[Libva] codec parser issues between gst-plugins-bad and gstreamer-vaapi

[Yuan, Feng]

Hi Gwenole,
     We saw codec parser moved into gstreamer-vaapi as a submodule for a few weeks. PRC QA team reported some bugs of playbin2 errors but manual pipeline works good.  e.g. https://bugs.freedesktop.org/show_bug.cgi?id=55305. After Cong tracked this bug, he found the issue was caused by codec parser which may get confused when APIs exist both in gst-plugins-bad and gst-vaapi.
     Plugin <h264parse>, which is a gst-plugins-bad element, it calls API *gst_h264_parser_parse_sps* in gsth264parser.c to parse SPS data which should be in libgstcodecparser.so. The problem is that this API also exist in gstream-vaapi as submodule which was a built-in in libgstvaapi-0.10.so.  This API may get unexpected result since *GstH264SPS* has different definitions between gst-plugins-bad and gstreamer-vaapi.
     This issue blocked us, it seems we have to rebuild gst-plugins-bad every time by force copy codec-parser from gst-vaapi to gst-plugins-bad. Do you have any better idea to solve this issue?
      BTW, Why codec-parser was moved into gst-vaapi?Is it the reason that gst-plugins-bad accept patches slow or something? How long would codec-parser be in gst-vaapi, Temporally or always?

Thanks,
Wind