How do i copy to a List? - c++-cli

I have this code in CLI
List<Codec^> ^GetCodecs()
{
List<Codec^> ^l = gcnew List<Codec^>;
bool KeepLooping = Encoder_MoveToFirstCodec();
while (KeepLooping)
{
Codec ^codec = gcnew Codec(); // here... and that call encoder_init many times... which call register codec many times... which is a mass...
codec->Name = gcnew String(Encoder_GetCurrentCodecName());
codec->Type = Encoder_GetCurrentCodecType();
char pix_fmts[200]; // array of 200 is probably enough
int actual_pix_fmts_sz = Encoder_GetCurrentCodecPixFmts( pix_fmts , 200 );
for (int i = 0 ; i < actual_pix_fmts_sz ; i++)
{
//copy from pix_fmts to the :List
codec->SupportedPixelFormats->Add(pix_fmts[i]);
}
This is the Encoder_GetCurrentCodecPixFmts function in C:
int Encoder_GetCurrentCodecPixFmts( char *outbuf , int buf_sz )
{
int i=0;
while ( (i<buf_sz) && (codec->pix_fmts[i]!=-1) )
{
outbuf[i] = codec->pix_fmts[i];
i++;
}
return i;
}
This is a new class i did:
#pragma once
using namespace System;
using namespace System::Collections::Generic;
public ref class Codec
{
public:
String^ Name;
int ID; // this is the index
int Type; // this is the type
List<int> ^SupportedPixelFormats;
Codec(void)
{
SupportedPixelFormats = gcnew List<int>;
// do nothing in the constructor;
}
};
Which contain also the: SupportedPixelFormats
The constructor in this new class should be empty but i needed somewhere to make an instance for the List make a NEW for the List.
Now in the C++ i need to transfer from pix_fmts char array to codec->Supported
Or to copy from pix_fmts to the :List
So i did as above:
codec->SupportedPixelFormats->Add(pix_fmts[i]);
But i'm not sure if this the meaning of copy.
Is that right what i did ?

It works, it's a kind of a deep copy. What makes you think it doesn't work? Do the results turn out wrong? If they do, put a breakpoint in there and try to get what is wrong.
Instead of copying one by one perhaps you can use the Enumerable::ToList extension method.
I hope this helped you.

Related

private data member in C++ OOP

I am new to OOP in C++. I got a doubt. I know it may be a silly doubt.
In the code below in main function, commented line will give error as I can not access private data memebers directly. but in the member function complex add(complex &C) I created a object temp of class complex. How can I access the data member of object temp directly and modify them as those are private. Like in the main function, should it not throw error? Is there any rule that in the member function of class we can access private data of a object of same class directly.
using namespace std;
class complex{
private:
int real;
int img;
public:
complex(int r = 0, int i = 0);
complex add(complex &C);
};
complex :: complex(int r, int i){
real = r;
img = i;
}
complex complex :: add(complex &C){
complex temp;
temp.real = real + C.real;
temp.img = img + C.img;
return temp;
}
int main() {
complex c1(3,4);
complex c2(5,7);
complex c3;
// c3.real = 3;
// c3.img = 5;
c3 = c1.add(c2);
return 0;
}
I try and stick to rule, keep your member variables private, if you need to change them or access them once the object is created, use a public get / set function.
e.g:
int complex::GetReal() const { return m_real; }
void complex::SetReal(const int i) { m_real = i; }

How to acquire skeletal joint data to text file from two kinect cameras in SkeletalViewer? (C++)

I am currently working on a project to use multiple kinect cameras to acquire x,y,z coordinates of skeletal data in SkeletalViewer. I have an idea to use the KinectID or index of different kinect cameras to extract the sets of skeletal joints data into 2 different text files. But I am not sure if I am doing right. Please help to take a look at the modification below, or I will appreciate all your kind advice on other method to solve this problem.
In SkeletalViewer.h, I modified as following:
public:
FILE* mp3DFile0;
FILE* mp3DFile1;
char mText[1024];
INuiSensor * m_pNuiSensor;
BSTR m_instanceId;
array SensorIndex;
In NuiImpl.cpp, I modified as following:
1) define array
ref class MyClass {
public:
int m_i;
};
array<MyClass^>^ arrSensor() {
int i;
array< MyClass^ >^ local = gcnew array< MyClass^ >(2);
for (i = 0; i < 2; i++) {
local[i] = gcnew MyClass;
local[i]->m_i = i;
}
return local;
}
2) create array to store sensor index to do for loop later
HRESULT CSkeletalViewerApp::Nui_Init( )
{
HRESULT hr;
bool result;
//create an array to store two file pointers
FILE* mp3DFile[] = { mp3DFile0, mp3DFile1 };
fopen_s(mp3DFile0, "D:/Kinect/KinectCam0.txt", "w+");
fopen_s(mp3DFile1, "D:/Kinect/KinectCam1.txt", "w+");
.
.
if ( !m_pNuiSensor )
{
hr = NuiCreateSensorByIndex(0, &m_pNuiSensor);
//I am not sure about how to utilize this index in this case
.
.
}
if (NuiGetSensorCount(&m_pNuiSensor) > 1)
{
array< MyClass^ >^ SensorIndex;
SensorIndex = arrSensor();
}
}
3) use for loop to store data to different text file using index
void CSkeletalViewerApp::Nui_DrawSkeleton( const NUI_SKELETON_DATA & skel, int windowWidth, int windowHeight )
{
int i;
int h;
for (h = 0; h < 2; h++)
{
//when index point to the current kinect
if (SensorIndex[h] == &m_pNuiSensor)
{
for (i = 0; i < NUI_SKELETON_POSITION_COUNT; i++)
{
m_Points[i] = SkeletonToScreen(skel.SkeletonPositions[i], windowWidth, windowHeight);
memset(mText, 0, 1024);
sprintf(mText, "(%0.3f,%0.3f,%0.3f)", skel.SkeletonPositions[i].x, skel.SkeletonPositions[i].y, skel.SkeletonPositions[i].z);
if (mp3DFile[h]) {
fputs((const char*)mText, mp3DFile[h]);
}
}
if (mp3DFile[h]) {
fputs("\n", mp3DFile[h]);
}
}
}
.
.
}
I am a newbie in this Kinect programming. Thank you very much for your help! :)

How do i get the codec's List of ffmpeg by names?

I have this function in C
int Encoder_GetCurrentCodecType()
{
if (current_codec != NULL)
return (int) current_codec->type;
return AVMEDIA_TYPE_UNKNOWN;
}
But the function return the code of each codec type.
Like: 0,1,2,3,4,5,6,7
If i'm doing for the test in the function i type: AVMediaType::
Then i see the List of all 7 codec's types there is for example:
AVMEDIA_TYPE_AUDIO
So i want to make a function like the one with the int but string or const char* that will return me the names of the types and not the codes.
How can i do it ?
EDIT
In the C file i did:
const char* Encoder_av_get_media_type_string(enum AVMediaType media_type)
{
switch (media_type) {
case AVMEDIA_TYPE_VIDEO: return "video";
case AVMEDIA_TYPE_AUDIO: return "audio";
case AVMEDIA_TYPE_DATA: return "data";
case AVMEDIA_TYPE_SUBTITLE: return "subtitle";
case AVMEDIA_TYPE_ATTACHMENT: return "attachment";
default: return NULL;
}
}
Then in the header file that connecting between the C and C++ i did:
const char* Encoder_av_get_media_type_string(enum AVMediaType media_type);
Then in the C++ header file i did:
property List<String^> ^GetCodec
{
List<String^>^ get()
{
List<String^> ^l = gcnew List<String^>;
String ^s;
s = gcnew String(Encoder_av_get_media_type_string(avm));
l->Add(s);
return l;
}
}
Then in CSHARP i did:
for (int i = 0; i < f.GetCodec.Count; i++)
{
ss.Add(f.GetCodec[i]);
}
So maybe in C++ it shouldn't be property i thought to do something that in CSHARP when i make f.GetCodec. then it will show me a List of all the codec's types names.
Like a property like when i'm doing f.GetCodec.Add and see list of properties so f.GetCodec.(and here i will the list of all types names)
If it's impossible then just to make in CSHARP a List with all types names.
But for now i'm getting only 1 name "video" that's it.
According to this, there exists a function to do just that.
const char* av_get_media_type_string(enum AVMediaType media_type)

Array allocate in function

I ve got a problem with allocating cli::array in function.
I have this kind of object:
array<double>^ tmsr2;
now I want to allocate it in function so:
void allocate(array<double>^ tmsr2)
{
tmsr2=gcnew array<double>(100);
}
Now, tmsr2 in function gets allocated well but I lose the pointer when returning to main()
The problem is clear to me, just like if I want to allocate simple array "double *a"; I need to pass pointer to function so "&a" and then everything works fine. I just don't know the syntax with managed arrays. Help much appreciated.
Peter
Since array<double> is a managed type, you can use a managed tracking reference here, instead of a plain reference.
void allocate(array<double>^% tmsr2)
{
tmsr2 = gcnew array<double>(100);
}
Here's my test app:
public ref class AsAClassField
{
public:
array<double>^ b;
AsAClassField()
{
allocate(b);
Debug::WriteLine("b = " + (b != nullptr ? "array" : "null"));
}
};
int main(array<System::String ^> ^args)
{
array<double>^ a = nullptr;
allocate(a);
Debug::WriteLine("a = " + (a != nullptr ? "array" : "null"));
AsAClassField^ foo = gcnew AsAClassField();
return 0;
}
Output:
a = array
b = array
Of course, you could always switch your allocate function to return the newly allocated array, rather than taking it as a reference. That would be more in the managed style.
You can pass the array as a reference:
void allocate(array<double>^ &tmsr2)
{
tmsr2=gcnew array<double>(100);
}

serialize/deserialize user defined class variable?

Suppose I have two classes:
class1 {
int m_i;
std::string m_s;
};
class2 {
int m_i2;
class1 *m_ptr;
};
Now, I want to send a class2 variable over network, and want to use any of the libraries that does serialization.(Protocol-buffers, Thrift, MessagePack..)
Which one can I use?(note the class1* m_ptr)
You could use thrift for this.
the definition would look something like
struct class1 {
1: required i32 m_i;
2: required string m_s;
}
struct class2 {
1: required i32 m_i2;
2: optional class1 m_ptr;
}
You would like to read this excellent guide
http://diwakergupta.github.com/thrift-missing-guide/
and to get clarity on concern about the "pointer" issue that you mentioned in the question,read the section on "How are nested structs initialized?" in the above guide.
Using google protocol buffers, you would need a .proto file (say test.proto) like:
package serialisation; // puts this in namespace serialisation
message class1 {
required int32 m_i = 1;
required bytes m_s = 2;
}
message class2 {
required int32 m_i2 = 1;
optional class1 m_ptr = 2;
}
Using C++, once you run the protoc compiler against this, you end up with test.pb.cc and test.pb.h
You can then use these like:
#include <string>
#include "test.pb.h"
struct class1 {
int m_i;
std::string m_s;
};
struct class2 {
int m_i2;
class1 *m_ptr;
};
int main() {
class2 second_class;
second_class.m_i2 = 2;
second_class.m_ptr = new class1;
second_class.m_ptr->m_i = 1;
second_class.m_ptr->m_s = "one";
// Serialise class 2
serialisation::class2 serialisable_second_class;
serialisable_second_class.set_m_i2(second_class.m_i2);
if (second_class.m_ptr) {
serialisation::class1* serialisable_first_class = serialisable_second_class.mutable_m_ptr();
serialisable_first_class->set_m_i(second_class.m_ptr->m_i);
serialisable_first_class->set_m_s(second_class.m_ptr->m_s);
}
std::string serialised(serialisable_second_class.SerializeAsString());
// Parse class 2
serialisation::class2 parsed_second_class;
parsed_second_class.ParseFromString(serialised);
class2 retrieved_second_class;
retrieved_second_class.m_i2 = parsed_second_class.m_i2();
if (parsed_second_class.has_m_ptr()) {
retrieved_second_class.m_ptr = new class1;
retrieved_second_class.m_ptr->m_i = parsed_second_class.m_ptr().m_i();
retrieved_second_class.m_ptr->m_s = parsed_second_class.m_ptr().m_s();
} else {
retrieved_second_class.m_ptr = nullptr;
}
return 0;
}
Note, for the sake of brevity I'm not doing any error checking or exception handling here - this would be needed in production code. I'm also not managing the lifetime of the class1 pointer.