h264parse: send h264 level, profile, constraint downstream in tags
Manifest for adaptive HLS is expected to have #EXT-X-STREAM-INF tag describing each of the HLS variants, for example
#EXT-X-STREAM-INF:CODECS="avc1.640029,mp4a.40.2",AVERAGE-BANDWIDTH=2526299,RESOLUTION=960x540,SUBTITLES="subtitles",FRAME-RATE=29.97,BANDWIDTH=2665726
To generate correct CODECS tag we need to know h264 profile, constraints, level. In this example profile is 0x64 (high), constraint is 0, level is 0x29 (4.1).
The best place to get these is in h264parse.