Can not transcode mpeg2 correctly if lose frame rate info

gst-launch-1.0 filesrc location=vintage_car_1920x1080_24p_4_0_1920x1080p_71frames.264 ! h264parse ! vaapih264dec ! queue ! vaapimpeg2enc ! mpegvideoparse ! filesink location=trans.m2v

failed for iHD driver, we find frame rate info lost in vaapimpeg2encvintage_car_1920x1080_24p_4_0_1920x1080p_71frames.264.