Hi Charles,
~/yocto_3.14.52-1.1.0/sources/meta-fsl-bsp-release/imx/meta-sdk/recipes-fsl/images$vim fsl-image-gui.bb
# set mm image install specific to SOC
MM_IMAGE_INSTALL = ""
MM_IMAGE_INSTALL_mx6 = "packagegroup-fsl-gstreamer packagegroup-fsl-multimedia-gstreamer1.0-core packagegroup-fsl-multimedia-gstreamer1.0-testapps" <---------------- add packagegroup-fsl-gstreamer to this line.