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#include <fcntl.h> (61_=,jv\h
#include <stdio.h> JE<zQf( &
#include <sys/ioctl.h> ;m;a"j5
#include <stdlib.h> Gg\805L@
#include <linux/types.h> }nQni?
#include <linux/videodev2.h> &@c?5Ie5
#include <malloc.h> x*EzX4$x
#include <math.h> 33{(IzL0
#include <string.h>
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#include <sys/mman.h> ^+ hJ& 9W
#include <errno.h> Ls<.&3X2
#include <assert.h> (&w'"-`
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#define FILE_VIDEO "/dev/video0" p;GT[Ds^
#define JPG "./image%d.jpg" abHW[VP9
qm.30 2
typedef struct{ =*AAXNs@3
void *start; \G3P[E[
int length; {EoRY/]
}BUFTYPE; T4O H,^J
BUFTYPE *usr_buf; =9lrPQ]w
static unsigned int n_buffer = 0; Bc/'LI.%
#!m`A+!~!
//set video capture ways(mmap) \,w*K'B_Y
int init_mmap(int fd) Lqt.S|
{ "w)Y0Qq*z
//to request frame cache, contain requested counts MpV3.
struct v4l2_requestbuffers reqbufs; >d`XR"_e
//request V4L2 driver allocation video cache a cSm+t
//this cache is locate in kernel and need mmap mapping T,Bu5:@#
memset(&reqbufs, 0, sizeof(reqbufs)); C)7T'[
reqbufs.count = 4; 8>E_bxC
reqbufs.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; !T((d7;
reqbufs.memory = V4L2_MEMORY_MMAP; "k8Yc<`u
uN:|4/;{&
if(-1 == ioctl(fd,VIDIOC_REQBUFS,&reqbufs)){ Wz}8O]#/.
perror("Fail to ioctl 'VIDIOC_REQBUFS'"); Vr1Wr%
exit(EXIT_FAILURE); COE,pb17
} dFd^@b
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n_buffer = reqbufs.count; !n=?H1@
printf("n_buffer = %d\n", n_buffer); n~1'M/wh
usr_buf = calloc(reqbufs.count, sizeof(BUFTYPE)); K/2k/\Jk[_
if(usr_buf == NULL){ !besMZ
printf("Out of memory\n"); I^M%+\
exit(-1); 6 9 PTo
} ?P+n0S!
;g3z?Uz)
//map kernel cache to user process 19Cs
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for(n_buffer = 0; n_buffer < reqbufs.count; ++n_buffer){ @R5jUPUVV
//stand for a frame Bf72 .gx{0
struct v4l2_buffer buf; n21Pfig
memset(&buf, 0, sizeof(buf)); B! `Dj,_
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; m15MA.R>
buf.memory = V4L2_MEMORY_MMAP; vhw"Nl
buf.index = n_buffer; pjC2jlwm*
*V\z]Dy-[
//check the information of the kernel cache requested m=^`u:=
if(-1 == ioctl(fd,VIDIOC_QUERYBUF,&buf)) 61Z#;2]
{ F{#m~4O
perror("Fail to ioctl : VIDIOC_QUERYBUF"); 6.o8vC/PZ
exit(EXIT_FAILURE); thoAEG80
} [-Zp[
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printf(" buf.length =%d\n", buf.length); ?_\t7f
}{! #`'s
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usr_buf[n_buffer].length = buf.length; xW$F-n
usr_buf[n_buffer].start = /5:f[-\s
mmap( U({20
NULL, +Zaew679
buf.length, U($sH9,
PROT_READ | PROT_WRITE, +3HukoR(
MAP_SHARED, HT]v S}s
fd, M*DF tp<
buf.m.offset \JJ>y
); //mmap(0, fbSize, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); k,EI+lC X
}pE8G#O&
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if(MAP_FAILED == usr_buf[n_buffer].start) l!n<.tQW
{ #q;hX;Va
perror("Fail to mmap"); f@ &?K<
exit(EXIT_FAILURE); '%W'HqVcG1
} ;z6Gk&?
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printf(" usr_buf[%d].start=0x%x length=0x%x \n" , n_buffer, usr_buf[n_buffer].start ,buf.length); PGT*4r21
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} ~,
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return 0; VZOf| o
} <Tq&Va_w
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//initial camera device ?/mk FDN
int init_camera_device(int fd) ryz
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{ NF&
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//decive fuction, such as video input s]=s2.=
struct v4l2_capability cap; e=11EmN9
//video standard,such as PAL,NTSC N4 O'{
struct v4l2_standard std; "J0,SFu:
//frame format _9Pxtf
struct v4l2_format tv_fmt; F&{RP>
//check control yOn +Y
struct v4l2_queryctrl query; b\/:-][
//detail control value *>Z|!{bI
struct v4l2_fmtdesc fmt; %-~W|Y
int ret; @PXb^x#k
//get the format of video supply KRS_6G],{
memset(&fmt, 0, sizeof(fmt)); >U~B"'!xV
fmt.index = 0; $#4J^(I*:
//supply to image capture f%LzWXA
fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; b8V]/
// show all format of supply )"
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printf("Support format:\n"); RP]hW{:U
while(ioctl(fd, VIDIOC_ENUM_FMT, &fmt) == 0){ JPS7L} Kv
fmt.index++; \`w!v,aM$
printf("pixelformat = ''%c%c%c%c''\ndescription = ''%s''\n",fmt.pixelformat & 0xFF, (fmt.pixelformat >> 8) & 0xFF,(fmt.pixelformat >> 16) & 0xFF, (fmt.pixelformat >> 24) & 0xFF,fmt.description); 1Aq*|JSk(
} F+;{s(wx
//check video decive driver capability #4(/#K 1j
ret = ioctl(fd, VIDIOC_QUERYCAP, &cap); SrV+Ox
if(ret < 0){ :kycIM]s
perror("Fail to ioctl VIDEO_QUERYCAP"); I0 y+,~\
exit(EXIT_FAILURE); q% Eze
} @MfuV4*
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//judge wherher or not to be a video-get device Rd5ni2-nve
if(!(cap.capabilities & V4L2_BUF_TYPE_VIDEO_CAPTURE)) =d/\8\4
{ !HA[:-JCz
printf("The Current device is not a video capture device\n"); VjU;[
exit(-1); <!.'"*2
} m1 78S3
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a
//judge whether or not to supply the form of video stream 15Vb`Vf`N
if(!(cap.capabilities & V4L2_CAP_STREAMING)) fH.:#O:
{ W~GbB:-
printf("The Current device does not support streaming i/o\n"); wj>mk
exit(EXIT_FAILURE); $|v_ pjUu]
} rs01@
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//set the form of camera capture data &z;;Bx0s
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tv_fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; U;n$
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#if 0 s8| =1{
tv_fmt.fmt.pix.width = 640; \14"B gj1
tv_fmt.fmt.pix.height = 360; 1xM'5C?~7
#else MnvFmYgxA
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tv_fmt.fmt.pix.width = 1280; "|CzQ&e
tv_fmt.fmt.pix.height = 960; #5GIO
v\*43RL
de{KfM`W;
#endif u7>b}+ak&
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#LlHsY530N
:8}QKp
tv_fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_MJPEG; ^Yei9bXl
//V4L2_PIX_FMT_YUYV y@[}FgVOh
tv_fmt.fmt.pix.field = V4L2_FIELD_INTERLACED; -SaH_Nuj
if (ioctl(fd, VIDIOC_S_FMT, &tv_fmt)< 0) { |w2H5f{fR
printf("VIDIOC_S_FMT\n"); Y)Y`9u<?
exit(-1); q10gKVJum
close(fd); o.t$hv|
} xwa5dtcng
//initial video capture way(mmap) &eV& +j
init_mmap(fd); PL/as3O^A
return 0; mH>oF|
} $: "r$7
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int open_camera_device() u2
a
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{ _aVrQ@9
int fd; I|lz;i}$
//open video device with block >TUs~
fd = open(FILE_VIDEO, O_RDWR /* required */ | O_NONBLOCK, 0);//打开设备 V6"<lK8"
if(fd < 0){ a'w~7y!}
perror(FILE_VIDEO); M}NmA
exit(EXIT_FAILURE); tS,nO:+x
} -x2/y:q `
return fd; zVe@`gc
} zCKZv|j6
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int start_capture(int fd) yfeX=h
{ \o9-[V#Gm
unsigned int i; ]Mi
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q
enum v4l2_buf_type type; yiGq?WA7
//place the kernel cache to a queue v5l)T}Nb
for(i = 0; i < n_buffer; i++){ fk4s19;?
struct v4l2_buffer buf; /*g3TbUs
memset(&buf, 0, sizeof(buf)); `O(ec
buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; /2-S/,a
buf.memory = V4L2_MEMORY_MMAP; / <WB%O
buf.index = i; Etty{r}
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if(-1 == ioctl(fd, VIDIOC_QBUF, &buf)){ 7PO3{I
perror("Fail to ioctl 'VIDIOC_QBUF'"); cVJ"^wgBt
exit(EXIT_FAILURE); |cStN[97%
} yC !`6$
} #+HLb
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//start capture data /kE3V`es
type = V4L2_BUF_TYPE_VIDEO_CAPTURE; M>dP
1
if(-1 == ioctl(fd, VIDIOC_STREAMON, &type)){ X=_pQ+j`^
printf("i=%d.\n", i); =8$//$
perror("VIDIOC_STREAMON"); B
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close(fd); C%d\DuJ5'~
exit(EXIT_FAILURE); qLBXyQ;U
} Htn=h~U`z
return 0; |t*(]U2O0
} >k,|N4(
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int process_image(void *addr, int length) `rsPIOu
{ x@I*(I
int fd; D"0:n.
static int num = 0; q65KxOf`
char image_name[20]; >_P7 k5Y^
4s nL((
printf("%s addr = 0x%x length= %d \n" , __func__,addr,length); zbK=yOIOd
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sprintf(image_name, JPG, num++); ,/AwR?m
$2qZds[
if((fd= open(image_name,O_CREAT|O_WRONLY)) == NULL){ I&~kwOP
&Oc^LV$6
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printf("Fail to fopen"); ,gGIkl&
exit(EXIT_FAILURE); S[,!
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} nmZz`P9g
s. I%[kada
write(fd,addr, length); Y$hYW
sync( ); xF:
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close(fd); "*W:
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return 0; I|69|^
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} >QO^h<.>
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int read_frame(int fd) j6v|D>I
{ 8*7t1$
struct v4l2_buffer buf; R<.<wQ4I
unsigned int i; 8G$ %DZ $
memset(&buf, 0, sizeof(buf)); \7rAQ[\#V
8:=&=9%
printf("%s run place 1 \n",__func__); gGF]Dq
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buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; V]I@&*O~r
buf.memory = V4L2_MEMORY_MMAP; 9U[Gh97Sf
//put cache from queue R_9 &V!fl
if(-1 == ioctl(fd, VIDIOC_DQBUF,&buf)){ rEz-\jLD~
perror("Fail to ioctl 'VIDIOC_DQBUF'"); AGaM
&x=
exit(EXIT_FAILURE); 6v8HR}iK
} %Aaf86pkp
\7b-w81M-
assert(buf.index < n_buffer); MKVz'-`u
//read process space's data to a file x/~qyX8vo
printf("buf.index=%d\n",buf.index); g4b-~1[S
^(z7?T
process_image(usr_buf[buf.index].start, buf.bytesused); 1Q_ C
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printf("%s run place 2 \n",__func__); ;R[ xo!
fM,!9}<
if(-1 == ioctl(fd, VIDIOC_QBUF,&buf)){ =&+]>g{T
perror("Fail to ioctl 'VIDIOC_QBUF'"); o95)-Wb
exit(EXIT_FAILURE); d4ANh+}X"_
} B
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u#(&
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printf("%s run place 3 \n",__func__); fP 1V1ao
c:#<g/-{wM
return 1; [zXKS|
} 5)712b(&
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int mainloop(int fd) 1.S7MSpTV
{
lMkDLobos
int count =20; a=ye!CN^
3K{XT),
while(count-- > 0) O
&/9wi>!q
{ j@w+>h
for(;;) =1!,A
{ +jpaBr-O#
fd_set fds; 4Sj;38F
.1
struct timeval tv; l7{]jKJue
int r; +&AKDVmx
C(w?`]Qs
printf("count = %d \n", count); Vki'pAN
v~l_6V}
FD_ZERO(&fds); n jfh4}g:
FD_SET(fd,&fds); tQ:g#EqL9B
A~2U9f+\
/*Timeout*/ WA'&