mkl library DCT function implementation issue

Question

I am trying to replace ipp.lib DCT function by using mkl.lib DCT function . I used following Ipp based API to do DCT:

ippsDCTFwdInitAlloc_32f
ippsDCTFwd_32f
ippsDCTFwdFree_32f

PFB my mkl based DCT sample code :

#include <time.h>
#include <stdlib.h>
#include "mkl.h"
int main(int argc, char* argv[]){

    float *dpar;
    float *out;
    MKL_INT    *ipar;
    MKL_INT tt_type,stat,n_1,nn;
    FILE *fp,*fw,*fonce;
    fp = fopen( "D:\\dump\\fileinput.txt","r" );
    if(fp == NULL){
        cout<<"file not created properly"<<endl;
    }
    DFTI_DESCRIPTOR_HANDLE handle = 0;
    int n = 150; /*Hardcoded to run for my code TODO: going to change after integrating into my main codebase.As I can't attach my full fileinput.txt .So just taken n value = 150 */
    nn = (MKL_INT)n;
    tt_type = MKL_STAGGERED_COSINE_TRANSFORM;

    n_1 = nn + 1 ;
    out = (float*)malloc((n+1)*sizeof(float));
    dpar= (float*)malloc((5*n_1/2+2)*sizeof(float));
    ipar= (MKL_INT*)malloc((128)*sizeof(int));
    s_init_trig_transform(&n_1,&tt_type,ipar,dpar,&stat);
    for (int srcSize =0 ;srcSize< n ; srcSize++)
    {
        fscanf(fp,"%f\n",&out[srcSize]);
    }
    fclose(fp);
    if (stat != 0)
    {
        printf("\n============================================================================\n");
        printf("FFTW2MKL FATAL ERROR: MKL TT initialization has failed with status=%d\n",(MKL_INT)stat);
        printf("Please refer to the Trigonometric Transform Routines Section of MKL Manual\n");
        printf("to find what went wrong...\n");
        printf("============================================================================\n");
        return NULL;
    }
    ipar[10] = 1;    //nx, that is, the number of intervals along the x-axis, in the Cartesian case.
    ipar[14] = n_1;  //specifies the internal partitioning of the dpar array.
    ipar[15] = 1;    //value of ipar[14]+1,Specifies the internal partitioning of the dpar array.
    s_commit_trig_transform(out,&handle,ipar,dpar,&stat);
    if (stat != 0)
    {
        printf("\n============================================================================\n");
        printf("FFTW2MKL FATAL ERROR: MKL TT commit step has failed with status=%d\n",(MKL_INT)stat);
        printf("Please refer to the Trigonometric Transform Routines Section of MKL Manual\n");
        printf("to find what went wrong...\n");
        printf("============================================================================\n");
        return NULL;
    }
    s_forward_trig_transform(out,&handle,ipar,dpar,&stat);
    if (stat != 0)
    {
        printf("\n============================================================================\n");
        printf("FFTW2MKL FATAL ERROR: MKL TT commit step has failed with status=%d\n",(MKL_INT)stat);
        printf("Please refer to the Trigonometric Transform Routines Section of MKL Manual\n");
        printf("to find what went wrong...\n");
        printf("============================================================================\n");
        return NULL;
    }
    free_trig_transform(&handle,ipar,&stat);
    printf("\n===== DCT GOT OVER ======== \n");

    return 0;

}

But I am not getting the correct output . I am getting confused that whether my implementation is correct or not .

As I don't know How to attach my fileinput.txt,So I put the file content here. Sorry for that :(

129.000000  128.000000  145.000000  140.000000  102.000000  93.000000   100.000000  97.000000   94.000000   88.000000   58.000000   67.000000   
79.000000   62.000000   62.000000   64.000000   63.000000   63.000000   70.000000   80.000000   61.000000   62.000000   63.000000   64.000000   
62.000000   78.000000   66.000000   65.000000   68.000000   74.000000   78.000000   66.000000   67.000000   76.000000   67.000000   65.000000   
76.000000   83.000000   66.000000   66.000000   65.000000   66.000000   72.000000   80.000000   65.000000   66.000000   69.000000   80.000000   
75.000000   66.000000   71.000000   80.000000   69.000000   80.000000   85.000000   70.000000   77.000000   68.000000   67.000000   80.000000   
83.000000   69.000000   71.000000   73.000000   69.000000   70.000000   71.000000   71.000000   70.000000   71.000000   88.000000   86.000000   
78.000000   78.000000   70.000000   73.000000   81.000000   83.000000   76.000000   75.000000   72.000000   72.000000   73.000000   75.000000   
79.000000   76.000000   80.000000   87.000000   84.000000   79.000000   73.000000   72.000000   72.000000   72.000000   73.000000   79.000000   
76.000000   74.000000   76.000000   78.000000   76.000000   74.000000   73.000000   76.000000   78.000000   78.000000   73.000000   74.000000   
73.000000   72.000000   72.000000   73.000000   75.000000   77.000000   76.000000   75.000000   74.000000   74.000000   75.000000   78.000000   
81.000000   78.000000   75.000000   74.000000   74.000000   74.000000   75.000000   77.000000   79.000000   80.000000   81.000000   78.000000   
76.000000   75.000000   74.000000   74.000000   74.000000   75.000000   76.000000   76.000000   75.000000   77.000000   78.000000   79.000000   
80.000000   79.000000   79.000000   79.000000   78.000000   76.000000   76.000000   76.000000   76.000000   77.000000   77.000000   77.000000   
78.000000   80.000000   80.000000   80.000000   80.000000   80.000000   78.000000   78.000000   78.000000   78.000000   78.000000   80.000000

Answer 1

I think you are talking the dpar parameter for these functions. Actually, they are not used for the computed result. They are just used for store the intermediate sin/cos data that are used in the TT computation.

For the computation function: d_forward_trig_transform(double f[], DFTI_DESCRIPTOR_HANDLE *handle, MKL_INT ipar[], double dpar[], MKL_INT *stat);

Both the input and output is F[], which is the same size. for more information You can refer below link : link here