+++ /dev/null
-/*
-
-QOI - The "Quite OK Image" format for fast, lossless image compression
-
-Dominic Szablewski - https://phoboslab.org
-
-
--- LICENSE: The MIT License(MIT)
-
-Copyright(c) 2021 Dominic Szablewski
-
-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, subject to the following conditions :
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-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.
-
-
--- About
-
-QOI encodes and decodes images in a lossless format. Compared to stb_image and
-stb_image_write QOI offers 20x-50x faster encoding, 3x-4x faster decoding and
-20% better compression.
-
-
--- Synopsis
-
-// Define `QOI_IMPLEMENTATION` in *one* C/C++ file before including this
-// library to create the implementation.
-
-#define QOI_IMPLEMENTATION
-#include "qoi.h"
-
-// Encode and store an RGBA buffer to the file system. The qoi_desc describes
-// the input pixel data.
-qoi_write("image_new.qoi", rgba_pixels, &(qoi_desc){
- .width = 1920,
- .height = 1080,
- .channels = 4,
- .colorspace = QOI_SRGB
-});
-
-// Load and decode a QOI image from the file system into a 32bbp RGBA buffer.
-// The qoi_desc struct will be filled with the width, height, number of channels
-// and colorspace read from the file header.
-qoi_desc desc;
-void *rgba_pixels = qoi_read("image.qoi", &desc, 4);
-
-
-
--- Documentation
-
-This library provides the following functions;
-- qoi_read -- read and decode a QOI file
-- qoi_decode -- decode the raw bytes of a QOI image from memory
-- qoi_write -- encode and write a QOI file
-- qoi_encode -- encode an rgba buffer into a QOI image in memory
-
-See the function declaration below for the signature and more information.
-
-If you don't want/need the qoi_read and qoi_write functions, you can define
-QOI_NO_STDIO before including this library.
-
-This library uses malloc() and free(). To supply your own malloc implementation
-you can define QOI_MALLOC and QOI_FREE before including this library.
-
-This library uses memset() to zero-initialize the index. To supply your own
-implementation you can define QOI_ZEROARR before including this library.
-
-
--- Data Format
-
-A QOI file has a 14 byte header, followed by any number of data "chunks" and an
-8-byte end marker.
-
-struct qoi_header_t {
- char magic[4]; // magic bytes "qoif"
- uint32_t width; // image width in pixels (BE)
- uint32_t height; // image height in pixels (BE)
- uint8_t channels; // 3 = RGB, 4 = RGBA
- uint8_t colorspace; // 0 = sRGB with linear alpha, 1 = all channels linear
-};
-
-Images are encoded row by row, left to right, top to bottom. The decoder and
-encoder start with {r: 0, g: 0, b: 0, a: 255} as the previous pixel value. An
-image is complete when all pixels specified by width * height have been covered.
-
-Pixels are encoded as
- - a run of the previous pixel
- - an index into an array of previously seen pixels
- - a difference to the previous pixel value in r,g,b
- - full r,g,b or r,g,b,a values
-
-The color channels are assumed to not be premultiplied with the alpha channel
-("un-premultiplied alpha").
-
-A running array[64] (zero-initialized) of previously seen pixel values is
-maintained by the encoder and decoder. Each pixel that is seen by the encoder
-and decoder is put into this array at the position formed by a hash function of
-the color value. In the encoder, if the pixel value at the index matches the
-current pixel, this index position is written to the stream as QOI_OP_INDEX.
-The hash function for the index is:
-
- index_position = (r * 3 + g * 5 + b * 7 + a * 11) % 64
-
-Each chunk starts with a 2- or 8-bit tag, followed by a number of data bits. The
-bit length of chunks is divisible by 8 - i.e. all chunks are byte aligned. All
-values encoded in these data bits have the most significant bit on the left.
-
-The 8-bit tags have precedence over the 2-bit tags. A decoder must check for the
-presence of an 8-bit tag first.
-
-The byte stream's end is marked with 7 0x00 bytes followed a single 0x01 byte.
-
-
-The possible chunks are:
-
-
-.- QOI_OP_INDEX ----------.
-| Byte[0] |
-| 7 6 5 4 3 2 1 0 |
-|-------+-----------------|
-| 0 0 | index |
-`-------------------------`
-2-bit tag b00
-6-bit index into the color index array: 0..63
-
-A valid encoder must not issue 2 or more consecutive QOI_OP_INDEX chunks to the
-same index. QOI_OP_RUN should be used instead.
-
-
-.- QOI_OP_DIFF -----------.
-| Byte[0] |
-| 7 6 5 4 3 2 1 0 |
-|-------+-----+-----+-----|
-| 0 1 | dr | dg | db |
-`-------------------------`
-2-bit tag b01
-2-bit red channel difference from the previous pixel between -2..1
-2-bit green channel difference from the previous pixel between -2..1
-2-bit blue channel difference from the previous pixel between -2..1
-
-The difference to the current channel values are using a wraparound operation,
-so "1 - 2" will result in 255, while "255 + 1" will result in 0.
-
-Values are stored as unsigned integers with a bias of 2. E.g. -2 is stored as
-0 (b00). 1 is stored as 3 (b11).
-
-The alpha value remains unchanged from the previous pixel.
-
-
-.- QOI_OP_LUMA -------------------------------------.
-| Byte[0] | Byte[1] |
-| 7 6 5 4 3 2 1 0 | 7 6 5 4 3 2 1 0 |
-|-------+-----------------+-------------+-----------|
-| 1 0 | green diff | dr - dg | db - dg |
-`---------------------------------------------------`
-2-bit tag b10
-6-bit green channel difference from the previous pixel -32..31
-4-bit red channel difference minus green channel difference -8..7
-4-bit blue channel difference minus green channel difference -8..7
-
-The green channel is used to indicate the general direction of change and is
-encoded in 6 bits. The red and blue channels (dr and db) base their diffs off
-of the green channel difference and are encoded in 4 bits. I.e.:
- dr_dg = (cur_px.r - prev_px.r) - (cur_px.g - prev_px.g)
- db_dg = (cur_px.b - prev_px.b) - (cur_px.g - prev_px.g)
-
-The difference to the current channel values are using a wraparound operation,
-so "10 - 13" will result in 253, while "250 + 7" will result in 1.
-
-Values are stored as unsigned integers with a bias of 32 for the green channel
-and a bias of 8 for the red and blue channel.
-
-The alpha value remains unchanged from the previous pixel.
-
-
-.- QOI_OP_RUN ------------.
-| Byte[0] |
-| 7 6 5 4 3 2 1 0 |
-|-------+-----------------|
-| 1 1 | run |
-`-------------------------`
-2-bit tag b11
-6-bit run-length repeating the previous pixel: 1..62
-
-The run-length is stored with a bias of -1. Note that the run-lengths 63 and 64
-(b111110 and b111111) are illegal as they are occupied by the QOI_OP_RGB and
-QOI_OP_RGBA tags.
-
-
-.- QOI_OP_RGB ------------------------------------------.
-| Byte[0] | Byte[1] | Byte[2] | Byte[3] |
-| 7 6 5 4 3 2 1 0 | 7 .. 0 | 7 .. 0 | 7 .. 0 |
-|-------------------------+---------+---------+---------|
-| 1 1 1 1 1 1 1 0 | red | green | blue |
-`-------------------------------------------------------`
-8-bit tag b11111110
-8-bit red channel value
-8-bit green channel value
-8-bit blue channel value
-
-The alpha value remains unchanged from the previous pixel.
-
-
-.- QOI_OP_RGBA ---------------------------------------------------.
-| Byte[0] | Byte[1] | Byte[2] | Byte[3] | Byte[4] |
-| 7 6 5 4 3 2 1 0 | 7 .. 0 | 7 .. 0 | 7 .. 0 | 7 .. 0 |
-|-------------------------+---------+---------+---------+---------|
-| 1 1 1 1 1 1 1 1 | red | green | blue | alpha |
-`-----------------------------------------------------------------`
-8-bit tag b11111111
-8-bit red channel value
-8-bit green channel value
-8-bit blue channel value
-8-bit alpha channel value
-
-*/
-
-
-/* -----------------------------------------------------------------------------
-Header - Public functions */
-
-#ifndef QOI_H
-#define QOI_H
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/* A pointer to a qoi_desc struct has to be supplied to all of qoi's functions.
-It describes either the input format (for qoi_write and qoi_encode), or is
-filled with the description read from the file header (for qoi_read and
-qoi_decode).
-
-The colorspace in this qoi_desc is an enum where
- 0 = sRGB, i.e. gamma scaled RGB channels and a linear alpha channel
- 1 = all channels are linear
-You may use the constants QOI_SRGB or QOI_LINEAR. The colorspace is purely
-informative. It will be saved to the file header, but does not affect
-how chunks are en-/decoded. */
-
-#define QOI_SRGB 0
-#define QOI_LINEAR 1
-
-typedef struct {
- unsigned int width;
- unsigned int height;
- unsigned char channels;
- unsigned char colorspace;
-} qoi_desc;
-
-#ifndef QOI_NO_STDIO
-
-/* Encode raw RGB or RGBA pixels into a QOI image and write it to the file
-system. The qoi_desc struct must be filled with the image width, height,
-number of channels (3 = RGB, 4 = RGBA) and the colorspace.
-
-The function returns 0 on failure (invalid parameters, or fopen or malloc
-failed) or the number of bytes written on success. */
-
-int qoi_write(const char *filename, const void *data, const qoi_desc *desc);
-
-
-/* Read and decode a QOI image from the file system. If channels is 0, the
-number of channels from the file header is used. If channels is 3 or 4 the
-output format will be forced into this number of channels.
-
-The function either returns NULL on failure (invalid data, or malloc or fopen
-failed) or a pointer to the decoded pixels. On success, the qoi_desc struct
-will be filled with the description from the file header.
-
-The returned pixel data should be free()d after use. */
-
-void *qoi_read(const char *filename, qoi_desc *desc, int channels);
-
-#endif /* QOI_NO_STDIO */
-
-
-/* Encode raw RGB or RGBA pixels into a QOI image in memory.
-
-The function either returns NULL on failure (invalid parameters or malloc
-failed) or a pointer to the encoded data on success. On success the out_len
-is set to the size in bytes of the encoded data.
-
-The returned qoi data should be free()d after use. */
-
-void *qoi_encode(const void *data, const qoi_desc *desc, int *out_len);
-
-
-/* Decode a QOI image from memory.
-
-The function either returns NULL on failure (invalid parameters or malloc
-failed) or a pointer to the decoded pixels. On success, the qoi_desc struct
-is filled with the description from the file header.
-
-The returned pixel data should be free()d after use. */
-
-void *qoi_decode(const void *data, int size, qoi_desc *desc, int channels);
-
-
-#ifdef __cplusplus
-}
-#endif
-#endif /* QOI_H */
-
-
-/* -----------------------------------------------------------------------------
-Implementation */
-
-#ifdef QOI_IMPLEMENTATION
-#include <stdlib.h>
-#include <string.h>
-
-#ifndef QOI_MALLOC
- #define QOI_MALLOC(sz) malloc(sz)
- #define QOI_FREE(p) free(p)
-#endif
-#ifndef QOI_ZEROARR
- #define QOI_ZEROARR(a) memset((a),0,sizeof(a))
-#endif
-
-#define QOI_OP_INDEX 0x00 /* 00xxxxxx */
-#define QOI_OP_DIFF 0x40 /* 01xxxxxx */
-#define QOI_OP_LUMA 0x80 /* 10xxxxxx */
-#define QOI_OP_RUN 0xc0 /* 11xxxxxx */
-#define QOI_OP_RGB 0xfe /* 11111110 */
-#define QOI_OP_RGBA 0xff /* 11111111 */
-
-#define QOI_MASK_2 0xc0 /* 11000000 */
-
-#define QOI_COLOR_HASH(C) (C.rgba.r*3 + C.rgba.g*5 + C.rgba.b*7 + C.rgba.a*11)
-#define QOI_MAGIC \
- (((unsigned int)'q') << 24 | ((unsigned int)'o') << 16 | \
- ((unsigned int)'i') << 8 | ((unsigned int)'f'))
-#define QOI_HEADER_SIZE 14
-
-/* 2GB is the max file size that this implementation can safely handle. We guard
-against anything larger than that, assuming the worst case with 5 bytes per
-pixel, rounded down to a nice clean value. 400 million pixels ought to be
-enough for anybody. */
-#define QOI_PIXELS_MAX ((unsigned int)400000000)
-
-typedef union {
- struct { unsigned char r, g, b, a; } rgba;
- unsigned int v;
-} qoi_rgba_t;
-
-static const unsigned char qoi_padding[8] = {0,0,0,0,0,0,0,1};
-
-static void qoi_write_32(unsigned char *bytes, int *p, unsigned int v) {
- bytes[(*p)++] = (0xff000000 & v) >> 24;
- bytes[(*p)++] = (0x00ff0000 & v) >> 16;
- bytes[(*p)++] = (0x0000ff00 & v) >> 8;
- bytes[(*p)++] = (0x000000ff & v);
-}
-
-static unsigned int qoi_read_32(const unsigned char *bytes, int *p) {
- unsigned int a = bytes[(*p)++];
- unsigned int b = bytes[(*p)++];
- unsigned int c = bytes[(*p)++];
- unsigned int d = bytes[(*p)++];
- return a << 24 | b << 16 | c << 8 | d;
-}
-
-void *qoi_encode(const void *data, const qoi_desc *desc, int *out_len) {
- int i, max_size, p, run;
- int px_len, px_end, px_pos, channels;
- unsigned char *bytes;
- const unsigned char *pixels;
- qoi_rgba_t index[64];
- qoi_rgba_t px, px_prev;
-
- if (
- data == NULL || out_len == NULL || desc == NULL ||
- desc->width == 0 || desc->height == 0 ||
- desc->channels < 3 || desc->channels > 4 ||
- desc->colorspace > 1 ||
- desc->height >= QOI_PIXELS_MAX / desc->width
- ) {
- return NULL;
- }
-
- max_size =
- desc->width * desc->height * (desc->channels + 1) +
- QOI_HEADER_SIZE + sizeof(qoi_padding);
-
- p = 0;
- bytes = (unsigned char *) QOI_MALLOC(max_size);
- if (!bytes) {
- return NULL;
- }
-
- qoi_write_32(bytes, &p, QOI_MAGIC);
- qoi_write_32(bytes, &p, desc->width);
- qoi_write_32(bytes, &p, desc->height);
- bytes[p++] = desc->channels;
- bytes[p++] = desc->colorspace;
-
-
- pixels = (const unsigned char *)data;
-
- QOI_ZEROARR(index);
-
- run = 0;
- px_prev.rgba.r = 0;
- px_prev.rgba.g = 0;
- px_prev.rgba.b = 0;
- px_prev.rgba.a = 255;
- px = px_prev;
-
- px_len = desc->width * desc->height * desc->channels;
- px_end = px_len - desc->channels;
- channels = desc->channels;
-
- for (px_pos = 0; px_pos < px_len; px_pos += channels) {
- if (channels == 4) {
- px = *(qoi_rgba_t *)(pixels + px_pos);
- }
- else {
- px.rgba.r = pixels[px_pos + 0];
- px.rgba.g = pixels[px_pos + 1];
- px.rgba.b = pixels[px_pos + 2];
- }
-
- if (px.v == px_prev.v) {
- run++;
- if (run == 62 || px_pos == px_end) {
- bytes[p++] = QOI_OP_RUN | (run - 1);
- run = 0;
- }
- }
- else {
- int index_pos;
-
- if (run > 0) {
- bytes[p++] = QOI_OP_RUN | (run - 1);
- run = 0;
- }
-
- index_pos = QOI_COLOR_HASH(px) % 64;
-
- if (index[index_pos].v == px.v) {
- bytes[p++] = QOI_OP_INDEX | index_pos;
- }
- else {
- index[index_pos] = px;
-
- if (px.rgba.a == px_prev.rgba.a) {
- signed char vr = px.rgba.r - px_prev.rgba.r;
- signed char vg = px.rgba.g - px_prev.rgba.g;
- signed char vb = px.rgba.b - px_prev.rgba.b;
-
- signed char vg_r = vr - vg;
- signed char vg_b = vb - vg;
-
- if (
- vr > -3 && vr < 2 &&
- vg > -3 && vg < 2 &&
- vb > -3 && vb < 2
- ) {
- bytes[p++] = QOI_OP_DIFF | (vr + 2) << 4 | (vg + 2) << 2 | (vb + 2);
- }
- else if (
- vg_r > -9 && vg_r < 8 &&
- vg > -33 && vg < 32 &&
- vg_b > -9 && vg_b < 8
- ) {
- bytes[p++] = QOI_OP_LUMA | (vg + 32);
- bytes[p++] = (vg_r + 8) << 4 | (vg_b + 8);
- }
- else {
- bytes[p++] = QOI_OP_RGB;
- bytes[p++] = px.rgba.r;
- bytes[p++] = px.rgba.g;
- bytes[p++] = px.rgba.b;
- }
- }
- else {
- bytes[p++] = QOI_OP_RGBA;
- bytes[p++] = px.rgba.r;
- bytes[p++] = px.rgba.g;
- bytes[p++] = px.rgba.b;
- bytes[p++] = px.rgba.a;
- }
- }
- }
- px_prev = px;
- }
-
- for (i = 0; i < (int)sizeof(qoi_padding); i++) {
- bytes[p++] = qoi_padding[i];
- }
-
- *out_len = p;
- return bytes;
-}
-
-void *qoi_decode(const void *data, int size, qoi_desc *desc, int channels) {
- const unsigned char *bytes;
- unsigned int header_magic;
- unsigned char *pixels;
- qoi_rgba_t index[64];
- qoi_rgba_t px;
- int px_len, chunks_len, px_pos;
- int p = 0, run = 0;
-
- if (
- data == NULL || desc == NULL ||
- (channels != 0 && channels != 3 && channels != 4) ||
- size < QOI_HEADER_SIZE + (int)sizeof(qoi_padding)
- ) {
- return NULL;
- }
-
- bytes = (const unsigned char *)data;
-
- header_magic = qoi_read_32(bytes, &p);
- desc->width = qoi_read_32(bytes, &p);
- desc->height = qoi_read_32(bytes, &p);
- desc->channels = bytes[p++];
- desc->colorspace = bytes[p++];
-
- if (
- desc->width == 0 || desc->height == 0 ||
- desc->channels < 3 || desc->channels > 4 ||
- desc->colorspace > 1 ||
- header_magic != QOI_MAGIC ||
- desc->height >= QOI_PIXELS_MAX / desc->width
- ) {
- return NULL;
- }
-
- if (channels == 0) {
- channels = desc->channels;
- }
-
- px_len = desc->width * desc->height * channels;
- pixels = (unsigned char *) QOI_MALLOC(px_len);
- if (!pixels) {
- return NULL;
- }
-
- QOI_ZEROARR(index);
- px.rgba.r = 0;
- px.rgba.g = 0;
- px.rgba.b = 0;
- px.rgba.a = 255;
-
- chunks_len = size - (int)sizeof(qoi_padding);
- for (px_pos = 0; px_pos < px_len; px_pos += channels) {
- if (run > 0) {
- run--;
- }
- else if (p < chunks_len) {
- int b1 = bytes[p++];
-
- if (b1 == QOI_OP_RGB) {
- px.rgba.r = bytes[p++];
- px.rgba.g = bytes[p++];
- px.rgba.b = bytes[p++];
- }
- else if (b1 == QOI_OP_RGBA) {
- px.rgba.r = bytes[p++];
- px.rgba.g = bytes[p++];
- px.rgba.b = bytes[p++];
- px.rgba.a = bytes[p++];
- }
- else if ((b1 & QOI_MASK_2) == QOI_OP_INDEX) {
- px = index[b1];
- }
- else if ((b1 & QOI_MASK_2) == QOI_OP_DIFF) {
- px.rgba.r += ((b1 >> 4) & 0x03) - 2;
- px.rgba.g += ((b1 >> 2) & 0x03) - 2;
- px.rgba.b += ( b1 & 0x03) - 2;
- }
- else if ((b1 & QOI_MASK_2) == QOI_OP_LUMA) {
- int b2 = bytes[p++];
- int vg = (b1 & 0x3f) - 32;
- px.rgba.r += vg - 8 + ((b2 >> 4) & 0x0f);
- px.rgba.g += vg;
- px.rgba.b += vg - 8 + (b2 & 0x0f);
- }
- else if ((b1 & QOI_MASK_2) == QOI_OP_RUN) {
- run = (b1 & 0x3f);
- }
-
- index[QOI_COLOR_HASH(px) % 64] = px;
- }
-
- if (channels == 4) {
- *(qoi_rgba_t*)(pixels + px_pos) = px;
- }
- else {
- pixels[px_pos + 0] = px.rgba.r;
- pixels[px_pos + 1] = px.rgba.g;
- pixels[px_pos + 2] = px.rgba.b;
- }
- }
-
- return pixels;
-}
-
-#ifndef QOI_NO_STDIO
-#include <stdio.h>
-
-int qoi_write(const char *filename, const void *data, const qoi_desc *desc) {
- FILE *f = fopen(filename, "wb");
- int size;
- void *encoded;
-
- if (!f) {
- return 0;
- }
-
- encoded = qoi_encode(data, desc, &size);
- if (!encoded) {
- fclose(f);
- return 0;
- }
-
- fwrite(encoded, 1, size, f);
- fclose(f);
-
- QOI_FREE(encoded);
- return size;
-}
-
-void *qoi_read(const char *filename, qoi_desc *desc, int channels) {
- FILE *f = fopen(filename, "rb");
- int size, bytes_read;
- void *pixels, *data;
-
- if (!f) {
- return NULL;
- }
-
- fseek(f, 0, SEEK_END);
- size = ftell(f);
- if (size <= 0) {
- fclose(f);
- return NULL;
- }
- fseek(f, 0, SEEK_SET);
-
- data = QOI_MALLOC(size);
- if (!data) {
- fclose(f);
- return NULL;
- }
-
- bytes_read = fread(data, 1, size, f);
- fclose(f);
-
- pixels = qoi_decode(data, bytes_read, desc, channels);
- QOI_FREE(data);
- return pixels;
-}
-
-#endif /* QOI_NO_STDIO */
-#endif /* QOI_IMPLEMENTATION */
projects / fishladder.git / blobdiff