discoverer: Fix caps handling in pad-added signal handler
commit af32b42c1bd90faa6b4c2bb30329e100637b7848 (HEAD -> discoverer-negotiated-caps, gitlab-slomo/discoverer-negotiated-caps)
Author: Sebastian Dröge <sebastian@centricular.com>
Date: Wed May 6 11:44:39 2020 +0300
discoverer: Ensure that we have fixed, non-empty caps before passing passing to is_subtitle_caps()
commit ddd54c5aa5457305ffd67c646d85e4d4e9427f15
Author: Sebastian Dröge <sebastian@centricular.com>
Date: Wed May 6 11:42:05 2020 +0300
discoverer: Try to get negotiated caps first on pad-added and only then fall back to a caps query
The negotiated caps will be more accurate and are fixed caps in any
case.
Fixes https://gitlab.freedesktop.org/gstreamer/gstreamer/-/issues/498