User guide

Chapter 15: Deinterlacer MegaCore Function 15–11
Parameter Settings
January 2013 Altera Corporation Video and Image Processing Suite
User Guide
Frame buffering mode
(1)
,
(3)
,
(4)
,
(5)
No buffering,
Double buffering,
Triple buffering with rate
conversion
Specifies whether external frame buffers are used. In no buffering
mode, data is piped directly from input to output without using
external memory. This is possible only with the bob method.
Double-buffering routes data via a pair of buffers in external
memory. This is required by the weave and motion-adaptive
methods, and can ease throughput issues for the bob method.
Triple-buffering uses three buffers in external memory and has
the advantage over double-buffering that the Deinterlacer can
drop or repeat frames, to perform simple frame rate conversion.
Output frame rate
(9)
As input frame rate
(F0 synchronized),
As input frame rate
(F1 synchronized),
As input field rate
Specifies whether to produce a frame out for every field which is
input, or a frame output for every frame (pair of fields) input.
Each deinterlacing method is defined in terms of its processing of
the current field and some number of preceding fields. In the case
where a frame is produced only for every two input fields, the
current field is either always an F1 field or always an F0 field.
Passthrough mode On or Off
Turn on to propagate progressive frames unchanged. When off,
the progressive frames are discarded.
Run-time control for
locked frame rate
conversion
(2)
,
(6)
On or Off
Turn on to add an Avalon-MM slave interface that synchronizes
the input and output frame rates.
4:2:2 support for motion
adaptive algorithm
(2)
On or Off
Turn on to avoid color artefacts when processing 4:2:2 Y’CbCr
data when the Motion Adaptive deinterlacing method is selected.
This option cannot be turned on if you are not using either two
channels in sequence or two channels in parallel.
Motion bleed On or Off
Turn on to compare the motion value with the corresponding
motion value for the same location in the previous frame. If it is
greater, the new value is kept, but if the new value is less than the
stored value, the motion value used is the mean of the two values.
This reduces unpleasant flickering artefacts but increases the
memory usage and memory bandwidth requirements.
(2)
Run-time control of the
motion-adaptive blending
On or Off
Turn on to add an Avalon-MM slave interface that controls the
behavior of the motion adaptive algorithm at run time. The pixel-
based motion value computed by the algorithm can be replaced
by a user selected frame-based motion value that varies between
the two extremes of being entirely bob or entirely weave.
(4)
,
(6)
Number of packets
buffered per field
1–32
Specify the number of packets that can be buffered with each
field. Older packets are discarded first in case of an overflow.
(5)
Maximum packet length 10–1024
Choose the maximum packet length as a number of symbols. The
minimum value is 10 because this is the size of an Avalon-ST
control packet (header included). Extra samples are discarded if
packets are larger than allowed.
(5)
Use separate clocks for
the Avalon-MM master
interfaces
On or Off
Turn on to add a separate clock signal for the Avalon-MM master
interfaces so that they can run at a different speed to the Avalon-
ST processing. This decouples the memory speed from the speed
of the data path and is sometimes necessary to reach
performance target.
Avalon-MM master ports
width
(3)
16, 32, 64,128, 256
Specifies the width of the Avalon-MM ports used to access
external memory when double-buffering or triple-buffering is
used.
Table 15–3. Deinterlacer Parameter Settings (Part 2 of 3)
Parameter Value Description