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Rangi42Rangi42
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Implement QOI image format
1 parent a809dea commit 80e87ff

13 files changed

+171
-6
lines changed

‎docs/alpha.md

+1
Original file line numberDiff line numberDiff line change
@@ -68,6 +68,7 @@ Ordering is pure ASCII (that is, all uppercase letters come before all lowercase
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- [`PLUM_IMAGE_NONE` constant](constants.md#image-types)
6969
- [`PLUM_IMAGE_PNG` constant](constants.md#image-types)
7070
- [`PLUM_IMAGE_PNM` constant](constants.md#image-types)
71+
- [`PLUM_IMAGE_QOI` constant](constants.md#image-types)
7172
- [`PLUM_MAX_MEMORY_SIZE` constant](constants.md#special-loading-and-storing-modes)
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- [`PLUM_METADATA_BACKGROUND` constant](constants.md#metadata-node-types)
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- [`PLUM_METADATA_COLOR_DEPTH` constant](constants.md#metadata-node-types)

‎docs/constants.md

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@@ -66,6 +66,7 @@ image used (when loading it) or will use (when storing it).
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- `PLUM_IMAGE_JPEG`: JPEG (Joint Photographers Expert Group) file.
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- `PLUM_IMAGE_PNM`: netpbm's PNM (Portable Anymap) format.
6868
When loading, it represents any possible PNM file; however, only PPM and PAM files will be written.
69+
- `PLUM_IMAGE_QOI`: QOI (Quite OK Image) file.
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For more information, see the [Supported file formats][formats] page.
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‎docs/formats.md

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@@ -13,6 +13,7 @@ All supported formats are documented here, along with their restrictions and som
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- [APNG](#apng)
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- [JPEG](#jpeg)
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- [PNM](#pnm)
16+
- [QOI](#qoi)
1617

1718
## Definitions
1819

@@ -67,8 +68,8 @@ The maximum width and height for an image is `0x7fffffff`; larger dimensions wil
6768
Images using [indexed-color mode][indexed] are fully supported, but they cannot contain transparency.
6869
Therefore, if an image uses transparency, the file will be generated without a palette.
6970

70-
If an image has a [true bit depth](#definitions) of 8 or less and it doesn't use transparency, the usual RGB888 format
71-
is used for output.
71+
If an image has a [true bit depth](#definitions) of 8 or less and it doesn't use transparency, 8-bit RGB components
72+
are used for output.
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Otherwise, variable bit masks are used, with each component having the width determined by its true bit depth.
7374
Variable bit width files are limited to a total of 32 bits per color, so if the sum of the true bit depths for all
7475
components exceeds 32, they are proportionally reduced to fit.
@@ -341,6 +342,15 @@ All [animation-related metadata][animation] will be ignored when generating a PN
341342

342343
PNM files don't support palettes; [indexed-color mode images][indexed] will be converted when a PNM file is generated.
343344

345+
## QOI
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347+
The Quite OK Image (QOI) format version 1.0 is supported.
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349+
QOI files only support a single frame; attempting to generate a file with two or more frames will fail with
350+
[`PLUM_ERR_NO_MULTI_FRAME`][errors].
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352+
QOI files don't support palettes; [indexed-color mode images][indexed] will be converted when a QOI file is generated.
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344354
* * *
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346356
Prev: [C++ helper methods](methods.md)

‎header/enum.h

+1
Original file line numberDiff line numberDiff line change
@@ -39,6 +39,7 @@ enum plum_image_types {
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PLUM_IMAGE_APNG,
4040
PLUM_IMAGE_JPEG,
4141
PLUM_IMAGE_PNM,
42+
PLUM_IMAGE_QOI,
4243
PLUM_NUM_IMAGE_TYPES
4344
};
4445

‎src/bmpwrite.c

+3-3
Original file line numberDiff line numberDiff line change
@@ -342,13 +342,13 @@ void generate_BMP_RGB_data (struct context * context, unsigned char * offset_poi
342342
padding = 4 - (rowsize & 3);
343343
rowsize += padding;
344344
}
345-
unsigned char * out = append_output_node(context, rowsize * context -> source -> height);
345+
unsigned char * output = append_output_node(context, rowsize * context -> source -> height);
346346
uint_fast32_t row = context -> source -> height - 1;
347347
do {
348348
size_t pos = (size_t) row * context -> source -> width;
349349
for (uint_fast32_t remaining = context -> source -> width; remaining; pos ++, remaining --)
350-
out += byteappend(out, data[pos] >> 16, data[pos] >> 8, data[pos]);
351-
for (uint_fast32_t p = 0; p < padding; p ++) *(out ++) = 0;
350+
output += byteappend(output, data[pos] >> 16, data[pos] >> 8, data[pos]);
351+
for (uint_fast32_t p = 0; p < padding; p ++) *(output ++) = 0;
352352
} while (row --);
353353
if (data != context -> source -> data) ctxfree(context, data);
354354
}

‎src/inline.h

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Original file line numberDiff line numberDiff line change
@@ -51,6 +51,16 @@ static inline void * append_output_node (struct context * context, size_t size)
5151
return node -> data;
5252
}
5353

54+
static inline void * resize_output_node (struct context * context, void * data, size_t size) {
55+
struct data_node * node = (struct data_node *) ((char *) data - offsetof(struct data_node, data));
56+
if (node -> size != size) {
57+
node = ctxrealloc(context, node, sizeof *node + size);
58+
node -> size = size;
59+
if (node -> previous) node -> previous -> next = node;
60+
}
61+
return node -> data;
62+
}
63+
5464
static inline bool bit_depth_less_than (uint32_t depth, uint32_t target) {
5565
// formally "less than or equal to", but that would be a very long name
5666
return !((target - depth) & 0x80808080u);

‎src/load.c

+2
Original file line numberDiff line numberDiff line change
@@ -60,6 +60,8 @@ void load_image_buffer_data (struct context * context, unsigned flags, size_t li
6060
else if (bytematch(context -> data, 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a))
6161
// APNG files disguise as PNG files, so handle them all as PNG and split them later
6262
load_PNG_data(context, flags, limit);
63+
else if (bytematch(context -> data, 0x71, 0x6f, 0x69, 0x66))
64+
load_QOI_data(context, flags, limit);
6365
else if (*context -> data == 0x50 && context -> data[1] >= 0x31 && context -> data[1] <= 0x37)
6466
load_PNM_data(context, flags, limit);
6567
else if (bytematch(context -> data, 0xef, 0xbb, 0xbf, 0x50) && context -> data[4] >= 0x31 && context -> data[4] <= 0x37)

‎src/misc.c

+2-1
Original file line numberDiff line numberDiff line change
@@ -71,7 +71,8 @@ const char * plum_get_file_format_name (unsigned format) {
7171
[PLUM_IMAGE_PNG] = "PNG",
7272
[PLUM_IMAGE_APNG] = "APNG",
7373
[PLUM_IMAGE_JPEG] = "JPEG",
74-
[PLUM_IMAGE_PNM] = "PNM"
74+
[PLUM_IMAGE_PNM] = "PNM",
75+
[PLUM_IMAGE_QOI] = "QOI"
7576
};
7677
if (format >= PLUM_NUM_IMAGE_TYPES) format = PLUM_IMAGE_NONE;
7778
return formats[format];

‎src/proto.h

+6
Original file line numberDiff line numberDiff line change
@@ -340,6 +340,12 @@ internal size_t write_PNM_number(unsigned char * restrict, uint32_t);
340340
internal void generate_PNM_frame_data(struct context *, const uint64_t *, uint32_t, uint32_t, unsigned, bool);
341341
internal void generate_PNM_frame_data_from_palette(struct context *, const uint8_t *, const uint64_t *, uint32_t, uint32_t, unsigned, bool);
342342

343+
// qoiread.c
344+
internal void load_QOI_data(struct context *, unsigned, size_t);
345+
346+
// qoiwrite.c
347+
internal void generate_QOI_data(struct context *);
348+
343349
// sort.c
344350
internal void sort_values(uint64_t * restrict, uint64_t);
345351
internal void quicksort_values(uint64_t * restrict, uint64_t);

‎src/qoiread.c

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,54 @@
1+
#include "proto.h"
2+
3+
void load_QOI_data (struct context * context, unsigned flags, size_t limit) {
4+
if (context -> size < 22) throw(context, PLUM_ERR_INVALID_FILE_FORMAT);
5+
context -> image -> type = PLUM_IMAGE_QOI;
6+
context -> image -> frames = 1;
7+
context -> image -> width = read_be32_unaligned(context -> data + 4);
8+
context -> image -> height = read_be32_unaligned(context -> data + 8);
9+
validate_image_size(context, limit);
10+
allocate_framebuffers(context, flags, false);
11+
add_color_depth_metadata(context, 8, 8, 8, 8, 0);
12+
uint64_t * frame = ctxmalloc(context, sizeof *frame * context -> source -> width * context -> source -> height);
13+
const unsigned char * data = context -> data + 14;
14+
const unsigned char * dataend = context -> data + context -> size - 22;
15+
struct QOI_pixel lookup[64] = {0};
16+
struct QOI_pixel px = {.r = 0, .g = 0, .b = 0, .a = 0xff};
17+
unsigned char run = 0;
18+
for (uint_fast64_t cell = 0; cell < context -> source -> width * context -> source -> height; cell ++) {
19+
if (run > 0)
20+
run --;
21+
else if (data + 1 < dataend) {
22+
unsigned char v = *(data ++);
23+
if (v == 0xfe && data + 3 < dataend) {
24+
px.r = *(data ++);
25+
px.g = *(data ++);
26+
px.b = *(data ++);
27+
} else if (v == 0xff && data + 4 < dataend) {
28+
px.r = *(data ++);
29+
px.g = *(data ++);
30+
px.b = *(data ++);
31+
px.a = *(data ++);
32+
} else if (!(v & 0xc0) && v < sizeof lookup)
33+
px = lookup[v];
34+
else if ((v & 0xc0) == 0x40) {
35+
px.r += ((v >> 4) & 3) - 2;
36+
px.g += ((v >> 2) & 3) - 2;
37+
px.b += (v & 3) - 2;
38+
} else if ((v & 0xc0) == 0x80 && data + 1 < dataend) {
39+
unsigned char v2 = *(data ++);
40+
int_fast16_t dg = (v & 0x3f) - 32;
41+
px.r += dg + ((v2 >> 4) & 0xf) - 8;
42+
px.g += dg;
43+
px.b += dg + (v2 & 0xf) - 8;
44+
} else if ((v & 0xc0) == 0xc0)
45+
run = v & 0x3f;
46+
else
47+
throw(context, PLUM_ERR_INVALID_FILE_FORMAT);
48+
lookup[(px.r * 3 + px.g * 5 + px.b * 7 + px.a * 11) % sizeof lookup] = px;
49+
}
50+
frame[cell] = (((uint64_t) (px.a ^ 0xff) << 48) | ((uint64_t) px.b << 32) | ((uint64_t) px.g << 16) | (uint64_t) px.r) * 0x101;
51+
}
52+
write_framebuffer_to_image(context -> image, frame, 0, flags);
53+
ctxfree(context, frame);
54+
}

‎src/qoiwrite.c

+71
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@@ -0,0 +1,71 @@
1+
#include "proto.h"
2+
3+
#define equalpixels(p1, p2) ((p1).r == (p2).r && (p1).g == (p2).g && (p1).b == (p2).b && (p1).a == (p2).a)
4+
5+
void generate_QOI_data (struct context * context) {
6+
if (context -> source -> frames > 1) throw(context, PLUM_ERR_NO_MULTI_FRAME);
7+
if (!(context -> source -> width && context -> source -> height)) throw(context, PLUM_ERR_IMAGE_TOO_LARGE);
8+
unsigned char * header = append_output_node(context, 14);
9+
bytewrite(header, 0x71, 0x6f, 0x69, 0x66);
10+
write_be32_unaligned(header + 4, context -> source -> width);
11+
write_be32_unaligned(header + 8, context -> source -> height);
12+
uint8_t channels = 3 + image_has_transparency(context -> source);
13+
header[12] = channels;
14+
header[13] = 0;
15+
uint32_t * data;
16+
if ((context -> source -> color_format & PLUM_COLOR_MASK) == PLUM_COLOR_32)
17+
data = context -> source -> data;
18+
else {
19+
data = ctxmalloc(context, sizeof *data * context -> source -> width * context -> source -> height);
20+
plum_convert_colors(data, context -> source -> data, (size_t) context -> source -> width * context -> source -> height,
21+
PLUM_COLOR_32, context -> source -> color_format);
22+
}
23+
size_t max_size = context -> source -> width * context -> source -> height * (channels + 1) + 22;
24+
unsigned char * node = append_output_node(context, max_size);
25+
unsigned char * output = node;
26+
struct QOI_pixel lookup[64] = {0};
27+
struct QOI_pixel px = {.r = 0, .g = 0, .b = 0, .a = 0xff};
28+
struct QOI_pixel prev = px;
29+
unsigned char run = 0;
30+
for (uint_fast64_t cell = 0; cell < context -> source -> width * context -> source -> height; cell ++) {
31+
px.r = data[cell];
32+
px.g = data[cell] >> 8;
33+
px.b = data[cell] >> 16;
34+
px.a = (data[cell] >> 24) ^ 0xff;
35+
if (equalpixels(px, prev)) {
36+
run ++;
37+
if (run == 62 || cell == context -> source -> width * context -> source -> height - 1) {
38+
*(output ++) = 0xc0 | (run - 1);
39+
run = 0;
40+
}
41+
} else {
42+
if (run > 0) {
43+
*(output ++) = 0xc0 | (run - 1);
44+
run = 0;
45+
}
46+
uint8_t index = (px.r * 3 + px.g * 5 + px.b * 7 + px.a * 11) % sizeof lookup;
47+
if (equalpixels(px, lookup[index]))
48+
*(output ++) = index;
49+
else {
50+
lookup[index] = px;
51+
if (px.a == prev.a) {
52+
int8_t dr = px.r - prev.r, dg = px.g - prev.g, db = px.b - prev.b;
53+
int8_t drg = dr - dg, dbg = db - dg;
54+
if (dr >= -2 && dr < 2 && dg >= -2 && dg < 2 && db >= -2 && db < 2)
55+
*(output ++) = 0x40 | ((dr + 2) << 4) | ((dg + 2) << 2) | (db + 2);
56+
else if (drg >= -8 && drg < 8 && dg >= -32 && dg < 32 && dbg >= -8 && dbg < 8)
57+
output += byteappend(output, 0x80 | (dg + 32), ((drg + 8) << 4) | (dbg + 8));
58+
else
59+
output += byteappend(output, 0xfe, px.r, px.g, px.b);
60+
} else
61+
output += byteappend(output, 0xff, px.r, px.g, px.b, px.a);
62+
}
63+
}
64+
prev = px;
65+
}
66+
output += byteappend(output, 0, 0, 0, 0, 0, 0, 0, 1);
67+
resize_output_node(context, node, output - node);
68+
if (data != context -> source -> data) ctxfree(context, data);
69+
}
70+
71+
#undef equalpixels

‎src/store.c

+1
Original file line numberDiff line numberDiff line change
@@ -19,6 +19,7 @@ size_t plum_store_image (const struct plum_image * image, void * restrict buffer
1919
case PLUM_IMAGE_APNG: generate_APNG_data(context); break;
2020
case PLUM_IMAGE_JPEG: generate_JPEG_data(context); break;
2121
case PLUM_IMAGE_PNM: generate_PNM_data(context); break;
22+
case PLUM_IMAGE_QOI: generate_QOI_data(context); break;
2223
default: throw(context, PLUM_ERR_INVALID_FILE_FORMAT);
2324
}
2425
size_t output_size = get_total_output_size(context);

‎src/struct.h

+7
Original file line numberDiff line numberDiff line change
@@ -147,3 +147,10 @@ struct PNM_image_header {
147147
size_t datastart;
148148
size_t datalength;
149149
};
150+
151+
struct QOI_pixel {
152+
uint8_t r;
153+
uint8_t g;
154+
uint8_t b;
155+
uint8_t a;
156+
};

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