docs: Update interlaced video design document

The RFF flag is to be reused for buffers in the telecine state to
indicate that the buffer contains only unneeded repeated fields that are
present in other buffers and as such this buffer can be dropped.
This commit is contained in:
Robert Swain 2011-04-06 16:11:02 +02:00
parent 9cf76f114f
commit e284455272

View file

@ -77,9 +77,20 @@ Telecine
If the caps have interlaced=true and interlacing-method=telecine then the
buffers are in some form of telecine state.
The TFF, RFF and ONEFIELD flags have the same semantics as for the plain
interlaced state, however, for the telecine state require one additional flag to
be able to identify progressive buffers.
The TFF and ONEFIELD flags have the same semantics as for the plain interlaced
state.
GST_VIDEO_BUFFER_RFF in the telecine state indicates that the buffer contains
only repeated fields that are present in other buffers and are as such
unneeded. For example, in a sequence of three telecined frames, we might have:
AtAb AtBb BtBb
In this situation, we only need the first and third buffers as the second
buffer contains fields present in the first and third.
The telecine state require one additional flag to be able to identify
progressive buffers.
GST_VIDEO_BUFFER_PROGRESSIVE means that the buffer containing two fields is a
progressive frame. The implication is that if this flag is not set, the buffer