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交叉编译libzbar和libjpeg的简单笔记

cstriker1407的笔记本 7 阅读

最近项目上需要使用二维码识别,网上简单的搜索了下相关知识,这里简单的笔记下流水账。

zbar

首先下载zbar源码,官方网址:

解压后发现是configure这种方式编译的。

正常编译

cstriker1407:/zbar/zbar-0.10$ ./configure --help
`configure' configures zbar 0.10 to adapt to many kinds of systems.
。。。。。。
。。。。。。
Report bugs to <spadix@users.sourceforge.net>.

由于项目只用于识别二维码,因此简单起见,去掉所有的编译可选项。

cstriker1407:/zbar/zbar-0.10$ ./configure  --disable-video --without-imagemagick --without-xv --without-xshm --without-gtk --without-python -without-qt  --disable-assert
。。。。。。。。
。。。。。。。。
cstriker1407:/zbar/zbar-0.10$ make
。。。。。。。。
。。。。。。。。

编译完成后的库就在 zbar/.libs/ 中。

交叉编译

cstriker1407:/zbar/zbar-0.10$ CC=XXXXXXXX/bin/arm-unknown-linux-uclibcgnueabi-gcc  ./configure  --disable-video --without-imagemagick --without-xv --without-xshm --without-gtk --without-python -without-qt  --disable-assert --build=x86_64 -host=arm-unknown-linux-uclibcgnueabi --disable-shared
cstriker1407:/zbar/zbar-0.10$ make

libjpeg

libjpeg的下载地址
https://sourceforge.net/projects/libjpeg/

正常编译

cstriker1407:/libjpeg/jpeg-9b$ ./configure
cstriker1407:/libjpeg/jpeg-9b$ make

交叉编译

cstriker1407:/libjpeg/jpeg-9b$ CC=usr/bin/arm-unknown-linux-uclibcgnueabi-gcc  ./configure --build=x86_64 -host=arm-unknown-linux-uclibcgnueabi
cstriker1407:/libjpeg/jpeg-9b$ make

DEMO

#include <stdio.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

#include <zbar.h>
#include <jpeglib.h>
#include <jerror.h>

static void _convert_data (const unsigned char *p_jpg_buffer, unsigned int jpg_size, int *width, int *height, void **raw)
{
	struct jpeg_decompress_struct cinfo;
	struct jpeg_error_mgr err;
	cinfo.err = jpeg_std_error(&err);
	jpeg_create_decompress(&cinfo);
	jpeg_mem_src(&cinfo, (unsigned char *)p_jpg_buffer, jpg_size);
	(void)jpeg_read_header(&cinfo, TRUE);
	cinfo.out_color_space = JCS_GRAYSCALE;
//	cinfo.two_pass_quantize = TRUE;
	(void)jpeg_start_decompress(&cinfo);
	*width = cinfo.image_width;
	*height = cinfo.image_height;
	*raw = (void *)malloc(cinfo.output_width * cinfo.output_height * 3);
	unsigned bpl = cinfo.output_width * cinfo.output_components;
	JSAMPROW buf = (void *)*raw;
	JSAMPARRAY line = &buf;
	for (; cinfo.output_scanline < cinfo.output_height; buf += bpl) 
	{
		jpeg_read_scanlines(&cinfo, line, 1);
	}
	(void)jpeg_finish_decompress(&cinfo);
	jpeg_destroy_decompress(&cinfo);
}


int main (int argc, char **argv)
{
    if(argc < 2) return(1);

    FILE *pFile = fopen(argv[1], "r+b");
    unsigned char *p_ReadBuffer = malloc(81920);
	memset(p_ReadBuffer, 0, 81920);
    int freadResult = fread(p_ReadBuffer, 1, 81920, pFile);
    printf("read %d \r\n", freadResult);

    zbar_image_scanner_t *scanner = NULL;
    scanner = zbar_image_scanner_create();
    zbar_image_scanner_set_config(scanner, ZBAR_QRCODE, ZBAR_CFG_ENABLE, 1);


    /* obtain image data */
    int width = 0, height = 0;
    void *raw = NULL;

    _convert_data(p_ReadBuffer, freadResult, &width, &height, &raw);
    free(p_ReadBuffer);

    printf("width:%d  height:%d \r\n", width, height);

    /* wrap image data */
    zbar_image_t *image = zbar_image_create();
    zbar_image_set_format(image, *(int*)"Y800");
    zbar_image_set_size(image, width, height);
    zbar_image_set_data(image, raw, width * height, zbar_image_free_data);

    /* scan the image for barcodes */
    int n = zbar_scan_image(scanner, image);
    
    /* extract results */
    const zbar_symbol_t *symbol = zbar_image_first_symbol(image);
    for(; symbol; symbol = zbar_symbol_next(symbol)) 
    {
        /* do something useful with results */
        zbar_symbol_type_t typ = zbar_symbol_get_type(symbol);
        const char *data = zbar_symbol_get_data(symbol);
        printf("decoded %s symbol \"%s\"\n", zbar_get_symbol_name(typ), data);
    }

    /* clean up */
    zbar_image_destroy(image);
    zbar_image_scanner_destroy(scanner);

    return 0;
}
作者:cstriker1407的笔记本
好记性不如烂笔头
原文地址:交叉编译libzbar和libjpeg的简单笔记, 感谢原作者分享。

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