avfilter/vf_libplacebo: refactor status handling

Instead of having a single s->status field to track the most recently
EOF'd stream, track the number of active streams directly and only query
the most recent status at the end.

The reason this worked before is because we implicitly relied on the
assumption that `ok` would always be true until all streams are EOF, but
because it's possible to have gaps in the timeline when mixing multiple
streams, this is not always the case in principle.

In practice, this fixes a bug where the filter would early-exit (EOF)
too soon, when any input reached EOF and there is a gap in the timeline.

0 files changed, 0 insertions, 0 deletions