Re: can anyone suggest how to convert matlab code into c code..for resampling function - C / C++ / MFC Discussion Boards

Re: can anyone suggest how to convert matlab code into c code..for resampling function

Richard MacCutchan21-Aug-14 23:23

Richard MacCutchan

21-Aug-14 23:23

maibam debina wrote:
what is this catalysis MCS tool.

Sorry, I have no idea.

Re: can anyone suggest how to convert matlab code into c code..for resampling function

mybm121-Aug-14 23:25

mybm1

21-Aug-14 23:25

actually in matlab the function is available for resample but in c for me its hard so can u suggest some.

Re: can anyone suggest how to convert matlab code into c code..for resampling function

Richard MacCutchan22-Aug-14 0:19

Richard MacCutchan

22-Aug-14 0:19

Sorry, but I do not know matlab, you would probably get better response by going to a dedicateed forum.

Re: can anyone suggest how to convert matlab code into c code..for resampling function

mybm122-Aug-14 0:21

mybm1

22-Aug-14 0:21

but i know u r master in c program..so leaving matlab aside do u know how to represent in c code for resampling..

Re: can anyone suggest how to convert matlab code into c code..for resampling function

Richard MacCutchan22-Aug-14 0:34

Richard MacCutchan

22-Aug-14 0:34

maibam debina wrote:
c code for resampling

I have no idea what you mean by resampling. If you have a specific coding issue then put the details here and people will try to help you. But it is unlikely that anyone has the time to write your code, or convert from one language to another.

Re: can anyone suggest how to convert matlab code into c code..for resampling function

C^hris L^osinger22-Aug-14 8:32

C^hris L^osinger

22-Aug-14 8:32

what kind of resampling (bilinear, bicubic, trilinear, spline, sinc, etc)? and for what (audio, video, statistical, etc.) ?

image processing toolkits | batch image processing

Re: can anyone suggest how to convert matlab code into c code..for resampling function

mybm122-Aug-14 18:41

mybm1

22-Aug-14 18:41

audio and do please guide how to find the time duration of the .wave file?

Re: can anyone suggest how to convert matlab code into c code..for resampling function

enhzflep23-Aug-14 18:31

enhzflep

23-Aug-14 18:31

Here's some code that does re-sampling of audio. No idea if it'll be of any use to you - googling for how to do it it was not much easier than implementing it. It was used for up-sampling 8363 samples/sec sound into 44100 samples/sec sound. It was used for working with the audio samples as found in .XM files (somewhat similar to Amiga .mod files, or less-so, .MIDI files)

There's bound to be a bunch of code here that's useless to you, but I've no idea which format your .WAV files are, so I'll leave it to you to use that which you need. You're also on-your-own when it comes to reading the samples from a WAV file - in my instance, the header of the samples is different to the .WAV file header - my data also came with a single header - the wav file contains a number of chunks, each of these has its own header.

The re-sampling is of the linear variety.
You can determine the play-time of the WAV file by looking at a number of the chunk headers inside it. Don't ask me how, as I haven't bothered to do it, and don't know. (nor am I interested)

This page seems to be an easier read than the Wikipedia WAV page - http://www.sonicspot.com/guide/wavefiles.html[^]

C++

float *convert8tofloat(char *input, int numSamples)
{
    float *result = new float[numSamples];
    int i;
    for (i=0; i<numSamples; i++)
    {
        result[i] = input[i] / 128.0; //(((input[i]+128)/255.0) - 0.5) * 2.0;
    }
    return result;
}

float *convert16tofloat(short *input, int numSamples)
{
    float *result = new float[numSamples];
    int i;
    for (i=0; i<numSamples; i++)
    {
        result[i] = (int)input[i] / 32768.0; //(((input[i]+128)/255.0) - 0.5) * 2.0;
    }
    return result;
}

// t in range [0..1]
char interpolate8(char val1, char val2, float t)
{
    short difference;
    difference = val2 - val1;
    return val1 + t*difference;
}
// t in range [0..1]
short interpolate16(short val1, short val2, float t)
{
    int difference;
    difference = val2 - val1;
    return val1 + t*difference;
}
// t in range [0..1]
float interpolateFloat32(float val1, float val2, float t)
{
    float difference;
    difference = val2 - val1;
    return val1 + t*difference;
}


char *resample8Interp(char *input, int numSamplesIn, int numSamplesOut)
{
    char *output;
    output = new char[numSamplesOut];
    float curIndex, proportion, step;
    char curVal;
    int i, intPart;

    output[0] = input[0];
    output[numSamplesOut-1] = input[numSamplesIn-1];
    step = (float) (numSamplesIn-1) / (numSamplesOut-1);

    for (i=1; i<numSamplesOut-1; i++)
    {
        curIndex = (float) i * step;
        intPart = floor(curIndex);
        proportion = curIndex - intPart;
        curVal = interpolate8(input[intPart], input[intPart+1], proportion);
        output[i] = curVal;
    }
    return(output);
}

short *resample16Interp(short *input, int numSamplesIn, int numSamplesOut)
{
    short *output;
    output = new short[numSamplesOut];
    float curIndex, proportion, step;
    short curVal;
    int i, intPart;

    output[0] = input[0];
    output[numSamplesOut-1] = input[numSamplesIn-1];
    step = (float) (numSamplesIn-1) / (numSamplesOut-1);

    for (i=1; i<numSamplesOut-1; i++)
    {
        curIndex = (float) i * step;
        intPart = floor(curIndex);
        proportion = curIndex - intPart;
        curVal = interpolate16(input[intPart], input[intPart+1], proportion);
        output[i] = curVal;
    }
    return(output);
}

float *reSampleFloat32(float *srcArray, int origNumSamples, int origRate, int newRate, int &outNumSamples)
{
    outNumSamples = (origNumSamples * newRate) / origRate;
    float *output = new float[outNumSamples];
    int i, intPart;
    float fractionalPart, curIndex, curVal, step;

    step = (float)(origNumSamples-1) / (outNumSamples-1);
    output[0] = srcArray[0];
    output[outNumSamples-1] = srcArray[origNumSamples-1];
    for (i=0; i<outNumSamples; i++)
    {
        curIndex = step * i;
        intPart = floor(curIndex);
        fractionalPart = curIndex - intPart;
        curVal = interpolateFloat32(srcArray[intPart], srcArray[intPart+1], fractionalPart);
        output[i] = curVal;
    }
    return output;
}

Here's some examples of implementation. I dont remember a thing about the code, haven't touched it in years - nor am I inclined to. That's an exercise for you. I assume some of the comments are misleading - I just changed the one that says "only works for 16 bit samples" - it had said "only works for 8 bit samples, which was clearly inaccurate.

Finally, not that in my case I wanted to convert the samples to be a 32-bit floating point format in the range [-1..1] which simplifies drawing them to screen.

Good luck!

C++

void onSmpListChange(HWND smpListBox, XMFile *mSong)
{
    int curIns, curSmp;
    HWND dlg = GetParent(smpListBox);
    HWND insList = GetDlgItem(dlg, IDC_INS_LIST);

    curIns = SendMessage(insList, LB_GETCURSEL, 0, 0);
    curSmp = SendMessage(smpListBox, LB_GETCURSEL, 0, 0);

    XMSample *curSample = &mSong->instruments[curIns].samples[curSmp];
    int bits=8, numSamples = curSample->header.sampleLength;
    float *tmpBuffer;

    if (curSample->header.compression == 0)
        SetDlgItemText(dlg, IDC_COMP, "Delta");
    else
    {
        SetDlgItemText(dlg, IDC_COMP, "ADPCM");
        return;
    }

    // only works for 16 bit samples
    if (curSample->header.type & 0x16)
    {
        printf("Resampling 16bit sound, %d samples - %20.20s\n", numSamples, curSample->header.sampleName);
        numSamples /= 2;
        SetDlgItemInt(dlg, IDC_BITS, 16, true);
        char fileName[48];
        strcpy(fileName, "16bit 8363hz.wav");
//        strncat(fileName, curSample->header.sampleName, 20);
        writeWavFile(fileName, curSample->data, numSamples, 16, 1, 8363);

        short *sBuf = resample16Interp((short*)curSample->data, numSamples, 44100*numSamples / 8363);
        strcpy(fileName, "16bit 44100hz.wav");
//        strncat(fileName, curSample->header.sampleName, 20);
        writeWavFile(fileName, sBuf, (44100*numSamples)/8363, 16, 1, 44100);
        delete sBuf;

        tmpBuffer = convert16tofloat((short*)curSample->data, numSamples);
    }

    else
    {
        printf("Resampling 8bit sound, %d samples - %20.20s\n", numSamples, curSample->header.sampleName);
        SetDlgItemInt(dlg, IDC_BITS, 8, true);
        char fileName[48];
        strcpy(fileName, "8bit 8363hz.wav");
//        strncat(fileName, curSample->header.sampleName, 20);
        writeWavFile(fileName, curSample->data, numSamples, 8, 1, 8363);

        char *cBuf = resample8Interp((char*)curSample->data, numSamples, 44100*numSamples / 8363);
        strcpy(fileName, "8bit 44100hz.wav");
//        strncat(fileName, curSample->header.sampleName, 20);
        writeWavFile(fileName, cBuf, (44100*numSamples)/8363, 8, 1, 44100);
        delete cBuf;

        tmpBuffer = convert8tofloat((char*)curSample->data, numSamples);
    }
    // wParam = buffer (float)  // lParam = count
    SetDlgItemInt(dlg, IDC_NUM, numSamples, true);

    SendDlgItemMessage(dlg, IDC_WAV_IMG, WM_SET_DATA, (WPARAM)tmpBuffer, (LPARAM)numSamples);// * 44100 / 8835);



    delete g_curSamples;
    g_curSamples = tmpBuffer;
    g_numSamples = numSamples;// * 44100/8355;
}


void onConvertBtn(HWND parentDlg)
{
    float *mSamples;
    int nSamples;

//    mSamples = reSample(g_curSamples, g_numSamples, 8363, 44100, nSamples);
    mSamples = reSampleFloat32(g_curSamples, g_numSamples, xmRate, 44100, nSamples);
    SendDlgItemMessage(parentDlg, IDC_WAV_IMG2, WM_SET_DATA, (WPARAM)mSamples, (LPARAM)nSamples);
    delete mSamples;
}

Re: can anyone suggest how to convert matlab code into c code..for resampling function

mybm124-Aug-14 19:30

mybm1

24-Aug-14 19:30

thank you fren....

Re: can anyone suggest how to convert matlab code into c code..for resampling function

jschell22-Aug-14 10:21

jschell

22-Aug-14 10:21

Steps
- Analyze matlab code to understand it. This might involve researching matlab provided methods.
- Learn C
- Use the above to write C code.

Researching existing C libraries might also be helpful.

Re: can anyone suggest how to convert matlab code into c code..for resampling function

Albert Holguin28-Aug-14 5:51

Albert Holguin

28-Aug-14 5:51

Best answer really... I have yet to see a "code converter" that did a good job without generating cluttered, hard to read code (that can run slow compared to if you have just done the conversion manually).

how to call a function inside another function in file like utility.c

mybm120-Aug-14 0:03

mybm1

20-Aug-14 0:03

Quote:
how to call a function inside another function in file like utility.c

Re: how to call a function inside another function in file like utility.c

Richard MacCutchan20-Aug-14 1:00

Richard MacCutchan

20-Aug-14 1:00

That question is impossible to answer. Please give some proper detailed context about your problem. Calling a function is just the same wherever you call it from.

Re: how to call a function inside another function in file like utility.c

mybm120-Aug-14 1:22

mybm1

20-Aug-14 1:22

utility.c file consist of following function:

function list_file_directory() // function 1
{
//listing wave file from directory;
}
function wavread()   // function 2<pre>

{
// reading the .wav file;
}
function noise
{
//here i want to call the both above function and perform futher calculation //is it possible?
}

main.c
{
call function 1
{display}
call function 2
{
display
}
}

Re: how to call a function inside another function in file like utility.c

Richard MacCutchan20-Aug-14 3:06

Richard MacCutchan

20-Aug-14 3:06

maibam debina wrote:
i want to call the both above function and perform futher calculation //is it possible?

Of course it is; just call them. What is your problem with this?

Re: how to call a function inside another function in file like utility.c

WuRunZhe21-Aug-14 2:20

WuRunZhe

21-Aug-14 2:20

It can not be understood. Could you tell more detail? Smile | :)

Re: how to call a function inside another function in file like utility.c

Richard Andrew x6422-Aug-14 8:59

Richard Andrew x64

22-Aug-14 8:59

In C, you cannot define a function inside another function. All functions must stand on their own.

The difficult we do right away...
...the impossible takes slightly longer.

error: invalid operands to binary / (have ‘float’ and ‘int *’)

mybm119-Aug-14 20:24

mybm1

19-Aug-14 20:24

Quote:
error: invalid operands to binary / (have ‘float’ and ‘int *’)

how to solve this error?

Re: error: invalid operands to binary / (have ‘float’ and ‘int *’)

enhzflep19-Aug-14 20:51

enhzflep

19-Aug-14 20:51

You can't divide by a pointer. You can divide by what it points to, but you cant divide the pointer itself.

Take a look at the following. Basically, you need to dereference the pointer, as I've done in #3.

C++

#include <cstdio>

int main()
{
    int numerator = 10;
    float denominator = 2.7;

    // 1. Using no pointers
    float result = numerator / denominator;
    printf("%d / %f = %f\n", numerator, denominator, result);



    // 2. Using pointers incorrectly
    int *ptrToNumerator;
    ptrToNumerator = &numerator;
    // below line causes the following error:
    // error: invalid operands of types 'int*' and 'float' to binary 'operator/'|
    result = ptrToNumerator / denominator;
    printf("%f\n", result);



    // 3. Using pointers appropriately
    result = *ptrToNumerator / denominator;
    printf("%f\n", result);

    return 0;
}

Re: error: invalid operands to binary / (have ‘float’ and ‘int *’)

mybm119-Aug-14 21:01

mybm1

19-Aug-14 21:01

<blockquote class="quote"><div class="op">Quote:</div>
	for(i=0;i<*SizeOfData;i++)
	{
	datasample[i]=square(samplesValue1[i]);
	squaring1=(datasample[i]*datasample[i]);
	sum +=squaring1;
        }
	summation_input=(float)sum/ *SizeOfData;   
	printf("\n%f",summation_input);
	
	fclose(fp);</blockquote>

wen i change summation_input=(float)sum/SizeOfData;
to summation_input=(float)sum/ *SizeOfData some unknown error is generating given below

Quote:
dithermain.c text+0x430): undefined reference to `square'
collect2: ld returned 1 exit status

Re: error: invalid operands to binary / (have ‘float’ and ‘int *’)

enhzflep19-Aug-14 21:18

enhzflep

19-Aug-14 21:18

That error is telling you that the linker can't find the function body for your function square.
If it's in another c/cpp file, you have to compile and link it too.

Otherwise, you can just place the square function in the same c/cpp file, but make sure it appears before it's first used. (otherwise you'll get a compiler error that says the symbol is unrecognized)

Re: error: invalid operands to binary / (have ‘float’ and ‘int *’)

mybm120-Aug-14 0:42

mybm1

20-Aug-14 0:42

in function after writing return();
is it possible to continue process will it be effective ?

Re: error: invalid operands to binary / (have ‘float’ and ‘int *’)

David Crow20-Aug-14 3:15

David Crow

20-Aug-14 3:15

maibam debina wrote:
in function after writing return();
is it possible to continue process...

Not in that same function.

"One man's wage rise is another man's price increase." - Harold Wilson

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"You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

Variable not same across process in DLL

peterasloan17-Aug-14 18:49

peterasloan

17-Aug-14 18:49

I have 2 dlls where one is run time loaded (Run.dll) and calls the other(other.dll)
Also the application calls the other.dll as well.

Now the other.dll has a static variable in it that is only used in itself i.e internally to the dll which gets changed by one of it's functions.

At the start of the program I call a this function in the other.dll to set the variable but later on when I run time load the run.dll which calls the function in the other.dll the variable is not set.

I thought the any variables in the other.dll which is statically linked to the app and to the run.dll will only have one instance of itself in memory especially regarding the variables?

How can I solve it to ensure that the variable in other.dll is the same across the process?

I forget to mention that I'm using the windows api etc.

Re: Variable not same across process in DLL

Richard MacCutchan17-Aug-14 20:39

Richard MacCutchan

17-Aug-14 20:39

It's difficult to visualise the actual sequence of events here, but it may be that on the second call into this dll it is getting reloaded somehow. Either that or there is another bug somewhere.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.