set_first_layer

Sets the index of the first layer that the sink will use for its rendering.

This is useful if the application wants to have custom layers that appear before the layers added by the sink. In that case by default the sink's layers will be modulated with the result of the application's layers that come before first_layer.

Note that if this function is called then the name of the function to call in the shader snippets to sample the video will also change. For example, if first_layer is three then the function will be cogl_gst_sample_video3.

Parameters: