get digest of aac stream

aacparse.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/md5.h>
// find /mnt/c/Users/Akimasa/Documents/radikocompare/ -name "*.aac" -print0 | xargs -0 -P1 -I {} ./a.out {}
// gcc main.c -lcrypto
void main(int argc, char *argv[])
{
    MD5_CTX c;
    char *data = "hoge";
    unsigned char md[MD5_DIGEST_LENGTH];
    char mdString[33];
    int r, i;
    FILE *fp;
    // /mnt/c/Users/Akimasa/Documents/aacparse/QRR-20190715003000-小倉唯のyui＊room.aac
    if ((fp = fopen(argv[1], "r")) == NULL) {
        perror("fopen err");
        exit(1);
    }
    if (fseek(fp, 0, SEEK_END) != 0) {
        perror("fopen err");
        exit(1);
    }
    fpos_t pos;
    if (fgetpos (fp, &pos) != 0) {
        perror("fopen err");
        exit(1);
    }
    long filesize = (long)(pos.__pos);
    fseek(fp, 0, SEEK_SET);
    
    r = MD5_Init(&c);
    if(r != 1) {
        perror("init");
        exit(1);
    }
    int blk=0;
    for(long i=0; i<filesize; i++){

        uint8_t cont[8];
        fseek(fp, i, SEEK_SET);
        fread(cont, sizeof(uint8_t), 8, fp);
        uint16_t sync = cont[0] <<8 | cont[1];
        sync = (0xfff9 & sync) == 0xfff9;
        if(sync){
            int crc = cont[0] & 1;
            long len = cont[3] << 16 | cont[4] << 8 | cont[5];
            len = (len >> 5) & 0x1ff;
            if(len == 0){
                printf("len=0\n");
                                continue;

            }
            uint8_t pkt[1024] = {0};
            if(len > 1024){
                perror("lent too long!\n");
                exit(1);
            }
            fseek(fp, i, SEEK_SET);
            int sizeread = fread(pkt, sizeof(uint8_t), len, fp);
            // if(sizeread != len){
            //     printf("cannnot read len: %d, %d\n", sizeread, len);
            //     exit(1);
            // }

           if(0 && ++blk > 24257 && blk < 24260){
            for(int j = 0; j < len-1; j++)
             printf("%02x", (unsigned int)pkt[j]);
             printf("\n");
           }
            r = MD5_Update(&c, pkt, len);
            if (r != 1)
            {
                perror("update");
                exit(1);
            }
            // printf("len:%d\n", len);
            i += len-1;
        }
    }





    

    
    r = MD5_Final(md, &c);
    if(r != 1) {
        perror("final");
        exit(1);
    }
 
    for(i = 0; i < 16; i++)
         sprintf(&mdString[i * 2], "%02x", (unsigned int)md[i]);
 
    printf("%s: %s\n", argv[1], mdString);
}