playback: autoplug selection fails if no suitable decoder is found.
Describe your issue
During an autoplug selection in a decodebin/parsebin pipeline, the process may fails if no suitable decoder can be found in the installation.
For example, if no h264 decoder is available on the system and you want to create a pipeline which exposes the pad after the parser, the autoplug selection will fail because no factory will be found for h264 except the h264parse which is already used in the chain. The signal unknown pad will be triggered and the pad wont be exposed.
The bug happens with both uridecodebin
and urisourcebin ! parsebin
Expected Behavior
In the case of parsebin I expect the pad to exposed after the parser such as h264parse
Observed Behavior
Unknown pad is triggered and the pipeline fails to be created on this pad
Setup
- Operating System: Linux
- Device: Computer
- GStreamer Version: 1.23
- Command line: dedicated code in GstVkVideoParser
Steps to reproduce the bug
you need to build GstVkVideoParser and run with a minimal build of GStreamer without any decoders but parsers.
How reproducible is the bug?
Always.