pipeline: avoid some type checks
pipeline: avoid some type checks

Avoid type checks when we can
Don't need to peek the parent_class, the boilerplate does that for us.

mparis/gstreamer,justinjoy/gstreamer,krichter722/gstreamer,lovebug356/gstreamer,surround-io/gstreamer,ensonic/gstreamer,ylatuya/gstreamer,StreamUtils/gstreamer,shelsonjava/gstreamer,ylatuya/gstreamer,ensonic/gstreamer,mrchapp/gstreamer,Lachann/gstreamer,jpxiong/gstreamer,mrchapp/gstreamer,magcius/gstreamer,Distrotech/gstreamer,Lachann/gstreamer,ensonic/gstreamer,drothlis/gstreamer,cfoch/gstreamer,Distrotech/gstreamer,lubosz/gstreamer,centricular/gstreamer,krieger-od/gstreamer,cfoch/gstreamer,Distrotech/gstreamer,ylatuya/gstreamer,justinjoy/gstreamer,StreamUtils/gstreamer,Lachann/gstreamer,ylatuya/gstreamer,collects/gstreamer,magcius/gstreamer,Distrotech/gstreamer,surround-io/gstreamer,cfoch/gstreamer,jpakkane/gstreamer,lovebug356/gstreamer,mparis/gstreamer,ahmedammar/platform_external_gst_gstreamer,jpxiong/gstreamer,surround-io/gstreamer,krichter722/gstreamer,drothlis/gstreamer,justinjoy/gstreamer,StreamUtils/gstreamer,jpxiong/gstreamer,jpakkane/gstreamer,cablelabs/gstreamer,shelsonjava/gstreamer,lovebug356/gstreamer,magcius/gstreamer,mparis/gstreamer,mrchapp/gstreamer,collects/gstreamer,shelsonjava/gstreamer,lubosz/gstreamer,centricular/gstreamer,StreamUtils/gstreamer,drothlis/gstreamer,drothlis/gstreamer,lubosz/gstreamer,lovebug356/gstreamer,jpakkane/gstreamer,cablelabs/gstreamer,magcius/gstreamer,mparis/gstreamer,jpxiong/gstreamer,mrchapp/gstreamer,krieger-od/gstreamer,ahmedammar/platform_external_gst_gstreamer,Lachann/gstreamer,jpxiong/gstreamer,Distrotech/gstreamer,justinjoy/gstreamer,StreamUtils/gstreamer,krichter722/gstreamer,jpakkane/gstreamer,magcius/gstreamer,collects/gstreamer,cablelabs/gstreamer,collects/gstreamer,krieger-od/gstreamer,mrchapp/gstreamer,ahmedammar/platform_external_gst_gstreamer,drothlis/gstreamer,ylatuya/gstreamer,shelsonjava/gstreamer,ahmedammar/platform_external_gst_gstreamer,mparis/gstreamer,centricular/gstreamer,lubosz/gstreamer,surround-io/gstreamer,cfoch/gstreamer,Lachann/gstreamer,krieger-od/gstreamer,lovebug356/gstreamer,ahmedammar/platform_external_gst_gstreamer,cablelabs/gstreamer,centricular/gstreamer,justinjoy/gstreamer,jpakkane/gstreamer,lubosz/gstreamer,shelsonjava/gstreamer,krieger-od/gstreamer,centricular/gstreamer,collects/gstreamer,surround-io/gstreamer,krichter722/gstreamer,ensonic/gstreamer,ensonic/gstreamer,krichter722/gstreamer,cablelabs/gstreamer,cfoch/gstreamer