Bin with one filesink won't preroll

[Simon Guillot]

Following up because the outcome may be of interest if it pops up in a search engine result.

> On 5 Aug 2022, at 15:40, Simon Guillot <simon at vivid-machines.com> wrote:
> 
> `async=false` indeed solves the issue of having the pipeline change its state when linking. That leaves
> me with two questions though:
> - Is there no way to achieve an insertion without putting back the pipeline in preroll mode with `async=true`?
> - If that doesn't change the overall behaviour, on what occasions would I even want to keep `async=true`?

It only went downhill from there. No amount of careful probing, elements swapping, pre-rolling etc. led
to a stabledynamic  pipeline given the complexity involved. EOS events in particular are very problematic
to deal with.

The solution was in the end quite simple: have multiple pipelines and connect them with gst-interpipe so that
each of them can be individually played and stopped.