#unconditional
V4L2_BUF_FLAG_MAPPED
V4L2_BUF_FLAG_QUEUED
V4L2_BUF_FLAG_DONE
V4L2_BUF_FLAG_KEYFRAME
V4L2_BUF_FLAG_PFRAME
V4L2_BUF_FLAG_BFRAME
V4L2_BUF_FLAG_ERROR
V4L2_BUF_FLAG_IN_REQUEST
V4L2_BUF_FLAG_TIMECODE
V4L2_BUF_FLAG_INPUT
V4L2_BUF_FLAG_PREPARED
V4L2_BUF_FLAG_NO_CACHE_INVALIDATE
V4L2_BUF_FLAG_NO_CACHE_CLEAN
V4L2_BUF_FLAG_LAST
V4L2_BUF_FLAG_REQUEST_FD