Set the playback speed during the playback of UOB equipment

background

I used to be a video surveillance client for many years , For a time, it was connected to Dahua , The sea, ,axis, First pass, etc sdk, Use in our own monitoring system .

When the network is unstable , Controlling the playback speed is always a headache .
There are two ways to set the playback speed , One is to transfer and calculate according to speed , One is calculated according to the frame rate .
Because Dahua's sdk By default, the frame rate is used to calculate , If it is converted into rate, the workload is very large , Try not to please . It's better to call the interface directly , Set frame rate .

Set the rate using only the original pause state , There is such a workload .

Code

void CDevReplay::SetPlaySpeed( DOUBLE dOldSpeed, DOUBLE dNewSpeed )
{
	if(dOldSpeed == dNewSpeed)// Do not change the original speed 
	{
		return 0;
	}
	if (dNewSpeed >= (-0.01) && dNewSpeed <= 0.01)
	{
		PauseOrContinue(1);// If set to 0, Pause ;
		return;
	}

	PauseOrContinue(0);
	if (dOldSpeed >= (-0.01) && dOldSpeed <= 0.01)
	{
		if (dNewSpeed < (-1.01) && dOldSpeed >= -8.00)
		{
			SetPlayDirection(TRUE);
			while(dNewSpeed < -1.01)
			{
				FastPlay();
				dNewSpeed += 1.0;
			}
		}
		else if (dOldSpeed <= -0.99 && dOldSpeed >= -1.01)
		{
			NormalPlay();
		}
		else if (dNewSpeed < (-0.01) && dNewSpeed > -0.99)
		{
			SetPlayDirection(TRUE);
			while(dNewSpeed > -1.0)
			{
				SlowPlay();
				dNewSpeed *= 2.0;
			}
		}
		else if ( dNewSpeed > 0.01 && dOldSpeed < 0.99)
		{
			while(dNewSpeed < 1.0)
			{
				SlowPlay();
				dNewSpeed *= 2.0;
			}
		}
		else if (dOldSpeed >= 0.99 && dOldSpeed <= 1.01)
		{
			NormalPlay();
		}
		else if (dOldSpeed > 1.01 && dOldSpeed < 8.00)
		{
			while(dNewSpeed > -1.01)
			{
				FastPlay();
				dNewSpeed -= 1.0;
			}
		}
	}
	else if(dOldSpeed > 0.01)
	{
	...
	}
	else if(dOldSpeed < -0.01)
	{
	...
	}
	return ;
}

void CDevReplay::SetPlaySpeed( DOUBLE dOldSpeed, DOUBLE dNewSpeed )
{
	if(dOldSpeed == dNewSpeed)// Do not change the original speed 
	{
		return 0;
	}
	if (dNewSpeed >= (-0.01) && dNewSpeed <= 0.01)
	{
		PauseOrContinue(1);// If set to 0, Pause ;
		return;
	}

	if (dOldSpeed >= (-0.01) && dOldSpeed <= 0.01)
	{
		dOldSpeed = 1.0;
	}
	if (dOldSpeed * dNewSpeed < 0)
	{
		BOOL bBackward = (dNewSpeed < 0);
		SetPlayDirection(bBackward);
		NormalPlay();
		return;
	}

	PauseOrContinue(0);

	LONG nRate = GetFrameRate();
	DOUBLE fZoom = dNewSpeed/dOldSpeed;
	nRate = nRate*fZoom;
	SetFrameRate(nRate);

	return ;
}

LONG CDevReplay::GetFrameRate()
{
	if(0 == m_lPlayBack)return 10;

	int fileframerate = 25;
	int playframerate = 25;
	BOOL bRet = CLIENT_GetFramePlayBack(m_lPlayBack,&fileframerate,&playframerate);
	ATLASSERT(bRet);

	return playframerate;
}

LONG CDevReplay::SetFrameRate( LONG nRate )
{
	if(0 == m_lPlayBack)return 0;

	// Set playback frame rate , The scope of the current definition is (1~120), Beyond this range, return FALSE
	if (nRate < 1)nRate = 1;

	BOOL bRet =  CLIENT_SetFramePlayBack(m_lPlayBack,nRate);
	ATLASSERT(bRet);

	return 1;
}