filename.c

avr MP3 的源程序,包含文件系统,适合初学者

//**********************************************************************
//FileName     : fileName.c
//Created by   : ZhengYanbo
//Created Date : 09/09/2005
//Version      : v1.1
//Last modified: 2007.5.2, for printing file name to pc
//**********************************************************************

#include "fileName.h"
#include "type.h"
#include "global_def.h"
#include "fat.h"


//**********************************************************************
// This function is used to convert an Unicode to a GB2312
// code. Unicode table is stored in harddisk or CF Card.
// Return GBcode if succeed,or return its unicode. 
// Unicode: low byte first here!
// For mega162 cpu: and sectorBuffer is 512 bytes, 2007.5.2
word Unicode2GB(word unicode)
//********************************************************************** 
{ 
  byte i;
  UNICODE_TAB *p; word trueCode;
  
  trueCode=(unicode>>8) & 0x00FF;
  trueCode=((unicode<<8) & 0xFF00) | trueCode;
  if(trueCode>0x00a3) //unicode start at 0x00a4
  {
  //Load first cluster of UNICODE.BIN
  currentCluster=tableStartCluster; 
  readPos=0; sectorPos=0;
  filePos=0;
  do { //search a matched GBcode in the UNICODE.BIN file
  read_a_sector_file(sectorBuffer.data);
  //please notice: sectorBuffer is 512 bytes 
  p=(UNICODE_TAB *) sectorBuffer.data; //init pointer
  for(i=0; i<128; i++)
  {//Total Unicode:7446, sectorBuffer holds 128 GBcodes only
  if(p->unicode==unicode)
  { //matched
    trueCode=p->GBcode;
    return(trueCode);
  }
  else p++;
  }//for(i=0; i<128; i++)
  }//do-while loop
  while(filePos < tableFileSize);
  }
  return unicode; //can't find  
}

//********************************************************************** 
//This function can convert an unicode string to GB string.
//do the proccess for chinese character displaying.
//This function is written for filename conversion. 
void file_name_to_GB(void)
//**********************************************************************  
{ 
  unsigned int *p; unsigned char i=0;
  unsigned char length;
  
  length=(FILE_NAME_LENGTH>>1)-1;
  p=(unsigned int *)fileName; //init pointer
  while(((*p)!=0)&&(i<length)) {*p=Unicode2GB(*p); p++; i++; }
}

//**********************************************************************
byte get_string_word_length(byte *string)
//**********************************************************************
{ 
  byte length;
  word *p;
  p=(unsigned int *)string;
  length=0;
  while((*p)!=0) {length++; p++; }
  return length;
}

void fileNameInsertSpace(void)
{ 
  byte len; byte i;
  
  len=get_string_word_length(fileName);
  len = len << 1; //len * 2
  i = 0;
  while(i < len){if(fileName[i] == 0) fileName[i] = ' ', i++;}; 
}
  
//********************************************************************** 
void string_array(byte *string)
//********************************************************************** 
{ byte ascNum;
  byte newpos,offset;
  byte length; 
  
  newpos=0; ascNum=0; //clear ascii code number
  offset=0; //p pointer offset
  length=get_string_word_length(string);
  length=length<<1; //word length-->byte length
  do
  { 
  if(string[offset]!=0)
  { if(string[offset]>0x7F)
    { //Found GB code
      if((ascNum % 2)!=0)
      { //insert 0x20
        string[newpos++]=0x20;
      }
      ascNum=0;
    }
    else   
    { //if its ascii code
      ascNum++; //found an ascii code
    }   
    string[newpos++]=string[offset];
    offset++; //point to next byte
  } 
  else
  offset++;
  }
  while(offset<length); //NULL is an end sign 
  string[newpos]=0; //Set last char to NULL
}
/*
void print_file_name(byte *p)
{      
  byte i;
  
  file_name_to_GB();
  string_array(p);
  while(*p != 0) USART_put_char(*p++);
}*/

void print_file_name(byte *p)
{
  byte i;
  
  file_name_to_GB();
  for(i=0; i<FILE_NAME_LENGTH; i++)
  {if(p[i] != 0) USART_put_char(p[i]);};
}


//end of fileName.c