Morning Kevin,
Nice to hear from you again!
Unfortunately not. And I had some other issues with the pipes (e.g. creating mp4 files seemed not to be possible). So at the end I decided to go for a file-based approach, since that is the standard way to use it. And for systems that mostly don't have a hard drive ( like a Raspberry PI 3), I have been experimenting with in-memory filesystems. Those allow you to achieve better results as the pipe-approach (i.e. all ffmpeg commands are possible). You only need enough ram...
I have summarized it into another discussion.
Kind regards,
Bart