rtsp server media factory launch line configuration

Helo,

Is it possible to set a launch line for a Media Factory and use a decodebin
and stop decoding at h264/h265 via the caps property then let the decodebin
add a parser (h264/h265) as well?

I was only able to get h264/h265 and a default stream format of avc but I
wanna force it to be byte-stream.

I configured my decodebin in the launch line as follows:
`decodebin caps=video/x-h264,stream-format=byte-stream,alignment=au`

The following works but it's missing a parser which I can not add at
runtime after submitting the launch line.
`decodebin caps=video/x-h264`

Please advise, Thanks in advance!
Eslam