Wei Dongshan Digital Photo Frame Project Learning (5) Transplantation of libjpeg-turbo

韦东山 数码相框 项目学习（五）libjpeg-turbo的移植

效果图

能够在100ask STM32MP157show oneJPG图片

一、下载源码

首先去libjpeg-turbo官网下载源码,这里我们使用1.2.1版本的libjpeg-turbo
libjpeg-turbo-1.2.1
把压缩包上传到服务器,Then execute the following command to decompress

tar xvf libjpeg-turbo-1.2.1.tar.gz

There will be one more in the same level directorylibjpeg-turbo-1.2.1的目录,如下图所示

二、交叉编译

Then go into this folder,使用如下命令进行配置

./configure --host=arm-buildroot-linux-gnueabihf --prefix=$PWD/tmp

Then execute the following two commands in sequence

make
make install

After these two commands are run,会在当前目录下生成一个tmp目录,这个tmpWe are in the directorylibjpeg-turboCross-compile the generated header files and library files, etc

三、复制文件

现在,We need to copy the header and library files to the header and library directories of our cross-compilation toolchain,There is also the library file directory of the development board
My cross-compilation toolchain is in /home/tao/learn/100ask/100ask_stm32mp157_pro-sdk/ToolChain/arm-buildroot-linux-gnueabihf_sdk-buildroot/bin这个目录下,进入到这个目录,然后返回上一层目录,搜索stdio.hheader files to find our header files directory

cd /home/tao/learn/100ask/100ask_stm32mp157_pro-sdk/ToolChain/arm-buildroot-linux-gnueabihf_sdk-buildroot/bin
cd ..
find -name 'stdio.h'

Then there is the following output

很明显,The third one is more reliable,Put the two paths together,This is the header file directory of our cross-compilation toolchain

/home/tao/learn/100ask/100ask_stm32mp157_pro-sdk/ToolChain/arm-buildroot-linux-gnueabihf_sdk-buildroot/arm-buildroot-linux-gnueabihf/sysroot/usr/include/

With the header file directory,It's easy to think that the library file directory is the same level as the header file directory,所以,The library file directory is

/home/tao/learn/100ask/100ask_stm32mp157_pro-sdk/ToolChain/arm-buildroot-linux-gnueabihf_sdk-buildroot/arm-buildroot-linux-gnueabihf/sysroot/usr/lib/

再次回到tmp目录下
Execute the following two commands to copy the corresponding content into our cross-compilation toolchain

# 复制头文件
cp include/* /home/tao/learn/100ask/100ask_stm32mp157_pro-sdk/ToolChain/arm-buildroot-linux-gnueabihf_sdk-buildroot/arm-buildroot-linux-gnueabihf/sysroot/usr/include/ -rd

# 复制库文件
cp lib/* /home/tao/learn/100ask/100ask_stm32mp157_pro-sdk/ToolChain/arm-buildroot-linux-gnueabihf_sdk-buildroot/arm-buildroot-linux-gnueabihf/sysroot/usr/lib/ -rd

Then copy the library files to the development board,大功告成

demo代码

Put both codes in the same directory,执行makecommand to compile and generate oneexample_libjpeg 的测试程序,Get this app with oneJPG文件复制到开发板上,Run the following command to get thereLCD上显示图片

./example_libjpeg-turbo light.jpg

Makefile

# 1. 使用不同的开发板内核时, 一定要修改KERN_DIR
# 2. KERN_DIR中的内核要事先配置、编译, 为了能编译内核, 要先设置下列环境变量:
# 2.1 ARCH, 比如: export ARCH=arm64
# 2.2 CROSS_COMPILE, 比如: export CROSS_COMPILE=aarch64-linux-gnu-
# 2.3 PATH, 比如: export PATH=$PATH:/home/book/100ask_roc-rk3399-pc/ToolChain-6.3.1/gcc-linaro-6.3.1-2017.05-x86_64_aarch64-linux-gnu/bin 
# 注意: 不同的开发板不同的编译器上述3个环境变量不一定相同,
# 请参考各开发板的高级用户使用手册

KERN_DIR = /home/tao/learn/100ask/100ask_stm32mp157_pro-sdk/Linux-5.4

all:
	$(CROSS_COMPILE)gcc -o example_libjpeg-turbo example.c -ljpeg

clean:
	rm -rf example_libjpeg 

example.c

example.c

#include <stdio.h>
#include "jpeglib.h"
#include <setjmp.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/fb.h>
#include <sys/mman.h>
#include <string.h>
#include <stdlib.h>

#define DBG_PRINT printf

static int g_iFdFb;
static struct fb_var_screeninfo g_tVar;
static int g_iScreenSize = 0;
static int g_iLineWidth = 0;
static int g_iPixelWidth = 0;
static unsigned char *g_pucFbMem = NULL;

static int 	FbDeviceInit(void)
{
    
	
	int ret = 0;

	/* 打开fb0 */
	g_iFdFb = open("/dev/fb0", O_RDWR);
	if(g_iFdFb < 0)
	{
    
		DBG_PRINT("can't open /dev/fb0");
		return -1;
	}


	/* 获取参数 */
	if(ioctl(g_iFdFb, FBIOGET_VSCREENINFO, &g_tVar))
	{
    
		DBG_PRINT("can't get screen var\n");
		ret = -1;
		goto fail_get_var;
	}
	
	g_iScreenSize = g_tVar.xres * g_tVar.yres * g_tVar.bits_per_pixel / 8;
	g_iLineWidth = g_tVar.xres * g_tVar.bits_per_pixel / 8;
	g_iPixelWidth = g_tVar.bits_per_pixel / 8;

	

	/* 映射内存 */
	g_pucFbMem = (unsigned char *)mmap(NULL, g_iScreenSize, PROT_WRITE | PROT_READ, MAP_SHARED,
				  g_iFdFb, 0);

	if(g_pucFbMem == (unsigned char *)-1)
	{
    
		DBG_PRINT("can't mmap to g_pucFbMem\n");
		ret = -1;
		goto fail_mmap_fb0;
	}

fail_mmap_fb0:
fail_get_var:
	close(g_iFdFb);
	return ret;
}

static int	FbScreenClean(unsigned int dwBackColor)
{
    
	int i;
	unsigned char *pucPen8 = (unsigned char *)g_pucFbMem;
	unsigned short *pwPen16 = (unsigned short *)pucPen8;
	unsigned int *pdwPen32 = (unsigned int *)pucPen8;
	unsigned char red, green, blue;


	switch(g_tVar.bits_per_pixel)
	{
    
		case 8:
		{
    
			memset(pucPen8, dwBackColor, g_iScreenSize);
			break;
		}

		case 16:
		{
    
			/* 565 */
			red = (dwBackColor >> 16) & 0xff;
			green = (dwBackColor >> 8) & 0xff;
			blue = (dwBackColor >> 0) & 0xff;
			dwBackColor = (red >> 3) << 11 | (green >> 2) << 5 | (blue >> 3) << 0;

			i = 0;
			for(i = 0; i < g_iScreenSize; i += 2)
			{
    
				*pwPen16 = dwBackColor;
				pwPen16++;
			}
			
			break;
		}

		case 32:
		{
    
			i = 0;
			for(i = 0; i < g_iScreenSize; i += 4)
			{
    
				*pdwPen32 = dwBackColor;
				pdwPen32++;
			}
			break;
		}

		default:
		{
    
			DBG_PRINT("can't support this bits_per_pixel\n");
			return -1;
			break;
		}
	}

	return 0;
}

static int	FbDrawPixel(int iX, int iY, unsigned int dwColor)
{
    
	
	unsigned char *pucPen8 = (unsigned char *)g_pucFbMem + iY * g_iLineWidth + iX * g_iPixelWidth;
	unsigned short *pwPen16 = (unsigned short *)pucPen8;
	unsigned int *pdwPen32 = (unsigned int *)pucPen8;

	unsigned char red, green, blue;


	switch(g_tVar.bits_per_pixel)
	{
    
		case 8:
		{
    
			*pucPen8 = dwColor;
			break;
		}

		case 16:
		{
    
			/* 565 */
			red = (dwColor >> 16) & 0xff;
			green = (dwColor >> 8) & 0xff;
			blue = (dwColor >> 0) & 0xff;
			dwColor = (red >> 3) << 11 | (green >> 2) << 5 | (blue >> 3) << 0;
			*pwPen16 = dwColor;
			break;
		}

		case 32:
		{
    
			*pdwPen32 = dwColor;
			break;
		}

		default:
		{
    
			DBG_PRINT("can't support this bits_per_pixel\n");
			return -1;
			break;
		}
	}

	return 0;
}

static int FbShowLine(int iStartX, int iEndX, int iY, unsigned char *pucBuffer)
{
    
	int i = iStartX * 3;
	unsigned int dwColor = 0;
	int iX;

	if(iY > g_tVar.yres)
		return -1;


	if(iStartX > g_tVar.xres)
		return -1;

	if(iEndX > g_tVar.xres)
		iEndX = g_tVar.xres;
	
	
	for(iX = iStartX; iX <= iEndX; iX ++)
	{
    
		dwColor = (pucBuffer[i] << 16) | (pucBuffer[i + 1] << 8) | (pucBuffer[i + 2]);
		FbDrawPixel(iX, iY, dwColor);
		i += 3;
	}
}


int main(int argc, char **argv)
{
    

	struct jpeg_decompress_struct cinfo;
	struct jpeg_error_mgr jerr;
	FILE * infile;
	int row_stride;
	unsigned char *buffer;		  /* Output row buffer */

	unsigned int dwBackColor;


	
	if(argc != 2)
	{
    
		printf("Useage: %s <jpeg_file>\n", argv[0]);
		return -1;
	}

	if(FbDeviceInit())
	{
    
		printf("FbDeviceInit err\n");
		return -1;
	}

	dwBackColor = 0x00000000;
	FbScreenClean(dwBackColor);

	
	
	cinfo.err = jpeg_std_error(&jerr);
	jpeg_create_decompress(&cinfo);

	if ((infile = fopen(argv[1], "rb")) == NULL) {
    
	    fprintf(stderr, "can't open %s\n", argv[1]);
	    return -1;
	}
	jpeg_stdio_src(&cinfo, infile);
	
	jpeg_read_header(&cinfo, TRUE);
	printf("image_width = %d\n", cinfo.image_width);
	printf("image_height = %d\n", cinfo.image_height);
	printf("num_components = %d\n", cinfo.num_components);

	jpeg_start_decompress(&cinfo);

	printf("output_width = %d\n", cinfo.output_width);
	printf("output_height = %d\n", cinfo.output_height);
	printf("out_color_components = %d\n", cinfo.out_color_components);
	printf("output_components = %d\n", cinfo.output_components);

	row_stride = cinfo.output_width * cinfo.output_components;

	buffer = malloc(row_stride);

	while(cinfo.output_scanline < cinfo.output_height)
	{
    
		jpeg_read_scanlines(&cinfo, &buffer, 1);
		// printf("%d %d %d\n", 0, cinfo.output_width, cinfo.output_scanline);
		FbShowLine(0, cinfo.output_width, cinfo.output_scanline, buffer);
	}

	jpeg_finish_decompress(&cinfo);
	jpeg_destroy_decompress(&cinfo);

	return 0;
}