環境：
硬體：radxa rock開發板，藍色妖姬t998無驅攝像頭
系統：lubuntu 3月15號韌體，v4l2
其實我只是把草根老師的部落格**改了些引數：
1.攝像頭的模式由o_rdwr | o_nonblock改為o_rdwr，若不改，會報dq_buf的bug
3.n_buffer中途會莫名其妙改變，所以在程式中人為賦值
程式執行後，會儲存count個bin檔案在選定目錄下。檔案內容是yuyv422的影象資料。
1.2.
#include #include #include #include #include #include #include #include #include #include #include #include "unistd.h"
typedef struct
buftype;
buftype user_buf_real;
buftype *user_buf=&user_buf_real;
int n_buffer = 0;
//鎵撳紑鎽勫儚澶磋澶?int open_camer_device()
printf("open camer %d \n",fd);
return fd;
}int init_mmap(int fd)
n_buffer = reqbuf.count; //mark reatch here
printf("n_buffer = %d\n",n_buffer);
//test_yz = calloc(reqbuf.count,sizeof(buftype));
//test
//user_buf->start =(void*)calloc(reqbuf.count,sizeof(*user_buf)); //mark-err
user_buf->start = calloc(reqbuf.count,sizeof(*user_buf));
//user_buf = (buftype*)(calloc(reqbuf.count,sizeof(*user_buf))); //mark-err
// printf("start \n");
printf("start %d \n",user_buf->start);
// if(user_buf == null)
//灝嗗唴鏍哥紦鍐插尯鏄犲皠鍒扮敤鎴瘋繘紼嬬┖闂? for(i = 0; i < reqbuf.count; i ++)
user_buf[i].length = buf.length;
user_buf[i].start =
mmap(
null,/*start anywhere*/
buf.length,
prot_read | prot_write,
map_shared,
fd,buf.m.offset
);test
printf("user_buf: %d \t start addr:%d \n",i,user_buf->start);
if(map_failed == user_buf[i].start)
} return 0;
}//鍒濆鍖栬棰戣澶?int init_camer_device(int fd)
,description = '%s'\n",
fmt.pixelformat & 0xff,(fmt.pixelformat >> 8)&0xff,
(fmt.pixelformat >> 16) & 0xff,(fmt.pixelformat >> 24)&0xff,
fmt.description);
} //鏌ヨ瑙嗛璁懼椹卞姩鐨勫姛鑳? ret = ioctl(fd,vidioc_querycap,&cap);
if(ret < 0)
printf("catability : \n");
printf("driver = %s \n",cap.driver);
printf("card = %s \n",cap.card);
//鍒ゆ柇鏄惁鏄竴涓棰戞崟鎹夎澶? if(!(cap.capabilities & v4l2_buf_type_video_capture))
//鍒ゆ柇鏄惁鏀寔瑙嗛嫻佸艦寮? if(!(cap.capabilities & v4l2_cap_streaming))
//璁劇疆鎽勫儚澶撮噰板嗘暟鎹牸寮忥紝濡傝緗噰板嗘暟鎹殑
//闀?瀹斤紝鍥懼儚鏍煎紡(jpeg,yuyv,mjpeg絳夋牸寮?
stream_fmt.type = v4l2_buf_type_video_capture;
stream_fmt.fmt.pix.width = 640;
stream_fmt.fmt.pix.height = 480;
stream_fmt.fmt.pix.pixelformat = v4l2_pix_fmt_yuyv;
stream_fmt.fmt.pix.field = v4l2_field_interlaced;
if(-1 == ioctl(fd,vidioc_s_fmt,&stream_fmt))
//鍒濆鍖栬棰戦噰板嗘柟寮?mmap)
init_mmap(fd);
return 0;
}int start_capturing(int fd)
} //寮€濮嬮噰板嗘暟鎹? type = v4l2_buf_type_video_capture;
if(-1 == ioctl(fd,vidioc_streamon,&type))
return 0;
}//灝嗛噰板嗗ソ鐨勬暟鎹斁鍒版枃浠朵腑
int process_image(void *addr,int length)
fwrite(addr,length,1,fp);
usleep(500);
fclose(fp);
return 0;
}int read_frame(int fd)
assert(buf.index < n_buffer);
//璇誨彇榪涗▼絀洪棿鐨勬暟鎹埌涓€涓枃浠朵腑
printf("buf.index: %d \n",buf.index);
process_image(user_buf[buf.index].start,user_buf[buf.index].length);
//process_image(user_buf->start,user_buf->length);
if(-1 == ioctl(fd,vidioc_qbuf,&buf))
return 1;
}int mainloop(int fd)
if(0 == r)
if(read_frame(fd))
break;
} }return 0;
}void stop_capturing(int fd)
return;
}void uninit_camer_device() }
//free(user_buf);
printf("start addr: %d \n",user_buf->start);
free(user_buf->start);
return;
}void close_camer_device(int fd)
return;
}int main()
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