音乐播放器1-FATFS相关操作

　　　　音乐播放器的两个关键点：1、用FATFS对音乐文件进行管理，包括打开，读取等。2、配置Codec芯片，通过DMA，把读取的音乐文件数据送到Codec。
这个工程中，主要实现第一个大点的一些操作。
　　　　直接上程序，需要注意的几个点。
#include "sys.h"
#include "delay.h"
#include "usart.h"
#include "led.h"
#include "lcd.h"
#include "key.h"  
#include "sram.h"   
#include "malloc.h" 
#include "sdio_sdcard.h"    
#include "malloc.h" 
#include "ff.h"  
#include "string.h"
#include "fattester.h"void upper(char *p);　　　　//这个函数用来把小写字母转换成大写
u8 tell_type(char *p);　　　//通过后缀名识别文件类型
u8 wav_decode(FIL *p);    //WAV文件的解码

u8 *readbuf;       
UINT mybr;        

int main(void)
{        
    u8 key,res,music_number;
    char *myfn;                
    char *myfn_temp;              
    char *filename_temp;
    
　　　//FATFS相关的变量
    FATFS *fs[1];   
    FIL *myfile;
    DIR mydir; 
    FILINFO    myfileinfo;
    FRESULT myres;
        
    //初始化
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); 
    delay_init(168);   
    uart_init(115200);         
    LED_Init();                     
     KEY_Init();                     
    my_mem_init(SRAMIN);        
    my_mem_init(SRAMCCM);        
    
  　　//SD卡初始化
     while(SD_Init())
    {
        delay_ms(500);
        LED0=!LED0; 
    }
    
    //FATFS相关的很多函数，用到的结构体，需要申请内存，不然会出错，比如f_mount/f_open
    fs[0]=(FATFS*)mymalloc(SRAMIN,sizeof(FATFS));    
    myfile=(FIL*)mymalloc(SRAMIN,sizeof(FIL));
    myfileinfo.lfsize = _MAX_LFN * 2 + 1;
    myfileinfo.lfname = mymalloc(SRAMIN,myfileinfo.lfsize);     // 支持长文件名，方法为3，需要动态申请内存 _USE_LFN=3
    readbuf=(u8*)mymalloc(SRAMIN,512);    //读文件的缓冲区
    myfn_temp= (char *)mymalloc(SRAMIN,myfileinfo.lfsize);
    
    res=f_mount(fs[0],"0:",1);                     //挂载
    while(1)
    {
        key=KEY_Scan(0);
        
        if(key==1)                    //测试当前目录的文件读取，f_open-----f_read
        {
            f_open(myfile,"test1.txt",FA_READ);
            res=f_read(myfile,readbuf,20,&mybr);
            if(res)
                printf("Read Error:%d
",res);
            else
                while(*readbuf!='')
                {
                    printf("%c",*readbuf);
                    readbuf++;
                }
        }
        
        if(key==2)                    //文件类型识别
        {    
            music_number=0;    
            f_opendir(&mydir,"0:/MUSIC");     // 
            while(1)
            {
                myres=f_readdir(&mydir,&myfileinfo); //循环读取文件夹中所有的文件
                if(myres != FR_OK || myfileinfo.fname[0] == 0)
                    break;
                myfn = *myfileinfo.lfname ? myfileinfo.lfname : myfileinfo.fname; 
                printf("
File name is %s
",myfn);
                filename_temp=myfn;
                res=tell_type(myfn);
              if(res==0) 
              {
                  printf("This is a music file.
");
                    music_number++;//strcat(myfn_temp,myfn);
                    strcpy((char*)myfn_temp,"0:/MUSIC/");                
                    strcat((char*)myfn_temp,(const char*)myfn);   //获取文件的绝对路径
                    printf("
File name is %s
",myfn_temp);
                    f_open(myfile,myfn_temp,FA_READ);
                    wav_decode(myfile);
              }            
            }
            printf("
There is %d music file
",music_number);
        }
        
        if(key==3)                  //
        {
            f_opendir(&mydir,"0:/MUSIC");  
            f_open(myfile,"0:/MUSIC/µË×ÏÆå-Äã°ÑÎÒ¹à×í.wav",FA_READ); 
            wav_decode(myfile);
        }
    } 
}



//把字符串中的大写改成小写
void upper(char *p)
{
    while(*p!='')
    {
        if((*p>=97)&&(*p<=120))
            *p=*p-32;
        p++;
    }
}


//通过后缀名识别文件类型
u8 tell_type(char *p)
{
    int i=0;
    char *attr;
    while(i<200)
    {
        if(*p=='') 
            break;
        i++;
        p++;
    }
    if(i==200)  
        return 1;
    i=0;
    while(i<5)
    {
        if(*p=='.')  
        {
            p++;
            attr=p;   
            break;
        }
        i++;
        p--;
    }
    if(i==5)   
        return 2;

    if((strcmp(attr,"WAV")==0)||(strcmp(attr,"wav")==0))
    {
        return 0;                
    }
    else
        {  
            return 4;
        }
}

//RIFF¿é
typedef __packed struct
{
    u32 ChunkID;               // 0X46464952
    u32 ChunkSize ;              
    u32 Format;                   
}ChunkRIFF ;
//fmt¿é
typedef __packed struct
{
    u32 ChunkID;               
    u32 ChunkSize ;               
    u16 AudioFormat;          
      u16 NumOfChannels;        
      u32 SampleRate;            
      u32 ByteRate;            
      u16 BlockAlign;            
      u16 BitsPerSample;        //    u16 ByteExtraData;         
}ChunkFMT;       
//fact¿é 
typedef __packed struct 
{
    u32 ChunkID;               
    u32 ChunkSize ;               
    u32 NumOfSamples;          
}ChunkFACT;






u8 wav_decode(FIL *p)
{        
        u8 res;
        ChunkRIFF *riff;
        ChunkFMT  *fmt;

        res=f_read(p,readbuf,512,&mybr); //ÔÚÍâÃæÖÐÒÑ¾open
        if(res==FR_OK)
        {        
                riff=(ChunkRIFF *)readbuf;
                printf("This is RIFF Chunk Read-----------
");
                printf("RIFF ChunkID is %x
",riff->ChunkID);
                printf("RIFF ChunkSize is %d MB
",riff->ChunkSize>>20);
                printf("RIFF Format is %x
",riff->Format);
            
                printf("This is FMT Chunk Read-----------
");
                fmt=(ChunkFMT *)(readbuf+12);
                printf("FMT ChunkID is %x
",fmt->ChunkID);
                printf("FMT ChunkSize is %d
",fmt->ChunkSize);
                printf("FMT Channle is %d
",fmt->NumOfChannels);    
            
        }
        else 
        {    
                printf("Read Err:%d
",res);
        }
        return res;
}