libjpge-turbo decoder

libjpeg-turbo is a JPEG image codec that uses SIMD instructions to accelerate baseline JPEG compression and decompression on x86, x86-64, Arm, PowerPC, and MIPS systems, as well as progressive JPEG compression on x86, x86-64, and Arm systems. Detailed introduction: libjpeg-turbo.

Install

sudo apt install libjpeg-turbo8-dev

Add libjpge-turbo to your project

find_package(JPEG REQUIRED)
include_directories(${JPEG_INCLUDE_DIR})
target_link_libraries(${PROJECT_NAME} PRIVATE ${JPEG_LIBRARIES})

Usage

Enable LV_USE_LIBJEPG_TURBO in lv_conf.h.

See the examples below. It should be noted that each image of this decoder needs to consume image width x image height x 3 bytes of RAM, and it needs to be combined with the ref:image-caching feature to ensure that the memory usage is within a reasonable range.

Example

Load an JPG image

#include "../../lv_examples.h"
#if LV_BUILD_EXAMPLES

#if LV_USE_LIBJPEG_TURBO

/**
 * Load a JPG image
 */
void lv_example_libjpeg_turbo_1(void)
{
    lv_obj_t * wp;

    wp = lv_image_create(lv_screen_active());
    /* Assuming a File system is attached to letter 'A'
     * E.g. set LV_USE_FS_STDIO 'A' in lv_conf.h */
    lv_image_set_src(wp, "A:lvgl/examples/libs/libjpeg_turbo/flower.jpg");
    lv_obj_center(wp);
}

#else

void lv_example_libjpeg_turbo_1(void)
{
    lv_obj_t * label = lv_label_create(lv_screen_active());
    lv_label_set_text(label, "LibJPEG-Turbo is not installed");
    lv_obj_center(label);
}

#endif

#endif

#!/opt/bin/lv_micropython -i
import lvgl as lv
import display_driver
import fs_driver

fs_drv = lv.fs_drv_t()
fs_driver.fs_register(fs_drv, 'S')

wp = lv.image(lv.screen_active())
# The File system is attached to letter 'S'

wp.set_src("S:flower.jpg")
wp.center()

API

libjpeg_turbo