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Diffstat (limited to 'libpanto/src/cdeps/jebp.h')
| -rw-r--r-- | libpanto/src/cdeps/jebp.h | 2457 |
1 files changed, 2457 insertions, 0 deletions
diff --git a/libpanto/src/cdeps/jebp.h b/libpanto/src/cdeps/jebp.h new file mode 100644 index 0000000..dc95d06 --- /dev/null +++ b/libpanto/src/cdeps/jebp.h @@ -0,0 +1,2457 @@ +/** + * JebP - Single header WebP decoder + */ + +/** + * LICENSE + ** + * MIT No Attribution + * + * Copyright 2022 Jasmine Minter + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +// Attribution is not required, but would be appreciated :) + +/** + * DOCUMENTATION + ** + * First and foremost, this project uses some custom types: + * `jebp_byte`/`jebp_ubyte` is a singular byte. + * `jebp_short`/jebp_ushort` is an integer of atleast 16-bits. + * `jebp_int`/`jebp_uint` is an integer of atleast 32-bits. + * + * This is a header only file. This means that it operates as a standard header + * and to generate the source file you define `JEBP_IMPLEMENTATION` in ONE file + * only. For example: + * ```c + * #define JEBP_IMPLEMENTATION + * #include "jebp.h" + * ``` + * + * The most basic API call in this library is: + * ```c + * err = jebp_decode(&image, size, data); + * ``` + * where: + * `jebp_image_t *image` is a pointer to an image structure to receive the + * decoded data. + * `size_t size` is the size of the WebP-encoded data buffer. + * `const void *data` is a pointer to the WebP encoded data buffer, `size` + * bytes large. + * `jebp_error_t err` is the result of the operation (OK or an error code). + * + * For reading from a provided file path, this API call can be used instead: + * ```c + * err = jebp_read(&image, path); + * ``` + * where: + * `const char *path` is the path of the file to be read. + * + * It is currently not possible to read from a `FILE *` object. + * If you only want to get the size of the image without a full read, these + * functions can be used instead: + * ```c + * err = jebp_decode_size(&image, size, data); + * err = jebp_read_size(&image, path); + * ``` + * + * The `jebp_image_t` structure has the following properties: + * `jebp_int width` is the width of the image. + * `jebp_int height` is the height of the image. + * `jebp_color_t *pixels` is a pointer to an array pixels. Each `jebp_color_t` + * structure contains four `jebp_ubyte` values for `r`, + * `g`, `b` and `a`. This allows the `pixels` pointer + * to be cast to `jebp_ubyte *` to get an RGBA pixel + * buffer. + * The allocated data in the image can be free'd with: + * ```c + * jebp_free_image(&image); + * ``` + * This function will also clear the structure, notably width and height will be + * set to 0. + * + * The `jebp_error_t` enumeration has the following values: + * `JEBP_OK` means the operation completed successfully. + * `JEBP_ERROR_INVAL` means one of the arguments provided is invalid, usually + * this refers to a NULL pointer. + * `JEBP_ERROR_INVDATA` means the WebP-encoded data is invalid or corrupted. + * `JEBP_ERROR_INVDATA_HEADER` is a suberror of `INVDATA` that indicates that + * the header bytes are invalid. This file is likely not a + * WebP file. + * `JEBP_ERROR_EOF` means the end of the file (or data buffer) was reached + * before the operation could successfully complete. + * `JEBP_ERROR_NOSUP` means there is a feature in the WebP stream that is not + * currently supported (see below). This can also represent + * new features, versions or RIFF-chunks that were not in + * the specification when writing. + * `JEBP_ERROR_NOSUP_CODEC` is a suberror of `NOSUP` that indicates that the + * RIFF chunk that is most likely for the codec is not + * recognized. Currently lossy images are not supported + * (see below) and lossless image support can be disabled + * (see `JEBP_NO_VP8L`). + * `JEBP_ERROR_NOSUP_PALETTE` is a suberror of `NOSUP` that indicates that the + * image has a color-index transform (in WebP terminology, + * this would be a paletted image). Color-indexing + * transforms are not currently supported (see below). Note + * that this error code might be removed after + * color-indexing transform support is added, this is only + * here for now to help detecting common issues. + * `JEBP_ERROR_NOMEM` means that a memory allocation failed, indicating that + * there is no more memory available. + * `JEBP_ERROR_IO` represents any generic I/O error, usually from + * file-reading. + * `JEBP_ERROR_UNKNOWN` means any unknown error. Currently this is only used + * when an unknown value is passed into + * `jebp_error_string`. + * To get a human-readable string of the error, the following function can be + * used: + * ```c + * const char *error = jebp_error_string(err); + * ``` + * + * This is not a feature-complete WebP decoder and has the following + * limitations: + * - Does not support decoding lossy files with VP8. + * - Does not support extended file-formats with VP8X. + * - Does not support VP8L lossless images with the color-indexing transform + * (palleted images). + * - Does not support VP8L images with more than 256 huffman groups. This is + * an arbitrary limit to prevent bad images from using too much memory. In + * theory, images requiring more groups should be very rare. This limit may + * be increased in the future. + * + * Features that will probably never be supported due to complexity or API + * constraints: + * - Decoding color profiles. + * - Decoding metadata. + * - Full color-indexing/palette support will be a bit of a mess, so don't + * expect full support of that coming anytime soon. Simple color-indexing + * support (more than 16 colors, skipping the need for bit-packing) is + * definitely alot more do-able. + * + * Along with `JEBP_IMPLEMENTATION` defined above, there are a few other macros + * that can be defined to change how JebP operates: + * `JEBP_NO_STDIO` will disable the file-reading API. + * `JEBP_NO_SIMD` will disable SIMD optimizations. These are currently + * not-used but the detection is there ready for further work. + * `JEBP_NO_VP8L` will disable VP8L (lossless) decoding support. Note that + * currently this will make all images fail since VP8L is the + * only supported codec right now. + * `JEBP_ALLOC` and `JEBP_FREE` can be defined to functions for a custom + * allocator. They either both have to be defined or neither + * defined. + * + * This single-header library requires C99 to be supported. Along with this it + * requires the following headers from the system to successfully compile. Some + * of these can be disabled with the above macros: + * `stddef.h` is used for the definition of the `size_t` type. + * `limits.h` is used for the `UINT_MAX` macro to check the size of `int`. If + * `int` is not 32-bits, `long` will be used for `jebp_int` + * instead. + * `string.h` is used for `memset` to clear out memory. + * `stdio.h` is used for I/O support and logging errors. If `JEBP_NO_STDIO` is + * defined and `JEBP_LOG_ERRORS` is not defined, this will not be + * included. + * `stdlib.h` is used for the default implementations of `JEBP_ALLOC` + * and `JEBP_FREE`, using `malloc` and `free` respectively. If + * those macros are already defined to something else, this will + * not be included. + * `emmintrin.h` and `arm_neon.h` is used for SIMD intrinsice. If + * `JEBP_NO_SIMD` is defined these will not be included. + * + * The following predefined macros are also used for compiler-feature, SIMD and + * endianness detection. These can be changed or modified before import to + * change JebP's detection logic: + * `__STDC_VERSION__` is used to detect if the compiler supports C99 and also + * checks for C11 support to use `_Noreturn`. + * `__has_attribute` and `__has_builtin` are used to detect the `noreturn` and + * `always_inline` attributes, along with the + * `__builtin_bswap32` builtin. Note that `__has_attribute` + * does not fallback to compiler-version checks since most + * compilers already support `__has_attribute`. + * `__GNUC__` and `__GNUC_MINOR__` are used to detect if the compiler is GCC + * (or GCC compatible) and what version of GCC it is. This, in + * turn, is used to polyfill `__has_builtin` on older compilers + * that may not support it. + * `__clang__` is used to detect the Clang compiler. This is only used to set + * the detected GCC version higher since Clang still marks itself + * as GCC 4.2 by default. No Clang version detection is done. + * `_MSC_VER` is used to detect the MSVC compiler. This is used to check + * support for `__declspec(noreturn)`, `__forceinline` and + * `_byteswap_ulong`. No MSVC version detection is done. + * `__LITTLE_ENDIAN__` is used to check if the architecture is little-endian. + * Note that this is only checked either if the + * architecture cannot be detected or, in special cases, + * where there is not enough information from the + * architecture or compiler to detect endianness. Also + * note that big-endian and other more-obscure endian + * types are not detected. Little-endian is the only + * endianness detected and is used for optimization in a + * few areas. If the architecture is not little-endian or + * cannot be detected as such, a naive solution is used + * instead. + * `__i386`, `__i386__` and `_M_IX86` are used to detect if this is being + * compiled for x86-32 (also known as x86, IA-32, or i386). If one of + * these are defined, it is also assumed that the architecture is + * little-endian. `_M_IX86` is usually present on MSVC, while + * the other two are usually present on most other compilers. + * `__SSE2__` and `_M_IX86_FP` are used to detect SSE2 support on x86-32. + * `_M_IX86`, which is usually present on MSVC, must equal 2 to + * indicate that the code is being compiled for a SSE2-compatible + * floating-point unit. `__SSE2__` is usually present on most other + * compilers. + * `__x86_64`, `__x86_64__` and `_M_X64` are used to detect if this is being + * compiled for x86-64 (also known as AMD64). If one of these are + * defined, it is also assumed that the architecture is little-endian + * and that SSE2 is supported (which is required for x86-64 support). + * `_M_X64` is usually present on MSVC, while the other two are + * usually present on most other compilers. + * `__arm`, `__arm__` and `_M_ARM` are used to detect if this is being + * compiled for AArch32 (also known as arm32 or armhf). If one of + * these are defined on Windows, it is also assumed that Neon is + * supported (which is required for Windows). `_M_ARM` is usually + * present on MSVC while the other two are usually present on most + * other compilers. + * `__ARM_NEON` is used to detect Neon support on AArch32. MSVC doesn't seem + * to support this and I can't find any info on detecting Neon + * support for MSVC. I have found mentions of Windows requiring + * Neon support but cannot find any concrete proof anywhere. + * `__aarch64`, `__aarch64__` and `_M_ARM64` are used to detect if this is + * being compiled for AArch64 (also known as arm64). If one of + * these are defined, it is also assumed that Neon is supported + * (which is required for AArch64 support). `_M_ARM64` is usually + * present on MSVC, while the other two are usually present on + * most other compilers. + * `__ARM_BIG_ENDIAN` is used to detect, on AArch/ARM architectures, if it is + * in big-endian mode. However, as mentioned above, there + * is no special code for big-endian and it's worth noting + * that this is just used to force-disable little-endian. + * If this is not present, it falls back to using + * `__LITTLE_ENDIAN__`. It is also worth noting that MSVC + * does not seem to provide a way to detect endianness. It + * may be that Windows requires little-endian but I can't + * find any concrete sources on this so currently + * little-endian detection is not supported on MSVC. + */ + +/** + * HEADER + */ +#ifndef JEBP__HEADER +#define JEBP__HEADER +#ifdef __cplusplus +extern "C" { +#endif // __cplusplus +#include <limits.h> +#include <stddef.h> + +#if UINT_MAX >= 0xffffffff +#define JEBP__INT int +#else +#define JEBP__INT long +#endif +typedef signed char jebp_byte; +typedef unsigned char jebp_ubyte; +typedef short jebp_short; +typedef unsigned short jebp_ushort; +typedef JEBP__INT jebp_int; +typedef unsigned JEBP__INT jebp_uint; + +typedef enum jebp_error_t { + JEBP_OK, + JEBP_ERROR_INVAL, + JEBP_ERROR_INVDATA, + JEBP_ERROR_INVDATA_HEADER, + JEBP_ERROR_EOF, + JEBP_ERROR_NOSUP, + JEBP_ERROR_NOSUP_CODEC, + JEBP_ERROR_NOSUP_PALETTE, + JEBP_ERROR_NOMEM, + JEBP_ERROR_IO, + JEBP_ERROR_UNKNOWN, + JEBP_NB_ERRORS +} jebp_error_t; + +typedef struct jebp_color_t { + jebp_ubyte r; + jebp_ubyte g; + jebp_ubyte b; + jebp_ubyte a; +} jebp_color_t; + +typedef struct jebp_image_t { + jebp_int width; + jebp_int height; + jebp_color_t *pixels; +} jebp_image_t; + +const char *jebp_error_string(jebp_error_t err); +void jebp_free_image(jebp_image_t *image); +jebp_error_t jebp_decode_size(jebp_image_t *image, size_t size, + const void *data); +jebp_error_t jebp_decode(jebp_image_t *image, size_t size, const void *data); + +// I/O API +#ifndef JEBP_NO_STDIO +jebp_error_t jebp_read_size(jebp_image_t *image, const char *path); +jebp_error_t jebp_read(jebp_image_t *image, const char *path); +#endif // JEBP_NO_STDIO + +#ifdef __cplusplus +} +#endif // __cplusplus +#endif // JEBP__HEADER + +/** + * IMPLEMENTATION + */ +#ifdef JEBP_IMPLEMENTATION +#include <string.h> +#if !defined(JEBP_NO_STDIO) || defined(JEBP_LOG_ERRORS) +#include <stdio.h> +#endif +#if !defined(JEBP_ALLOC) && !defined(JEBP_FREE) +#include <stdlib.h> +#define JEBP_ALLOC malloc +#define JEBP_FREE free +#elif !defined(JEBP_ALLOC) || !defined(JEBP_FREE) +#error "Both JEBP_ALLOC and JEBP_FREE have to be defined" +#endif + +/** + * Predefined macro detection + */ +#ifdef __STDC_VERSION__ +#if __STDC_VERSION__ < 199901 +#error "Standard C99 support is required" +#endif +#else // __STDC_VERSION__ +#if defined(__GNUC__) +#warning "C version cannot be checked, compilation may fail" +#elif defined(_MSC_VER) +#pragma message( \ + "MSVC by default is C89 'with extensions', use /std:c11 to ensure there are no errors") +#endif +#endif // __STDC_VERSION__ +#if defined(__clang__) +// The default GNUC version provided by Clang is just short of what we need +#define JEBP__GNU_VERSION 403 +#elif defined(__GNUC__) +#define JEBP__GNU_VERSION ((__GNUC__ * 100) + __GNUC_MINOR__) +#else +#define JEBP__GNU_VERSION 0 +#endif // __GNUC__ + +#ifdef __has_attribute +#define JEBP__HAS_ATTRIBUTE __has_attribute +#else // __has_attribute +// We don't add GCC version checks since, unlike __has_builtin, __has_attribute +// has been out for so long that its more likely that the compiler supports it. +#define JEBP__HAS_ATTRIBUTE(attr) 0 +#endif // __has_attribute +#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L +#define JEBP__NORETURN _Noreturn +#elif JEBP__HAS_ATTRIBUTE(noreturn) +#define JEBP__NORETURN __attribute__((noreturn)) +#elif defined(_MSC_VER) +#define JEBP__NORETURN __declspec(noreturn) +#else +#define JEBP__NORETURN +#endif +#if JEBP__HAS_ATTRIBUTE(always_inline) +#define JEBP__ALWAYS_INLINE __attribute__((always_inline)) +#elif defined(_MSC_VER) +#define JEBP__ALWAYS_INLINE __forceinline +#else +#define JEBP__ALWAYS_INLINE +#endif +#define JEBP__INLINE static inline JEBP__ALWAYS_INLINE + +#ifdef __has_builtin +#define JEBP__HAS_BUILTIN __has_builtin +#else // __has_builtin +#define JEBP__HAS_BUILTIN(builtin) \ + JEBP__VERSION##builtin != 0 && JEBP__GNU_VERSION >= JEBP__VERSION##builtin +// I believe this was added earlier but GCC 4.3 is the first time it was +// mentioned in the changelog and manual. +#define JEBP__VERSION__builtin_bswap32 403 +#endif // __has_builtin +#if JEBP__HAS_BUILTIN(__builtin_bswap32) +#define JEBP__SWAP32(value) __builtin_bswap32(value) +#elif defined(_MSC_VER) +#define JEBP__SWAP32(value) _byteswap_ulong(value) +#endif + +// We don't do any SIMD runtime detection since that causes alot of +// heavily-documented issues that I won't go into here. Instead, if the compiler +// supports it (and requests it) we will use it. It helps that both x86-64 and +// AArch64 always support the SIMD from their 32-bit counterparts. +#if defined(__i386) || defined(__i386__) || defined(_M_IX86) +#define JEBP__ARCH_X86 +#if defined(__SSE2__) || _M_IX86_FP == 2 +#define JEBP__SIMD_SSE2 +#endif +#elif defined(__x86_64) || defined(__x86_64__) || defined(_M_X64) +#define JEBP__ARCH_X86 +#define JEBP__SIMD_SSE2 +#elif defined(__arm) || defined(__arm__) || defined(_M_ARM) +#define JEBP__ARCH_ARM +#if defined(__ARM_NEON) || defined(_MSC_VER) +// According to the following article, MSVC requires Neon support +// https://docs.microsoft.com/en-us/cpp/build/overview-of-arm-abi-conventions +#define JEBP__SIMD_NEON +#endif +#elif defined(__aarch64) || defined(__aarch64__) || defined(_M_ARM64) +#define JEBP__ARCH_ARM +#define JEBP__SIMD_NEON +#define JEBP__SIMD_NEON64 +#endif + +#if defined(JEBP__ARCH_X86) +// x86 is always little-endian +#define JEBP__LITTLE_ENDIAN +#elif defined(JEBP__ARCH_ARM) && defined(__ARM_BIG_ENDIAN) +// The ACLE big-endian define overrules everything else, including the defualt +// endianness detection +#elif defined(JEBP__ARCH_ARM) && (defined(__ARM_ACLE) || defined(_MSC_VER)) +// If ACLE is supported and big-endian is not defined, it must be little-endian +// According to the article linked above, MSVC only supports little-endian +#define JEBP__LITTLE_ENDIAN +#elif defined(__LITTLE_ENDIAN__) || __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ +#define JEBP__LITTLE_ENDIAN +#endif + +#ifdef JEBP_NO_SIMD +#undef JEBP__SIMD_SSE2 +#undef JEBP__SIMD_NEON +#endif // JEBP_NO_SIMD +#ifdef JEBP__SIMD_SSE2 +#include <emmintrin.h> +#endif // JEBP__SIMD_SSE2 +#ifdef JEBP__SIMD_NEON +#include <arm_neon.h> +#endif // JEBP__SIMD_NEON + +/** + * Common utilities + */ +// TODO: Maybe we should have a logging flag and add custom logs with more +// information to each error (and maybe other stuff like allocations) +#define JEBP__MIN(a, b) ((a) < (b) ? (a) : (b)) +#define JEBP__MAX(a, b) ((a) > (b) ? (a) : (b)) +#define JEBP__ABS(a) ((a) < 0 ? -(a) : (a)) +#define JEBP__AVG(a, b) (((a) + (b)) / 2) +#define JEBP__CEIL_SHIFT(a, b) (((a) + (1 << (b)) - 1) >> (b)) +#define JEBP__CLAMP(x, min, max) JEBP__MIN(JEBP__MAX(x, min), max) +#define JEBP__CLAMP_UBYTE(x) JEBP__CLAMP(x, 0, 255) +#define JEBP__CLEAR(ptr, size) memset(ptr, 0, size) + +// A simple utility that updates an error pointer if it currently does not have +// an error +JEBP__INLINE jebp_error_t jebp__error(jebp_error_t *err, jebp_error_t error) { + if (*err == JEBP_OK) { + *err = error; + } + return *err; +} + +// Currently only used by VP8L +// TODO: after VP8(no-L) support is added, make it an error to remove both +// VP8 and VP8L +#ifndef JEBP_NO_VP8L +static jebp_error_t jebp__alloc_image(jebp_image_t *image) { + image->pixels = + JEBP_ALLOC(image->width * image->height * sizeof(jebp_color_t)); + if (image->pixels == NULL) { + return JEBP_ERROR_NOMEM; + } + return JEBP_OK; +} +#endif // JEBP_NO_VP8L + +/** + * Reader abstraction + */ +#define JEBP__BUFFER_SIZE 4096 + +typedef struct jebp__reader_t { + size_t nb_bytes; + const jebp_ubyte *bytes; +#ifndef JEBP_NO_STDIO + FILE *file; + void *buffer; +#endif // JEBP_NO_STDIO +} jebp__reader_t; + +static void jebp__init_memory(jebp__reader_t *reader, size_t size, + const void *data) { + reader->nb_bytes = size; + reader->bytes = data; +#ifndef JEBP_NO_STDIO + reader->file = NULL; +#endif // JEBP_NO_STDIO +} + +#ifndef JEBP_NO_STDIO +static jebp_error_t jebp__open_file(jebp__reader_t *reader, const char *path) { + reader->nb_bytes = 0; + reader->file = fopen(path, "rb"); + if (reader->file == NULL) { + return JEBP_ERROR_IO; + } + reader->buffer = JEBP_ALLOC(JEBP__BUFFER_SIZE); + if (reader->buffer == NULL) { + fclose(reader->file); + return JEBP_ERROR_NOMEM; + } + return JEBP_OK; +} + +static void jebp__close_file(jebp__reader_t *reader) { + JEBP_FREE(reader->buffer); + fclose(reader->file); +} +#endif // JEBP_NO_STDIO + +static jebp_error_t jebp__buffer_bytes(jebp__reader_t *reader) { + if (reader->nb_bytes > 0) { + return JEBP_OK; + } +#ifndef JEBP_NO_STDIO + if (reader->file != NULL) { + reader->nb_bytes = + fread(reader->buffer, 1, JEBP__BUFFER_SIZE, reader->file); + reader->bytes = reader->buffer; + if (ferror(reader->file)) { + return JEBP_ERROR_IO; + } + } +#endif // JEBP_NO_STDIO + if (reader->nb_bytes == 0) { + return JEBP_ERROR_EOF; + } + return JEBP_OK; +} + +// TODO: Most reads are only a few bytes so maybe I should optimize for that +static jebp_error_t jebp__read_bytes(jebp__reader_t *reader, size_t size, + void *data) { + jebp_error_t err; + jebp_ubyte *bytes = data; + while (size > 0) { + if ((err = jebp__buffer_bytes(reader)) != JEBP_OK) { + return err; + } + size_t nb_bytes = JEBP__MIN(size, reader->nb_bytes); + if (bytes != NULL) { + memcpy(bytes, reader->bytes, nb_bytes); + bytes += nb_bytes; + } + size -= nb_bytes; + reader->nb_bytes -= nb_bytes; + reader->bytes += nb_bytes; + } + return JEBP_OK; +} + +// 8-bit uint reading is currently only used by the bit-reader +#ifndef JEBP_NO_VP8L +static jebp_ubyte jebp__read_uint8(jebp__reader_t *reader, jebp_error_t *err) { + if (*err != JEBP_OK) { + return 0; + } + if ((*err = jebp__buffer_bytes(reader)) != JEBP_OK) { + return 0; + } + reader->nb_bytes -= 1; + return *(reader->bytes++); +} +#endif // JEBP_NO_VP8L + +static jebp_uint jebp__read_uint32(jebp__reader_t *reader, jebp_error_t *err) { + if (*err != JEBP_OK) { + return 0; + } +#ifdef JEBP__LITTLE_ENDIAN + jebp_uint value = 0; + *err = jebp__read_bytes(reader, 4, &value); + return value; +#else // JEBP__LITTLE_ENDIAN + jebp_ubyte bytes[4]; + *err = jebp__read_bytes(reader, 4, bytes); + return (jebp_uint)bytes[0] | ((jebp_uint)bytes[1] << 8) | + ((jebp_uint)bytes[2] << 16) | ((jebp_uint)bytes[3] << 24); +#endif // JEBP__LITTLE_ENDIAN +} + +/** + * RIFF container + */ +#define JEBP__RIFF_TAG 0x46464952 +#define JEBP__WEBP_TAG 0x50424557 + +typedef struct jebp__chunk_t { + jebp_uint tag; + jebp_uint size; +} jebp__chunk_t; + +typedef struct jebp__riff_reader_t { + jebp__reader_t *reader; + jebp__chunk_t header; +} jebp__riff_reader_t; + +static jebp_error_t jebp__read_chunk(jebp__riff_reader_t *riff, + jebp__chunk_t *chunk) { + jebp_error_t err = JEBP_OK; + chunk->tag = jebp__read_uint32(riff->reader, &err); + chunk->size = jebp__read_uint32(riff->reader, &err); + chunk->size += chunk->size % 2; // round up to even + return err; +} + +static jebp_error_t jebp__read_riff_header(jebp__riff_reader_t *riff, + jebp__reader_t *reader) { + jebp_error_t err; + riff->reader = reader; + if ((err = jebp__read_chunk(riff, &riff->header)) != JEBP_OK) { + return err; + } + if (riff->header.tag != JEBP__RIFF_TAG) { + return JEBP_ERROR_INVDATA_HEADER; + } + if (jebp__read_uint32(reader, &err) != JEBP__WEBP_TAG) { + return jebp__error(&err, JEBP_ERROR_INVDATA_HEADER); + } + return err; +} + +static jebp_error_t jebp__read_riff_chunk(jebp__riff_reader_t *riff, + jebp__chunk_t *chunk) { + jebp_error_t err; + if ((err = jebp__read_chunk(riff, chunk)) != JEBP_OK) { + return err; + } + if (chunk->size > riff->header.size) { + return JEBP_ERROR_INVDATA; + } + riff->header.size -= chunk->size; + return JEBP_OK; +} + +/** + * Bit reader + */ +#ifndef JEBP_NO_VP8L +typedef struct jebp__bit_reader_t { + jebp__reader_t *reader; + size_t nb_bytes; + jebp_int nb_bits; + jebp_uint bits; +} jebp__bit_reader_t; + +static void jepb__init_bit_reader(jebp__bit_reader_t *bits, + jebp__reader_t *reader, size_t size) { + bits->reader = reader; + bits->nb_bytes = size; + bits->nb_bits = 0; + bits->bits = 0; +} + +// buffer/peek/skip should be used together to optimize bit-reading +static jebp_error_t jebp__buffer_bits(jebp__bit_reader_t *bits, jebp_int size) { + jebp_error_t err = JEBP_OK; + while (bits->nb_bits < size && bits->nb_bytes > 0) { + bits->bits |= jebp__read_uint8(bits->reader, &err) << bits->nb_bits; + bits->nb_bits += 8; + bits->nb_bytes -= 1; + } + return err; +} + +JEBP__INLINE jebp_int jepb__peek_bits(jebp__bit_reader_t *bits, jebp_int size) { + return bits->bits & ((1 << size) - 1); +} + +JEBP__INLINE jebp_error_t jebp__skip_bits(jebp__bit_reader_t *bits, + jebp_int size) { + if (size > bits->nb_bits) { + return JEBP_ERROR_INVDATA; + } + bits->nb_bits -= size; + bits->bits >>= size; + return JEBP_OK; +} + +static jebp_uint jebp__read_bits(jebp__bit_reader_t *bits, jebp_int size, + jebp_error_t *err) { + if (*err != JEBP_OK) { + return 0; + } + if ((*err = jebp__buffer_bits(bits, size)) != JEBP_OK) { + return 0; + } + jebp_uint value = jepb__peek_bits(bits, size); + if ((*err = jebp__skip_bits(bits, size)) != JEBP_OK) { + return 0; + } + return value; +} + +/** + * Huffman coding + */ +#define JEBP__MAX_HUFFMAN_LENGTH 15 +#define JEBP__MAX_PRIMARY_LENGTH 8 +#define JEBP__MAX_SECONDARY_LENGTH \ + (JEBP__MAX_HUFFMAN_LENGTH - JEBP__MAX_PRIMARY_LENGTH) +#define JEBP__NB_PRIMARY_HUFFMANS (1 << JEBP__MAX_PRIMARY_LENGTH) +#define JEBP__NO_HUFFMAN_SYMBOL 0xffff + +#define JEBP__NB_META_SYMBOLS 19 +#define JEBP__NB_COLOR_SYMBOLS 256 +#define JEBP__NB_LENGTH_SYMBOLS 24 +#define JEBP__NB_DIST_SYMBOLS 40 +#define JEBP__NB_MAIN_SYMBOLS (JEBP__NB_COLOR_SYMBOLS + JEBP__NB_LENGTH_SYMBOLS) + +// The huffman decoding is done in one or two steps, both using a lookup table. +// These tables are called the "primary" table and "secondary" tables. First +// 8-bits are peeked from the stream to index the primary table. If the symbol +// is in this table (indicated by length <= 8) then the symbol from that is used +// and the length is used to skip that many bits. Codes which are smaller than +// 8-bits are represented by filling the table such that any index with a prefix +// of the given code will have the same entry. If the symbol requires more bits +// (indiciated by length > 8) then the symbol is used as an offset pointing to +// the secondary table which has an index size of (length - 8) bits. +typedef struct jebp__huffman_t { + // <= 8: length is the number of bits actually used, and symbol is the + // decoded symbol or `JEBP__NO_HUFFMAN_SYMBOL` for an invalid code. + // > 8: length is the maximum number of bits for any code with this prefix, + // and symbol is the offset in the array to the secondary table. + jebp_short length; + jebp_ushort symbol; +} jebp__huffman_t; + +typedef struct jebp__huffman_group_t { + jebp__huffman_t *main; + jebp__huffman_t *red; + jebp__huffman_t *blue; + jebp__huffman_t *alpha; + jebp__huffman_t *dist; +} jebp__huffman_group_t; + +static const jebp_byte jebp__meta_length_order[JEBP__NB_META_SYMBOLS]; + +// Reverse increment, returns truthy on overflow +JEBP__INLINE jebp_int jebp__increment_code(jebp_int *code, jebp_int length) { + jebp_int inc = 1 << (length - 1); + while (*code & inc) { + inc >>= 1; + } + if (inc == 0) { + return 1; + } + *code = (*code & (inc - 1)) + inc; + return 0; +} + +// This function is a bit confusing so I have attempted to document it well +static jebp_error_t jebp__alloc_huffman(jebp__huffman_t **huffmans, + jebp_int nb_lengths, + const jebp_byte *lengths) { + // Stack allocate the primary table and set it all to invalid values + jebp__huffman_t primary[JEBP__NB_PRIMARY_HUFFMANS]; + for (jebp_int i = 0; i < JEBP__NB_PRIMARY_HUFFMANS; i += 1) { + primary[i].symbol = JEBP__NO_HUFFMAN_SYMBOL; + } + + // Fill in the 8-bit codes in the primary table + jebp_int len = 1; + jebp_int code = 0; + jebp_int overflow = 0; + jebp_ushort symbol = JEBP__NO_HUFFMAN_SYMBOL; + jebp_int nb_symbols = 0; + for (; len <= JEBP__MAX_PRIMARY_LENGTH; len += 1) { + for (jebp_int i = 0; i < nb_lengths; i += 1) { + if (lengths[i] != len) { + continue; + } + if (overflow) { + // Fail now if the last increment overflowed + return JEBP_ERROR_INVDATA; + } + for (jebp_int c = code; c < JEBP__NB_PRIMARY_HUFFMANS; + c += 1 << len) { + primary[c].length = len; + primary[c].symbol = i; + } + overflow = jebp__increment_code(&code, len); + symbol = i; + nb_symbols += 1; + } + } + + // Fill in the secondary table lengths in the primary table + jebp_int secondary_code = code; + for (; len <= JEBP__MAX_HUFFMAN_LENGTH; len += 1) { + for (jebp_int i = 0; i < nb_lengths; i += 1) { + if (lengths[i] != len) { + continue; + } + if (overflow) { + return JEBP_ERROR_INVDATA; + } + jebp_int prefix = code & (JEBP__NB_PRIMARY_HUFFMANS - 1); + primary[prefix].length = len; + overflow = jebp__increment_code(&code, len); + symbol = i; + nb_symbols += 1; + } + } + + // Calculate the total no. of huffman entries and fill in the secondary + // table offsets + jebp_int nb_huffmans = JEBP__NB_PRIMARY_HUFFMANS; + for (jebp_int i = 0; i < JEBP__NB_PRIMARY_HUFFMANS; i += 1) { + if (nb_symbols <= 1) { + // Special case: if there is only one symbol, use this iteration to + // instead fill the primary table with 0-length + // entries + primary[i].length = 0; + primary[i].symbol = symbol; + continue; + } + jebp_int suffix_length = primary[i].length - JEBP__MAX_PRIMARY_LENGTH; + if (suffix_length > 0) { + primary[i].symbol = nb_huffmans; + nb_huffmans += 1 << suffix_length; + } + } + + // Allocate, copy over the primary table, and assign the rest to invalid + // values + *huffmans = JEBP_ALLOC(nb_huffmans * sizeof(jebp__huffman_t)); + if (*huffmans == NULL) { + return JEBP_ERROR_NOMEM; + } + memcpy(*huffmans, primary, sizeof(primary)); + if (nb_huffmans == JEBP__NB_PRIMARY_HUFFMANS) { + // Special case: we can stop here if we don't have to fill any secondary + // tables + return JEBP_OK; + } + for (jebp_int i = JEBP__NB_PRIMARY_HUFFMANS; i < nb_huffmans; i += 1) { + (*huffmans)[i].symbol = JEBP__NO_HUFFMAN_SYMBOL; + } + + // Fill in the secondary tables + len = JEBP__MAX_PRIMARY_LENGTH + 1; + code = secondary_code; + for (; len <= JEBP__MAX_HUFFMAN_LENGTH; len += 1) { + for (jebp_int i = 0; i < nb_lengths; i += 1) { + if (lengths[i] != len) { + continue; + } + jebp_int prefix = code & (JEBP__NB_PRIMARY_HUFFMANS - 1); + jebp_int nb_secondary_huffmans = 1 << primary[prefix].length; + jebp__huffman_t *secondary = *huffmans + primary[prefix].symbol; + for (jebp_int c = code; c < nb_secondary_huffmans; c += 1 << len) { + secondary[c >> JEBP__MAX_PRIMARY_LENGTH].length = len; + secondary[c >> JEBP__MAX_PRIMARY_LENGTH].symbol = i; + } + jebp__increment_code(&code, len); + } + } + return JEBP_OK; +} + +static jebp_int jebp__read_symbol(jebp__huffman_t *huffmans, + jebp__bit_reader_t *bits, jebp_error_t *err) { + if (*err != JEBP_OK) { + return 0; + } + if ((*err = jebp__buffer_bits(bits, JEBP__MAX_HUFFMAN_LENGTH)) != JEBP_OK) { + return 0; + } + jebp_int code = jepb__peek_bits(bits, JEBP__MAX_PRIMARY_LENGTH); + if (huffmans[code].symbol == JEBP__NO_HUFFMAN_SYMBOL) { + *err = JEBP_ERROR_INVDATA; + return 0; + } + jebp_int length = huffmans[code].length; + jebp_int skip = JEBP__MIN(length, JEBP__MAX_PRIMARY_LENGTH); + if ((*err = jebp__skip_bits(bits, skip)) != JEBP_OK) { + return 0; + } + if (skip == length) { + return huffmans[code].symbol; + } + + huffmans += huffmans[code].symbol; + code = jepb__peek_bits(bits, length - skip); + if (huffmans[code].symbol == JEBP__NO_HUFFMAN_SYMBOL) { + *err = JEBP_ERROR_INVDATA; + return 0; + } + if ((*err = jebp__skip_bits(bits, huffmans[code].length - skip)) != + JEBP_OK) { + return 0; + } + return huffmans[code].symbol; +} + +static jebp_error_t jebp__read_huffman(jebp__huffman_t **huffmans, + jebp__bit_reader_t *bits, + jebp_int nb_lengths, + jebp_byte *lengths) { + // This part of the spec is INCREDIBLY wrong and partly missing + jebp_error_t err = JEBP_OK; + JEBP__CLEAR(lengths, nb_lengths); + + if (jebp__read_bits(bits, 1, &err)) { + // simple length storage with only 1 (first) or 2 (second) symbols, both + // with a length of 1 + jebp_int has_second = jebp__read_bits(bits, 1, &err); + jebp_int first_bits = jebp__read_bits(bits, 1, &err) ? 8 : 1; + jebp_int first = jebp__read_bits(bits, first_bits, &err); + if (first >= nb_lengths) { + return jebp__error(&err, JEBP_ERROR_INVDATA); + } + lengths[first] = 1; + if (has_second) { + jebp_int second = jebp__read_bits(bits, 8, &err); + if (second >= nb_lengths) { + return jebp__error(&err, JEBP_ERROR_INVDATA); + } + lengths[second] = 1; + } + + } else { + jebp_byte meta_lengths[JEBP__NB_META_SYMBOLS] = {0}; + jebp_int nb_meta_lengths = jebp__read_bits(bits, 4, &err) + 4; + for (jebp_int i = 0; i < nb_meta_lengths; i += 1) { + meta_lengths[jebp__meta_length_order[i]] = + jebp__read_bits(bits, 3, &err); + } + if (err != JEBP_OK) { + return err; + } + jebp__huffman_t *meta_huffmans; + if ((err = jebp__alloc_huffman(&meta_huffmans, JEBP__NB_META_SYMBOLS, + meta_lengths)) != JEBP_OK) { + return err; + } + + jebp_int nb_meta_symbols = nb_lengths; + if (jebp__read_bits(bits, 1, &err)) { + // limit codes + jebp_int symbols_bits = jebp__read_bits(bits, 3, &err) * 2 + 2; + nb_meta_symbols = jebp__read_bits(bits, symbols_bits, &err) + 2; + } + + jebp_int prev_length = 8; + for (jebp_int i = 0; i < nb_lengths && nb_meta_symbols > 0; + nb_meta_symbols -= 1) { + jebp_int symbol = jebp__read_symbol(meta_huffmans, bits, &err); + jebp_int length; + jebp_int repeat; + switch (symbol) { + case 16: + length = prev_length; + repeat = jebp__read_bits(bits, 2, &err) + 3; + break; + case 17: + length = 0; + repeat = jebp__read_bits(bits, 3, &err) + 3; + break; + case 18: + length = 0; + repeat = jebp__read_bits(bits, 7, &err) + 11; + break; + default: + prev_length = symbol; + /* fallthrough */ + case 0: + // We don't ever repeat 0 values. + lengths[i++] = symbol; + continue; + } + if (i + repeat > nb_lengths) { + jebp__error(&err, JEBP_ERROR_INVDATA); + break; + } + for (jebp_int j = 0; j < repeat; j += 1) { + lengths[i++] = length; + } + } + JEBP_FREE(meta_huffmans); + } + + if (err != JEBP_OK) { + return err; + } + return jebp__alloc_huffman(huffmans, nb_lengths, lengths); +} + +static jebp_error_t jebp__read_huffman_group(jebp__huffman_group_t *group, + jebp__bit_reader_t *bits, + jebp_int nb_main_symbols, + jebp_byte *lengths) { + jebp_error_t err; + if ((err = jebp__read_huffman(&group->main, bits, nb_main_symbols, + lengths)) != JEBP_OK) { + return err; + } + if ((err = jebp__read_huffman(&group->red, bits, JEBP__NB_COLOR_SYMBOLS, + lengths)) != JEBP_OK) { + return err; + } + if ((err = jebp__read_huffman(&group->blue, bits, JEBP__NB_COLOR_SYMBOLS, + lengths)) != JEBP_OK) { + return err; + } + if ((err = jebp__read_huffman(&group->alpha, bits, JEBP__NB_COLOR_SYMBOLS, + lengths)) != JEBP_OK) { + return err; + } + if ((err = jebp__read_huffman(&group->dist, bits, JEBP__NB_DIST_SYMBOLS, + lengths)) != JEBP_OK) { + return err; + } + return JEBP_OK; +} + +static void jebp__free_huffman_group(jebp__huffman_group_t *group) { + JEBP_FREE(group->main); + JEBP_FREE(group->red); + JEBP_FREE(group->blue); + JEBP_FREE(group->alpha); + JEBP_FREE(group->dist); +} + +/** + * Color cache + */ +typedef struct jebp__colcache_t { + jebp_int bits; + jebp_color_t *colors; +} jebp__colcache_t; + +static jebp_error_t jebp__read_colcache(jebp__colcache_t *colcache, + jebp__bit_reader_t *bits) { + jebp_error_t err = JEBP_OK; + if (!jebp__read_bits(bits, 1, &err)) { + // no color cache + colcache->bits = 0; + return err; + } + colcache->bits = jebp__read_bits(bits, 4, &err); + if (err != JEBP_OK || colcache->bits < 1 || colcache->bits > 11) { + return jebp__error(&err, JEBP_ERROR_INVDATA); + } + + size_t colcache_size = ((size_t)1 << colcache->bits) * sizeof(jebp_color_t); + colcache->colors = JEBP_ALLOC(colcache_size); + if (colcache->colors == NULL) { + return JEBP_ERROR_NOMEM; + } + JEBP__CLEAR(colcache->colors, colcache_size); + return JEBP_OK; +} + +static void jebp__free_colcache(jebp__colcache_t *colcache) { + if (colcache->bits > 0) { + JEBP_FREE(colcache->colors); + } +} + +static void jebp__colcache_insert(jebp__colcache_t *colcache, + jebp_color_t *color) { + if (colcache->bits == 0) { + return; + } +#if defined(JEBP__LITTLE_ENDIAN) && defined(JEBP__SWAP32) + jebp_uint hash = *(jebp_uint *)color; // ABGR due to little-endian + hash = JEBP__SWAP32(hash); // RGBA + hash = (hash >> 8) | (hash << 24); // ARGB +#else + jebp_uint hash = ((jebp_uint)color->a << 24) | ((jebp_uint)color->r << 16) | + ((jebp_uint)color->g << 8) | (jebp_uint)color->b; +#endif + hash = (0x1e35a7bd * hash) >> (32 - colcache->bits); + colcache->colors[hash] = *color; +} + +/** + * VP8L image + */ +#define JEBP__NB_VP8L_OFFSETS 120 + +typedef struct jebp__subimage_t { + jebp_int width; + jebp_int height; + jebp_color_t *pixels; + jebp_int block_bits; +} jebp__subimage_t; + +static const jebp_byte jebp__vp8l_offsets[JEBP__NB_VP8L_OFFSETS][2]; + +JEBP__INLINE jebp_int jebp__read_vp8l_extrabits(jebp__bit_reader_t *bits, + jebp_int symbol, + jebp_error_t *err) { + if (*err != JEBP_OK) { + return 1; + } + if (symbol < 4) { + return symbol + 1; + } + jebp_int extrabits = symbol / 2 - 1; + symbol = ((symbol % 2 + 2) << extrabits) + 1; + return symbol + jebp__read_bits(bits, extrabits, err); +} + +static jebp_error_t jebp__read_vp8l_image(jebp_image_t *image, + jebp__bit_reader_t *bits, + jebp__colcache_t *colcache, + jebp__subimage_t *huffman_image) { + jebp_error_t err; + jebp_int nb_groups = 1; + jebp__huffman_group_t *groups = &(jebp__huffman_group_t){0}; + if (huffman_image != NULL) { + for (jebp_int i = 0; i < huffman_image->width * huffman_image->height; + i += 1) { + jebp_color_t *huffman = &huffman_image->pixels[i]; + if (huffman->r != 0) { + // Currently only 256 huffman groups are supported + return JEBP_ERROR_NOSUP; + } + nb_groups = JEBP__MAX(nb_groups, huffman->g + 1); + huffman += 1; + } + if (nb_groups > 1) { + groups = JEBP_ALLOC(nb_groups * sizeof(jebp__huffman_group_t)); + if (groups == NULL) { + return JEBP_ERROR_NOMEM; + } + } + } + + jebp_int nb_main_symbols = JEBP__NB_MAIN_SYMBOLS; + if (colcache->bits > 0) { + nb_main_symbols += 1 << colcache->bits; + } + jebp_byte *lengths = JEBP_ALLOC(nb_main_symbols); + if (lengths == NULL) { + err = JEBP_ERROR_NOMEM; + goto free_groups; + } + jebp_int nb_read_groups = 0; + for (; nb_read_groups < nb_groups; nb_read_groups += 1) { + if ((err = jebp__read_huffman_group(&groups[nb_read_groups], bits, + nb_main_symbols, lengths)) != + JEBP_OK) { + break; + } + } + JEBP_FREE(lengths); + if (err != JEBP_OK) { + goto free_read_groups; + } + if ((err = jebp__alloc_image(image)) != JEBP_OK) { + goto free_read_groups; + } + + jebp_color_t *pixel = image->pixels; + jebp_color_t *end = pixel + image->width * image->height; + jebp_int x = 0; + for (jebp_int y = 0; y < image->height;) { + jebp_color_t *huffman_row = NULL; + if (huffman_image != NULL) { + huffman_row = + &huffman_image->pixels[(y >> huffman_image->block_bits) * + huffman_image->width]; + } + do { + jebp__huffman_group_t *group; + if (huffman_image == NULL) { + group = groups; + } else { + jebp_color_t *huffman = + &huffman_row[x >> huffman_image->block_bits]; + group = &groups[huffman->g]; + } + + jebp_int main = jebp__read_symbol(group->main, bits, &err); + if (main < JEBP__NB_COLOR_SYMBOLS) { + pixel->g = main; + pixel->r = jebp__read_symbol(group->red, bits, &err); + pixel->b = jebp__read_symbol(group->blue, bits, &err); + pixel->a = jebp__read_symbol(group->alpha, bits, &err); + jebp__colcache_insert(colcache, pixel++); + x += 1; + } else if (main >= JEBP__NB_MAIN_SYMBOLS) { + *(pixel++) = colcache->colors[main - JEBP__NB_MAIN_SYMBOLS]; + x += 1; + } else { + jebp_int length = jebp__read_vp8l_extrabits( + bits, main - JEBP__NB_COLOR_SYMBOLS, &err); + jebp_int dist = jebp__read_symbol(group->dist, bits, &err); + dist = jebp__read_vp8l_extrabits(bits, dist, &err); + if (dist > JEBP__NB_VP8L_OFFSETS) { + dist -= JEBP__NB_VP8L_OFFSETS; + } else { + const jebp_byte *offset = jebp__vp8l_offsets[dist - 1]; + dist = offset[1] * image->width + offset[0]; + dist = JEBP__MAX(dist, 1); + } + jebp_color_t *repeat = pixel - dist; + if (repeat < image->pixels || pixel + length > end) { + jebp__error(&err, JEBP_ERROR_INVDATA); + break; + } + for (jebp_int i = 0; i < length; i += 1) { + jebp__colcache_insert(colcache, repeat); + *(pixel++) = *(repeat++); + } + x += length; + } + } while (x < image->width); + y += x / image->width; + x %= image->width; + } + + if (err != JEBP_OK) { + jebp_free_image(image); + } +free_read_groups: + for (nb_read_groups -= 1; nb_read_groups >= 0; nb_read_groups -= 1) { + jebp__free_huffman_group(&groups[nb_read_groups]); + } +free_groups: + if (nb_groups > 1) { + JEBP_FREE(groups); + } + return err; +} + +static jebp_error_t jebp__read_subimage(jebp__subimage_t *subimage, + jebp__bit_reader_t *bits, + jebp_image_t *image) { + jebp_error_t err = JEBP_OK; + subimage->block_bits = jebp__read_bits(bits, 3, &err) + 2; + subimage->width = JEBP__CEIL_SHIFT(image->width, subimage->block_bits); + subimage->height = JEBP__CEIL_SHIFT(image->height, subimage->block_bits); + if (err != JEBP_OK) { + return err; + } + jebp__colcache_t colcache; + if ((err = jebp__read_colcache(&colcache, bits)) != JEBP_OK) { + return err; + } + err = + jebp__read_vp8l_image((jebp_image_t *)subimage, bits, &colcache, NULL); + jebp__free_colcache(&colcache); + return err; +} + +/** + * VP8L predictions + */ +#define JEBP__NB_VP8L_PRED_TYPES 14 + +// I don't like the way it formats this +// clang-format off +#define JEBP__UNROLL4(var, body) \ + { var = 0; body } \ + { var = 1; body } \ + { var = 2; body } \ + { var = 3; body } +// clang-format on + +typedef void (*jebp__vp8l_pred_t)(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width); + +#ifdef JEBP__SIMD_SSE2 +typedef struct jebp__m128x4i { + __m128i v[4]; +} jebp__m128x4i; + +JEBP__INLINE __m128i jebp__sse_move_px1(__m128i v_dst, __m128i v_src) { + __m128 v_dstf = _mm_castsi128_ps(v_dst); + __m128 v_srcf = _mm_castsi128_ps(v_src); + __m128 v_movf = _mm_move_ss(v_dstf, v_srcf); + return _mm_castps_si128(v_movf); +} + +JEBP__INLINE __m128i jebp__sse_avg_u8x16(__m128i v1, __m128i v2) { + __m128i v_one = _mm_set1_epi8(1); + __m128i v_avg = _mm_avg_epu8(v1, v2); + // SSE2 `avg` rounds up, we have to check if a round-up occured (one of the + // low bits was set but the other wasn't) and subtract 1 if so + __m128i v_err = _mm_xor_si128(v1, v2); + v_err = _mm_and_si128(v_err, v_one); + return _mm_sub_epi8(v_avg, v_err); +} + +JEBP__INLINE __m128i jebp__sse_avg2_u8x16(__m128i v1, __m128i v2, __m128i v3) { + __m128i v_one = _mm_set1_epi8(1); + // We can further optimise two avg calls but noting that the error will + // propogate + __m128i v_avg1 = _mm_avg_epu8(v1, v2); + __m128i v_err1 = _mm_xor_si128(v1, v2); + __m128i v_avg2 = _mm_avg_epu8(v_avg1, v3); + __m128i v_err2 = _mm_xor_si128(v_avg1, v3); + v_err2 = _mm_or_si128(v_err1, v_err2); + v_err2 = _mm_and_si128(v_err2, v_one); + return _mm_sub_epi8(v_avg2, v_err2); +} + +JEBP__INLINE __m128i jebp__sse_flatten_px4(jebp__m128x4i v_pixel4) { + __m128i v_pixello = jebp__sse_move_px1(v_pixel4.v[1], v_pixel4.v[0]); + __m128i v_pixel3 = _mm_bsrli_si128(v_pixel4.v[3], 4); + __m128i v_pixelhi = _mm_unpackhi_epi32(v_pixel4.v[2], v_pixel3); + return _mm_unpacklo_epi64(v_pixello, v_pixelhi); +} + +// Bit-select and accumulate, used by prediction filters 11-13 +JEBP__INLINE __m128i jebp__sse_bsela_u8x16(__m128i v_acc, __m128i v_mask, + __m128i v1, __m128i v0) { + // This is faster than using and/andnot/or since SSE only supports two + // operands so prefers chaining outputs + __m128i v_sel = _mm_xor_si128(v0, v1); + v_sel = _mm_and_si128(v_sel, v_mask); + v_sel = _mm_xor_si128(v_sel, v0); + return _mm_add_epi8(v_acc, v_sel); +} +#endif // JEBP__SIMD_SSE2 + +#ifdef JEBP__SIMD_NEON +JEBP__INLINE uint8x16_t jebp__neon_load_px1(jebp_color_t *pixel) { + uint8x16_t v_pixel = vreinterpretq_u8_u32(vld1q_dup_u32((uint32_t *)pixel)); +#ifndef JEBP__LITTLE_ENDIAN + v_pixel = vrev32q_u8(v_pixel); +#endif // JEBP__LITTLE_ENDIAN + return v_pixel; +} + +JEBP__INLINE uint8x16_t jebp__neon_flatten_px4(uint8x16x4_t v_pixel4) { +#ifdef JEBP__SIMD_NEON64 + uint8x16_t v_table = vcombine_u8(vcreate_u8(0x1716151403020100), + vcreate_u8(0x3f3e3d3c2b2a2928)); + return vqtbl4q_u8(v_pixel4, v_table); +#else // JEBP__SIMD_NEON64 + uint8x16_t v_mask1 = + vcombine_u8(vcreate_u8((uint32_t)-1), vcreate_u8((uint32_t)-1)); + uint8x16_t v_mask2 = vcombine_u8(vcreate_u8((uint64_t)-1), vcreate_u8(0)); + uint8x16_t v_pixello = vbslq_u8(v_mask1, v_pixel4.val[0], v_pixel4.val[1]); + uint8x16_t v_pixelhi = vbslq_u8(v_mask1, v_pixel4.val[2], v_pixel4.val[3]); + return vbslq_u8(v_mask2, v_pixello, v_pixelhi); +#endif // JEBP__SIMD_NEON64 +} + +JEBP__INLINE uint32x4_t jebp__neon_sad_px4(uint8x16_t v_pix1, + uint8x16_t v_pix2) { + uint8x16_t v_diff8 = vabdq_u8(v_pix1, v_pix2); + uint16x8_t v_diff16 = vpaddlq_u8(v_diff8); + return vpaddlq_u16(v_diff16); +} +#endif // JEBP__SIMD_NEON + +JEBP__INLINE void jebp__vp8l_pred_black(jebp_color_t *pixel, jebp_int width) { + jebp_int x = 0; +#if defined(JEBP__SIMD_SSE2) + __m128i v_black = _mm_set1_epi32((int)0xff000000); + for (; x + 4 <= width; x += 4) { + __m128i v_pixel = _mm_loadu_si128((__m128i *)&pixel[x]); + v_pixel = _mm_add_epi8(v_pixel, v_black); + _mm_storeu_si128((__m128i *)&pixel[x], v_pixel); + } +#elif defined(JEBP__SIMD_NEON) + uint8x8_t v_black = vdup_n_u8(0xff); + for (; x + 8 <= width; x += 8) { + uint8x8x4_t v_pixel = vld4_u8((uint8_t *)&pixel[x]); + v_pixel.val[3] = vadd_u8(v_pixel.val[3], v_black); + vst4_u8((uint8_t *)&pixel[x], v_pixel); + } +#endif + for (; x < width; x += 1) { + pixel[x].a += 0xff; + } +} + +static void jebp__vp8l_pred0(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + (void)top; + jebp__vp8l_pred_black(pixel, width); +} + +JEBP__INLINE void jebp__vp8l_pred_left(jebp_color_t *pixel, jebp_int width) { + jebp_int x = 0; +#if defined(JEBP__SIMD_SSE2) + __m128i v_left; + if (width >= 4) { + v_left = _mm_cvtsi32_si128(*(int *)&pixel[-1]); + } + for (; x + 4 <= width; x += 4) { + __m128i v_pixel = _mm_loadu_si128((__m128i *)&pixel[x]); + v_pixel = _mm_add_epi8(v_pixel, v_left); + v_left = _mm_bslli_si128(v_pixel, 4); + v_pixel = _mm_add_epi8(v_pixel, v_left); + v_left = _mm_bslli_si128(v_pixel, 8); + v_pixel = _mm_add_epi8(v_pixel, v_left); + _mm_storeu_si128((__m128i *)&pixel[x], v_pixel); + v_left = _mm_bsrli_si128(v_pixel, 12); + } +#elif defined(JEBP__SIMD_NEON) + uint8x16_t v_zero = vdupq_n_u8(0); + uint8x16_t v_left; + if (width >= 4) { + v_left = jebp__neon_load_px1(&pixel[-1]); + v_left = vextq_u8(v_left, v_zero, 12); + } + for (; x + 4 <= width; x += 4) { + uint8x16_t v_pixel = vld1q_u8((uint8_t *)&pixel[x]); + v_pixel = vaddq_u8(v_pixel, v_left); + v_left = vextq_u8(v_zero, v_pixel, 12); + v_pixel = vaddq_u8(v_pixel, v_left); + v_left = vextq_u8(v_zero, v_pixel, 8); + v_pixel = vaddq_u8(v_pixel, v_left); + vst1q_u8((uint8_t *)&pixel[x], v_pixel); + v_left = vextq_u8(v_pixel, v_zero, 12); + } +#endif + for (; x < width; x += 1) { + pixel[x].r += pixel[x - 1].r; + pixel[x].g += pixel[x - 1].g; + pixel[x].b += pixel[x - 1].b; + pixel[x].a += pixel[x - 1].a; + } +} + +static void jebp__vp8l_pred1(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + (void)top; + jebp__vp8l_pred_left(pixel, width); +} + +JEBP__INLINE void jebp__vp8l_pred_top(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + jebp_int x = 0; +#if defined(JEBP__SIMD_SSE2) + for (; x + 4 <= width; x += 4) { + __m128i v_pixel = _mm_loadu_si128((__m128i *)&pixel[x]); + __m128i v_top = _mm_loadu_si128((__m128i *)&top[x]); + v_pixel = _mm_add_epi8(v_pixel, v_top); + _mm_storeu_si128((__m128i *)&pixel[x], v_pixel); + } +#elif defined(JEBP__SIMD_NEON) + for (; x + 4 <= width; x += 4) { + uint8x16_t v_pixel = vld1q_u8((uint8_t *)&pixel[x]); + uint8x16_t v_top = vld1q_u8((uint8_t *)&top[x]); + v_pixel = vaddq_u8(v_pixel, v_top); + vst1q_u8((uint8_t *)&pixel[x], v_pixel); + } +#endif + for (; x < width; x += 1) { + pixel[x].r += top[x].r; + pixel[x].g += top[x].g; + pixel[x].b += top[x].b; + pixel[x].a += top[x].a; + } +} + +static void jebp__vp8l_pred2(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + jebp__vp8l_pred_top(pixel, top, width); +} + +static void jebp__vp8l_pred3(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + jebp__vp8l_pred_top(pixel, &top[1], width); +} + +static void jebp__vp8l_pred4(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + jebp__vp8l_pred_top(pixel, &top[-1], width); +} + +static void jebp__vp8l_pred5(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + jebp_int x = 0; +#if defined(JEBP__SIMD_SSE2) + __m128i v_left; + __m128i v_top; + if (width >= 4) { + v_left = _mm_cvtsi32_si128(*(int *)&pixel[-1]); + v_top = _mm_loadu_si128((__m128i *)top); + } + for (; x + 4 <= width; x += 4) { + __m128i v_pixel = _mm_loadu_si128((__m128i *)&pixel[x]); + __m128i v_next = _mm_loadu_si128((__m128i *)&top[x + 4]); + __m128i v_tr = jebp__sse_move_px1(v_top, v_next); + v_tr = _mm_shuffle_epi32(v_tr, _MM_SHUFFLE(0, 3, 2, 1)); + jebp__m128x4i v_pixel4; + JEBP__UNROLL4(jebp_int i, { + __m128i v_avg = jebp__sse_avg2_u8x16(v_left, v_tr, v_top); + v_pixel4.v[i] = _mm_add_epi8(v_pixel, v_avg); + v_left = _mm_shuffle_epi32(v_pixel4.v[i], _MM_SHUFFLE(2, 1, 0, 3)); + }) + v_pixel = jebp__sse_flatten_px4(v_pixel4); + _mm_storeu_si128((__m128i *)&pixel[x], v_pixel); + v_top = v_next; + } +#elif defined(JEBP__SIMD_NEON) + uint8x16_t v_left; + uint8x16_t v_top; + if (width >= 4) { + v_left = jebp__neon_load_px1(&pixel[-1]); + v_top = vld1q_u8((uint8_t *)top); + } + for (; x + 4 <= width; x += 4) { + uint8x16_t v_pixel = vld1q_u8((uint8_t *)&pixel[x]); + uint8x16_t v_next = vld1q_u8((uint8_t *)&top[x + 4]); + uint8x16_t v_tr = vextq_u8(v_top, v_next, 4); + uint8x16x4_t v_pixel4; + JEBP__UNROLL4(jebp_int i, { + uint8x16_t v_avg = vhaddq_u8(v_left, v_tr); + v_avg = vhaddq_u8(v_avg, v_top); + v_pixel4.val[i] = vaddq_u8(v_pixel, v_avg); + v_left = vextq_u8(v_pixel4.val[i], v_pixel4.val[i], 12); + }) + v_pixel = jebp__neon_flatten_px4(v_pixel4); + vst1q_u8((uint8_t *)&pixel[x], v_pixel); + v_top = v_next; + } +#endif + for (; x < width; x += 1) { + pixel[x].r += + JEBP__AVG(JEBP__AVG(pixel[x - 1].r, top[x + 1].r), top[x].r); + pixel[x].g += + JEBP__AVG(JEBP__AVG(pixel[x - 1].g, top[x + 1].g), top[x].g); + pixel[x].b += + JEBP__AVG(JEBP__AVG(pixel[x - 1].b, top[x + 1].b), top[x].b); + pixel[x].a += + JEBP__AVG(JEBP__AVG(pixel[x - 1].a, top[x + 1].a), top[x].a); + } +} + +JEBP__INLINE void jebp__vp8l_pred_avgtl(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + jebp_int x = 0; +#if defined(JEBP__SIMD_SSE2) + __m128i v_left; + if (width >= 4) { + v_left = _mm_cvtsi32_si128(*(int *)&pixel[-1]); + } + for (; x + 4 <= width; x += 4) { + __m128i v_pixel = _mm_loadu_si128((__m128i *)&pixel[x]); + __m128i v_top = _mm_loadu_si128((__m128i *)&top[x]); + jebp__m128x4i v_pixel4; + JEBP__UNROLL4(jebp_int i, { + __m128i v_avg = jebp__sse_avg_u8x16(v_left, v_top); + v_pixel4.v[i] = _mm_add_epi8(v_pixel, v_avg); + v_left = _mm_shuffle_epi32(v_pixel4.v[i], _MM_SHUFFLE(2, 1, 0, 3)); + }) + v_pixel = jebp__sse_flatten_px4(v_pixel4); + _mm_storeu_si128((__m128i *)&pixel[x], v_pixel); + } +#elif defined(JEBP__SIMD_NEON) + uint8x16_t v_left; + if (width >= 4) { + v_left = jebp__neon_load_px1(&pixel[-1]); + } + for (; x + 4 <= width; x += 4) { + uint8x16_t v_pixel = vld1q_u8((uint8_t *)&pixel[x]); + uint8x16_t v_top = vld1q_u8((uint8_t *)&top[x]); + uint8x16x4_t v_pixel4; + JEBP__UNROLL4(jebp_int i, { + uint8x16_t v_avg = vhaddq_u8(v_left, v_top); + v_pixel4.val[i] = vaddq_u8(v_pixel, v_avg); + v_left = vextq_u8(v_pixel4.val[i], v_pixel4.val[i], 12); + }) + v_pixel = jebp__neon_flatten_px4(v_pixel4); + vst1q_u8((uint8_t *)&pixel[x], v_pixel); + } +#endif + for (; x < width; x += 1) { + pixel[x].r += JEBP__AVG(pixel[x - 1].r, top[x].r); + pixel[x].g += JEBP__AVG(pixel[x - 1].g, top[x].g); + pixel[x].b += JEBP__AVG(pixel[x - 1].b, top[x].b); + pixel[x].a += JEBP__AVG(pixel[x - 1].a, top[x].a); + } +} + +static void jebp__vp8l_pred6(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + jebp__vp8l_pred_avgtl(pixel, &top[-1], width); +} + +static void jebp__vp8l_pred7(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + jebp__vp8l_pred_avgtl(pixel, top, width); +} + +JEBP__INLINE void jebp__vp8l_pred_avgtr(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + jebp_int x = 0; +#if defined(JEBP__SIMD_SSE2) + __m128i v_top; + if (width >= 4) { + v_top = _mm_loadu_si128((__m128i *)top); + } + for (; x + 4 <= width; x += 4) { + __m128i v_pixel = _mm_loadu_si128((__m128i *)&pixel[x]); + __m128i v_next = _mm_loadu_si128((__m128i *)&top[x + 4]); + __m128i v_tr = jebp__sse_move_px1(v_top, v_next); + v_tr = _mm_shuffle_epi32(v_tr, _MM_SHUFFLE(0, 3, 2, 1)); + v_tr = jebp__sse_avg_u8x16(v_top, v_tr); + v_pixel = _mm_add_epi8(v_pixel, v_tr); + _mm_storeu_si128((__m128i *)&pixel[x], v_pixel); + v_top = v_next; + } +#elif defined(JEBP__SIMD_NEON) + uint8x16_t v_top; + if (width >= 4) { + v_top = vld1q_u8((uint8_t *)top); + } + for (; x + 4 <= width; x += 4) { + uint8x16_t v_pixel = vld1q_u8((uint8_t *)&pixel[x]); + uint8x16_t v_next = vld1q_u8((uint8_t *)&top[x + 4]); + uint8x16_t v_tr = vextq_u8(v_top, v_next, 4); + v_tr = vhaddq_u8(v_top, v_tr); + v_pixel = vaddq_u8(v_pixel, v_tr); + vst1q_u8((uint8_t *)&pixel[x], v_pixel); + v_top = v_next; + } +#endif + for (; x < width; x += 1) { + pixel[x].r += JEBP__AVG(top[x].r, top[x + 1].r); + pixel[x].g += JEBP__AVG(top[x].g, top[x + 1].g); + pixel[x].b += JEBP__AVG(top[x].b, top[x + 1].b); + pixel[x].a += JEBP__AVG(top[x].a, top[x + 1].a); + } +} + +static void jebp__vp8l_pred8(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + jebp__vp8l_pred_avgtr(pixel, &top[-1], width); +} + +static void jebp__vp8l_pred9(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + jebp__vp8l_pred_avgtr(pixel, top, width); +} + +static void jebp__vp8l_pred10(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + jebp_int x = 0; +#if defined(JEBP__SIMD_SSE2) + __m128i v_left; + __m128i v_tl; + __m128i v_top; + if (width >= 4) { + v_left = _mm_cvtsi32_si128(*(int *)&pixel[-1]); + v_tl = _mm_cvtsi32_si128(*(int *)&top[-1]); + v_top = _mm_loadu_si128((__m128i *)top); + } + for (; x + 4 <= width; x += 4) { + __m128i v_pixel = _mm_loadu_si128((__m128i *)&pixel[x]); + __m128i v_next = _mm_loadu_si128((__m128i *)&top[x + 4]); + __m128i v_rot = _mm_shuffle_epi32(v_top, _MM_SHUFFLE(2, 1, 0, 3)); + v_tl = jebp__sse_move_px1(v_rot, v_tl); + __m128i v_tr = jebp__sse_move_px1(v_top, v_next); + v_tr = _mm_shuffle_epi32(v_tr, _MM_SHUFFLE(0, 3, 2, 1)); + v_tr = jebp__sse_avg_u8x16(v_top, v_tr); + jebp__m128x4i v_pixel4; + JEBP__UNROLL4(jebp_int i, { + __m128i v_avg = jebp__sse_avg2_u8x16(v_left, v_tl, v_tr); + v_pixel4.v[i] = _mm_add_epi8(v_pixel, v_avg); + v_left = _mm_shuffle_epi32(v_pixel4.v[i], _MM_SHUFFLE(2, 1, 0, 3)); + }) + v_pixel = jebp__sse_flatten_px4(v_pixel4); + _mm_storeu_si128((__m128i *)&pixel[x], v_pixel); + v_tl = v_rot; + v_top = v_next; + } +#elif defined(JEBP__SIMD_NEON) + uint8x16_t v_left; + uint8x16_t v_tl; + uint8x16_t v_top; + if (width >= 4) { + v_left = jebp__neon_load_px1(&pixel[-1]); + v_tl = jebp__neon_load_px1(&top[-1]); + v_top = vld1q_u8((uint8_t *)top); + } + for (; x + 4 <= width; x += 4) { + uint8x16_t v_pixel = vld1q_u8((uint8_t *)&pixel[x]); + uint8x16_t v_next = vld1q_u8((uint8_t *)&top[x + 4]); + v_tl = vextq_u8(v_tl, v_top, 12); + uint8x16_t v_tr = vextq_u8(v_top, v_next, 4); + v_tr = vhaddq_u8(v_top, v_tr); + uint8x16x4_t v_pixel4; + JEBP__UNROLL4(jebp_int i, { + uint8x16_t v_avg = vhaddq_u8(v_left, v_tl); + v_avg = vhaddq_u8(v_avg, v_tr); + v_pixel4.val[i] = vaddq_u8(v_pixel, v_avg); + v_left = vextq_u8(v_pixel4.val[i], v_pixel4.val[i], 12); + }) + v_pixel = jebp__neon_flatten_px4(v_pixel4); + vst1q_u8((uint8_t *)&pixel[x], v_pixel); + v_tl = v_top; + v_top = v_next; + } +#endif + for (; x < width; x += 1) { + pixel[x].r += JEBP__AVG(JEBP__AVG(pixel[x - 1].r, top[x - 1].r), + JEBP__AVG(top[x].r, top[x + 1].r)); + pixel[x].g += JEBP__AVG(JEBP__AVG(pixel[x - 1].g, top[x - 1].g), + JEBP__AVG(top[x].g, top[x + 1].g)); + pixel[x].b += JEBP__AVG(JEBP__AVG(pixel[x - 1].b, top[x - 1].b), + JEBP__AVG(top[x].b, top[x + 1].b)); + pixel[x].a += JEBP__AVG(JEBP__AVG(pixel[x - 1].a, top[x - 1].a), + JEBP__AVG(top[x].a, top[x + 1].a)); + } +} + +JEBP__INLINE jebp_int jebp__vp8l_pred_dist(jebp_color_t *pix1, + jebp_color_t *pix2) { + return JEBP__ABS(pix1->r - pix2->r) + JEBP__ABS(pix1->g - pix2->g) + + JEBP__ABS(pix1->b - pix2->b) + JEBP__ABS(pix1->a - pix2->a); +} + +static void jebp__vp8l_pred11(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + jebp_int x = 0; +#if defined(JEBP__SIMD_SSE2) + __m128i v_left; + __m128i v_tl; + if (width >= 4) { + v_left = _mm_cvtsi32_si128(*(int *)&pixel[-1]); + v_tl = _mm_cvtsi32_si128(*(int *)&top[-1]); + } + for (; x + 4 <= width; x += 4) { + __m128i v_ldist, v_tdist, v_cmp, v_pixello, v_pixelhi; + __m128i v_pixel = _mm_loadu_si128((__m128i *)&pixel[x]); + __m128i v_top = _mm_loadu_si128((__m128i *)&top[x]); + __m128i v_rot = _mm_shuffle_epi32(v_top, _MM_SHUFFLE(2, 1, 0, 3)); + v_tl = jebp__sse_move_px1(v_rot, v_tl); + // Pixel 0 + // This does double the SAD result but if both distances are doubled the + // comparison should still be the same + __m128i v_tllo = _mm_unpacklo_epi32(v_tl, v_tl); + __m128i v_toplo = _mm_unpacklo_epi32(v_top, v_top); + v_ldist = _mm_sad_epu8(v_tllo, v_toplo); + v_tdist = _mm_unpacklo_epi32(v_left, v_left); + v_tdist = _mm_sad_epu8(v_tllo, v_tdist); + v_cmp = _mm_cmplt_epi32(v_ldist, v_tdist); + v_pixello = jebp__sse_bsela_u8x16(v_pixel, v_cmp, v_left, v_top); + v_left = _mm_bslli_si128(v_pixello, 4); + // Pixel 1 + v_tdist = _mm_unpacklo_epi32(v_left, v_left); + v_tdist = _mm_sad_epu8(v_tllo, v_tdist); + v_cmp = _mm_cmplt_epi32(v_ldist, v_tdist); + v_cmp = _mm_bsrli_si128(v_cmp, 4); + v_pixello = jebp__sse_bsela_u8x16(v_pixel, v_cmp, v_left, v_top); + v_pixello = _mm_unpacklo_epi32(v_left, v_pixello); + v_left = _mm_bsrli_si128(v_pixello, 4); + // Pixel 2 + __m128i v_tlhi = _mm_shuffle_epi32(v_tl, _MM_SHUFFLE(2, 2, 3, 3)); + __m128i v_tophi = _mm_shuffle_epi32(v_top, _MM_SHUFFLE(2, 2, 3, 3)); + v_ldist = _mm_sad_epu8(v_tlhi, v_tophi); + v_tdist = _mm_shuffle_epi32(v_left, _MM_SHUFFLE(2, 2, 3, 3)); + v_tdist = _mm_sad_epu8(v_tlhi, v_tdist); + v_cmp = _mm_cmplt_epi32(v_ldist, v_tdist); + v_pixelhi = jebp__sse_bsela_u8x16(v_pixel, v_cmp, v_left, v_top); + v_left = _mm_bslli_si128(v_pixelhi, 4); + // Pixel 3 + v_tdist = _mm_shuffle_epi32(v_left, _MM_SHUFFLE(2, 2, 3, 3)); + v_tdist = _mm_sad_epu8(v_tlhi, v_tdist); + v_cmp = _mm_cmplt_epi32(v_ldist, v_tdist); + v_cmp = _mm_bslli_si128(v_cmp, 12); + v_pixelhi = jebp__sse_bsela_u8x16(v_pixel, v_cmp, v_left, v_top); + v_pixelhi = _mm_unpackhi_epi32(v_left, v_pixelhi); + v_left = _mm_bsrli_si128(v_pixelhi, 12); + v_pixel = _mm_unpackhi_epi64(v_pixello, v_pixelhi); + _mm_storeu_si128((__m128i *)&pixel[x], v_pixel); + v_tl = v_rot; + } +#elif defined(JEBP__SIMD_NEON) + uint8x16_t v_left; + uint8x16_t v_tl; + if (width >= 4) { + v_left = jebp__neon_load_px1(&pixel[-1]); + v_tl = jebp__neon_load_px1(&top[-1]); + } + for (; x + 4 <= width; x += 4) { + uint8x16_t v_pixel = vld1q_u8((uint8_t *)&pixel[x]); + uint8x16_t v_top = vld1q_u8((uint8_t *)&top[x]); + v_tl = vextq_u8(v_tl, v_top, 12); + uint32x4_t v_ldist = jebp__neon_sad_px4(v_tl, v_top); + uint8x16x4_t v_pixel4; + JEBP__UNROLL4(jebp_int i, { + uint32x4_t v_tdist = jebp__neon_sad_px4(v_tl, v_left); + uint32x4_t v_cmp = vcltq_u32(v_ldist, v_tdist); + uint8x16_t v_pred = vbslq_u8((uint8x16_t)v_cmp, v_left, v_top); + v_pixel4.val[i] = vaddq_u8(v_pixel, v_pred); + v_left = vextq_u8(v_pixel4.val[i], v_pixel4.val[i], 12); + }) + v_pixel = jebp__neon_flatten_px4(v_pixel4); + vst1q_u8((uint8_t *)&pixel[x], v_pixel); + v_tl = v_top; + } +#endif + for (; x < width; x += 1) { + jebp_int ldist = jebp__vp8l_pred_dist(&top[x - 1], &top[x]); + jebp_int tdist = jebp__vp8l_pred_dist(&top[x - 1], &pixel[x - 1]); + if (ldist < tdist) { + jebp__vp8l_pred_left(&pixel[x], 1); + } else { + jebp__vp8l_pred_top(&pixel[x], &top[x], 1); + } + } +} + +static void jebp__vp8l_pred12(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + jebp_int x = 0; +#if defined(JEBP__SIMD_SSE2) + __m128i v_left; + __m128i v_tl; + if (width >= 4) { + v_left = _mm_cvtsi32_si128(*(int *)&pixel[-1]); + v_tl = _mm_cvtsi32_si128(*(int *)&top[-1]); + } + for (; x + 4 <= width; x += 4) { + __m128i v_pixel = _mm_loadu_si128((__m128i *)&pixel[x]); + __m128i v_top = _mm_loadu_si128((__m128i *)&top[x]); + __m128i v_rot = _mm_shuffle_epi32(v_top, _MM_SHUFFLE(2, 1, 0, 3)); + v_tl = jebp__sse_move_px1(v_rot, v_tl); + __m128i v_max = _mm_max_epu8(v_top, v_tl); + __m128i v_min = _mm_min_epu8(v_top, v_tl); + __m128i v_diff = _mm_sub_epi8(v_max, v_min); + __m128i v_pos = _mm_cmpeq_epi8(v_max, v_top); + jebp__m128x4i v_pixel4; + JEBP__UNROLL4(jebp_int i, { + __m128i v_add = _mm_adds_epu8(v_left, v_diff); + __m128i v_sub = _mm_subs_epu8(v_left, v_diff); + v_pixel4.v[i] = jebp__sse_bsela_u8x16(v_pixel, v_pos, v_add, v_sub); + v_left = _mm_shuffle_epi32(v_pixel4.v[i], _MM_SHUFFLE(2, 1, 0, 3)); + }) + v_pixel = jebp__sse_flatten_px4(v_pixel4); + _mm_storeu_si128((__m128i *)&pixel[x], v_pixel); + v_tl = v_rot; + } +#elif defined(JEBP__SIMD_NEON) + uint8x16_t v_left; + uint8x16_t v_tl; + if (width >= 4) { + v_left = jebp__neon_load_px1(&pixel[-1]); + v_tl = jebp__neon_load_px1(&top[-1]); + } + for (; x + 4 <= width; x += 4) { + uint8x16_t v_pixel = vld1q_u8((uint8_t *)&pixel[x]); + uint8x16_t v_top = vld1q_u8((uint8_t *)&top[x]); + v_tl = vextq_u8(v_tl, v_top, 12); + uint8x16_t v_diff = vabdq_u8(v_top, v_tl); + uint8x16_t v_neg = vcltq_u8(v_top, v_tl); + uint8x16x4_t v_pixel4; + JEBP__UNROLL4(jebp_int i, { + uint8x16_t v_add = vqaddq_u8(v_left, v_diff); + uint8x16_t v_sub = vqsubq_u8(v_left, v_diff); + uint8x16_t v_pred = vbslq_u8(v_neg, v_sub, v_add); + v_pixel4.val[i] = vaddq_u8(v_pixel, v_pred); + v_left = vextq_u8(v_pixel4.val[i], v_pixel4.val[i], 12); + }) + v_pixel = jebp__neon_flatten_px4(v_pixel4); + vst1q_u8((uint8_t *)&pixel[x], v_pixel); + v_tl = v_top; + } +#endif + for (; x < width; x += 1) { + pixel[x].r += + JEBP__CLAMP_UBYTE(pixel[x - 1].r + top[x].r - top[x - 1].r); + pixel[x].g += + JEBP__CLAMP_UBYTE(pixel[x - 1].g + top[x].g - top[x - 1].g); + pixel[x].b += + JEBP__CLAMP_UBYTE(pixel[x - 1].b + top[x].b - top[x - 1].b); + pixel[x].a += + JEBP__CLAMP_UBYTE(pixel[x - 1].a + top[x].a - top[x - 1].a); + } +} + +static void jebp__vp8l_pred13(jebp_color_t *pixel, jebp_color_t *top, + jebp_int width) { + jebp_int x = 0; +#if defined(JEBP__SIMD_SSE2) + __m128i v_mask = _mm_set1_epi8(0x7f); + __m128i v_left; + __m128i v_tl; + if (width >= 4) { + v_left = _mm_cvtsi32_si128(*(int *)&pixel[-1]); + v_tl = _mm_cvtsi32_si128(*(int *)&top[-1]); + } + for (; x + 4 <= width; x += 4) { + __m128i v_pixel = _mm_loadu_si128((__m128i *)&pixel[x]); + __m128i v_top = _mm_loadu_si128((__m128i *)&top[x]); + __m128i v_rot = _mm_shuffle_epi32(v_top, _MM_SHUFFLE(2, 1, 0, 3)); + v_tl = jebp__sse_move_px1(v_rot, v_tl); + jebp__m128x4i v_pixel4; + JEBP__UNROLL4(jebp_int i, { + __m128i v_avg = jebp__sse_avg_u8x16(v_left, v_top); + __m128i v_max = _mm_max_epu8(v_avg, v_tl); + __m128i v_min = _mm_min_epu8(v_avg, v_tl); + __m128i v_diff = _mm_sub_epi8(v_max, v_min); + v_diff = _mm_srli_epi16(v_diff, 1); + v_diff = _mm_and_si128(v_diff, v_mask); + __m128i v_pos = _mm_cmpeq_epi8(v_max, v_avg); + __m128i v_add = _mm_adds_epu8(v_avg, v_diff); + __m128i v_sub = _mm_subs_epu8(v_avg, v_diff); + v_pixel4.v[i] = jebp__sse_bsela_u8x16(v_pixel, v_pos, v_add, v_sub); + v_left = _mm_shuffle_epi32(v_pixel4.v[i], _MM_SHUFFLE(2, 1, 0, 3)); + }) + v_pixel = jebp__sse_flatten_px4(v_pixel4); + _mm_storeu_si128((__m128i *)&pixel[x], v_pixel); + v_tl = v_rot; + } +#elif defined(JEBP__SIMD_NEON) + uint8x16_t v_left; + uint8x16_t v_tl; + if (width >= 4) { + v_left = jebp__neon_load_px1(&pixel[-1]); + v_tl = jebp__neon_load_px1(&top[-1]); + } + for (; x + 4 <= width; x += 4) { + uint8x16_t v_pixel = vld1q_u8((uint8_t *)&pixel[x]); + uint8x16_t v_top = vld1q_u8((uint8_t *)&top[x]); + v_tl = vextq_u8(v_tl, v_top, 12); + uint8x16x4_t v_pixel4; + JEBP__UNROLL4(jebp_int i, { + uint8x16_t v_avg = vhaddq_u8(v_left, v_top); + uint8x16_t v_diff = vabdq_u8(v_avg, v_tl); + v_diff = vshrq_n_u8(v_diff, 1); + uint8x16_t v_neg = vcltq_u8(v_avg, v_tl); + uint8x16_t v_add = vqaddq_u8(v_avg, v_diff); + uint8x16_t v_sub = vqsubq_u8(v_avg, v_diff); + uint8x16_t v_pred = vbslq_u8(v_neg, v_sub, v_add); + v_pixel4.val[i] = vaddq_u8(v_pixel, v_pred); + v_left = vextq_u8(v_pixel4.val[i], v_pixel4.val[i], 12); + }) + v_pixel = jebp__neon_flatten_px4(v_pixel4); + vst1q_u8((uint8_t *)&pixel[x], v_pixel); + v_tl = v_top; + } +#endif + for (; x < width; x += 1) { + jebp_color_t avg = {JEBP__AVG(pixel[x - 1].r, top[x].r), + JEBP__AVG(pixel[x - 1].g, top[x].g), + JEBP__AVG(pixel[x - 1].b, top[x].b), + JEBP__AVG(pixel[x - 1].a, top[x].a)}; + pixel[x].r += JEBP__CLAMP_UBYTE(avg.r + (avg.r - top[x - 1].r) / 2); + pixel[x].g += JEBP__CLAMP_UBYTE(avg.g + (avg.g - top[x - 1].g) / 2); + pixel[x].b += JEBP__CLAMP_UBYTE(avg.b + (avg.b - top[x - 1].b) / 2); + pixel[x].a += JEBP__CLAMP_UBYTE(avg.a + (avg.a - top[x - 1].a) / 2); + } +} + +static const jebp__vp8l_pred_t jebp__vp8l_preds[JEBP__NB_VP8L_PRED_TYPES] = { + jebp__vp8l_pred0, jebp__vp8l_pred1, jebp__vp8l_pred2, jebp__vp8l_pred3, + jebp__vp8l_pred4, jebp__vp8l_pred5, jebp__vp8l_pred6, jebp__vp8l_pred7, + jebp__vp8l_pred8, jebp__vp8l_pred9, jebp__vp8l_pred10, jebp__vp8l_pred11, + jebp__vp8l_pred12, jebp__vp8l_pred13}; + +/** + * VP8L transforms + */ +typedef enum jebp__transform_type_t { + JEBP__TRANSFORM_PREDICT, + JEBP__TRANSFORM_COLOR, + JEBP__TRANSFORM_GREEN, + JEBP__TRANSFORM_PALETTE, + JEBP__NB_TRANSFORMS +} jebp__transform_type_t; + +typedef struct jebp__transform_t { + jebp__transform_type_t type; + jebp__subimage_t image; +} jebp__transform_t; + +static jebp_error_t jebp__read_transform(jebp__transform_t *transform, + jebp__bit_reader_t *bits, + jebp_image_t *image) { + jebp_error_t err = JEBP_OK; + transform->type = jebp__read_bits(bits, 2, &err); + if (err != JEBP_OK) { + return err; + } + if (transform->type == JEBP__TRANSFORM_PALETTE) { + // TODO: support palette images + return JEBP_ERROR_NOSUP_PALETTE; + } else if (transform->type != JEBP__TRANSFORM_GREEN) { + err = jebp__read_subimage(&transform->image, bits, image); + } + return err; +} + +static void jebp__free_transform(jebp__transform_t *transform) { + if (transform->type != JEBP__TRANSFORM_GREEN) { + jebp_free_image((jebp_image_t *)&transform->image); + } +} + +JEBP__INLINE jebp_error_t jebp__apply_predict_row(jebp_color_t *pixel, + jebp_color_t *top, + jebp_int width, + jebp_color_t *predict_pixel) { + if (predict_pixel->g >= JEBP__NB_VP8L_PRED_TYPES) { + return JEBP_ERROR_INVDATA; + } + jebp__vp8l_preds[predict_pixel->g](pixel, top, width); + return JEBP_OK; +} + +JEBP__INLINE jebp_error_t jebp__apply_predict_transform( + jebp_image_t *image, jebp__subimage_t *predict_image) { + jebp_error_t err; + jebp_color_t *pixel = image->pixels; + jebp_color_t *top = pixel; + jebp_int predict_width = predict_image->width - 1; + jebp_int block_size = 1 << predict_image->block_bits; + jebp_int end_size = + image->width - (predict_width << predict_image->block_bits); + if (predict_width == 0) { + // Special case: if there is only one block the first block which is + // shortened by one pixel (due to the left prediction) + // needs to be `end_size` and the proper end block then + // needs to be skipped. + block_size = end_size; + end_size = 0; + } + // Use opaque-black prediction for the top-left pixel + jebp__vp8l_pred_black(pixel, 1); + // Use left prediction for the top row + jebp__vp8l_pred_left(pixel + 1, image->width - 1); + pixel += image->width; + for (jebp_int y = 1; y < image->height; y += 1) { + jebp_color_t *predict_row = + &predict_image->pixels[(y >> predict_image->block_bits) * + predict_image->width]; + // Use top prediction for the left column + jebp__vp8l_pred_top(pixel, top, 1); + // Finish the rest of the first block + if ((err = jebp__apply_predict_row(pixel + 1, top + 1, block_size - 1, + predict_row)) != JEBP_OK) { + return err; + } + pixel += block_size; + top += block_size; + for (jebp_int x = 1; x < predict_width; x += 1) { + if ((err = jebp__apply_predict_row(pixel, top, block_size, + &predict_row[x])) != JEBP_OK) { + return err; + } + pixel += block_size; + top += block_size; + } + jebp__apply_predict_row(pixel, top, end_size, + &predict_row[predict_width]); + pixel += end_size; + top += end_size; + } + return JEBP_OK; +} + +JEBP__INLINE void jebp__apply_color_row(jebp_color_t *pixel, jebp_int width, + jebp_color_t *color_pixel) { + jebp_int x = 0; +#if defined(JEBP__SIMD_SSE2) + jebp_ushort color_r = ((jebp_short)(color_pixel->r << 8) >> 5); + jebp_ushort color_g = ((jebp_short)(color_pixel->g << 8) >> 5); + jebp_ushort color_b = ((jebp_short)(color_pixel->b << 8) >> 5); + __m128i v_color_bg = _mm_set1_epi32(color_b | ((jebp_uint)color_g << 16)); + __m128i v_color_r = _mm_set1_epi32(color_r); + __m128i v_masklo = _mm_set1_epi16((short)0x00ff); + __m128i v_maskhi = _mm_set1_epi16((short)0xff00); + for (; x + 4 <= width; x += 4) { + __m128i v_pixel = _mm_loadu_si128((__m128i *)&pixel[x]); + __m128i v_green = _mm_and_si128(v_pixel, v_maskhi); + v_green = _mm_shufflelo_epi16(v_green, _MM_SHUFFLE(2, 2, 0, 0)); + v_green = _mm_shufflehi_epi16(v_green, _MM_SHUFFLE(2, 2, 0, 0)); + __m128i v_bg = _mm_mulhi_epi16(v_green, v_color_bg); + v_bg = _mm_and_si128(v_bg, v_masklo); + v_pixel = _mm_add_epi8(v_pixel, v_bg); + __m128i v_red = _mm_slli_epi16(v_pixel, 8); + v_red = _mm_mulhi_epi16(v_red, v_color_r); + v_red = _mm_and_si128(v_red, v_masklo); + v_red = _mm_slli_epi32(v_red, 16); + v_pixel = _mm_add_epi8(v_pixel, v_red); + _mm_storeu_si128((__m128i *)&pixel[x], v_pixel); + } +#elif defined(JEBP__SIMD_NEON) + int8x8x3_t v_color_pixel = vld3_dup_s8((jebp_byte *)color_pixel); + for (; x + 8 <= width; x += 8) { + int16x8_t v_mul; + int8x8_t v_shr; + int8x8x4_t v_pixel = vld4_s8((jebp_byte *)&pixel[x]); + v_mul = vmull_s8(v_pixel.val[1], v_color_pixel.val[2]); + v_shr = vshrn_n_s16(v_mul, 5); + v_pixel.val[0] = vadd_s8(v_pixel.val[0], v_shr); + v_mul = vmull_s8(v_pixel.val[1], v_color_pixel.val[1]); + v_shr = vshrn_n_s16(v_mul, 5); + v_pixel.val[2] = vadd_s8(v_pixel.val[2], v_shr); + v_mul = vmull_s8(v_pixel.val[0], v_color_pixel.val[0]); + v_shr = vshrn_n_s16(v_mul, 5); + v_pixel.val[2] = vadd_s8(v_pixel.val[2], v_shr); + vst4_s8((jebp_byte *)&pixel[x], v_pixel); + } +#endif + for (; x < width; x += 1) { + pixel[x].r += ((jebp_byte)pixel[x].g * (jebp_byte)color_pixel->b) >> 5; + pixel[x].b += ((jebp_byte)pixel[x].g * (jebp_byte)color_pixel->g) >> 5; + pixel[x].b += ((jebp_byte)pixel[x].r * (jebp_byte)color_pixel->r) >> 5; + } +} + +JEBP__INLINE jebp_error_t jebp__apply_color_transform( + jebp_image_t *image, jebp__subimage_t *color_image) { + jebp_color_t *pixel = image->pixels; + jebp_int color_width = color_image->width - 1; + jebp_int block_size = 1 << color_image->block_bits; + jebp_int end_size = image->width - (color_width << color_image->block_bits); + for (jebp_int y = 0; y < image->height; y += 1) { + jebp_color_t *color_row = + &color_image + ->pixels[(y >> color_image->block_bits) * color_image->width]; + for (jebp_int x = 0; x < color_width; x += 1) { + jebp__apply_color_row(pixel, block_size, &color_row[x]); + pixel += block_size; + } + jebp__apply_color_row(pixel, end_size, &color_row[color_width]); + pixel += end_size; + } + return JEBP_OK; +} + +JEBP__INLINE jebp_error_t jebp__apply_green_transform(jebp_image_t *image) { + jebp_int size = image->width * image->height; + jebp_int i = 0; +#if defined(JEBP__SIMD_SSE2) + for (; i + 4 <= size; i += 4) { + __m128i *pixel = (__m128i *)&image->pixels[i]; + __m128i v_pixel = _mm_loadu_si128(pixel); + __m128i v_green = _mm_srli_epi16(v_pixel, 8); + v_green = _mm_shufflelo_epi16(v_green, _MM_SHUFFLE(2, 2, 0, 0)); + v_green = _mm_shufflehi_epi16(v_green, _MM_SHUFFLE(2, 2, 0, 0)); + v_pixel = _mm_add_epi8(v_pixel, v_green); + _mm_storeu_si128(pixel, v_pixel); + } +#elif defined(JEBP__SIMD_NEON) + for (; i + 16 <= size; i += 16) { + jebp_ubyte *pixel = (jebp_ubyte *)&image->pixels[i]; + uint8x16x4_t v_pixel = vld4q_u8(pixel); + v_pixel.val[0] = vaddq_u8(v_pixel.val[0], v_pixel.val[1]); + v_pixel.val[2] = vaddq_u8(v_pixel.val[2], v_pixel.val[1]); + vst4q_u8(pixel, v_pixel); + } +#endif + for (; i < size; i += 1) { + jebp_color_t *pixel = &image->pixels[i]; + pixel->r += pixel->g; + pixel->b += pixel->g; + } + return JEBP_OK; +} + +static jebp_error_t jebp__apply_transform(jebp__transform_t *transform, + jebp_image_t *image) { + switch (transform->type) { + case JEBP__TRANSFORM_PREDICT: + return jebp__apply_predict_transform(image, &transform->image); + case JEBP__TRANSFORM_COLOR: + return jebp__apply_color_transform(image, &transform->image); + case JEBP__TRANSFORM_GREEN: + return jebp__apply_green_transform(image); + default: + return JEBP_ERROR_NOSUP; + } +} + +/** + * VP8L lossless codec + */ +#define JEBP__VP8L_TAG 0x4c385056 +#define JEBP__VP8L_MAGIC 0x2f + +static jebp_error_t jebp__read_vp8l_header(jebp_image_t *image, + jebp__reader_t *reader, + jebp__bit_reader_t *bits, + jebp__chunk_t *chunk) { + jebp_error_t err = JEBP_OK; + if (chunk->size < 5) { + return JEBP_ERROR_INVDATA_HEADER; + } + if (jebp__read_uint8(reader, &err) != JEBP__VP8L_MAGIC) { + return jebp__error(&err, JEBP_ERROR_INVDATA_HEADER); + } + jepb__init_bit_reader(bits, reader, chunk->size - 1); + image->width = jebp__read_bits(bits, 14, &err) + 1; + image->height = jebp__read_bits(bits, 14, &err) + 1; + jebp__read_bits(bits, 1, &err); // alpha does not impact decoding + if (jebp__read_bits(bits, 3, &err) != 0) { + // version must be 0 + return jebp__error(&err, JEBP_ERROR_NOSUP); + } + return err; +} + +static jebp_error_t jebp__read_vp8l_size(jebp_image_t *image, + jebp__reader_t *reader, + jebp__chunk_t *chunk) { + jebp__bit_reader_t bits; + return jebp__read_vp8l_header(image, reader, &bits, chunk); +} + +static jebp_error_t jebp__read_vp8l_nohead(jebp_image_t *image, + jebp__bit_reader_t *bits) { + jebp_error_t err = JEBP_OK; + jebp__transform_t transforms[4]; + jebp_int nb_transforms = 0; + for (; nb_transforms <= JEBP__NB_TRANSFORMS; nb_transforms += 1) { + if (!jebp__read_bits(bits, 1, &err)) { + // no more transforms to read + break; + } + if (err != JEBP_OK || nb_transforms == JEBP__NB_TRANSFORMS) { + // too many transforms + jebp__error(&err, JEBP_ERROR_INVDATA); + goto free_transforms; + } + if ((err = jebp__read_transform(&transforms[nb_transforms], bits, + image)) != JEBP_OK) { + goto free_transforms; + } + } + if (err != JEBP_OK) { + goto free_transforms; + } + + jebp__colcache_t colcache; + if ((err = jebp__read_colcache(&colcache, bits)) != JEBP_OK) { + goto free_transforms; + } + jebp__subimage_t *huffman_image = &(jebp__subimage_t){0}; + if (!jebp__read_bits(bits, 1, &err)) { + // there is no huffman image + huffman_image = NULL; + } + if (err != JEBP_OK) { + jebp__free_colcache(&colcache); + goto free_transforms; + } + if (huffman_image != NULL) { + if ((err = jebp__read_subimage(huffman_image, bits, image)) != + JEBP_OK) { + jebp__free_colcache(&colcache); + goto free_transforms; + } + } + err = jebp__read_vp8l_image(image, bits, &colcache, huffman_image); + jebp__free_colcache(&colcache); + jebp_free_image((jebp_image_t *)huffman_image); + +free_transforms: + for (nb_transforms -= 1; nb_transforms >= 0; nb_transforms -= 1) { + if (err == JEBP_OK) { + err = jebp__apply_transform(&transforms[nb_transforms], image); + } + jebp__free_transform(&transforms[nb_transforms]); + } + return err; +} + +static jebp_error_t jebp__read_vp8l(jebp_image_t *image, jebp__reader_t *reader, + jebp__chunk_t *chunk) { + jebp_error_t err; + jebp__bit_reader_t bits; + if ((err = jebp__read_vp8l_header(image, reader, &bits, chunk)) != + JEBP_OK) { + return err; + } + if ((err = jebp__read_vp8l_nohead(image, &bits)) != JEBP_OK) { + return err; + } + return JEBP_OK; +} +#endif // JEBP_NO_VP8L + +/** + * Public API + */ +static const char *const jebp__error_strings[JEBP_NB_ERRORS]; + +const char *jebp_error_string(jebp_error_t err) { + if (err < 0 || err >= JEBP_NB_ERRORS) { + err = JEBP_ERROR_UNKNOWN; + } + return jebp__error_strings[err]; +} + +void jebp_free_image(jebp_image_t *image) { + if (image != NULL) { + JEBP_FREE(image->pixels); + JEBP__CLEAR(image, sizeof(jebp_image_t)); + } +} + +static jebp_error_t jebp__read_size(jebp_image_t *image, + jebp__reader_t *reader) { + jebp_error_t err; + jebp__riff_reader_t riff; + JEBP__CLEAR(image, sizeof(jebp_image_t)); + if ((err = jebp__read_riff_header(&riff, reader)) != JEBP_OK) { + return err; + } + jebp__chunk_t chunk; + if ((err = jebp__read_riff_chunk(&riff, &chunk)) != JEBP_OK) { + return err; + } + + switch (chunk.tag) { +#ifndef JEBP_NO_VP8L + case JEBP__VP8L_TAG: + return jebp__read_vp8l_size(image, reader, &chunk); +#endif // JEBP_NO_VP8L + default: + return JEBP_ERROR_NOSUP_CODEC; + } +} + +jebp_error_t jebp_decode_size(jebp_image_t *image, size_t size, + const void *data) { + if (image == NULL || data == NULL) { + return JEBP_ERROR_INVAL; + } + jebp__reader_t reader; + jebp__init_memory(&reader, size, data); + return jebp__read_size(image, &reader); +} + +static jebp_error_t jebp__read(jebp_image_t *image, jebp__reader_t *reader) { + jebp_error_t err; + jebp__riff_reader_t riff; + JEBP__CLEAR(image, sizeof(jebp_image_t)); + if ((err = jebp__read_riff_header(&riff, reader)) != JEBP_OK) { + return err; + } + jebp__chunk_t chunk; + if ((err = jebp__read_riff_chunk(&riff, &chunk)) != JEBP_OK) { + return err; + } + + switch (chunk.tag) { +#ifndef JEBP_NO_VP8L + case JEBP__VP8L_TAG: + return jebp__read_vp8l(image, reader, &chunk); +#endif // JEBP_NO_VP8L + default: + return JEBP_ERROR_NOSUP_CODEC; + } +} + +jebp_error_t jebp_decode(jebp_image_t *image, size_t size, const void *data) { + if (image == NULL || data == NULL) { + return JEBP_ERROR_INVAL; + } + jebp__reader_t reader; + jebp__init_memory(&reader, size, data); + return jebp__read(image, &reader); +} + +#ifndef JEBP_NO_STDIO +jebp_error_t jebp_read_size(jebp_image_t *image, const char *path) { + jebp_error_t err; + if (image == NULL || path == NULL) { + return JEBP_ERROR_INVAL; + } + jebp__reader_t reader; + if ((err = jebp__open_file(&reader, path)) != JEBP_OK) { + return err; + } + err = jebp__read_size(image, &reader); + jebp__close_file(&reader); + return err; +} + +jebp_error_t jebp_read(jebp_image_t *image, const char *path) { + jebp_error_t err; + if (image == NULL || path == NULL) { + return JEBP_ERROR_INVAL; + } + jebp__reader_t reader; + if ((err = jebp__open_file(&reader, path)) != JEBP_OK) { + return err; + } + err = jebp__read(image, &reader); + jebp__close_file(&reader); + return err; +} +#endif // JEBP_NO_STDIO + +/** + * Lookup tables + */ +// These are moved to the end of the file since some of them are very large and +// putting them in the middle of the code would disrupt the flow of reading. +// Especially since in most situations the values in these tables are +// unimportant to the developer. +#ifndef JEBP_NO_VP8L +// The order that meta lengths are read +static const jebp_byte jebp__meta_length_order[JEBP__NB_META_SYMBOLS] = { + 17, 18, 0, 1, 2, 3, 4, 5, 16, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}; + +// {X, Y} offsets from the pixel when decoding short distance codes +static const jebp_byte jebp__vp8l_offsets[JEBP__NB_VP8L_OFFSETS][2] = { + {0, 1}, {1, 0}, {1, 1}, {-1, 1}, {0, 2}, {2, 0}, {1, 2}, {-1, 2}, + {2, 1}, {-2, 1}, {2, 2}, {-2, 2}, {0, 3}, {3, 0}, {1, 3}, {-1, 3}, + {3, 1}, {-3, 1}, {2, 3}, {-2, 3}, {3, 2}, {-3, 2}, {0, 4}, {4, 0}, + {1, 4}, {-1, 4}, {4, 1}, {-4, 1}, {3, 3}, {-3, 3}, {2, 4}, {-2, 4}, + {4, 2}, {-4, 2}, {0, 5}, {3, 4}, {-3, 4}, {4, 3}, {-4, 3}, {5, 0}, + {1, 5}, {-1, 5}, {5, 1}, {-5, 1}, {2, 5}, {-2, 5}, {5, 2}, {-5, 2}, + {4, 4}, {-4, 4}, {3, 5}, {-3, 5}, {5, 3}, {-5, 3}, {0, 6}, {6, 0}, + {1, 6}, {-1, 6}, {6, 1}, {-6, 1}, {2, 6}, {-2, 6}, {6, 2}, {-6, 2}, + {4, 5}, {-4, 5}, {5, 4}, {-5, 4}, {3, 6}, {-3, 6}, {6, 3}, {-6, 3}, + {0, 7}, {7, 0}, {1, 7}, {-1, 7}, {5, 5}, {-5, 5}, {7, 1}, {-7, 1}, + {4, 6}, {-4, 6}, {6, 4}, {-6, 4}, {2, 7}, {-2, 7}, {7, 2}, {-7, 2}, + {3, 7}, {-3, 7}, {7, 3}, {-7, 3}, {5, 6}, {-5, 6}, {6, 5}, {-6, 5}, + {8, 0}, {4, 7}, {-4, 7}, {7, 4}, {-7, 4}, {8, 1}, {8, 2}, {6, 6}, + {-6, 6}, {8, 3}, {5, 7}, {-5, 7}, {7, 5}, {-7, 5}, {8, 4}, {6, 7}, + {-6, 7}, {7, 6}, {-7, 6}, {8, 5}, {7, 7}, {-7, 7}, {8, 6}, {8, 7}}; +#endif // JEBP_NO_VP8L + +// Error strings to return from jebp_error_string +static const char *const jebp__error_strings[JEBP_NB_ERRORS] = { + "Ok", + "Invalid value or argument", + "Invalid data or corrupted file", + "Invalid WebP header or corrupted file", + "End of file", + "Feature not supported", + "Codec not supported", + "Color-indexing or palettes are not supported", + "Not enough memory", + "I/O error", + "Unknown error"}; +#endif // JEBP_IMPLEMENTATION |