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aomedia / libavif / c02cae89e542f4ee18f7de9f66ff867a493644cf / . / include / avif / avif.h
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// Copyright 2019 Joe Drago. All rights reserved.
// SPDX-License-Identifier: BSD-2-Clause
#ifndef AVIF_AVIF_H
#define AVIF_AVIF_H
#include <stddef.h>
#include <stdint.h>
#ifdef __cplusplus
extern "C" {
#endif
// ---------------------------------------------------------------------------
// Export macros
// AVIF_BUILDING_SHARED_LIBS should only be defined when libavif is being built
// as a shared library.
// AVIF_DLL should be defined if libavif is a shared library. If you are using
// libavif as a CMake dependency, through a CMake package config file or through
// pkg-config, this is defined automatically.
//
// Here's what AVIF_API will be defined as in shared build:
// | | Windows | Unix |
// | Build | __declspec(dllexport) | __attribute__((visibility("default"))) |
// | Use | __declspec(dllimport) | |
//
// For static build, AVIF_API is always defined as nothing.
#if defined(_WIN32)
#define AVIF_HELPER_EXPORT __declspec(dllexport)
#define AVIF_HELPER_IMPORT __declspec(dllimport)
#elif defined(__GNUC__) && __GNUC__ >= 4
#define AVIF_HELPER_EXPORT __attribute__((visibility("default")))
#define AVIF_HELPER_IMPORT
#else
#define AVIF_HELPER_EXPORT
#define AVIF_HELPER_IMPORT
#endif
#if defined(AVIF_DLL)
#if defined(AVIF_BUILDING_SHARED_LIBS)
#define AVIF_API AVIF_HELPER_EXPORT
#else
#define AVIF_API AVIF_HELPER_IMPORT
#endif // defined(AVIF_BUILDING_SHARED_LIBS)
#else
#define AVIF_API
#endif // defined(AVIF_DLL)
#if defined(AVIF_ENABLE_NODISCARD) || (defined(__cplusplus) && __cplusplus >= 201703L) || \
(defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202311L)
#define AVIF_NODISCARD [[nodiscard]]
#else
// Starting with 3.9, clang allows defining the warn_unused_result attribute for enums.
#if defined(__clang__) && defined(__has_attribute) && ((__clang_major__ << 8) | __clang_minor__) >= ((3 << 8) | 9)
#if __has_attribute(warn_unused_result)
#define AVIF_NODISCARD __attribute__((warn_unused_result))
#else
#define AVIF_NODISCARD
#endif
#else
#define AVIF_NODISCARD
#endif
#endif
// ---------------------------------------------------------------------------
// Constants
// AVIF_VERSION_DEVEL should always be 0 for official releases / version tags,
// and non-zero during development of the next release. This should allow for
// downstream projects to do greater-than preprocessor checks on AVIF_VERSION
// to leverage in-development code without breaking their stable builds.
#define AVIF_VERSION_MAJOR 1
#define AVIF_VERSION_MINOR 0
#define AVIF_VERSION_PATCH 4
#define AVIF_VERSION_DEVEL 1
#define AVIF_VERSION \
((AVIF_VERSION_MAJOR * 1000000) + (AVIF_VERSION_MINOR * 10000) + (AVIF_VERSION_PATCH * 100) + AVIF_VERSION_DEVEL)
typedef int avifBool;
#define AVIF_TRUE 1
#define AVIF_FALSE 0
#define AVIF_DIAGNOSTICS_ERROR_BUFFER_SIZE 256
// A reasonable default for maximum image size (in pixel count) to avoid out-of-memory errors or
// integer overflow in (32-bit) int or unsigned int arithmetic operations.
#define AVIF_DEFAULT_IMAGE_SIZE_LIMIT (16384 * 16384)
// A reasonable default for maximum image dimension (width or height).
#define AVIF_DEFAULT_IMAGE_DIMENSION_LIMIT 32768
// a 12 hour AVIF image sequence, running at 60 fps (a basic sanity check as this is quite ridiculous)
#define AVIF_DEFAULT_IMAGE_COUNT_LIMIT (12 * 3600 * 60)
#define AVIF_QUALITY_DEFAULT -1
#define AVIF_QUALITY_LOSSLESS 100
#define AVIF_QUALITY_WORST 0
#define AVIF_QUALITY_BEST 100
#define AVIF_QUANTIZER_LOSSLESS 0
#define AVIF_QUANTIZER_BEST_QUALITY 0
#define AVIF_QUANTIZER_WORST_QUALITY 63
#define AVIF_PLANE_COUNT_YUV 3
#define AVIF_SPEED_DEFAULT -1
#define AVIF_SPEED_SLOWEST 0
#define AVIF_SPEED_FASTEST 10
// This value is used to indicate that an animated AVIF file has to be repeated infinitely.
#define AVIF_REPETITION_COUNT_INFINITE -1
// This value is used if an animated AVIF file does not have repetitions specified using an EditList box. Applications can choose
// to handle this case however they want.
#define AVIF_REPETITION_COUNT_UNKNOWN -2
// The number of spatial layers in AV1, with spatial_id = 0..3.
#define AVIF_MAX_AV1_LAYER_COUNT 4
typedef enum avifPlanesFlag
{
AVIF_PLANES_YUV = (1 << 0),
AVIF_PLANES_A = (1 << 1),
AVIF_PLANES_ALL = 0xff
} avifPlanesFlag;
typedef uint32_t avifPlanesFlags;
typedef enum avifChannelIndex
{
// These can be used as the index for the yuvPlanes and yuvRowBytes arrays in avifImage.
AVIF_CHAN_Y = 0,
AVIF_CHAN_U = 1,
AVIF_CHAN_V = 2,
// This may not be used in yuvPlanes and yuvRowBytes, but is available for use with avifImagePlane().
AVIF_CHAN_A = 3
} avifChannelIndex;
// ---------------------------------------------------------------------------
// Version
AVIF_API const char * avifVersion(void);
AVIF_API void avifCodecVersions(char outBuffer[256]);
AVIF_API unsigned int avifLibYUVVersion(void); // returns 0 if libavif wasn't compiled with libyuv support
// ---------------------------------------------------------------------------
// Memory management
// Returns NULL on memory allocation failure.
AVIF_API void * avifAlloc(size_t size);
AVIF_API void avifFree(void * p);
// ---------------------------------------------------------------------------
// avifResult
typedef enum AVIF_NODISCARD avifResult
{
AVIF_RESULT_OK = 0,
AVIF_RESULT_UNKNOWN_ERROR = 1,
AVIF_RESULT_INVALID_FTYP = 2,
AVIF_RESULT_NO_CONTENT = 3,
AVIF_RESULT_NO_YUV_FORMAT_SELECTED = 4,
AVIF_RESULT_REFORMAT_FAILED = 5,
AVIF_RESULT_UNSUPPORTED_DEPTH = 6,
AVIF_RESULT_ENCODE_COLOR_FAILED = 7,
AVIF_RESULT_ENCODE_ALPHA_FAILED = 8,
AVIF_RESULT_BMFF_PARSE_FAILED = 9,
AVIF_RESULT_MISSING_IMAGE_ITEM = 10,
AVIF_RESULT_DECODE_COLOR_FAILED = 11,
AVIF_RESULT_DECODE_ALPHA_FAILED = 12,
AVIF_RESULT_COLOR_ALPHA_SIZE_MISMATCH = 13,
AVIF_RESULT_ISPE_SIZE_MISMATCH = 14,
AVIF_RESULT_NO_CODEC_AVAILABLE = 15,
AVIF_RESULT_NO_IMAGES_REMAINING = 16,
AVIF_RESULT_INVALID_EXIF_PAYLOAD = 17,
AVIF_RESULT_INVALID_IMAGE_GRID = 18,
AVIF_RESULT_INVALID_CODEC_SPECIFIC_OPTION = 19,
AVIF_RESULT_TRUNCATED_DATA = 20,
AVIF_RESULT_IO_NOT_SET = 21, // the avifIO field of avifDecoder is not set
AVIF_RESULT_IO_ERROR = 22,
AVIF_RESULT_WAITING_ON_IO = 23, // similar to EAGAIN/EWOULDBLOCK, this means the avifIO doesn't have necessary data available yet
AVIF_RESULT_INVALID_ARGUMENT = 24, // an argument passed into this function is invalid
AVIF_RESULT_NOT_IMPLEMENTED = 25, // a requested code path is not (yet) implemented
AVIF_RESULT_OUT_OF_MEMORY = 26,
AVIF_RESULT_CANNOT_CHANGE_SETTING = 27, // a setting that can't change is changed during encoding
AVIF_RESULT_INCOMPATIBLE_IMAGE = 28, // the image is incompatible with already encoded images
AVIF_RESULT_INTERNAL_ERROR = 29, // some invariants have not been satisfied (likely a bug in libavif)
#if defined(AVIF_ENABLE_EXPERIMENTAL_GAIN_MAP)
AVIF_RESULT_ENCODE_GAIN_MAP_FAILED = 30,
AVIF_RESULT_DECODE_GAIN_MAP_FAILED = 31,
AVIF_RESULT_INVALID_TONE_MAPPED_IMAGE = 32,
#endif
#if defined(AVIF_ENABLE_EXPERIMENTAL_SAMPLE_TRANSFORM)
AVIF_RESULT_ENCODE_SAMPLE_TRANSFORM_FAILED = 33,
AVIF_RESULT_DECODE_SAMPLE_TRANSFORM_FAILED = 34,
#endif
// Kept for backward compatibility; please use the symbols above instead.
AVIF_RESULT_NO_AV1_ITEMS_FOUND = AVIF_RESULT_MISSING_IMAGE_ITEM
} avifResult;
AVIF_API const char * avifResultToString(avifResult result);
// ---------------------------------------------------------------------------
// avifHeaderFormat
typedef enum avifHeaderFormat
{
// AVIF file with an "avif" brand, a MetaBox and all its required boxes for maximum compatibility.
AVIF_HEADER_FULL,
#if defined(AVIF_ENABLE_EXPERIMENTAL_METAV1)
// AVIF file with a "mif3" brand and a MetaBox with version 1 to reduce the encoded file size.
// This is based on the w23988 "Low-overhead image file format" MPEG proposal for HEIF.
// WARNING: Experimental feature. Produces files that are incompatible with older decoders.
AVIF_HEADER_REDUCED,
#endif
} avifHeaderFormat;
// ---------------------------------------------------------------------------
// avifROData/avifRWData: Generic raw memory storage
typedef struct avifROData
{
const uint8_t * data;
size_t size;
} avifROData;
// Note: Use avifRWDataFree() if any avif*() function populates one of these.
typedef struct avifRWData
{
uint8_t * data;
size_t size;
} avifRWData;
// clang-format off
// Initialize avifROData/avifRWData on the stack with this
#define AVIF_DATA_EMPTY { NULL, 0 }
// clang-format on
// The avifRWData input must be zero-initialized before being manipulated with these functions.
// If AVIF_RESULT_OUT_OF_MEMORY is returned, raw is left unchanged.
AVIF_API avifResult avifRWDataRealloc(avifRWData * raw, size_t newSize);
AVIF_API avifResult avifRWDataSet(avifRWData * raw, const uint8_t * data, size_t len);
AVIF_API void avifRWDataFree(avifRWData * raw);
// ---------------------------------------------------------------------------
// Metadata
// Validates the first bytes of the Exif payload and finds the TIFF header offset (up to UINT32_MAX).
AVIF_API avifResult avifGetExifTiffHeaderOffset(const uint8_t * exif, size_t exifSize, size_t * offset);
// Returns the offset to the Exif 8-bit orientation value and AVIF_RESULT_OK, or an error.
// If the offset is set to exifSize, there was no parsing error but no orientation tag was found.
AVIF_API avifResult avifGetExifOrientationOffset(const uint8_t * exif, size_t exifSize, size_t * offset);
// ---------------------------------------------------------------------------
// avifPixelFormat
//
// Note to libavif maintainers: The lookup tables in avifImageYUVToRGBLibYUV
// rely on the ordering of this enum values for their correctness. So changing
// the values in this enum will require auditing avifImageYUVToRGBLibYUV for
// correctness.
typedef enum avifPixelFormat
{
// No YUV pixels are present. Alpha plane can still be present.
AVIF_PIXEL_FORMAT_NONE = 0,
AVIF_PIXEL_FORMAT_YUV444,
AVIF_PIXEL_FORMAT_YUV422,
AVIF_PIXEL_FORMAT_YUV420,
AVIF_PIXEL_FORMAT_YUV400,
AVIF_PIXEL_FORMAT_COUNT
} avifPixelFormat;
AVIF_API const char * avifPixelFormatToString(avifPixelFormat format);
typedef struct avifPixelFormatInfo
{
avifBool monochrome;
int chromaShiftX;
int chromaShiftY;
} avifPixelFormatInfo;
// Returns the avifPixelFormatInfo depending on the avifPixelFormat.
// When monochrome is AVIF_TRUE, chromaShiftX and chromaShiftY are set to 1 according to the AV1 specification but they should be ignored.
//
// Note: This function implements the second table on page 119 of the AV1 specification version 1.0.0 with Errata 1.
// For monochrome 4:0:0, subsampling_x and subsampling are specified as 1 to allow
// an AV1 implementation that only supports profile 0 to hardcode subsampling_x and subsampling_y to 1.
AVIF_API void avifGetPixelFormatInfo(avifPixelFormat format, avifPixelFormatInfo * info);
// ---------------------------------------------------------------------------
// avifChromaSamplePosition
typedef enum avifChromaSamplePosition
{
AVIF_CHROMA_SAMPLE_POSITION_UNKNOWN = 0,
AVIF_CHROMA_SAMPLE_POSITION_VERTICAL = 1,
AVIF_CHROMA_SAMPLE_POSITION_COLOCATED = 2,
AVIF_CHROMA_SAMPLE_POSITION_RESERVED = 3
} avifChromaSamplePosition;
// ---------------------------------------------------------------------------
// avifRange
typedef enum avifRange
{
// avifRange is only applicable to YUV planes. RGB and alpha planes are always full range.
AVIF_RANGE_LIMITED = 0, /**<- Y [16..235], UV [16..240] (bit depth 8) */
/**<- Y [64..940], UV [64..960] (bit depth 10) */
/**<- Y [256..3760], UV [256..3840] (bit depth 12) */
AVIF_RANGE_FULL = 1 /**<- [0..255] (bit depth 8) */
/**<- [0..1023] (bit depth 10) */
/**<- [0..4095] (bit depth 12) */
} avifRange;
// ---------------------------------------------------------------------------
// CICP enums - https://www.itu.int/rec/T-REC-H.273-201612-S/en
enum
{
// This is actually reserved, but libavif uses it as a sentinel value.
AVIF_COLOR_PRIMARIES_UNKNOWN = 0,
AVIF_COLOR_PRIMARIES_BT709 = 1,
AVIF_COLOR_PRIMARIES_SRGB = 1,
AVIF_COLOR_PRIMARIES_IEC61966_2_4 = 1,
AVIF_COLOR_PRIMARIES_UNSPECIFIED = 2,
AVIF_COLOR_PRIMARIES_BT470M = 4,
AVIF_COLOR_PRIMARIES_BT470BG = 5,
AVIF_COLOR_PRIMARIES_BT601 = 6,
AVIF_COLOR_PRIMARIES_SMPTE240 = 7,
AVIF_COLOR_PRIMARIES_GENERIC_FILM = 8,
AVIF_COLOR_PRIMARIES_BT2020 = 9,
AVIF_COLOR_PRIMARIES_BT2100 = 9,
AVIF_COLOR_PRIMARIES_XYZ = 10,
AVIF_COLOR_PRIMARIES_SMPTE431 = 11,
AVIF_COLOR_PRIMARIES_SMPTE432 = 12,
AVIF_COLOR_PRIMARIES_DCI_P3 = 12,
AVIF_COLOR_PRIMARIES_EBU3213 = 22
};
typedef uint16_t avifColorPrimaries; // AVIF_COLOR_PRIMARIES_*
// outPrimaries: rX, rY, gX, gY, bX, bY, wX, wY
AVIF_API void avifColorPrimariesGetValues(avifColorPrimaries acp, float outPrimaries[8]);
AVIF_API avifColorPrimaries avifColorPrimariesFind(const float inPrimaries[8], const char ** outName);
enum
{
// This is actually reserved, but libavif uses it as a sentinel value.
AVIF_TRANSFER_CHARACTERISTICS_UNKNOWN = 0,
AVIF_TRANSFER_CHARACTERISTICS_BT709 = 1,
AVIF_TRANSFER_CHARACTERISTICS_UNSPECIFIED = 2,
AVIF_TRANSFER_CHARACTERISTICS_BT470M = 4, // 2.2 gamma
AVIF_TRANSFER_CHARACTERISTICS_BT470BG = 5, // 2.8 gamma
AVIF_TRANSFER_CHARACTERISTICS_BT601 = 6,
AVIF_TRANSFER_CHARACTERISTICS_SMPTE240 = 7,
AVIF_TRANSFER_CHARACTERISTICS_LINEAR = 8,
AVIF_TRANSFER_CHARACTERISTICS_LOG100 = 9,
AVIF_TRANSFER_CHARACTERISTICS_LOG100_SQRT10 = 10,
AVIF_TRANSFER_CHARACTERISTICS_IEC61966 = 11,
AVIF_TRANSFER_CHARACTERISTICS_BT1361 = 12,
AVIF_TRANSFER_CHARACTERISTICS_SRGB = 13,
AVIF_TRANSFER_CHARACTERISTICS_BT2020_10BIT = 14,
AVIF_TRANSFER_CHARACTERISTICS_BT2020_12BIT = 15,
AVIF_TRANSFER_CHARACTERISTICS_PQ = 16, // Perceptual Quantizer (HDR); BT.2100 PQ
AVIF_TRANSFER_CHARACTERISTICS_SMPTE2084 = 16,
AVIF_TRANSFER_CHARACTERISTICS_SMPTE428 = 17,
AVIF_TRANSFER_CHARACTERISTICS_HLG = 18 // Hybrid Log-Gamma (HDR); ARIB STD-B67; BT.2100 HLG
};
typedef uint16_t avifTransferCharacteristics; // AVIF_TRANSFER_CHARACTERISTICS_*
// If the given transfer characteristics can be expressed with a simple gamma value, sets 'gamma'
// to that value and returns AVIF_RESULT_OK. Returns an error otherwise.
AVIF_API avifResult avifTransferCharacteristicsGetGamma(avifTransferCharacteristics atc, float * gamma);
AVIF_API avifTransferCharacteristics avifTransferCharacteristicsFindByGamma(float gamma);
enum
{
AVIF_MATRIX_COEFFICIENTS_IDENTITY = 0,
AVIF_MATRIX_COEFFICIENTS_BT709 = 1,
AVIF_MATRIX_COEFFICIENTS_UNSPECIFIED = 2,
AVIF_MATRIX_COEFFICIENTS_FCC = 4,
AVIF_MATRIX_COEFFICIENTS_BT470BG = 5,
AVIF_MATRIX_COEFFICIENTS_BT601 = 6,
AVIF_MATRIX_COEFFICIENTS_SMPTE240 = 7,
AVIF_MATRIX_COEFFICIENTS_YCGCO = 8,
AVIF_MATRIX_COEFFICIENTS_BT2020_NCL = 9,
AVIF_MATRIX_COEFFICIENTS_BT2020_CL = 10,
AVIF_MATRIX_COEFFICIENTS_SMPTE2085 = 11,
AVIF_MATRIX_COEFFICIENTS_CHROMA_DERIVED_NCL = 12,
AVIF_MATRIX_COEFFICIENTS_CHROMA_DERIVED_CL = 13,
AVIF_MATRIX_COEFFICIENTS_ICTCP = 14,
#if defined(AVIF_ENABLE_EXPERIMENTAL_YCGCO_R)
AVIF_MATRIX_COEFFICIENTS_YCGCO_RE = 15,
AVIF_MATRIX_COEFFICIENTS_YCGCO_RO = 16,
#endif
AVIF_MATRIX_COEFFICIENTS_LAST
};
typedef uint16_t avifMatrixCoefficients; // AVIF_MATRIX_COEFFICIENTS_*
// ---------------------------------------------------------------------------
// avifDiagnostics
typedef struct avifDiagnostics
{
// Upon receiving an error from any non-const libavif API call, if the toplevel structure used
// in the API call (avifDecoder, avifEncoder) contains a diag member, this buffer may be
// populated with a NULL-terminated, freeform error string explaining the first encountered error in
// more detail. It will be cleared at the beginning of every non-const API call.
//
// Note: If an error string contains the "[Strict]" prefix, it means that you encountered an
// error that only occurs during strict decoding. If you disable strict mode, you will no
// longer encounter this error.
char error[AVIF_DIAGNOSTICS_ERROR_BUFFER_SIZE];
} avifDiagnostics;
AVIF_API void avifDiagnosticsClearError(avifDiagnostics * diag);
// ---------------------------------------------------------------------------
// Fraction utility
typedef struct avifFraction
{
int32_t n;
int32_t d;
} avifFraction;
// ---------------------------------------------------------------------------
// Optional transformation structs
typedef enum avifTransformFlag
{
AVIF_TRANSFORM_NONE = 0,
AVIF_TRANSFORM_PASP = (1 << 0),
AVIF_TRANSFORM_CLAP = (1 << 1),
AVIF_TRANSFORM_IROT = (1 << 2),
AVIF_TRANSFORM_IMIR = (1 << 3)
} avifTransformFlag;
typedef uint32_t avifTransformFlags;
typedef struct avifPixelAspectRatioBox
{
// 'pasp' from ISO/IEC 14496-12:2015 12.1.4.3
// define the relative width and height of a pixel
uint32_t hSpacing;
uint32_t vSpacing;
} avifPixelAspectRatioBox;
typedef struct avifCleanApertureBox
{
// 'clap' from ISO/IEC 14496-12:2015 12.1.4.3
// a fractional number which defines the exact clean aperture width, in counted pixels, of the video image
uint32_t widthN;
uint32_t widthD;
// a fractional number which defines the exact clean aperture height, in counted pixels, of the video image
uint32_t heightN;
uint32_t heightD;
// a fractional number which defines the horizontal offset of clean aperture centre minus (width-1)/2. Typically 0.
uint32_t horizOffN;
uint32_t horizOffD;
// a fractional number which defines the vertical offset of clean aperture centre minus (height-1)/2. Typically 0.
uint32_t vertOffN;
uint32_t vertOffD;
} avifCleanApertureBox;
typedef struct avifImageRotation
{
// 'irot' from ISO/IEC 23008-12:2017 6.5.10
// angle * 90 specifies the angle (in anti-clockwise direction) in units of degrees.
uint8_t angle; // legal values: [0-3]
} avifImageRotation;
typedef struct avifImageMirror
{
// 'imir' from ISO/IEC 23008-12:2022 6.5.12:
//
// 'axis' specifies how the mirroring is performed:
//
// 0 indicates that the top and bottom parts of the image are exchanged;
// 1 specifies that the left and right parts are exchanged.
//
// NOTE In Exif, orientation tag can be used to signal mirroring operations. Exif
// orientation tag 4 corresponds to axis = 0 of ImageMirror, and Exif orientation tag 2
// corresponds to axis = 1 accordingly.
//
// Legal values: [0, 1]
uint8_t axis;
} avifImageMirror;
// ---------------------------------------------------------------------------
// avifCropRect - Helper struct/functions to work with avifCleanApertureBox
typedef struct avifCropRect
{
uint32_t x;
uint32_t y;
uint32_t width;
uint32_t height;
} avifCropRect;
// These will return AVIF_FALSE if the resultant values violate any standards, and if so, the output
// values are not guaranteed to be complete or correct and should not be used.
AVIF_NODISCARD AVIF_API avifBool avifCropRectConvertCleanApertureBox(avifCropRect * cropRect,
const avifCleanApertureBox * clap,
uint32_t imageW,
uint32_t imageH,
avifPixelFormat yuvFormat,
avifDiagnostics * diag);
AVIF_NODISCARD AVIF_API avifBool avifCleanApertureBoxConvertCropRect(avifCleanApertureBox * clap,
const avifCropRect * cropRect,
uint32_t imageW,
uint32_t imageH,
avifPixelFormat yuvFormat,
avifDiagnostics * diag);
// ---------------------------------------------------------------------------
// avifContentLightLevelInformationBox
typedef struct avifContentLightLevelInformationBox
{
// 'clli' from ISO/IEC 23000-22:2019 (MIAF) 7.4.4.2.2. The SEI message semantics written above
// each entry were originally described in ISO/IEC 23008-2:2020 (HEVC) section D.3.35,
// available at https://standards.iso.org/ittf/PubliclyAvailableStandards/
// Given the red, green, and blue colour primary intensities in the linear light domain for the
// location of a luma sample in a corresponding 4:4:4 representation, denoted as E_R, E_G, and E_B,
// the maximum component intensity is defined as E_Max = Max(E_R, Max(E_G, E_B)).
// The light level corresponding to the stimulus is then defined as the CIE 1931 luminance
// corresponding to equal amplitudes of E_Max for all three colour primary intensities for red,
// green, and blue (with appropriate scaling to reflect the nominal luminance level associated
// with peak white, e.g. ordinarily scaling to associate peak white with 10 000 candelas per
// square metre when transfer_characteristics is equal to 16).
// max_content_light_level, when not equal to 0, indicates an upper bound on the maximum light
// level among all individual samples in a 4:4:4 representation of red, green, and blue colour
// primary intensities (in the linear light domain) for the pictures of the CLVS, in units of
// candelas per square metre. When equal to 0, no such upper bound is indicated by
// max_content_light_level.
uint16_t maxCLL;
// max_pic_average_light_level, when not equal to 0, indicates an upper bound on the maximum
// average light level among the samples in a 4:4:4 representation of red, green, and blue
// colour primary intensities (in the linear light domain) for any individual picture of the
// CLVS, in units of candelas per square metre. When equal to 0, no such upper bound is
// indicated by max_pic_average_light_level.
uint16_t maxPALL;
} avifContentLightLevelInformationBox;
#if defined(AVIF_ENABLE_EXPERIMENTAL_GAIN_MAP)
// ---------------------------------------------------------------------------
// avifGainMap
// Gain Maps are a solution for a consistent and adaptive display of HDR images.
// Gain Maps are a HIGHLY EXPERIMENTAL FEATURE. The format might still change and
// images containing a gain map encoded with the current version of libavif might
// not decode with a future version of libavif. The API is not guaranteed
// to be stable, and might even be removed in the future. Use at your own risk.
// This is based on ISO/IEC JTC 1/SC 29/WG 3 m64379
// This product includes Gain Map technology under license by Adobe.
//
// Terms:
// base image: main image stored in the file, shown by viewers that do not support
// gain maps
// alternate image: image obtained by combining the base image and the gain map
// gain map: data structure that contains pixels and metadata used for conversion
// between the base image and the alternate image
struct avifImage;
// Gain map metadata, to apply the gain map. Fully applying the gain map to the base
// image results in the alternate image.
// All field pairs ending with 'N' and 'D' are fractional values (numerator and denominator).
typedef struct avifGainMapMetadata
{
// Parameters for converting the gain map from its image encoding to log2 space.
// gainMapLog2 = lerp(gainMapMin, gainMapMax, pow(gainMapEncoded, gainMapGamma));
// where 'lerp' is a linear interpolation function.
// Minimum value in the gain map, log2-encoded, per RGB channel.
int32_t gainMapMinN[3];
uint32_t gainMapMinD[3];
// Maximum value in the gain map, log2-encoded, per RGB channel.
int32_t gainMapMaxN[3];
uint32_t gainMapMaxD[3];
// Gain map gamma value with which the gain map was encoded, per RGB channel.
// For decoding, the inverse value (1/gamma) should be used.
uint32_t gainMapGammaN[3];
uint32_t gainMapGammaD[3];
// Parameters used in gain map computation/tone mapping to avoid numerical
// instability.
// toneMappedLinear = ((baseImageLinear + baseOffset) * exp(gainMapLog * w)) - alternateOffset;
// Where 'w' is a weight parameter based on the display's HDR capacity
// (see below).
// Offset constants for the base image, per RGB channel.
int32_t baseOffsetN[3];
uint32_t baseOffsetD[3];
// Offset constants for the alternate image, per RGB channel.
int32_t alternateOffsetN[3];
uint32_t alternateOffsetD[3];
// -----------------------------------------------------------------------
// Parameters below can be manually tuned after the gain map has been
// created.
// Log2-encoded HDR headroom of the base and alternate images respectively.
// If baseHdrHeadroom is < alternateHdrHeadroom, the result of tone mapping
// for a display with an HDR headroom that is <= baseHdrHeadroom is the base
// image, and the result of tone mapping for a display with an HDR headroom >=
// alternateHdrHeadroom is the alternate image.
// Conversely, if baseHdrHeadroom is > alternateHdrHeadroom, the result of
// tone mapping for a display with an HDR headroom that is >= baseHdrHeadroom
// is the base image, and the result of tone mapping for a display with an HDR
// headroom <= alternateHdrHeadroom is the alternate image.
// For a display with a capacity between baseHdrHeadroom and alternateHdrHeadroom,
// tone mapping results in an interpolation between the base and alternate
// versions. baseHdrHeadroom and alternateHdrHeadroom can be tuned to change how
// the gain map should be applied.
//
// If 'H' is the display's current log2-encoded HDR capacity (HDR to SDR ratio),
// then the weight 'w' to apply the gain map is computed as follows:
// f = clamp((H - baseHdrHeadroom) /
// (alternateHdrHeadroom - baseHdrHeadroom), 0, 1);
// w = sign(alternateHdrHeadroom - baseHdrHeadroom) * f
uint32_t baseHdrHeadroomN;
uint32_t baseHdrHeadroomD;
uint32_t alternateHdrHeadroomN;
uint32_t alternateHdrHeadroomD;
// True if tone mapping should be performed in the color space of the
// base image. If false, the color space of the alternate image should
// be used.
avifBool useBaseColorSpace;
} avifGainMapMetadata;
// Gain map image and associated metadata.
// Must be allocated by calling avifGainMapCreate().
typedef struct avifGainMap
{
// Gain map pixels.
// Owned by the avifGainMap and gets freed when calling avifGainMapDestroy().
// Used fields: width, height, depth, yuvFormat, yuvRange,
// yuvChromaSamplePosition, yuvPlanes, yuvRowBytes, imageOwnsYUVPlanes,
// matrixCoefficients. The colorPrimaries and transferCharacteristics fields
// shall be 2. Other fields are ignored.
struct avifImage * image;
// When encoding an image grid, all metadata below shall be identical for all
// cells.
// Gain map metadata used to interpret and apply the gain map pixel data.
avifGainMapMetadata metadata;
// Colorimetry of the alternate image (ICC profile and/or CICP information
// of the alternate image that the gain map was created from).
avifRWData altICC;
avifColorPrimaries altColorPrimaries;
avifTransferCharacteristics altTransferCharacteristics;
avifMatrixCoefficients altMatrixCoefficients;
avifRange altYUVRange;
// Hint on the approximate amount of colour resolution available after fully
// applying the gain map ('pixi' box content of the alternate image that the
// gain map was created from).
uint32_t altDepth;
uint32_t altPlaneCount;
// Optimal viewing conditions of the alternate image ('clli' box content
// of the alternate image that the gain map was created from).
avifContentLightLevelInformationBox altCLLI;
} avifGainMap;
// Allocates a gain map. Returns NULL if a memory allocation failed.
// The 'image' field is NULL by default and must be allocated separately.
AVIF_API avifGainMap * avifGainMapCreate();
// Frees a gain map, including the 'image' field if non NULL.
AVIF_API void avifGainMapDestroy(avifGainMap * gainMap);
// Same as avifGainMapMetadata, but with fields of type double instead of uint32_t fractions.
// Use avifGainMapMetadataDoubleToFractions() to convert this to a avifGainMapMetadata.
// See avifGainMapMetadata for detailed descriptions of fields.
typedef struct avifGainMapMetadataDouble
{
double gainMapMin[3];
double gainMapMax[3];
double gainMapGamma[3];
double baseOffset[3];
double alternateOffset[3];
double baseHdrHeadroom;
double alternateHdrHeadroom;
avifBool useBaseColorSpace;
} avifGainMapMetadataDouble;
// Converts a avifGainMapMetadataDouble to avifGainMapMetadata by converting double values
// to the closest uint32_t fractions.
// Returns AVIF_FALSE if some field values are < 0 or > UINT32_MAX.
AVIF_NODISCARD AVIF_API avifBool avifGainMapMetadataDoubleToFractions(avifGainMapMetadata * dst, const avifGainMapMetadataDouble * src);
// Converts a avifGainMapMetadata to avifGainMapMetadataDouble by converting fractions to double values.
// Returns AVIF_FALSE if some denominators are zero.
AVIF_NODISCARD AVIF_API avifBool avifGainMapMetadataFractionsToDouble(avifGainMapMetadataDouble * dst, const avifGainMapMetadata * src);
#endif // AVIF_ENABLE_EXPERIMENTAL_GAIN_MAP
// ---------------------------------------------------------------------------
#if defined(AVIF_ENABLE_EXPERIMENTAL_SAMPLE_TRANSFORM)
// Sample Transforms are a HIGHLY EXPERIMENTAL FEATURE. The format might still
// change and images containing a sample transform item encoded with the current
// version of libavif might not decode with a future version of libavif.
// Use at your own risk.
// This is based on a proposal from the Alliance for Open Media.
typedef enum avifSampleTransformRecipe
{
AVIF_SAMPLE_TRANSFORM_NONE,
// Encode the 8 most significant bits of each input image sample losslessly
// into a base image. The remaining 8 least significant bits are encoded in
// a separate hidden image item. The two are combined at decoding into one
// image with the same bit depth as the original image. It is backward
// compatible in the sense that it is possible to decode only the base image
// (ignoring the hidden image item), leading to a valid image but with
// precision loss (16-bit samples truncated to the 8 most significant bits).
AVIF_SAMPLE_TRANSFORM_BIT_DEPTH_EXTENSION_8B_8B,
// Encode the 12 most significant bits of each input image sample losslessly
// into a base image. The remaining 4 least significant bits are encoded in
// a separate hidden image item. The two are combined at decoding into one
// image with the same bit depth as the original image. It is backward
// compatible in the sense that it is possible to decode only the base image
// (ignoring the hidden image item), leading to a valid image but with
// precision loss (16-bit samples truncated to the 12 most significant
// bits).
AVIF_SAMPLE_TRANSFORM_BIT_DEPTH_EXTENSION_12B_4B
} avifSampleTransformRecipe;
#endif // AVIF_ENABLE_EXPERIMENTAL_SAMPLE_TRANSFORM
// ---------------------------------------------------------------------------
// avifImage
// NOTE: The avifImage struct may be extended in a future release. Code outside the libavif library
// must allocate avifImage by calling the avifImageCreate() or avifImageCreateEmpty() function.
typedef struct avifImage
{
// Image information
uint32_t width;
uint32_t height;
uint32_t depth; // all planes must share this depth; if depth>8, all planes are uint16_t internally
avifPixelFormat yuvFormat;
avifRange yuvRange;
avifChromaSamplePosition yuvChromaSamplePosition;
uint8_t * yuvPlanes[AVIF_PLANE_COUNT_YUV];
uint32_t yuvRowBytes[AVIF_PLANE_COUNT_YUV];
avifBool imageOwnsYUVPlanes;
uint8_t * alphaPlane;
uint32_t alphaRowBytes;
avifBool imageOwnsAlphaPlane;
avifBool alphaPremultiplied;
// ICC Profile
avifRWData icc;
// CICP information:
// These are stored in the AV1 payload and used to signal YUV conversion. Additionally, if an
// ICC profile is not specified, these will be stored in the AVIF container's `colr` box with
// a type of `nclx`. If your system supports ICC profiles, be sure to check for the existence
// of one (avifImage.icc) before relying on the values listed here!
avifColorPrimaries colorPrimaries;
avifTransferCharacteristics transferCharacteristics;
avifMatrixCoefficients matrixCoefficients;
// CLLI information:
// Content Light Level Information. Used to represent maximum and average light level of an
// image. Useful for tone mapping HDR images, especially when using transfer characteristics
// SMPTE2084 (PQ). The default value of (0, 0) means the content light level information is
// unknown or unavailable, and will cause libavif to avoid writing a clli box for it.
avifContentLightLevelInformationBox clli;
// Transformations - These metadata values are encoded/decoded when transformFlags are set
// appropriately, but do not impact/adjust the actual pixel buffers used (images won't be
// pre-cropped or mirrored upon decode). Basic explanations from the standards are offered in
// comments above, but for detailed explanations, please refer to the HEIF standard (ISO/IEC
// 23008-12:2017) and the BMFF standard (ISO/IEC 14496-12:2015).
//
// To encode any of these boxes, set the values in the associated box, then enable the flag in
// transformFlags. On decode, only honor the values in boxes with the associated transform flag set.
// These also apply to gainMap->image, if any.
avifTransformFlags transformFlags;
avifPixelAspectRatioBox pasp;
avifCleanApertureBox clap;
avifImageRotation irot;
avifImageMirror imir;
// Metadata - set with avifImageSetMetadata*() before write, check .size>0 for existence after read
avifRWData exif; // exif_payload chunk from the ExifDataBlock specified in ISO/IEC 23008-12:2022 Section A.2.1.
// The value of the 4-byte exif_tiff_header_offset field, which is not part of this avifRWData
// byte sequence, can be retrieved by calling avifGetExifTiffHeaderOffset(avifImage.exif).
avifRWData xmp;
// Version 1.0.0 ends here. Add any new members after this line.
#if defined(AVIF_ENABLE_EXPERIMENTAL_GAIN_MAP)
// Gain map image and metadata. NULL if no gain map is present.
// Owned by the avifImage and gets freed when calling avifImageDestroy().
// gainMap->image->transformFlags is always AVIF_TRANSFORM_NONE.
avifGainMap * gainMap;
#endif
} avifImage;
// avifImageCreate() and avifImageCreateEmpty() return NULL if arguments are invalid or if a memory allocation failed.
AVIF_NODISCARD AVIF_API avifImage * avifImageCreate(uint32_t width, uint32_t height, uint32_t depth, avifPixelFormat yuvFormat);
AVIF_NODISCARD AVIF_API avifImage * avifImageCreateEmpty(void); // helper for making an image to decode into
// Performs a deep copy of an image, including all metadata and planes, and the gain map metadata/planes if present
// and if AVIF_ENABLE_EXPERIMENTAL_GAIN_MAP is defined.
AVIF_API avifResult avifImageCopy(avifImage * dstImage, const avifImage * srcImage, avifPlanesFlags planes);
// Performs a shallow copy of a rectangular area of an image. 'dstImage' does not own the planes.
// Ignores the gainMap field (which exists only if AVIF_ENABLE_EXPERIMENTAL_GAIN_MAP is defined).
AVIF_API avifResult avifImageSetViewRect(avifImage * dstImage, const avifImage * srcImage, const avifCropRect * rect);
AVIF_API void avifImageDestroy(avifImage * image);
AVIF_API avifResult avifImageSetProfileICC(avifImage * image, const uint8_t * icc, size_t iccSize);
// Sets Exif metadata. Attempts to parse the Exif metadata for Exif orientation. Sets
// image->transformFlags, image->irot and image->imir if the Exif metadata is parsed successfully,
// otherwise leaves image->transformFlags, image->irot and image->imir unchanged.
// Warning: If the Exif payload is set and invalid, avifEncoderWrite() may return AVIF_RESULT_INVALID_EXIF_PAYLOAD.
AVIF_API avifResult avifImageSetMetadataExif(avifImage * image, const uint8_t * exif, size_t exifSize);
// Sets XMP metadata.
AVIF_API avifResult avifImageSetMetadataXMP(avifImage * image, const uint8_t * xmp, size_t xmpSize);
// Allocate/free/steal planes. These functions ignore the gainMap field (which exists only if
// AVIF_ENABLE_EXPERIMENTAL_GAIN_MAP is defined).
AVIF_API avifResult avifImageAllocatePlanes(avifImage * image, avifPlanesFlags planes); // Ignores any pre-existing planes
AVIF_API void avifImageFreePlanes(avifImage * image, avifPlanesFlags planes); // Ignores already-freed planes
AVIF_API void avifImageStealPlanes(avifImage * dstImage, avifImage * srcImage, avifPlanesFlags planes);
// ---------------------------------------------------------------------------
// Understanding maxThreads
//
// libavif's structures and API use the setting 'maxThreads' in a few places. The intent of this
// setting is to limit concurrent thread activity/usage, not necessarily to put a hard ceiling on
// how many sleeping threads happen to exist behind the scenes. The goal of this setting is to
// ensure that at any given point during libavif's encoding or decoding, no more than *maxThreads*
// threads are simultaneously **active and taking CPU time**.
//
// As an important example, when encoding an image sequence that has an alpha channel, two
// long-lived underlying AV1 encoders must simultaneously exist (one for color, one for alpha). For
// each additional frame fed into libavif, its YUV planes are fed into one instance of the AV1
// encoder, and its alpha plane is fed into another. These operations happen serially, so only one
// of these AV1 encoders is ever active at a time. However, the AV1 encoders might pre-create a
// pool of worker threads upon initialization, so during this process, twice the amount of worker
// threads actually simultaneously exist on the machine, but half of them are guaranteed to be
// sleeping.
//
// This design ensures that AV1 implementations are given as many threads as possible to ensure a
// speedy encode or decode, despite the complexities of occasionally needing two AV1 codec instances
// (due to alpha payloads being separate from color payloads). If your system has a hard ceiling on
// the number of threads that can ever be in flight at a given time, please account for this
// accordingly.
// ---------------------------------------------------------------------------
// Scaling
// Scales the YUV/A planes in-place. dstWidth and dstHeight must both be <= AVIF_DEFAULT_IMAGE_DIMENSION_LIMIT and
// dstWidth*dstHeight should be <= AVIF_DEFAULT_IMAGE_SIZE_LIMIT.
AVIF_API avifResult avifImageScale(avifImage * image, uint32_t dstWidth, uint32_t dstHeight, avifDiagnostics * diag);
// ---------------------------------------------------------------------------
// Optional YUV<->RGB support
// To convert to/from RGB, create an avifRGBImage on the stack, call avifRGBImageSetDefaults() on
// it, and then tweak the values inside of it accordingly. At a minimum, you should populate
// ->pixels and ->rowBytes with an appropriately sized pixel buffer, which should be at least
// (->rowBytes * ->height) bytes, where ->rowBytes is at least (->width * avifRGBImagePixelSize()).
// If you don't want to supply your own pixel buffer, you can use the
// avifRGBImageAllocatePixels()/avifRGBImageFreePixels() convenience functions.
// avifImageRGBToYUV() and avifImageYUVToRGB() will perform depth rescaling and limited<->full range
// conversion, if necessary. Pixels in an avifRGBImage buffer are always full range, and conversion
// routines will fail if the width and height don't match the associated avifImage.
// If libavif is built with a version of libyuv offering a fast conversion between RGB and YUV for
// the given inputs, libavif will use it. See reformat_libyuv.c for the details.
// libyuv is faster but may have slightly less precision than built-in conversion, so avoidLibYUV
// can be set to AVIF_TRUE when AVIF_CHROMA_UPSAMPLING_BEST_QUALITY or
// AVIF_CHROMA_DOWNSAMPLING_BEST_QUALITY is used, to get the most precise but slowest results.
// Note to libavif maintainers: The lookup tables in avifImageYUVToRGBLibYUV
// rely on the ordering of this enum values for their correctness. So changing
// the values in this enum will require auditing avifImageYUVToRGBLibYUV for
// correctness.
typedef enum avifRGBFormat
{
AVIF_RGB_FORMAT_RGB = 0,
AVIF_RGB_FORMAT_RGBA, // This is the default format set in avifRGBImageSetDefaults().
AVIF_RGB_FORMAT_ARGB,
AVIF_RGB_FORMAT_BGR,
AVIF_RGB_FORMAT_BGRA,
AVIF_RGB_FORMAT_ABGR,
// RGB_565 format uses five bits for the red and blue components and six
// bits for the green component. Each RGB pixel is 16 bits (2 bytes), which
// is packed as follows:
// uint16_t: [r4 r3 r2 r1 r0 g5 g4 g3 g2 g1 g0 b4 b3 b2 b1 b0]
// r4 and r0 are the MSB and LSB of the red component respectively.
// g5 and g0 are the MSB and LSB of the green component respectively.
// b4 and b0 are the MSB and LSB of the blue component respectively.
// This format is only supported for YUV -> RGB conversion and when
// avifRGBImage.depth is set to 8.
AVIF_RGB_FORMAT_RGB_565,
AVIF_RGB_FORMAT_COUNT
} avifRGBFormat;
AVIF_API uint32_t avifRGBFormatChannelCount(avifRGBFormat format);
AVIF_API avifBool avifRGBFormatHasAlpha(avifRGBFormat format);
typedef enum avifChromaUpsampling
{
AVIF_CHROMA_UPSAMPLING_AUTOMATIC = 0, // Chooses best trade off of speed/quality (uses BILINEAR libyuv if available,
// or falls back to NEAREST libyuv if available, or falls back to BILINEAR built-in)
AVIF_CHROMA_UPSAMPLING_FASTEST = 1, // Chooses speed over quality (same as NEAREST)
AVIF_CHROMA_UPSAMPLING_BEST_QUALITY = 2, // Chooses the best quality upsampling, given settings (same as BILINEAR)
AVIF_CHROMA_UPSAMPLING_NEAREST = 3, // Uses nearest-neighbor filter
AVIF_CHROMA_UPSAMPLING_BILINEAR = 4 // Uses bilinear filter
} avifChromaUpsampling;
typedef enum avifChromaDownsampling
{
AVIF_CHROMA_DOWNSAMPLING_AUTOMATIC = 0, // Chooses best trade off of speed/quality (same as AVERAGE)
AVIF_CHROMA_DOWNSAMPLING_FASTEST = 1, // Chooses speed over quality (same as AVERAGE)
AVIF_CHROMA_DOWNSAMPLING_BEST_QUALITY = 2, // Chooses the best quality upsampling (same as AVERAGE)
AVIF_CHROMA_DOWNSAMPLING_AVERAGE = 3, // Uses averaging filter
AVIF_CHROMA_DOWNSAMPLING_SHARP_YUV = 4 // Uses sharp yuv filter (libsharpyuv), available for 4:2:0 only, ignored for 4:2:2
} avifChromaDownsampling;
// NOTE: avifRGBImage must be initialized with avifRGBImageSetDefaults() (preferred) or memset()
// before use.
typedef struct avifRGBImage
{
uint32_t width; // must match associated avifImage
uint32_t height; // must match associated avifImage
uint32_t depth; // legal depths [8, 10, 12, 16]. if depth>8, pixels must be uint16_t internally
avifRGBFormat format; // all channels are always full range
avifChromaUpsampling chromaUpsampling; // How to upsample from 4:2:0 or 4:2:2 UV when converting to RGB (ignored for 4:4:4 and 4:0:0).
// Ignored when converting to YUV. Defaults to AVIF_CHROMA_UPSAMPLING_AUTOMATIC.
avifChromaDownsampling chromaDownsampling; // How to downsample to 4:2:0 or 4:2:2 UV when converting from RGB (ignored for 4:4:4 and 4:0:0).
// Ignored when converting to RGB. Defaults to AVIF_CHROMA_DOWNSAMPLING_AUTOMATIC.
avifBool avoidLibYUV; // If AVIF_FALSE and libyuv conversion between RGB and YUV (including upsampling or downsampling if any)
// is available for the avifImage/avifRGBImage combination, then libyuv is used. Default is AVIF_FALSE.
avifBool ignoreAlpha; // Used for XRGB formats, treats formats containing alpha (such as ARGB) as if they were RGB, treating
// the alpha bits as if they were all 1.
avifBool alphaPremultiplied; // indicates if RGB value is pre-multiplied by alpha. Default: false
avifBool isFloat; // indicates if RGBA values are in half float (f16) format. Valid only when depth == 16. Default: false
int maxThreads; // Number of threads to be used for the YUV to RGB conversion. Note that this value is ignored for RGB to YUV
// conversion. Setting this to zero has the same effect as setting it to one. Negative values are invalid.
// Default: 1.
uint8_t * pixels;
uint32_t rowBytes;
} avifRGBImage;
// Sets rgb->width, rgb->height, and rgb->depth to image->width, image->height, and image->depth.
// Sets rgb->pixels to NULL and rgb->rowBytes to 0. Sets the other fields of 'rgb' to default
// values.
AVIF_API void avifRGBImageSetDefaults(avifRGBImage * rgb, const avifImage * image);
AVIF_API uint32_t avifRGBImagePixelSize(const avifRGBImage * rgb);
// Convenience functions. If you supply your own pixels/rowBytes, you do not need to use these.
AVIF_API avifResult avifRGBImageAllocatePixels(avifRGBImage * rgb);
AVIF_API void avifRGBImageFreePixels(avifRGBImage * rgb);
// The main conversion functions
AVIF_API avifResult avifImageRGBToYUV(avifImage * image, const avifRGBImage * rgb);
AVIF_API avifResult avifImageYUVToRGB(const avifImage * image, avifRGBImage * rgb);
// Premultiply handling functions.
// (Un)premultiply is automatically done by the main conversion functions above,
// so usually you don't need to call these. They are there for convenience.
AVIF_API avifResult avifRGBImagePremultiplyAlpha(avifRGBImage * rgb);
AVIF_API avifResult avifRGBImageUnpremultiplyAlpha(avifRGBImage * rgb);
// ---------------------------------------------------------------------------
// YUV Utils
AVIF_API int avifFullToLimitedY(uint32_t depth, int v);
AVIF_API int avifFullToLimitedUV(uint32_t depth, int v);
AVIF_API int avifLimitedToFullY(uint32_t depth, int v);
AVIF_API int avifLimitedToFullUV(uint32_t depth, int v);
// ---------------------------------------------------------------------------
// Codec selection
typedef enum avifCodecChoice
{
AVIF_CODEC_CHOICE_AUTO = 0,
AVIF_CODEC_CHOICE_AOM,
AVIF_CODEC_CHOICE_DAV1D, // Decode only
AVIF_CODEC_CHOICE_LIBGAV1, // Decode only
AVIF_CODEC_CHOICE_RAV1E, // Encode only
AVIF_CODEC_CHOICE_SVT, // Encode only
AVIF_CODEC_CHOICE_AVM // Experimental (AV2)
} avifCodecChoice;
typedef enum avifCodecFlag
{
AVIF_CODEC_FLAG_CAN_DECODE = (1 << 0),
AVIF_CODEC_FLAG_CAN_ENCODE = (1 << 1)
} avifCodecFlag;
typedef uint32_t avifCodecFlags;
// If this returns NULL, the codec choice/flag combination is unavailable
AVIF_API const char * avifCodecName(avifCodecChoice choice, avifCodecFlags requiredFlags);
AVIF_API avifCodecChoice avifCodecChoiceFromName(const char * name);
// ---------------------------------------------------------------------------
// avifIO
struct avifIO;
// Destroy must completely destroy all child structures *and* free the avifIO object itself.
// This function pointer is optional, however, if the avifIO object isn't intended to be owned by
// a libavif encoder/decoder.
typedef void (*avifIODestroyFunc)(struct avifIO * io);
// This function should return a block of memory that *must* remain valid until another read call to
// this avifIO struct is made (reusing a read buffer is acceptable/expected).
//
// * If offset exceeds the size of the content (past EOF), return AVIF_RESULT_IO_ERROR.
// * If offset is *exactly* at EOF, provide a 0-byte buffer and return AVIF_RESULT_OK.
// * If (offset+size) exceeds the contents' size, it must truncate the range to provide all
// bytes from the offset to EOF.
// * If the range is unavailable yet (due to network conditions or any other reason),
// return AVIF_RESULT_WAITING_ON_IO.
// * Otherwise, provide the range and return AVIF_RESULT_OK.
typedef avifResult (*avifIOReadFunc)(struct avifIO * io, uint32_t readFlags, uint64_t offset, size_t size, avifROData * out);
typedef avifResult (*avifIOWriteFunc)(struct avifIO * io, uint32_t writeFlags, uint64_t offset, const uint8_t * data, size_t size);
typedef struct avifIO
{
avifIODestroyFunc destroy;
avifIOReadFunc read;
// This is reserved for future use - but currently ignored. Set it to a null pointer.
avifIOWriteFunc write;
// If non-zero, this is a hint to internal structures of the max size offered by the content
// this avifIO structure is reading. If it is a static memory source, it should be the size of
// the memory buffer; if it is a file, it should be the file's size. If this information cannot
// be known (as it is streamed-in), set a reasonable upper boundary here (larger than the file
// can possibly be for your environment, but within your environment's memory constraints). This
// is used for sanity checks when allocating internal buffers to protect against
// malformed/malicious files.
uint64_t sizeHint;
// If true, *all* memory regions returned from *all* calls to read are guaranteed to be
// persistent and exist for the lifetime of the avifIO object. If false, libavif will make
// in-memory copies of samples and metadata content, and a memory region returned from read must
// only persist until the next call to read.
avifBool persistent;
// The contents of this are defined by the avifIO implementation, and should be fully destroyed
// by the implementation of the associated destroy function, unless it isn't owned by the avifIO
// struct. It is not necessary to use this pointer in your implementation.
void * data;
} avifIO;
// Returns NULL if the reader cannot be allocated.
AVIF_API avifIO * avifIOCreateMemoryReader(const uint8_t * data, size_t size);
// Returns NULL if the file cannot be opened or if the reader cannot be allocated.
AVIF_API avifIO * avifIOCreateFileReader(const char * filename);
AVIF_API void avifIODestroy(avifIO * io);
// ---------------------------------------------------------------------------
// avifDecoder
// Some encoders (including very old versions of avifenc) do not implement the AVIF standard
// perfectly, and thus create invalid files. However, these files are likely still recoverable /
// decodable, if it wasn't for the strict requirements imposed by libavif's decoder. These flags
// allow a user of avifDecoder to decide what level of strictness they want in their project.
typedef enum avifStrictFlag
{
// Disables all strict checks.
AVIF_STRICT_DISABLED = 0,
// Requires the PixelInformationProperty ('pixi') be present in AV1 image items. libheif v1.11.0
// or older does not add the 'pixi' item property to AV1 image items. If you need to decode AVIF
// images encoded by libheif v1.11.0 or older, be sure to disable this bit. (This issue has been
// corrected in libheif v1.12.0.)
AVIF_STRICT_PIXI_REQUIRED = (1 << 0),
// This demands that the values surfaced in the clap box are valid, determined by attempting to
// convert the clap box to a crop rect using avifCropRectConvertCleanApertureBox(). If this
// function returns AVIF_FALSE and this strict flag is set, the decode will fail.
AVIF_STRICT_CLAP_VALID = (1 << 1),
// Requires the ImageSpatialExtentsProperty ('ispe') be present in alpha auxiliary image items.
// avif-serialize 0.7.3 or older does not add the 'ispe' item property to alpha auxiliary image
// items. If you need to decode AVIF images encoded by the cavif encoder with avif-serialize
// 0.7.3 or older, be sure to disable this bit. (This issue has been corrected in avif-serialize
// 0.7.4.) See https://github.com/kornelski/avif-serialize/issues/3 and
// https://crbug.com/1246678.
AVIF_STRICT_ALPHA_ISPE_REQUIRED = (1 << 2),
// Maximum strictness; enables all bits above. This is avifDecoder's default.
AVIF_STRICT_ENABLED = AVIF_STRICT_PIXI_REQUIRED | AVIF_STRICT_CLAP_VALID | AVIF_STRICT_ALPHA_ISPE_REQUIRED
} avifStrictFlag;
typedef uint32_t avifStrictFlags;
// Useful stats related to a read/write
typedef struct avifIOStats
{
// Size in bytes of the AV1 image item or track data containing color samples.
size_t colorOBUSize;
// Size in bytes of the AV1 image item or track data containing alpha samples.
size_t alphaOBUSize;
} avifIOStats;
struct avifDecoderData;
typedef enum avifDecoderSource
{
// Honor the major brand signaled in the beginning of the file to pick between an AVIF sequence
// ('avis', tracks-based) or a single image ('avif', item-based). If the major brand is neither
// of these, prefer the AVIF sequence ('avis', tracks-based), if present.
AVIF_DECODER_SOURCE_AUTO = 0,
// Use the primary item and the aux (alpha) item in the avif(s).
// This is where single-image avifs store their image.
AVIF_DECODER_SOURCE_PRIMARY_ITEM,
// Use the chunks inside primary/aux tracks in the moov block.
// This is where avifs image sequences store their images.
AVIF_DECODER_SOURCE_TRACKS
// Decode the thumbnail item. Currently unimplemented.
// AVIF_DECODER_SOURCE_THUMBNAIL_ITEM
} avifDecoderSource;
// Information about the timing of a single image in an image sequence
typedef struct avifImageTiming
{
uint64_t timescale; // timescale of the media (Hz)
double pts; // presentation timestamp in seconds (ptsInTimescales / timescale)
uint64_t ptsInTimescales; // presentation timestamp in "timescales"
double duration; // in seconds (durationInTimescales / timescale)
uint64_t durationInTimescales; // duration in "timescales"
} avifImageTiming;
typedef enum avifProgressiveState
{
// The current AVIF/Source does not offer a progressive image. This will always be the state
// for an image sequence.
AVIF_PROGRESSIVE_STATE_UNAVAILABLE = 0,
// The current AVIF/Source offers a progressive image, but avifDecoder.allowProgressive is not
// enabled, so it will behave as if the image was not progressive and will simply decode the
// best version of this item.
AVIF_PROGRESSIVE_STATE_AVAILABLE,
// The current AVIF/Source offers a progressive image, and avifDecoder.allowProgressive is true.
// In this state, avifDecoder.imageCount will be the count of all of the available progressive
// layers, and any specific layer can be decoded using avifDecoderNthImage() as if it was an
// image sequence, or simply using repeated calls to avifDecoderNextImage() to decode better and
// better versions of this image.
AVIF_PROGRESSIVE_STATE_ACTIVE
} avifProgressiveState;
AVIF_API const char * avifProgressiveStateToString(avifProgressiveState progressiveState);
// NOTE: The avifDecoder struct may be extended in a future release. Code outside the libavif
// library must allocate avifDecoder by calling the avifDecoderCreate() function.
typedef struct avifDecoder
{
// --------------------------------------------------------------------------------------------
// Inputs
// Defaults to AVIF_CODEC_CHOICE_AUTO: Preference determined by order in availableCodecs table (avif.c)
avifCodecChoice codecChoice;
// Defaults to 1. -- NOTE: Please see the "Understanding maxThreads" comment block above
int maxThreads;
// avifs can have multiple sets of images in them. This specifies which to decode.
// Set this via avifDecoderSetSource().
avifDecoderSource requestedSource;
// If this is true and a progressive AVIF is decoded, avifDecoder will behave as if the AVIF is
// an image sequence, in that it will set imageCount to the number of progressive frames
// available, and avifDecoderNextImage()/avifDecoderNthImage() will allow for specific layers
// of a progressive image to be decoded. To distinguish between a progressive AVIF and an AVIF
// image sequence, inspect avifDecoder.progressiveState.
avifBool allowProgressive;
// If this is false, avifDecoderNextImage() will start decoding a frame only after there are
// enough input bytes to decode all of that frame. If this is true, avifDecoder will decode each
// subimage or grid cell as soon as possible. The benefits are: grid images may be partially
// displayed before being entirely available, and the overall decoding may finish earlier.
// Must be set before calling avifDecoderNextImage() or avifDecoderNthImage().
// WARNING: Experimental feature.
avifBool allowIncremental;
// Enable any of these to avoid reading and surfacing specific data to the decoded avifImage.
// These can be useful if your avifIO implementation heavily uses AVIF_RESULT_WAITING_ON_IO for
// streaming data, as some of these payloads are (unfortunately) packed at the end of the file,
// which will cause avifDecoderParse() to return AVIF_RESULT_WAITING_ON_IO until it finds them.
// If you don't actually leverage this data, it is best to ignore it here.
avifBool ignoreExif;
avifBool ignoreXMP;
// This represents the maximum size of an image (in pixel count) that libavif and the underlying
// AV1 decoder should attempt to decode. It defaults to AVIF_DEFAULT_IMAGE_SIZE_LIMIT, and can
// be set to a smaller value. The value 0 is reserved.
// Note: Only some underlying AV1 codecs support a configurable size limit (such as dav1d).
uint32_t imageSizeLimit;
// This represents the maximum dimension of an image (width or height) that libavif should
// attempt to decode. It defaults to AVIF_DEFAULT_IMAGE_DIMENSION_LIMIT. Set it to 0 to ignore
// the limit.
uint32_t imageDimensionLimit;
// This provides an upper bound on how many images the decoder is willing to attempt to decode,
// to provide a bit of protection from malicious or malformed AVIFs citing millions upon
// millions of frames, only to be invalid later. The default is AVIF_DEFAULT_IMAGE_COUNT_LIMIT
// (see comment above), and setting this to 0 disables the limit.
uint32_t imageCountLimit;
// Strict flags. Defaults to AVIF_STRICT_ENABLED. See avifStrictFlag definitions above.
avifStrictFlags strictFlags;
// --------------------------------------------------------------------------------------------
// Outputs
// All decoded image data; owned by the decoder. All information in this image is incrementally
// added and updated as avifDecoder*() functions are called. After a successful call to
// avifDecoderParse(), all values in decoder->image (other than the planes/rowBytes themselves)
// will be pre-populated with all information found in the outer AVIF container, prior to any
// AV1 decoding. If the contents of the inner AV1 payload disagree with the outer container,
// these values may change after calls to avifDecoderRead*(),avifDecoderNextImage(), or
// avifDecoderNthImage().
//
// The YUV and A contents of this image are likely owned by the decoder, so be sure to copy any
// data inside of this image before advancing to the next image or reusing the decoder. It is
// legal to call avifImageYUVToRGB() on this in between calls to avifDecoderNextImage(), but use
// avifImageCopy() if you want to make a complete, permanent copy of this image's YUV content or
// metadata.
avifImage * image;
// Counts and timing for the current image in an image sequence. Uninteresting for single image files.
int imageIndex; // 0-based
int imageCount; // Always 1 for non-progressive, non-sequence AVIFs.
avifProgressiveState progressiveState; // See avifProgressiveState declaration
avifImageTiming imageTiming; //
uint64_t timescale; // timescale of the media (Hz)
double duration; // duration of a single playback of the image sequence in seconds
// (durationInTimescales / timescale)
uint64_t durationInTimescales; // duration of a single playback of the image sequence in "timescales"
int repetitionCount; // number of times the sequence has to be repeated. This can also be one of
// AVIF_REPETITION_COUNT_INFINITE or AVIF_REPETITION_COUNT_UNKNOWN. Essentially, if
// repetitionCount is a non-negative integer `n`, then the image sequence should be
// played back `n + 1` times.
// This is true when avifDecoderParse() detects an alpha plane. Use this to find out if alpha is
// present after a successful call to avifDecoderParse(), but prior to any call to
// avifDecoderNextImage() or avifDecoderNthImage(), as decoder->image->alphaPlane won't exist yet.
avifBool alphaPresent;
// stats from the most recent read, possibly 0s if reading an image sequence
avifIOStats ioStats;
// Additional diagnostics (such as detailed error state)
avifDiagnostics diag;
// --------------------------------------------------------------------------------------------
// Internals
// Use one of the avifDecoderSetIO*() functions to set this
avifIO * io;
// Internals used by the decoder
struct avifDecoderData * data;
// Version 1.0.0 ends here.
// This is true when avifDecoderParse() detects an image sequence track in the image. If this is true, the image can be
// decoded either as an animated image sequence or as a still image (the primary image item) by setting avifDecoderSetSource
// to the appropriate source.
avifBool imageSequenceTrackPresent;
// Version 1.1.0 ends here. Add any new members after this line.
#if defined(AVIF_ENABLE_EXPERIMENTAL_GAIN_MAP)
// This is true when avifDecoderParse() detects a gain map.
avifBool gainMapPresent;
// Enable decoding the gain map image if present (defaults to AVIF_FALSE).
// (see also enableParsingGainMapMetadata below).
// gainMapPresent is still set if the presence of a gain map is detected, regardless
// of this setting.
avifBool enableDecodingGainMap;
// Enable parsing the gain map metadata if present (defaults to AVIF_FALSE).
// gainMapPresent is still set if the presence of a gain map is detected, regardless
// of this setting.
// Gain map metadata is read during avifDecoderParse(). Like Exif and XMP, this data
// can be (unfortunately) packed at the end of the file, which will cause
// avifDecoderParse() to return AVIF_RESULT_WAITING_ON_IO until it finds it.
// If you don't actually use this data, it's best to leave this to AVIF_FALSE (default).
avifBool enableParsingGainMapMetadata;
// Do not decode the color/alpha planes of the main image.
// Can be useful to decode the gain map image only.
avifBool ignoreColorAndAlpha;
#endif
} avifDecoder;
// Returns NULL in case of memory allocation failure.
AVIF_API avifDecoder * avifDecoderCreate(void);
AVIF_API void avifDecoderDestroy(avifDecoder * decoder);
// Simple interfaces to decode a single image, independent of the decoder afterwards (decoder may be destroyed).
AVIF_API avifResult avifDecoderRead(avifDecoder * decoder, avifImage * image); // call avifDecoderSetIO*() first
AVIF_API avifResult avifDecoderReadMemory(avifDecoder * decoder, avifImage * image, const uint8_t * data, size_t size);
AVIF_API avifResult avifDecoderReadFile(avifDecoder * decoder, avifImage * image, const char * filename);
// Multi-function alternative to avifDecoderRead() for image sequences and gaining direct access
// to the decoder's YUV buffers (for performance's sake). Data passed into avifDecoderParse() is NOT
// copied, so it must continue to exist until the decoder is destroyed.
//
// Usage / function call order is:
// * avifDecoderCreate()
// * avifDecoderSetSource() - optional, the default (AVIF_DECODER_SOURCE_AUTO) is usually sufficient
// * avifDecoderSetIO*()
// * avifDecoderParse()
// * avifDecoderNextImage() - in a loop, using decoder->image after each successful call
// * avifDecoderDestroy()
//
// NOTE: Until avifDecoderParse() returns AVIF_RESULT_OK, no data in avifDecoder should
// be considered valid, and no queries (such as Keyframe/Timing/MaxExtent) should be made.
//
// You can use avifDecoderReset() any time after a successful call to avifDecoderParse()
// to reset the internal decoder back to before the first frame. Calling either
// avifDecoderSetSource() or avifDecoderParse() will automatically Reset the decoder.
//
// avifDecoderSetSource() allows you not only to choose whether to parse tracks or
// items in a file containing both, but switch between sources without having to
// Parse again. Normally AVIF_DECODER_SOURCE_AUTO is enough for the common path.
AVIF_API avifResult avifDecoderSetSource(avifDecoder * decoder, avifDecoderSource source);
// Note: When avifDecoderSetIO() is called, whether 'decoder' takes ownership of 'io' depends on
// whether io->destroy is set. avifDecoderDestroy(decoder) calls avifIODestroy(io), which calls
// io->destroy(io) if io->destroy is set. Therefore, if io->destroy is not set, then
// avifDecoderDestroy(decoder) has no effects on 'io'.
AVIF_API void avifDecoderSetIO(avifDecoder * decoder, avifIO * io);
AVIF_API avifResult avifDecoderSetIOMemory(avifDecoder * decoder, const uint8_t * data, size_t size);
AVIF_API avifResult avifDecoderSetIOFile(avifDecoder * decoder, const char * filename);
AVIF_API avifResult avifDecoderParse(avifDecoder * decoder);
AVIF_API avifResult avifDecoderNextImage(avifDecoder * decoder);
AVIF_API avifResult avifDecoderNthImage(avifDecoder * decoder, uint32_t frameIndex);
AVIF_API avifResult avifDecoderReset(avifDecoder * decoder);
// Keyframe information
// frameIndex - 0-based, matching avifDecoder->imageIndex, bound by avifDecoder->imageCount
// "nearest" keyframe means the keyframe prior to this frame index (returns frameIndex if it is a keyframe)
// These functions may be used after a successful call (AVIF_RESULT_OK) to avifDecoderParse().
AVIF_NODISCARD AVIF_API avifBool avifDecoderIsKeyframe(const avifDecoder * decoder, uint32_t frameIndex);
AVIF_API uint32_t avifDecoderNearestKeyframe(const avifDecoder * decoder, uint32_t frameIndex);
// Timing helper - This does not change the current image or invoke the codec (safe to call repeatedly)
// This function may be used after a successful call (AVIF_RESULT_OK) to avifDecoderParse().
AVIF_API avifResult avifDecoderNthImageTiming(const avifDecoder * decoder, uint32_t frameIndex, avifImageTiming * outTiming);
// When avifDecoderNextImage() or avifDecoderNthImage() returns AVIF_RESULT_WAITING_ON_IO, this
// function can be called next to retrieve the number of top rows that can be immediately accessed
// from the luma plane of decoder->image, and alpha if any. The corresponding rows from the chroma planes,
// if any, can also be accessed (half rounded up if subsampled, same number of rows otherwise).
// If a gain map is present and AVIF_ENABLE_EXPERIMENTAL_GAIN_MAP is on and enableDecodingGainMap is also on,
// the gain map's planes can also be accessed in the same way. If the gain map's height is different from
// the main image, then the number of available gain map rows is at least:
// roundf((float)decoded_row_count / decoder->image->height * decoder->image->gainMap.image->height)
// When gain map scaling is needed, callers might choose to use a few less rows depending on how many rows
// are needed by the scaling algorithm, to avoid the last row(s) changing when more data becomes available.
// decoder->allowIncremental must be set to true before calling avifDecoderNextImage() or
// avifDecoderNthImage(). Returns decoder->image->height when the last call to avifDecoderNextImage() or
// avifDecoderNthImage() returned AVIF_RESULT_OK. Returns 0 in all other cases.
// WARNING: Experimental feature.
AVIF_API uint32_t avifDecoderDecodedRowCount(const avifDecoder * decoder);
// ---------------------------------------------------------------------------
// avifExtent
typedef struct avifExtent
{
uint64_t offset;
size_t size;
} avifExtent;
// Streaming data helper - Use this to calculate the maximal AVIF data extent encompassing all AV1
// sample data needed to decode the Nth image. The offset will be the earliest offset of all
// required AV1 extents for this frame, and the size will create a range including the last byte of
// the last AV1 sample needed. Note that this extent may include non-sample data, as a frame's
// sample data may be broken into multiple extents and interleaved with other data, or in
// non-sequential order. This extent will also encompass all AV1 samples that this frame's sample
// depends on to decode (such as samples for reference frames), from the nearest keyframe up to this
// Nth frame.
//
// If avifDecoderNthImageMaxExtent() returns AVIF_RESULT_OK and the extent's size is 0 bytes, this
// signals that libavif doesn't expect to call avifIO's Read for this frame's decode. This happens if
// data for this frame was read as a part of avifDecoderParse() (typically in an idat box inside of
// a meta box).
//
// This function may be used after a successful call (AVIF_RESULT_OK) to avifDecoderParse().
AVIF_API avifResult avifDecoderNthImageMaxExtent(const avifDecoder * decoder, uint32_t frameIndex, avifExtent * outExtent);
// ---------------------------------------------------------------------------
// avifEncoder
struct avifEncoderData;
struct avifCodecSpecificOptions;
typedef struct avifScalingMode
{
avifFraction horizontal;
avifFraction vertical;
} avifScalingMode;
// Notes:
// * The avifEncoder struct may be extended in a future release. Code outside the libavif library
// must allocate avifEncoder by calling the avifEncoderCreate() function.
// * If avifEncoderWrite() returns AVIF_RESULT_OK, output must be freed with avifRWDataFree()
// * If (maxThreads < 2), multithreading is disabled
// * NOTE: Please see the "Understanding maxThreads" comment block above
// * Quality range: [AVIF_QUALITY_WORST - AVIF_QUALITY_BEST]
// * Quantizer range: [AVIF_QUANTIZER_BEST_QUALITY - AVIF_QUANTIZER_WORST_QUALITY]
// * In older versions of libavif, the avifEncoder struct doesn't have the quality and qualityAlpha
// fields. For backward compatibility, if the quality field is not set, the default value of
// quality is based on the average of minQuantizer and maxQuantizer. Similarly the default value
// of qualityAlpha is based on the average of minQuantizerAlpha and maxQuantizerAlpha. New code
// should set quality and qualityAlpha and leave minQuantizer, maxQuantizer, minQuantizerAlpha,
// and maxQuantizerAlpha initialized to their default values.
// * To enable tiling, set tileRowsLog2 > 0 and/or tileColsLog2 > 0.
// Tiling values range [0-6], where the value indicates a request for 2^n tiles in that dimension.
// If autoTiling is set to AVIF_TRUE, libavif ignores tileRowsLog2 and tileColsLog2 and
// automatically chooses suitable tiling values.
// * Speed range: [AVIF_SPEED_SLOWEST - AVIF_SPEED_FASTEST]. Slower should make for a better quality
// image in less bytes. AVIF_SPEED_DEFAULT means "Leave the AV1 codec to its default speed settings"./
// If avifEncoder uses rav1e, the speed value is directly passed through (0-10). If libaom is used,
// a combination of settings are tweaked to simulate this speed range.
// * Extra layer count: [0 - (AVIF_MAX_AV1_LAYER_COUNT-1)]. Non-zero value indicates a layered
// (progressive) image.
// * Some encoder settings can be changed after encoding starts. Changes will take effect in the next
// call to avifEncoderAddImage().
typedef struct avifEncoder
{
// Defaults to AVIF_CODEC_CHOICE_AUTO: Preference determined by order in availableCodecs table (avif.c)
avifCodecChoice codecChoice;
// settings (see Notes above)
int maxThreads;
int speed;
int keyframeInterval; // Any set of |keyframeInterval| consecutive frames will have at least one keyframe. When it is 0,
// there is no such restriction.
uint64_t timescale; // timescale of the media (Hz)
int repetitionCount; // Number of times the image sequence should be repeated. This can also be set to
// AVIF_REPETITION_COUNT_INFINITE for infinite repetitions. Only applicable for image sequences.
// Essentially, if repetitionCount is a non-negative integer `n`, then the image sequence should be
// played back `n + 1` times. Defaults to AVIF_REPETITION_COUNT_INFINITE.
uint32_t extraLayerCount; // EXPERIMENTAL: Non-zero value encodes layered image.
// changeable encoder settings
int quality;
int qualityAlpha;
int minQuantizer;
int maxQuantizer;
int minQuantizerAlpha;
int maxQuantizerAlpha;
int tileRowsLog2;
int tileColsLog2;
avifBool autoTiling;
avifScalingMode scalingMode;
// stats from the most recent write
avifIOStats ioStats;
// Additional diagnostics (such as detailed error state)
avifDiagnostics diag;
// Internals used by the encoder
struct avifEncoderData * data;
struct avifCodecSpecificOptions * csOptions;
// Version 1.0.0 ends here.
// Defaults to AVIF_HEADER_FULL
avifHeaderFormat headerFormat;
// Version 1.1.0 ends here. Add any new members after this line.
#if defined(AVIF_ENABLE_EXPERIMENTAL_GAIN_MAP)
int qualityGainMap; // changeable encoder setting
#endif
#if defined(AVIF_ENABLE_EXPERIMENTAL_SAMPLE_TRANSFORM)
// Perform extra steps at encoding and decoding to extend AV1 features using bundled additional image items.
avifSampleTransformRecipe sampleTransformRecipe;
#endif
} avifEncoder;
// avifEncoderCreate() returns NULL if a memory allocation failed.
AVIF_NODISCARD AVIF_API avifEncoder * avifEncoderCreate(void);
AVIF_API avifResult avifEncoderWrite(avifEncoder * encoder, const avifImage * image, avifRWData * output);
AVIF_API void avifEncoderDestroy(avifEncoder * encoder);
typedef enum avifAddImageFlag
{
AVIF_ADD_IMAGE_FLAG_NONE = 0,
// Force this frame to be a keyframe (sync frame).
AVIF_ADD_IMAGE_FLAG_FORCE_KEYFRAME = (1 << 0),
// Use this flag when encoding a single frame, single layer image.
// Signals "still_picture" to AV1 encoders, which tweaks various compression rules.
// This is enabled automatically when using the avifEncoderWrite() single-image encode path.
AVIF_ADD_IMAGE_FLAG_SINGLE = (1 << 1)
} avifAddImageFlag;
typedef uint32_t avifAddImageFlags;
// Multi-function alternative to avifEncoderWrite() for advanced features.
//
// Usage / function call order is:
// * avifEncoderCreate()
// - Still image:
// * avifEncoderAddImage() [exactly once]
// - Still image grid:
// * avifEncoderAddImageGrid() [exactly once, AVIF_ADD_IMAGE_FLAG_SINGLE is assumed]
// - Image sequence:
// * Set encoder->timescale (Hz) correctly
// * avifEncoderAddImage() ... [repeatedly; at least once]
// - Still layered image:
// * Set encoder->extraLayerCount correctly
// * avifEncoderAddImage() ... [exactly encoder->extraLayerCount+1 times]
// - Still layered grid:
// * Set encoder->extraLayerCount correctly
// * avifEncoderAddImageGrid() ... [exactly encoder->extraLayerCount+1 times]
// * avifEncoderFinish()
// * avifEncoderDestroy()
//
// The image passed to avifEncoderAddImage() or avifEncoderAddImageGrid() is encoded during the
// call (which may be slow) and can be freed after the function returns.
// durationInTimescales is ignored if AVIF_ADD_IMAGE_FLAG_SINGLE is set in addImageFlags,
// or if we are encoding a layered image.
AVIF_API avifResult avifEncoderAddImage(avifEncoder * encoder, const avifImage * image, uint64_t durationInTimescales, avifAddImageFlags addImageFlags);
AVIF_API avifResult avifEncoderAddImageGrid(avifEncoder * encoder,
uint32_t gridCols,
uint32_t gridRows,
const avifImage * const * cellImages,
avifAddImageFlags addImageFlags);
AVIF_API avifResult avifEncoderFinish(avifEncoder * encoder, avifRWData * output);
// Codec-specific, optional "advanced" tuning settings, in the form of string key/value pairs,
// to be consumed by the codec in the next avifEncoderAddImage() call.
// See the codec documentation to know if a setting is persistent or applied only to the next frame.
// key must be non-NULL, but passing a NULL value will delete the pending key, if it exists.
// Setting an incorrect or unknown option for the current codec will cause errors of type
// AVIF_RESULT_INVALID_CODEC_SPECIFIC_OPTION from avifEncoderWrite() or avifEncoderAddImage().
AVIF_API avifResult avifEncoderSetCodecSpecificOption(avifEncoder * encoder, const char * key, const char * value);
#if defined(AVIF_ENABLE_EXPERIMENTAL_GAIN_MAP)
// Returns the size in bytes of the AV1 image item containing gain map samples, or 0 if no gain map was encoded.
AVIF_API size_t avifEncoderGetGainMapSizeBytes(avifEncoder * encoder);
#endif
// Helpers
AVIF_NODISCARD AVIF_API avifBool avifImageUsesU16(const avifImage * image);
AVIF_NODISCARD AVIF_API avifBool avifImageIsOpaque(const avifImage * image);
// channel can be an avifChannelIndex.
AVIF_API uint8_t * avifImagePlane(const avifImage * image, int channel);
AVIF_API uint32_t avifImagePlaneRowBytes(const avifImage * image, int channel);
AVIF_API uint32_t avifImagePlaneWidth(const avifImage * image, int channel);
AVIF_API uint32_t avifImagePlaneHeight(const avifImage * image, int channel);
// Returns AVIF_TRUE if input begins with a valid FileTypeBox (ftyp) that supports
// either the brand 'avif' or 'avis' (or both), without performing any allocations.
AVIF_NODISCARD AVIF_API avifBool avifPeekCompatibleFileType(const avifROData * input);
#if defined(AVIF_ENABLE_EXPERIMENTAL_GAIN_MAP)
// ---------------------------------------------------------------------------
// Gain Map utilities.
// Gain Maps are a HIGHLY EXPERIMENTAL FEATURE, see comments in the avifGainMap
// section above.
// Performs tone mapping on a base image using the provided gain map.
// The HDR headroom is log2 of the ratio of HDR to SDR white brightness of the display to tone map for.
// 'toneMappedImage' should have the 'format', 'depth', and 'isFloat' fields set to the desired values.
// If non NULL, 'clli' will be filled with the light level information of the tone mapped image.
// NOTE: only used in tests for now, might be added to the public API at some point.
AVIF_API avifResult avifImageApplyGainMap(const avifImage * baseImage,
const avifGainMap * gainMap,
float hdrHeadroom,
avifColorPrimaries outputColorPrimaries,
avifTransferCharacteristics outputTransferCharacteristics,
avifRGBImage * toneMappedImage,
avifContentLightLevelInformationBox * clli,
avifDiagnostics * diag);
// Same as above but takes an avifRGBImage as input instead of avifImage.
AVIF_API avifResult avifRGBImageApplyGainMap(const avifRGBImage * baseImage,
avifColorPrimaries baseColorPrimaries,
avifTransferCharacteristics baseTransferCharacteristics,
const avifGainMap * gainMap,
float hdrHeadroom,
avifColorPrimaries outputColorPrimaries,
avifTransferCharacteristics outputTransferCharacteristics,
avifRGBImage * toneMappedImage,
avifContentLightLevelInformationBox * clli,
avifDiagnostics * diag);
// Computes a gain map between two images: a base image and an alternate image.
// Both images should have the same width and height, and use the same color
// primaries. TODO(maryla): allow different primaries.
// gainMap->image should be initialized with avifImageCreate(), with the width,
// height, depth and yuvFormat fields set to the desired output values for the
// gain map. All of these fields may differ from the source images.
AVIF_API avifResult avifRGBImageComputeGainMap(const avifRGBImage * baseRgbImage,
avifColorPrimaries baseColorPrimaries,
avifTransferCharacteristics baseTransferCharacteristics,
const avifRGBImage * altRgbImage,
avifColorPrimaries altColorPrimaries,
avifTransferCharacteristics altTransferCharacteristics,
avifGainMap * gainMap,
avifDiagnostics * diag);
// Convenience function. Same as above but takes avifImage images as input
// instead of avifRGBImage. Gain map computation is performed in RGB space so
// the images are converted to RGB first.
AVIF_API avifResult avifImageComputeGainMap(const avifImage * baseImage,
const avifImage * altImage,
avifGainMap * gainMap,
avifDiagnostics * diag);
#endif // AVIF_ENABLE_EXPERIMENTAL_GAIN_MAP
#ifdef __cplusplus
} // extern "C"
#endif
#endif // ifndef AVIF_AVIF_H