[FFmpeg-user] Can I make ffmpeg to add bitrate, duration, stream size data for vbr streams?

[Zsolt]

Hello!
I've been encoding crf libx264 encodes with FLAC streams. What bothers me
is if I view the video files (meta)data with mediainfo or ffprobe these
information are unavailable. Ffmpeg gifes a summary of the stream sizes at
the end of the encode so I know at least that one is readily available. It
could just as well calculate the (average) bitrate and duration.
But neither is available. It would be great if at least the stream size
would be available. Average bitrate would be nice too.

PS:
Just noticed an old crf film for which mediainfo shows bitrate and stream
size and percentage, while ffprobe (with -show_streams) doesn't these
information. So it's at least doable.