moodstocks / jpec Goto Github PK

View Code? Open in Web Editor NEW

90.0 9.0 28.0 185 KB

A lightweight and portable JPEG encoder written in C.

License: MIT License

C 98.32% Makefile 1.68%

jpec's Introduction

jpec - a JPEG encoder in C

Overview

jpec is a minimalistic JPEG encoder written in C with a focus on simplicity.

It is both portable (tested on x86 and ARM) and lightweight (around 600 LOC).

The library has no external dependencies.

It is a perfect candidate if you have some embedded C code you need to extend with a JPEG encoder the easy way.

Features

The library allows you to write JPEG compressed images from input image data on memory. No more, no less.

More precisely:

it works in grayscale only (monochrome JPEG file): there is no support for color so far,
it produces baseline, DCT-based (SOF0), JFIF 1.01 (APP0) JPEG-s,
it supports 8x8 blocks only,
it includes default quantization and Huffman tables that are not customizable at runtime.

Build

Just type:

make

This produces:

libjpec.a: the static library,
jpec: a simple command-line tool used to test the library (see main.c)

NOTE the command-line tool depends on OpenCV 2 HighGUI module to easily read any kind of input image. You need to have OpenCV development libraries installed on your machine to use it (e.g. brew install opencv on Mac OS X with Homebrew).

Usage

If you want to embed the library into your own C code you are free to create the static library file, and include jpec.h main header, or to copy-paste the whole code into your project.

Then, encoding a raw image is a matter of a few lines of code:

/* Create a JPEG encoder provided image data */
jpec_enc_t *e = jpec_enc_new(img, w, h);

/* Compress */
int len;
const uint8_t *jpeg = jpec_enc_run(e, &len);

/* Do something with the JPEG blob (e.g. save into a file, etc) */

/* Release the encoder */
jpec_enc_del(e);

Authors

Maxime Brénon & Cédric Deltheil.

Copyright

jpec's People

Stargazers

Watchers

jpec's Issues

jpec_huff_encode_block simplification

in jpec_huff_encode_block:
why not:

  jpec_huff_state_t state;
  state.buffer = h->state.buffer;
  state.nbits = h->state.nbits;
  state.dc = h->state.dc;
  state.buf = buf;
  jpec_huff_encode_block_impl(block, &state);
  h->state.buffer = state.buffer;
  h->state.nbits = state.nbits;
  h->state.dc = state.dc;
  h->state.buf = state.buf;

  h->state.buf = buf;
  jpec_huff_encode_block_impl(block, &h->state);

? am I missing something?

assert fails on img size not multiple of 8 even though seems supported

isn't that un-necessary? (since it handles sizes not multiple of 8)

assert(img && w > 0 && !(w & 0x7) && h > 0 && !(h & 0x7));

ld fails at make

Hi,

I'm getting ld error on running make on freshly cloned project.

cc -std=c99 `pkg-config --cflags --libs opencv` -Iinclude -L. -ljpec main.c -o jpec
/tmp/cczUcblb.o: In function `main':
main.c:(.text+0x1482): undefined reference to `jpec_enc_new'
main.c:(.text+0x1499): undefined reference to `jpec_enc_run'
main.c:(.text+0x14e3): undefined reference to `jpec_enc_del'
collect2: error: ld returned 1 exit status
Makefile:32: recipe for target 'jpec' failed
make: *** [jpec] Error 1

SEGV caused by a READ memory access

hi, i compile this repo with ASAN to do some test, after compiling I feed test.png in this repo and it crash.
compile command: AFL_USE_ASAN=1 make CC=afl-clang-fast LDFLAGS="-lopencv"

and here is the crash info:

AddressSanitizer:DEADLYSIGNAL

==110236==ERROR: AddressSanitizer: SEGV on unknown address 0x000000001c78 (pc 0x0000004f4d2e bp 0x7ffeb85f5cd0 sp 0x7ffeb85f5bc0 T0)
==110236==The signal is caused by a READ memory access.
    #0 0x4f4d2e in load_image /home/bupt/Desktop/jpec/main.c:69:22
    #1 0x4f49b0 in main /home/bupt/Desktop/jpec/main.c:46:20
    #2 0x7ff2c275bc86 in __libc_start_main /build/glibc-CVJwZb/glibc-2.27/csu/../csu/libc-start.c:310
    #3 0x41c759 in _start (/home/bupt/Desktop/jpec/jpec+0x41c759)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /home/bupt/Desktop/jpec/main.c:69:22 in load_image
==110236==ABORTING

command to reproduce the crash: ./jpec test.png
test.zip