AppSrc.connectNeedData

gulong connectNeedData(T)(T callback,  Flag!"After" after =  No.After) if (isCallable!T
    &&  is(ReturnType!T ==  void)
   && (Parameters!T.length <  1 || (ParameterStorageClassTuple!T[0]  ==  ParameterStorageClass.none &&  is(Parameters!T[0]  ==  uint)))
   && (Parameters!T.length <  2 || (ParameterStorageClassTuple!T[1]  ==  ParameterStorageClass.none &&  is(Parameters!T[1] :  gstapp.app_src.AppSrc)))
   &&  Parameters!T.length <  3)

Connect to NeedData signal.

Signal that the source needs more data. In the callback or from another thread you should call push-buffer or end-of-stream.

length is just a hint and when it is set to -1, any number of bytes can be pushed into appsrc.

You can call push-buffer multiple times until the enough-data signal is fired.

Parameters

`callback`	signal callback delegate or function to connect `void callback(uint length, gstapp.app_src.AppSrc appSrc)` `length` the amount of bytes needed. (optional) `appSrc` the instance the signal is connected to (optional)
`after`	Yes.After to execute callback after default handler, No.After to execute before (default)

Returns

Signal ID