[gst-devel] Init pipeline in the function

[wl2776]

You can't change the function arguments in C, as they are passed by value.
You can, however, pass a pointer (a memory address) to a function, and it
can write something to that address. This will cause changing of values of
some variables outside the function.


Igor Mironchick wrote:
> 
> Why can't I init pipeline in function and then use it somewhere else?
> 
You must return the pointer from the function.


Igor Mironchick wrote:
> 
> Here is the code example:
> 
> void initPipeline( GstElement * pipeline )
> {
>   pipeline = gst_pipeline_new( "camera" )
> }
> 
> void main()
> {
>   GstElement * pipeline;
> 
>   initPipeline( pipeline );
> 
>   // And here pipeline == 0 !!! Why?
> }
> 

gst_pipeline_new allocates the memory and stores it in the variable
pipeline, but this variable is lost when the function returns.

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