WIP: h264parse/h265parse: Various fixes around alignment=nal and latency
The main focus for this patchset was to allow low latency parsing. So this patchset notably fixes nal alignment parsing, removes uneeded latency, honor the MARKER bit, etc. It also comes with many new tests which should cover most of the changes.
- also implement and test the PREFIX stuff in h265parse
- check and fix some FIXMEs that I added in the h265parse unit test (they also need fixing in h264parse)
implement an is_prefix helper that Nicolas suggested to avoid comparing with GST_H264_NAL_PREFIX_UNIT all the time and unifying the logic code in both h264parse & h265parseLooked at the result, and the improvement would be very minor really, not worth.