RTSP Gstreamer + Opencv control of FrameRate/ width/ height using Hardware

Hi all,
I want to use HVDEC for decoding the rtsp stream, but I want to control frame rate with gstreamer elements in opencv, and this is the gstreamer elements that I used and worked.

    gstream_elemets = (
        'rtspsrc location=rtsp latency=300!'
        'rtph264depay ! h264parse !'
        'queue max-size-buffers=100, leaky=2 !'
        'omxh264dec enable-max-performance=1 enable-low-outbuffer=1 !'
        'video/x-raw(memory:NVMM),format=(string)NV12 !'
        'nvvidconv ! video/x-raw , format=(string)BGRx !'
        'videoconvert ! '

cv2.VideoCapture(gstream_elemets, cv2.CAP_GSTREAMER)

Q1- First I want to add element for controlling FrameRate only?
Q2- Final I want to add element for controlling both Framerate and Height/width?

In both state I want to have best config of elements for cpu and ram usage.

The framerate/width/height is decided by the RTSP source. You may see if there is extra control you can set to change the setting in the souce. Please note that dynamic resolution change is not supported. You would need to terminate and re-initialize the pipeline when the resolution changes.

Please consider to use v4l2 plugins. We are deprecating omx plugins. Please check release note.

The RTSP source FPS is maybe variable, but I want to have fix FPS, How?
v4l2 plugins is supported in jetpack 4.2.2?
I want to use the multiple resolutions 8 for width/height. is it ok?

Not sure if the properties can be controlled/configured in rtspsrc. Suggest you go to gstreamer forum. Users in the forum should have more experience on advanced control.