Player actual combat 25 unpacking module add close

With the increase of open multimedia files , More and more memory will be used ：

The starting point for accessing media files is through xplay2.cpp Medium xdemuxthread.open（）, Therefore, cleaning also starts from xdemuxthread Start ：

void xdemuxthread::Close()
{
    
	isexit = true;
	wait();
	
	if (vt) vt->Close();
	if (at) at->Close();
	mux.lock();
	delete vt;
	delete at;
	vt = NULL;
	at = NULL;
	mux.unlock();
}

1.vt And at It is called by unpacking threads , Because the unpacking thread is responsible for cleaning up vt And at
2. To prevent the pointer from being deleted to half , Then other threads suddenly use the deleted pointer to cause bug, So lock these four sentences
3. After we delete a pointer , The compiler only frees the memory space that the pointer points to , Instead of deleting the pointer itself , So we have to put these new Out pointer setting null

about vt And at Of close Come on , Most of their functions are the same , So put the same functionality in their common base class xdecodethread in ：

void xdecodethread::Close()
{
    
	Clear();

	// Wait for thread to exit 
	isexit = true;
	wait();
	decode->close();
	mux.lock();
	delete decode;
	decode = NULL;
	mux.unlock();
}

class xaudiothread:public xdecodethread
{
    
public:
	long long pts = 0;
	xaudiothread();
	virtual ~xaudiothread();
	void run();
	virtual bool open(AVCodecParameters* par, int samplerate, int channels);
protected:
	std::mutex amux;

	xaudioplay* audioplay=0;
	xresample* resample=0;
};

```cpp
class xvideothread:public xdecodethread
{
    
public:
	xvideothread();
	virtual ~xvideothread();
	virtual bool open(AVCodecParameters*par,ivideocall*call,int width,int height);
	void run();
	long long synpts = 0;
protected:
	xvideowidget* video=0;
	ivideocall* call = 0;

	std::mutex  vmux;
};

Next, we will deal with the special part ：
Audio thread specific res And ap

void xaudiothread::Close()
{
    
	xdecodethread::Close();
	if (resample)
	{
    
		resample->Close();
		amux.lock();
		delete resample;
		resample = NULL;
		amux.unlock();
	}
	if (audioplay)
	{
    
		audioplay->close();
		amux.lock();
		audioplay = NULL;
		amux.unlock();
	}
}

First call the cleanup common part of its parent class , Clean up your own unique parts
audioplay It's a singleton mode , Unwanted delete
The singleton pattern ： Make sure there is only one instance of a class , And provide a global access point for the instance . ——《 Design patterns 》GoF
In software system , There are often special classes like this , It must be ensured that there is only one instance of them in the system , To ensure their logical correctness 、 And good efficiency .
For different media files , They all use the same audioplay

stay xplay2 The... Is called in the destructor of close：

Xplay2::~Xplay2()
{
    
	dt.Close();
}

But it was found that there was no egg
You can see from the graph of process memory that the memory occupied 2G, Therefore, the decoded video data is not released

Then look at the... About decoding receive（）, Sure enough, something went wrong here ：

// Maybe once send many times receive
		while (!isexit)
		{
    
			AVFrame* frame = decode->receive();
			if (!frame)break;
			if(call)
			{
    
				call->Repaint(frame);
			}
			else {
    
				cout << "repaint fail " << endl;
			}
			av_frame_free(&frame);
		}

When received from the decoding queue frame to repaint After finishing , This frame It's useless. , So with av_frame_free(&frame) Release it

At this time, the process memory is stable in 250MB about , Audio or video data per frame , After it is played or drawn , Will be released immediately .