Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

patterns/jpeg: small improvements #184

Merged
merged 6 commits into from
Oct 29, 2023
+35 −4
Merged

patterns/jpeg: small improvements #184

Changes from all commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
2c16adb
patterns/jpeg: exclude EOI marker from SOS image data
bgilbert Oct 25, 2023
f5c22ac
patterns/jpeg: use type::Magic for magic numbers
bgilbert Oct 25, 2023
b6dd321
patterns/jpeg: add RGB component IDs
bgilbert Oct 25, 2023
25d9936
patterns/jpeg: add struct for APP14 marker
bgilbert Oct 25, 2023
b5e6a95
patterns/jpeg: add definition for COM marker
bgilbert Oct 25, 2023
d78476d
patterns/jpeg: add some format_read() for better legibility
bgilbert Oct 25, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
39 changes: 35 additions & 4 deletions patterns/jpeg.hexpat
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,7 +1,9 @@
#pragma author WerWolv
#pragma description JPEG Image Format

#include <std/io.pat>
#include <std/mem.pat>
#include <type/magic.pat>
#pragma endian big

#pragma MIME image/jpeg
Expand Down Expand Up @@ -48,6 +50,12 @@ enum DensityUnit : u8 {
PixelsPerCm = 0x02
};

enum ColorTransform : u8 {
Unknown = 0x00,
YCbCr = 0x01,
YCCK = 0x02
};

struct Pixel {
u8 r, g, b;
} [[sealed, transform("transform_pixel")]];
Expand All @@ -58,26 +66,41 @@ fn transform_pixel(Pixel pixel) {


struct APP0 {
char magic[5];
type::Magic<"JFIF\x00"> magic;
u8 versionMajor, versionMinor;
DensityUnit densityUnit;
u16 densityX, densityY;
u8 thumbnailX, thumbnailY;
Pixel thumbnail[thumbnailX * thumbnailY] [[sealed]];
};

struct APP14 {
type::Magic<"Adobe"> magic;
u16 version;
u16 flags0;
u16 flags1;
ColorTransform transform;
};

enum ComponentId : u8 {
Y = 1,
CB = 2,
CR = 3,
I = 4,
Q = 5
Q = 5,
B = 66,
G = 71,
R = 82
};

struct SOF0Component {
ComponentId componentId;
u8 samplingFactors;
u8 quantizationTableId;
} [[format_read("sof0_component_read")]];

fn sof0_component_read(SOF0Component c) {
return std::format("({}, {}, {})", c.componentId, c.samplingFactors, c.quantizationTableId);
};

struct SOF0 {
Expand All @@ -99,11 +122,11 @@ struct SOS {
u8 endSpectral;
u8 apprBitPos;

u8 image_data[while(!std::mem::eof())] [[sealed]];
u8 image_data[std::mem::size() - $ - 2] [[sealed]];
};

struct Segment {
u8 magic;
type::Magic<"\xff"> magic;
Marker marker;

if (marker == Marker::SOI || marker == Marker::EOI) {
Expand All @@ -112,6 +135,10 @@ struct Segment {
u16 length;
if (marker == Marker::APP0) {
APP0 data;
} else if (marker == Marker::APP14) {
APP14 data;
} else if (marker == Marker::COM) {
char data[length - sizeof(length)];
} else if (marker == Marker::SOF0) {
SOF0 data;
} else if (marker == Marker::SOS) {
Expand All @@ -120,6 +147,10 @@ struct Segment {
u8 data[length - sizeof(length)] [[sealed]];
}
}
} [[format_read("segment_read")]];

fn segment_read(Segment s) {
return std::format("{}", s.marker);
};

Segment segments[while(!std::mem::eof())] @ 0x00 [[hex::visualize("image", this)]];
Loading