libjpeg-turbo Decoder
libjpeg-turbo is an LVGL interface to the libjpeg-turbo library — 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.
On such systems, libjpeg-turbo is generally 2-6x as fast as libjpeg, all else being equal.
For a detailed introduction, see: https://libjpeg-turbo.org .
Library source: https://github.com/libjpeg-turbo/libjpeg-turbo
Install
sudo apt install libjpeg-turbo8-dev
Adding libjpeg-turbo to Your Project
Cmake:
find_package(JPEG REQUIRED)
include_directories(${JPEG_INCLUDE_DIR})
target_link_libraries(${PROJECT_NAME} PRIVATE ${JPEG_LIBRARIES})
Usage
Set LV_USE_LIBJPEG_TURBO in lv_conf.h to 1.
See the examples below.
It should be noted that each image decoded needs to consume:
image width × image height × 3
bytes of RAM, and it needs to be combined with the Image caching feature to ensure that the memory usage is within a reasonable range.
Example
Load a JPG image
C code
View on GitHub#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