Lecture de l'en-tête du fichier WAVE

Question

J'ai essayé de lire le fichier d'en-tête du fichier RIFF. Tout a l'air bien. Mais quand j'ai respecté et couru, tous les fichiers que j'ai lus avaient la même taille de données. Je ne sais pas pourquoi? J'avais couru du code sur la lecture du header_file du fichier RIFF mais ce n'était pas différent.

#include <iostream> 
#include <fstream> 
#include <cstdio> 
#include <cstring> 
#include <vector> 
#include <stdint.h> 
#include <cmath> 

using namespace std; 

#define SWAPPED_US(x) (((x) >> 8) | ((x) << 8)) 
#define SWAPPED_UL(x) ((((x) >> 24) & 0xff) | (((x) << 8) & 0xff0000) | (((x) >> 8) & 0xff00) | (((x) << 24) & 0xff000000)) 

#pragma pack(push, 1) 
typedef struct { 
    char ID [4]; 
    uint32_t Size; 
    char Format [4]; 
    char SubID_1 [4]; 
    uint32_t SubSize_1; 
    uint16_t AudioFmt; 
    uint16_t Channel; 
    uint32_t Frequency; 
    uint32_t bytesRate; 
    uint16_t BlockAlign; 
    uint16_t BitsPerSample; 
    char SubID_2 [4]; 
    uint32_t SubSize_2; 
} RIFF_header; 
#pragma pack(pop) 

int getFileSize(FILE *inFile){ 
    int fileSize = 0; 
    fseek(inFile,0,SEEK_END); 
    fileSize=ftell(inFile); 
    fseek(inFile,0,SEEK_SET); 
    return fileSize; 
} 

int main() 
{ 
    FILE *fpoint; 
    fpoint = fopen ("test.wav", "rb"); 
    RIFF_header *wave_file; wave_file = new RIFF_header; 
    fread ((void*)wave_file, sizeof (RIFF_header), (size_t)1, fpoint); 


    wave_file->SubSize_2 = SWAPPED_UL(wave_file->SubSize_2); // I think it's big-endianess so we have to swap byte 

    cout << "Size of file:  " << getFileSize(fpoint) << endl; 
    cout << "Header:   " << wave_file->ID[0] 
         << wave_file->ID[1] 
         << wave_file->ID[2] 
         << wave_file->ID[3] << endl; 

    cout << "Format:   " << wave_file->Format[0] 
         << wave_file->Format[1] 
         << wave_file->Format[2] 
         << wave_file->Format[3] << endl; 

    cout << "Sub-chunk1 ID:   " << wave_file->SubID_1[0] 
          << wave_file->SubID_1[1] 
         << wave_file->SubID_1[2] 
         << wave_file->SubID_1[3] << endl; 

    cout << "Sub-chunk1 Size: " << wave_file->SubSize_1 << endl; 

    cout << "Audio Format:  " << wave_file->AudioFmt << endl; 

    cout << "Channel:  " << wave_file->Channel << endl; 

    cout << "Sample Rate:  " << wave_file->Frequency << endl; 

    cout << "Byte Rate:   " << wave_file->bytesRate << endl; 

    cout << "BlockAlign:  " << wave_file->BlockAlign << endl; 

    cout << "Bits per sample: " << wave_file->BitsPerSample << endl; 

    cout << "Sub-chunk2 ID:   " << wave_file->SubID_2[0] 
         << wave_file->SubID_2[1] 
         << wave_file->SubID_2[2] 
         << wave_file->SubID_2[3] << endl; 
    cout << "Sub-chunk2 Size: " << wave_file->SubSize_2 << endl; 
    return 0; 
} 

Answer 1

vérifier votre SubSize_1 ... il est parfois 16 octets, parfois 18. Si vous avez ce mal, votre SubSize_2 sera mal aussi ...