主要思路
1.找到视频文件
2.将视频文件名保存在一个链表中，以便切换
3，利用已经写好的mplayer将查找到的视频文件播放出来
4，交叉编译后在arm开发板上实现视频播放
总结：代码的编写一定要用心，打错一字母或者用错一个函数，当编译器不报错时我将可能会花一下午甚至更长的时间来找错。
思路一定要清晰，不然会花很多时间来改写代码。
以下代码没有只能通过键盘来实现播放操作，明天将利用线程来实现对播放的快进，暂停，切换等的操作
今日代码:
/*************************************************************************
> File Name: armplayer.c
> Author: csgec
> Mail: [email protected]
> Created Time: Wed 25 Jul 2018 09:36:33 AM HKT
************************************************************************/
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<fcntl.h>
#include<unistd.h>
#include<dirent.h>
#include<error.h>
#include<string.h>
#include<sys/stat.h>
typedef struct node
{
char name[256];
struct node *next;
struct node *pre;
}Node;
Node *head,*tail,*p;
Node * find(char *pathname)//找文件名,并存入链表中
{
printf("进入了查找函数&&&&&&\n");
DIR *dir;
char filename[512];
dir = opendir(pathname);
if(dir == NULL)
{
perror("打开路径失败\n");
return ;
}
struct dirent *dirp = NULL;
while(dirp = readdir(dir))
{
//当前目录和上级目录就跳过
if(strcmp(dirp->d_name,".") == 0 || strcmp(dirp->d_name,"..") == 0)
{
continue;
}
sprintf(filename,"%s/%s",pathname,dirp->d_name);
if(strcmp(filename+strlen(filename)-4,".mp4")==0 || strcmp(filename+strlen(filename)-4,".mp3")==0)
{
Node *p = (Node *)malloc(sizeof(Node));
strcpy(p->name,filename);
printf("找到的文件名 %s\n",p->name);
p->next = p->pre = NULL;
if(head == NULL)
{
head = tail = p;
}
else
{
tail->next = p;
p->pre = tail;
tail = p;
}
}
struct stat st;//申明stat结构体
stat(filename,&st);//将文件名放入结构体中
if(S_ISDIR(st.st_mode))//判断是不是目录
{
find(filename);//是就用递归来循环查找
}
}
closedir(dir);
return head;
}
pid_t pid;
int pipefd[2];
int wfd,rfd;
char buf[128];
Node *player(char *name)//播放函數
{
printf("进入了播放函数\n");
printf("播放的文件名为 %s\n",name);
mkfifo("fifo",0644);//有名管道的创建
pid = fork();
if(pid < 0)
{
perror("fork fail\n");//
exit(-1);
}
if(pipe(pipefd) < 0)//无名管道的创建以及判断
{
perror("pipe fail\n");
}
if(pid == 0)//子进程
{
close(pipefd[0]);//关闭读空间
rfd = open("fifo",O_RDONLY);//只读打开有名管道
if(rfd < 0)
{
perror("child open fifo fail\n");
exit(-1);
}
execlp("mplayer","","-ac","mad","-slave","-quiet","-input","file=fifo",name,NULL);
}
else if(pid > 0)//父进程
{
wfd = open("fifo",O_WRONLY);//只写打开有名管道
if(wfd < 0)
{
perror("parent open fifo fail\n");
waitpid(pid,NULL,0);
exit(-1);
}
close(pipefd[1]);//关闭写空间
while(1)
{
char ch;
ch = getchar();
if(ch == 'q')
break;
switch(ch)
{
case 'p':
write(wfd,"pause\n",strlen("pause\n"));
break;
case 'k':
write(wfd,"seek 3\n",strlen("seek 3\n"));
break;
case 'g':
write(wfd,"get_time_pos\n",strlen("get_time_pos\n"));
memset(buf,0,128);
read(pipefd[0],buf,128);
printf("read return；%s\n",buf);
break;
}
}
}
kill(pid);
waitpid(pid,NULL,0);
close(pipefd[0]);
}
int main(int argc,char *argv[])
{
Node *tail,*head,*p;
head = find(argv[1]);//找到文件名
p = head;
player(p->name);//播放;W
printf("end end end \n");
return 0;
}