wavefiletools.c

关于AMR-WB+语音压缩编码的实现代码

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "../include/amr_plus.h"
static void ExtractFormat(char *FormatString, short *ReadFlag, short *AppendFlag);
/*____________________________________________________________________________
 |
 |  FUNCTION NAME: Wave_fopen
 |____________________________________________________________________________
*/
FILE *Wave_fopen(char *Filename, char *Mode, short *NumOfChannels, long *SamplingRate, short *BitsPerSample,
				 long *DataSize)
{	
FILE *FilePtr, *FilePtrAppend=NULL;
short ReadFlag;
short AppendFlag;
char  WaveTag[4];
long  PCM_Size = 0L;
long  FileSize = 0L;		/* Actual size will be replaces in "Wave_fclose" -procedure */
long  FormatSize = 16L;		
short FormatTag = 1;		/* Format Tag (PCM=1) */
short BytesPerSample;
long  BytesPerSecond;
long  longtmp;
short shorttmp;
long sRate;
	ExtractFormat(Mode, &ReadFlag, &AppendFlag);
	if(!ReadFlag){
		if((FilePtr=fopen(Filename, Mode)) == NULL){
			return FilePtr;
		}
		if(!AppendFlag){
			if(*BitsPerSample != 8 && *BitsPerSample != 16){
				fprintf(stderr, "\n\n");
				fprintf(stderr, "\n ERROR: Only values 16 or 8 allowed for parameter 'BitsPerSample' in function Wave_fopen");
				fprintf(stderr, "\n        [value: %d received]", *BitsPerSample);
				fprintf(stderr, "\n\n");
				exit(-1);
			}
			BytesPerSample = (short)(*BitsPerSample /8 * *NumOfChannels);
			BytesPerSecond = *SamplingRate * BytesPerSample;
			/* RIFF chunk - 12 bytes */	
			fwrite("RIFF", 1, 4, FilePtr);				
			fwrite(&FileSize, 4, 1, FilePtr);			
			fwrite("WAVE", 1, 4, FilePtr);				
			/* FORMAT chunk - 24 bytes */	
			fwrite("fmt ", 1, 4, FilePtr);				
			fwrite(&FormatSize, 4, 1, FilePtr);			
			fwrite(&FormatTag,  2, 1, FilePtr);			
			fwrite(NumOfChannels,  2, 1, FilePtr);		
			sRate = (*SamplingRate);
			fwrite(&sRate,  4, 1, FilePtr);		
			fwrite(&BytesPerSecond, 4, 1, FilePtr);		
			fwrite(&BytesPerSample,  2, 1, FilePtr);	
			fwrite(BitsPerSample,  2, 1, FilePtr);		
			/* DATA chunk - Data length + 8 bytes */	
			fwrite("data",  1, 4, FilePtr);				
			fwrite(&PCM_Size,  4, 1, FilePtr);			
		}
		return FilePtr;
	}
	else{
		if((FilePtr=fopen(Filename, Mode)) == NULL){
			return FilePtr;
		}
		if(AppendFlag){
			FilePtrAppend = FilePtr;
		}
		fseek(FilePtr, 0, SEEK_SET);
		/* RIFF chunk - 12 bytes */	
		fread(&WaveTag, 4, 1, FilePtr);
		if(strncmp("RIFF", WaveTag, 4) != 0){
			return NULL;
		}
		fread(&longtmp, 4, 1, FilePtr);			
		fread(&WaveTag, 4, 1, FilePtr);
		if(strncmp("WAVE", WaveTag, 4) != 0){
			return NULL;
		}
		/* FORMAT chunk - 24 bytes */
		fread(&WaveTag, 4, 1, FilePtr);		
		if(strncmp("fmt ", WaveTag, 4) != 0){
			return NULL;
		}
		fread(&longtmp, 4, 1, FilePtr);		
		fread(&shorttmp, 2, 1, FilePtr);		
		fread(NumOfChannels,  2, 1, FilePtr);		
		fread(SamplingRate,  4, 1, FilePtr);
		fread(&longtmp, 4, 1, FilePtr);		
		fread(&BytesPerSample,  2, 1, FilePtr);	
		fread(BitsPerSample,  2, 1, FilePtr);
		/* DATA chunk - Data length + 8 bytes */	
		fread(&WaveTag, 4, 1, FilePtr);		
		if(strncmp("data", WaveTag, 4) != 0){
			return NULL;
		}
		fread(DataSize,  4, 1, FilePtr);
		*DataSize = *DataSize / BytesPerSample;
		if(AppendFlag) return FilePtrAppend;
		return FilePtr;
	}
}
/*____________________________________________________________________________
 |
 |  FUNCTION NAME: Wave_fclose
 |____________________________________________________________________________
*/
void Wave_fclose(FILE *FilePtr, short BitsPerSample)
{
long DataLen;
long FileLen;
long StartPos;
long EndPos;
	if(BitsPerSample != 8 && BitsPerSample != 16){
		fprintf(stderr, "\n\n");
		fprintf(stderr, "\n ERROR: Only values 16 or 8 allowed for parameter 'BitsPerSample' in function Wave_fclose");
		fprintf(stderr, "\n\n");
		exit(-1);
	}
	EndPos = ftell(FilePtr);
	fseek(FilePtr, 0, SEEK_SET);
	StartPos = ftell(FilePtr);
	FileLen = ((EndPos-StartPos) / (BitsPerSample/16)) - 8;
	DataLen = FileLen-44+8;					
	fseek(FilePtr, 4, SEEK_SET);
	fwrite(&FileLen,  1, 4, FilePtr);		
	fseek(FilePtr, 40, SEEK_SET);
	fwrite(&DataLen,  1, 4, FilePtr);		
	fclose(FilePtr);
}
/*____________________________________________________________________________
 |
 |  FUNCTION NAME: ExtractFormat
 |____________________________________________________________________________
*/
static void ExtractFormat(char *FormatString, short *ReadFlag, short *AppendFlag)
{
	*ReadFlag = 0;
	*AppendFlag = 0;
	if(strchr(FormatString, (int)'a') != NULL) *AppendFlag = 1;
	if(strchr(FormatString, (int)'A') != NULL) *AppendFlag = 1;
	if(strchr(FormatString, (int)'r') != NULL) *ReadFlag = 1;
	if(strchr(FormatString, (int)'R') != NULL) *ReadFlag = 1;
}