
* will be interpreted as asking the output writing to stop. In such a case,
* the library will return an error. The client is expected to set the size of
* the returned buffer based on the suggested `size` when this function is
* called.
*
* @param opaque user supplied parameters to the callback
* @param size points to a suggested buffer size when called; must be set to
* the size of the returned buffer once the function returns.
* @return a pointer to the acquired buffer or NULL to indicate a stop
* condition.
*/
void* (*get_buffer)(void* opaque, size_t* size);
/**
* Required.
* Notifies the user of library that the current buffer's data has been
* written and can be released. This function should advance the current
* position of the buffer by `written_bytes` number of bytes.
*
* @param opaque user supplied parameters to the callback
* @param written_bytes the number of bytes written to the buffer.
*/
void (*release_buffer)(void* opaque, size_t written_bytes);
/**
* Optional, can be NULL
* Seeks to a specific position in the output. This function is optional and
* can be set to NULL if the output doesn't support seeking. Can only be done
* when there is no buffer. Cannot be used to seek before the finalized
* position.
*
* @param opaque user supplied parameters to the callback
* @param position the position to seek to, in bytes.
*/
void (*seek)(void* opaque, uint64_t position);
/**
* Required.
* Sets a finalized position on the output data, at a specific position.
* Seeking will never request a position before the finalized position.
*
* Will only be called if there is no active buffer.
*
* @param opaque user supplied parameters to the callback
* @param finalized_position the position, in bytes, where the finalized
* position should be set.
*/
void (*set_finalized_position)(void* opaque, uint64_t finalized_position);
};
/**
* Sets the output processor for the encoder. This processor determines how the
* encoder will handle buffering, writing, seeking (if supported), and
* setting a finalized position during the encoding process.
*
* This should not be used when using @ref JxlEncoderProcessOutput.
*
* @param enc encoder object.
* @param output_processor the struct containing the callbacks for managing
* output.
* @return ::JXL_ENC_SUCCESS on success, ::JXL_ENC_ERROR on error.
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderSetOutputProcessor(
JxlEncoder* enc, struct JxlEncoderOutputProcessor output_processor);
/**
* Flushes any buffered input in the encoder, ensuring that all available input
* data has been processed and written to the output.
*
* This function can only be used after @ref JxlEncoderSetOutputProcessor.
* Before making the last call to @ref JxlEncoderFlushInput, users should call
* @ref JxlEncoderCloseInput to signal the end of input data.
*
* This should not be used when using @ref JxlEncoderProcessOutput.
*
* @param enc encoder object.
* @return ::JXL_ENC_SUCCESS on success, ::JXL_ENC_ERROR on error.
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderFlushInput(JxlEncoder* enc);
/**
* This struct provides callback functions to pass pixel data in a streaming
* manner instead of requiring the entire frame data in memory at once.
*/
struct JxlChunkedFrameInputSource {
/**
* A pointer to any user-defined data or state. This can be used to pass
* information to the callback functions.
*/
void* opaque;
/**
* Get the pixel format that color channel data will be provided in.
* When called, `pixel_format` points to a suggested pixel format; if
* color channel data can be given in this pixel format, processing might
* be more efficient.
*
* This function will be called exactly once, before any call to
* get_color_channel_at.
*
* @param opaque user supplied parameters to the callback
* @param pixel_format format for pixels
*/
void (*get_color_channels_pixel_format)(void* opaque,
JxlPixelFormat* pixel_format);
/**
* Callback to retrieve a rectangle of color channel data at a specific
* location. It is guaranteed that xpos and ypos are multiples of 8. xsize,
* ysize will be multiples of 8, unless the resulting rectangle would be out
* of image bounds. Moreover, xsize and ysize will be at most 2048. The
* returned data will be assumed to be in the format returned by the
* (preceding) call to get_color_channels_pixel_format, except the `align`
* parameter of the pixel format will be ignored. Instead, the `i`-th row will
* be assumed to start at position `return_value + i * *row_offset`, with the
* value of `*row_offset` decided by the callee.
*
* Note that multiple calls to `get_color_channel_data_at` may happen before a
* call to `release_buffer`.
*
* @param opaque user supplied parameters to the callback
* @param xpos horizontal position for the data.
* @param ypos vertical position for the data.
* @param xsize horizontal size of the requested rectangle of data.
* @param ysize vertical size of the requested rectangle of data.
* @param row_offset pointer to a the byte offset between consecutive rows of
* the retrieved pixel data.
* @return pointer to the retrieved pixel data.
*/
const void* (*get_color_channel_data_at)(void* opaque, size_t xpos,
size_t ypos, size_t xsize,
size_t ysize, size_t* row_offset);
/**
* Get the pixel format that extra channel data will be provided in.
* When called, `pixel_format` points to a suggested pixel format; if
* extra channel data can be given in this pixel format, processing might
* be more efficient.
*
* This function will be called exactly once per index, before any call to
* get_extra_channel_data_at with that given index.
*
* @param opaque user supplied parameters to the callback
* @param ec_index zero-indexed index of the extra channel
* @param pixel_format format for extra channel data
*/
void (*get_extra_channel_pixel_format)(void* opaque, size_t ec_index,
JxlPixelFormat* pixel_format);
/**
* Callback to retrieve a rectangle of extra channel `ec_index` data at a
* specific location. It is guaranteed that xpos and ypos are multiples of
* 8. xsize, ysize will be multiples of 8, unless the resulting rectangle
* would be out of image bounds. Moreover, xsize and ysize will be at most
* 2048. The returned data will be assumed to be in the format returned by the
* (preceding) call to get_extra_channels_pixel_format_at with the
* corresponding extra channel index `ec_index`, except the `align` parameter
* of the pixel format will be ignored. Instead, the `i`-th row will be
* assumed to start at position `return_value + i * *row_offset`, with the
* value of `*row_offset` decided by the callee.
*
* Note that multiple calls to `get_extra_channel_data_at` may happen before a
* call to `release_buffer`.
*
* @param opaque user supplied parameters to the callback
* @param xpos horizontal position for the data.
* @param ypos vertical position for the data.
* @param xsize horizontal size of the requested rectangle of data.
* @param ysize vertical size of the requested rectangle of data.
* @param row_offset pointer to a the byte offset between consecutive rows of
* the retrieved pixel data.
* @return pointer to the retrieved pixel data.
*/
const void* (*get_extra_channel_data_at)(void* opaque, size_t ec_index,
size_t xpos, size_t ypos,
size_t xsize, size_t ysize,
size_t* row_offset);
/**
* Releases the buffer `buf` (obtained through a call to
* `get_color_channel_data_at` or `get_extra_channel_data_at`). This function
* will be called exactly once per call to `get_color_channel_data_at` or
* `get_extra_channel_data_at`.
*
* @param opaque user supplied parameters to the callback
* @param buf pointer returned by `get_color_channel_data_at` or
* `get_extra_channel_data_at`
*/
void (*release_buffer)(void* opaque, const void* buf);
};
/**
* @brief Adds a frame to the encoder using a chunked input source.
*
* This function gives a way to encode a frame by providing pixel data in a
* chunked or streaming manner, which can be especially useful when dealing with
* large images that may not fit entirely in memory or when trying to optimize
* memory usage. The input data is provided through callbacks defined in the
* @ref JxlChunkedFrameInputSource struct. Once the frame data has been
* completely retrieved, this function will flush the input and close it if it
* is the last frame.
*
* @param frame_settings set of options and metadata for this frame. Also
* includes reference to the encoder object.
* @param is_last_frame indicates if this is the last frame.
* @param chunked_frame_input struct providing callback methods for retrieving
* pixel data in chunks.
*
* @return Returns a status indicating the success or failure of adding the
* frame.
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderAddChunkedFrame(
const JxlEncoderFrameSettings* frame_settings, JXL_BOOL is_last_frame,
struct JxlChunkedFrameInputSource chunked_frame_input);
/**
* Sets the buffer to read pixels from for an extra channel at a given index.
* The index must be smaller than the num_extra_channels in the associated
* @ref JxlBasicInfo. Must call @ref JxlEncoderSetExtraChannelInfo before @ref
* JxlEncoderSetExtraChannelBuffer.
*
* TODO(firsching): mention what data types in pixel formats are supported.
*
* It is required to call this function for every extra channel, except for the
* alpha channel if that was already set through @ref JxlEncoderAddImageFrame.
*
* @param frame_settings set of options and metadata for this frame. Also
* includes reference to the encoder object.
* @param pixel_format format for pixels. Object owned by the caller and its
* contents are copied internally. The num_channels value is ignored, since the
* number of channels for an extra channel is always assumed to be one.
* @param buffer buffer type to input the pixel data from. Owned by the caller
* and its contents are copied internally.
* @param size size of buffer in bytes. This size should match what is implied
* by the frame dimensions and the pixel format.
* @param index index of the extra channel to use.
* @return ::JXL_ENC_SUCCESS on success, ::JXL_ENC_ERROR on error
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderSetExtraChannelBuffer(
const JxlEncoderFrameSettings* frame_settings,
const JxlPixelFormat* pixel_format, const void* buffer, size_t size,
uint32_t index);
/** Adds a metadata box to the file format. @ref JxlEncoderProcessOutput must be
* used to effectively write the box to the output. @ref JxlEncoderUseBoxes must
* be enabled before using this function.
*
* Boxes allow inserting application-specific data and metadata (Exif, XML/XMP,
* JUMBF and user defined boxes).
*
* The box format follows ISO BMFF and shares features and box types with other
* image and video formats, including the Exif, XML and JUMBF boxes. The box
* format for JPEG XL is specified in ISO/IEC 18181-2.
*
* Boxes in general don't contain other boxes inside, except a JUMBF superbox.
* Boxes follow each other sequentially and are byte-aligned. If the container
* format is used, the JXL stream consists of concatenated boxes.
* It is also possible to use a direct codestream without boxes, but in that
* case metadata cannot be added.
*
* Each box generally has the following byte structure in the file:
* - 4 bytes: box size including box header (Big endian. If set to 0, an
* 8-byte 64-bit size follows instead).
* - 4 bytes: type, e.g. "JXL " for the signature box, "jxlc" for a codestream
* box.
* - N bytes: box contents.
*
* Only the box contents are provided to the contents argument of this function,
* the encoder encodes the size header itself. Most boxes are written
* automatically by the encoder as needed ("JXL ", "ftyp", "jxll", "jxlc",
* "jxlp", "jxli", "jbrd"), and this function only needs to be called to add
* optional metadata when encoding from pixels (using @ref
* JxlEncoderAddImageFrame). When recompressing JPEG files (using @ref
* JxlEncoderAddJPEGFrame), if the input JPEG contains EXIF, XMP or JUMBF
* metadata, the corresponding boxes are already added automatically.
*
* Box types are given by 4 characters. The following boxes can be added with
* this function:
* - "Exif": a box with EXIF metadata, can be added by libjxl users, or is
* automatically added when needed for JPEG reconstruction. The contents of
* this box must be prepended by a 4-byte tiff header offset, which may
* be 4 zero bytes in case the tiff header follows immediately.
* The EXIF metadata must be in sync with what is encoded in the JPEG XL
* codestream, specifically the image orientation. While this is not
* recommended in practice, in case of conflicting metadata, the JPEG XL
* codestream takes precedence.
* - "xml ": a box with XML data, in particular XMP metadata, can be added by
* libjxl users, or is automatically added when needed for JPEG reconstruction
* - "jumb": a JUMBF superbox, which can contain boxes with different types of
* metadata inside. This box type can be added by the encoder transparently,
* and other libraries to create and handle JUMBF content exist.
* - Application-specific boxes. Their typename should not begin with "jxl" or
* "JXL" or conflict with other existing typenames, and they should be
* registered with MP4RA (mp4ra.org).
*
* These boxes can be stored uncompressed or Brotli-compressed (using a "brob"
* box), depending on the compress_box parameter.
*
* @param enc encoder object.
* @param type the box type, e.g. "Exif" for EXIF metadata, "xml " for XMP or
* IPTC metadata, "jumb" for JUMBF metadata.
* @param contents the full contents of the box, for example EXIF
* data. ISO BMFF box header must not be included, only the contents. Owned by
* the caller and its contents are copied internally.
* @param size size of the box contents.
* @param compress_box Whether to compress this box as a "brob" box. Requires
* Brotli support.
* @return ::JXL_ENC_SUCCESS on success, ::JXL_ENC_ERROR on error, such as
* when using this function without @ref JxlEncoderUseContainer, or adding a box
* type that would result in an invalid file format.
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderAddBox(JxlEncoder* enc,
const JxlBoxType type,
const uint8_t* contents,
size_t size,
JXL_BOOL compress_box);
/**
* Indicates the intention to add metadata boxes. This allows @ref
* JxlEncoderAddBox to be used. When using this function, then it is required
* to use @ref JxlEncoderCloseBoxes at the end.
*
* By default the encoder assumes no metadata boxes will be added.
*
* This setting can only be set at the beginning, before encoding starts.
*
* @param enc encoder object.
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderUseBoxes(JxlEncoder* enc);
/**
* Declares that no further boxes will be added with @ref JxlEncoderAddBox.
* This function must be called after the last box is added so the encoder knows
* the stream will be finished. It is not necessary to use this function if
* @ref JxlEncoderUseBoxes is not used. Further frames may still be added.
*
* Must be called between @ref JxlEncoderAddBox of the last box
* and the next call to @ref JxlEncoderProcessOutput, or @ref
* JxlEncoderProcessOutput won't output the last box correctly.
*
* NOTE: if you don't need to close frames and boxes at separate times, you can
* use @ref JxlEncoderCloseInput instead to close both at once.
*
* @param enc encoder object.
*/
JXL_EXPORT void JxlEncoderCloseBoxes(JxlEncoder* enc);
/**
* Declares that no frames will be added and @ref JxlEncoderAddImageFrame and
* @ref JxlEncoderAddJPEGFrame won't be called anymore. Further metadata boxes
* may still be added. This function or @ref JxlEncoderCloseInput must be called
* after adding the last frame and the next call to
* @ref JxlEncoderProcessOutput, or the frame won't be properly marked as last.
*
* NOTE: if you don't need to close frames and boxes at separate times, you can
* use @ref JxlEncoderCloseInput instead to close both at once.
*
* @param enc encoder object.
*/
JXL_EXPORT void JxlEncoderCloseFrames(JxlEncoder* enc);
/**
* Closes any input to the encoder, equivalent to calling @ref
* JxlEncoderCloseFrames as well as calling @ref JxlEncoderCloseBoxes if needed.
* No further input of any kind may be given to the encoder, but further @ref
* JxlEncoderProcessOutput calls should be done to create the final output.
*
* The requirements of both @ref JxlEncoderCloseFrames and @ref
* JxlEncoderCloseBoxes apply to this function. Either this function or the
* other two must be called after the final frame and/or box, and the next
* @ref JxlEncoderProcessOutput call, or the codestream won't be encoded
* correctly.
*
* @param enc encoder object.
*/
JXL_EXPORT void JxlEncoderCloseInput(JxlEncoder* enc);
/**
* Sets the original color encoding of the image encoded by this encoder. This
* is an alternative to @ref JxlEncoderSetICCProfile and only one of these two
* must be used. This one sets the color encoding as a @ref JxlColorEncoding,
* while the other sets it as ICC binary data. Must be called after @ref
* JxlEncoderSetBasicInfo.
*
* @param enc encoder object.
* @param color color encoding. Object owned by the caller and its contents are
* copied internally.
* @return ::JXL_ENC_SUCCESS if the operation was successful, @ref
* JXL_ENC_ERROR otherwise
*/
JXL_EXPORT JxlEncoderStatus
JxlEncoderSetColorEncoding(JxlEncoder* enc, const JxlColorEncoding* color);
/**
* Sets the original color encoding of the image encoded by this encoder as an
* ICC color profile. This is an alternative to @ref JxlEncoderSetColorEncoding
* and only one of these two must be used. This one sets the color encoding as
* ICC binary data, while the other defines it as a @ref JxlColorEncoding. Must
* be called after @ref JxlEncoderSetBasicInfo.
*
* @param enc encoder object.
* @param icc_profile bytes of the original ICC profile
* @param size size of the icc_profile buffer in bytes
* @return ::JXL_ENC_SUCCESS if the operation was successful, @ref
* JXL_ENC_ERROR otherwise
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderSetICCProfile(JxlEncoder* enc,
const uint8_t* icc_profile,
size_t size);
/**
* Initializes a @ref JxlBasicInfo struct to default values.
* For forwards-compatibility, this function has to be called before values
* are assigned to the struct fields.
* The default values correspond to an 8-bit RGB image, no alpha or any
* other extra channels.
*
* @param info global image metadata. Object owned by the caller.
*/
JXL_EXPORT void JxlEncoderInitBasicInfo(JxlBasicInfo* info);
/**
* Initializes a @ref JxlFrameHeader struct to default values.
* For forwards-compatibility, this function has to be called before values
* are assigned to the struct fields.
* The default values correspond to a frame with no animation duration and the
* 'replace' blend mode. After using this function, For animation duration must
* be set, for composite still blend settings must be set.
*
* @param frame_header frame metadata. Object owned by the caller.
*/
JXL_EXPORT void JxlEncoderInitFrameHeader(JxlFrameHeader* frame_header);
/**
* Initializes a @ref JxlBlendInfo struct to default values.
* For forwards-compatibility, this function has to be called before values
* are assigned to the struct fields.
*
* @param blend_info blending info. Object owned by the caller.
*/
JXL_EXPORT void JxlEncoderInitBlendInfo(JxlBlendInfo* blend_info);
/**
* Sets the global metadata of the image encoded by this encoder.
*
* If the @ref JxlBasicInfo contains information of extra channels beyond an
* alpha channel, then @ref JxlEncoderSetExtraChannelInfo must be called between
* @ref JxlEncoderSetBasicInfo and @ref JxlEncoderAddImageFrame. In order to
* indicate extra channels, the value of `info.num_extra_channels` should be set
* to the number of extra channels, also counting the alpha channel if present.
*
* @param enc encoder object.
* @param info global image metadata. Object owned by the caller and its
* contents are copied internally.
* @return ::JXL_ENC_SUCCESS if the operation was successful,
* ::JXL_ENC_ERROR otherwise
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderSetBasicInfo(JxlEncoder* enc,
const JxlBasicInfo* info);
/**
* Sets the upsampling method the decoder will use in case there are frames
* with ::JXL_ENC_FRAME_SETTING_RESAMPLING set. This is useful in combination
* with the ::JXL_ENC_FRAME_SETTING_ALREADY_DOWNSAMPLED option, to control
* the type of upsampling that will be used.
*
* @param enc encoder object.
* @param factor upsampling factor to configure (1, 2, 4 or 8; for 1 this
* function has no effect at all)
* @param mode upsampling mode to use for this upsampling:
* -1: default (good for photographic images, no signaling overhead)
* 0: nearest neighbor (good for pixel art)
* 1: 'pixel dots' (same as NN for 2x, diamond-shaped 'pixel dots' for 4x/8x)
* @return ::JXL_ENC_SUCCESS if the operation was successful,
* ::JXL_ENC_ERROR otherwise
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderSetUpsamplingMode(JxlEncoder* enc,
int64_t factor,
int64_t mode);
/**
* Initializes a @ref JxlExtraChannelInfo struct to default values.
* For forwards-compatibility, this function has to be called before values
* are assigned to the struct fields.
* The default values correspond to an 8-bit channel of the provided type.
*
* @param type type of the extra channel.
* @param info global extra channel metadata. Object owned by the caller and its
* contents are copied internally.
*/
JXL_EXPORT void JxlEncoderInitExtraChannelInfo(JxlExtraChannelType type,
JxlExtraChannelInfo* info);
/**
* Sets information for the extra channel at the given index. The index
* must be smaller than num_extra_channels in the associated @ref JxlBasicInfo.
*
* @param enc encoder object
* @param index index of the extra channel to set.
* @param info global extra channel metadata. Object owned by the caller and its
* contents are copied internally.
* @return ::JXL_ENC_SUCCESS on success, ::JXL_ENC_ERROR on error
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderSetExtraChannelInfo(
JxlEncoder* enc, size_t index, const JxlExtraChannelInfo* info);
/**
* Sets the name for the extra channel at the given index in UTF-8. The index
* must be smaller than the num_extra_channels in the associated @ref
* JxlBasicInfo.
*
* TODO(lode): remove size parameter for consistency with
* @ref JxlEncoderSetFrameName
*
* @param enc encoder object
* @param index index of the extra channel to set.
* @param name buffer with the name of the extra channel.
* @param size size of the name buffer in bytes, not counting the terminating
* character.
* @return JXL_ENC_SUCCESS on success, JXL_ENC_ERROR on error
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderSetExtraChannelName(JxlEncoder* enc,
size_t index,
const char* name,
size_t size);
/**
* Sets a frame-specific option of integer type to the encoder options.
* The @ref JxlEncoderFrameSettingId argument determines which option is set.
*
* @param frame_settings set of options and metadata for this frame. Also
* includes reference to the encoder object.
* @param option ID of the option to set.
* @param value Integer value to set for this option.
* @return ::JXL_ENC_SUCCESS if the operation was successful, @ref
* JXL_ENC_ERROR in case of an error, such as invalid or unknown option id, or
* invalid integer value for the given option. If an error is returned, the
* state of the
* @ref JxlEncoderFrameSettings object is still valid and is the same as before
* this function was called.
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderFrameSettingsSetOption(
JxlEncoderFrameSettings* frame_settings, JxlEncoderFrameSettingId option,
int64_t value);
/**
* Sets a frame-specific option of float type to the encoder options.
* The @ref JxlEncoderFrameSettingId argument determines which option is set.
*
* @param frame_settings set of options and metadata for this frame. Also
* includes reference to the encoder object.
* @param option ID of the option to set.
* @param value Float value to set for this option.
* @return ::JXL_ENC_SUCCESS if the operation was successful, @ref
* JXL_ENC_ERROR in case of an error, such as invalid or unknown option id, or
* invalid integer value for the given option. If an error is returned, the
* state of the
* @ref JxlEncoderFrameSettings object is still valid and is the same as before
* this function was called.
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderFrameSettingsSetFloatOption(
JxlEncoderFrameSettings* frame_settings, JxlEncoderFrameSettingId option,
float value);
/** Forces the encoder to use the box-based container format (BMFF) even
* when not necessary.
*
* When using @ref JxlEncoderUseBoxes, @ref JxlEncoderStoreJPEGMetadata or @ref
* JxlEncoderSetCodestreamLevel with level 10, the encoder will automatically
* also use the container format, it is not necessary to use
* @ref JxlEncoderUseContainer for those use cases.
*
* By default this setting is disabled.
*
* This setting can only be set at the beginning, before encoding starts.
*
* @param enc encoder object.
* @param use_container true if the encoder should always output the JPEG XL
* container format, false to only output it when necessary.
* @return JXL_ENC_SUCCESS if the operation was successful, JXL_ENC_ERROR
* otherwise.
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderUseContainer(JxlEncoder* enc,
JXL_BOOL use_container);
/**
* Configure the encoder to store JPEG reconstruction metadata in the JPEG XL
* container.
*
* If this is set to true and a single JPEG frame is added, it will be
* possible to losslessly reconstruct the JPEG codestream.
*
* This setting can only be set at the beginning, before encoding starts.
*
* @param enc encoder object.
* @param store_jpeg_metadata true if the encoder should store JPEG metadata.
* @return ::JXL_ENC_SUCCESS if the operation was successful, @ref
* JXL_ENC_ERROR otherwise.
*/
JXL_EXPORT JxlEncoderStatus
JxlEncoderStoreJPEGMetadata(JxlEncoder* enc, JXL_BOOL store_jpeg_metadata);
/** Sets the feature level of the JPEG XL codestream. Valid values are 5 and
* 10, or -1 (to choose automatically). Using the minimum required level, or
* level 5 in most cases, is recommended for compatibility with all decoders.
*
* Level 5: for end-user image delivery, this level is the most widely
* supported level by image decoders and the recommended level to use unless a
* level 10 feature is absolutely necessary. Supports a maximum resolution
* 268435456 pixels total with a maximum width or height of 262144 pixels,
* maximum 16-bit color channel depth, maximum 120 frames per second for
* animation, maximum ICC color profile size of 4 MiB, it allows all color
* models and extra channel types except CMYK and the JXL_CHANNEL_BLACK
* extra channel, and a maximum of 4 extra channels in addition to the 3 color
* channels. It also sets boundaries to certain internally used coding tools.
*
* Level 10: this level removes or increases the bounds of most of the level
* 5 limitations, allows CMYK color and up to 32 bits per color channel, but
* may be less widely supported.
*
* The default value is -1. This means the encoder will automatically choose
* between level 5 and level 10 based on what information is inside the @ref
* JxlBasicInfo structure. Do note that some level 10 features, particularly
* those used by animated JPEG XL codestreams, might require level 10, even
* though the @ref JxlBasicInfo only suggests level 5. In this case, the level
* must be explicitly set to 10, otherwise the encoder will return an error.
* The encoder will restrict internal encoding choices to those compatible with
* the level setting.
*
* This setting can only be set at the beginning, before encoding starts.
*
* @param enc encoder object.
* @param level the level value to set, must be -1, 5, or 10.
* @return ::JXL_ENC_SUCCESS if the operation was successful, @ref
* JXL_ENC_ERROR otherwise.
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderSetCodestreamLevel(JxlEncoder* enc,
int level);
/** Returns the codestream level required to support the currently configured
* settings and basic info. This function can only be used at the beginning,
* before encoding starts, but after setting basic info.
*
* This does not support per-frame settings, only global configuration, such as
* the image dimensions, that are known at the time of writing the header of
* the JPEG XL file.
*
* If this returns 5, nothing needs to be done and the codestream can be
* compatible with any decoder. If this returns 10, @ref
* JxlEncoderSetCodestreamLevel has to be used to set the codestream level to
* 10, or the encoder can be configured differently to allow using the more
* compatible level 5.
*
* @param enc encoder object.
* @return -1 if no level can support the configuration (e.g. image dimensions
* larger than even level 10 supports), 5 if level 5 is supported, 10 if setting
* the codestream level to 10 is required.
*
*/
JXL_EXPORT int JxlEncoderGetRequiredCodestreamLevel(const JxlEncoder* enc);
/**
* Enables lossless encoding.
*
* This is not an option like the others on itself, but rather while enabled it
* overrides a set of existing options (such as distance, modular mode and
* color transform) that enables bit-for-bit lossless encoding.
*
* When disabled, those options are not overridden, but since those options
* could still have been manually set to a combination that operates losslessly,
* using this function with lossless set to ::JXL_FALSE does not
* guarantee lossy encoding, though the default set of options is lossy.
*
* @param frame_settings set of options and metadata for this frame. Also
* includes reference to the encoder object.
* @param lossless whether to override options for lossless mode
* @return ::JXL_ENC_SUCCESS if the operation was successful, @ref
* JXL_ENC_ERROR otherwise.
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderSetFrameLossless(
JxlEncoderFrameSettings* frame_settings, JXL_BOOL lossless);
/**
* Sets the distance level for lossy compression: target max butteraugli
* distance, lower = higher quality. Range: 0 .. 25.
* 0.0 = mathematically lossless (however, use @ref JxlEncoderSetFrameLossless
* instead to use true lossless, as setting distance to 0 alone is not the only
* requirement). 1.0 = visually lossless. Recommended range: 0.5 .. 3.0. Default
* value: 1.0.
*
* @param frame_settings set of options and metadata for this frame. Also
* includes reference to the encoder object.
* @param distance the distance value to set.
* @return ::JXL_ENC_SUCCESS if the operation was successful, @ref
* JXL_ENC_ERROR otherwise.
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderSetFrameDistance(
JxlEncoderFrameSettings* frame_settings, float distance);
/**
* Sets the distance level for lossy compression of extra channels.
* The distance is as in @ref JxlEncoderSetFrameDistance (lower = higher
* quality). If not set, or if set to the special value -1, the distance that
* was set with
* @ref JxlEncoderSetFrameDistance will be used.
*
* @param frame_settings set of options and metadata for this frame. Also
* includes reference to the encoder object.
* @param index index of the extra channel to set a distance value for.
* @param distance the distance value to set.
* @return ::JXL_ENC_SUCCESS if the operation was successful, @ref
* JXL_ENC_ERROR otherwise.
*/
JXL_EXPORT JxlEncoderStatus JxlEncoderSetExtraChannelDistance(
JxlEncoderFrameSettings* frame_settings, size_t index, float distance);
/**
* Maps JPEG-style quality factor to distance.
*
* This function takes in input a JPEG-style quality factor `quality` and
* produces as output a `distance` value suitable to be used with @ref
* JxlEncoderSetFrameDistance and @ref JxlEncoderSetExtraChannelDistance.
*
* The `distance` value influences the level of compression, with lower values
* indicating higher quality:
* - 0.0 implies lossless compression (however, note that calling @ref
* JxlEncoderSetFrameLossless is required).
* - 1.0 represents a visually lossy compression, which is also the default
* setting.
*
* The `quality` parameter, ranging up to 100, is inversely related to
* 'distance':
* - A `quality` of 100.0 maps to a `distance` of 0.0 (lossless).
* - A `quality` of 90.0 corresponds to a `distance` of 1.0.
*
* Recommended Range:
* - `distance`: 0.5 to 3.0.
* - corresponding `quality`: approximately 96 to 68.
*
* Allowed Range:
* - `distance`: 0.0 to 25.0.
* - corresponding `quality`: 100.0 to 0.0.
*
* Note: the `quality` parameter has no consistent psychovisual meaning
* across different codecs and libraries. Using the mapping defined by @ref
* JxlEncoderDistanceFromQuality will result in a visual quality roughly
* equivalent to what would be obtained with `libjpeg-turbo` with the same
* `quality` parameter, but that is by no means guaranteed; do not assume that
* the same quality value will result in similar file sizes and image quality
* across different codecs.
*/
JXL_EXPORT float JxlEncoderDistanceFromQuality(float quality);
/**
* Create a new set of encoder options, with all values initially copied from
* the @p source options, or set to default if @p source is NULL.
*
* The returned pointer is an opaque struct tied to the encoder and it will be
* deallocated by the encoder when @ref JxlEncoderDestroy() is called. For
* functions taking both a @ref JxlEncoder and a @ref JxlEncoderFrameSettings,
* only @ref JxlEncoderFrameSettings created with this function for the same
* encoder instance can be used.
*
* @param enc encoder object.
* @param source source options to copy initial values from, or NULL to get
* defaults initialized to defaults.
* @return the opaque struct pointer identifying a new set of encoder options.
*/
JXL_EXPORT JxlEncoderFrameSettings* JxlEncoderFrameSettingsCreate(
JxlEncoder* enc, const JxlEncoderFrameSettings* source);
/**
* Sets a color encoding to be sRGB.
*
* @param color_encoding color encoding instance.
* @param is_gray whether the color encoding should be gray scale or color.
*/
JXL_EXPORT void JxlColorEncodingSetToSRGB(JxlColorEncoding* color_encoding,
JXL_BOOL is_gray);
/**
* Sets a color encoding to be linear sRGB.
*
* @param color_encoding color encoding instance.
* @param is_gray whether the color encoding should be gray scale or color.
*/
JXL_EXPORT void JxlColorEncodingSetToLinearSRGB(
JxlColorEncoding* color_encoding, JXL_BOOL is_gray);
/**
* Enables usage of expert options.
*
* At the moment, the only expert option is setting an effort value of 11,
* which gives the best compression for pixel-lossless modes but is very slow.
*
* @param enc encoder object.
*/
JXL_EXPORT void JxlEncoderAllowExpertOptions(JxlEncoder* enc);
/**
* Function type for @ref JxlEncoderSetDebugImageCallback.
*
* The callback may be called simultaneously by different threads when using a
* threaded parallel runner, on different debug images.
*
* @param opaque optional user data, as given to @ref
* JxlEncoderSetDebugImageCallback.
* @param label label of debug image, can be used in filenames
* @param xsize width of debug image
* @param ysize height of debug image
* @param color color encoding of debug image
* @param pixels pixel data of debug image as big-endian 16-bit unsigned
* samples. The memory is not owned by the user, and is only valid during the
* time the callback is running.
*/
typedef void (*JxlDebugImageCallback)(void* opaque, const char* label,
size_t xsize, size_t ysize,
const JxlColorEncoding* color,
const uint16_t* pixels);
/**
* Sets the given debug image callback that will be used by the encoder to
* output various debug images during encoding.
*
* This only has any effect if the encoder was compiled with the appropriate
* debug build flags.
*
* @param frame_settings set of options and metadata for this frame. Also
* includes reference to the encoder object.
* @param callback used to return the debug image
* @param opaque user supplied parameter to the image callback
*/
JXL_EXPORT void JxlEncoderSetDebugImageCallback(
JxlEncoderFrameSettings* frame_settings, JxlDebugImageCallback callback,
void* opaque);
/**
* Sets the given stats object for gathering various statistics during encoding.
*
* This only has any effect if the encoder was compiled with the appropriate
* debug build flags.
*
* @param frame_settings set of options and metadata for this frame. Also
* includes reference to the encoder object.
* @param stats object that can be used to query the gathered stats (created
* by @ref JxlEncoderStatsCreate)
*/
JXL_EXPORT void JxlEncoderCollectStats(JxlEncoderFrameSettings* frame_settings,
JxlEncoderStats* stats);
#ifdef __cplusplus
}
#endif
#endif /* JXL_ENCODE_H_ */
/** @}*/