Horizontal
Blanking
Vertical
Blanking
Active Field
Active Field
time
Active Field
Active Video Y
and CbCr
Buffers X
Vertical
Ancillary Data
Buffer X+1
Vertical
Ancillary Data
Buffer X
Active Video Y
and CbCr
Buffers X+1
Internal Modules
143
SPRUHI7A – December 2012 – Revised June 2016
Copyright © 2012–2016, Texas Instruments Incorporated
High-Definition Video Processing Subsystem (HDVPSS)
1.2.8.2.3 Frame Buffers
The VIP/VPDMA supports Frame Buffers in DDR for Active Video and Ancillary Data.
4:2:2 data is always saved in packed pixel buffers.
4:2:0 data is saved in Planar Luma buffers and Planar CbCr pair buffers.
A Luma Frame Buffer is a Planar storage area. Each line is the width in pixels (1Byte/pixel) of the output
picture size format. The frame buffer contains the number of active video lines in the output picture size
format.
A Chroma Pair Frame Buffer is Planar storage of CbCr pixel pairs, with each pixel being a byte. For 4:2:0
storage, N lines in the output picture active video results in N/2 lines of CbCr pairs being stored.
The Ancillary Data buffer is different than the Active Video Frame Buffers. The Ancillary Data buffer only
stores Vertical Blanking Ancillary Data. The number of lines in the Ancillary Data buffer is the same as the
number of Vertical Blanking lines. Typically, only one channel is extracted from the Vertical Blanking data,
so the width of the Ancillary Data buffer is the same as the width of the Luma Buffer.
In 8-bit input mode, it is possible for both Luma and Chroma sites to be extracted for Vertical Ancillary
data. Each color component is strobed on separate input clock cycles. In this case, the line width of the
Ancillary data is twice the Luma line width of the picture. Both Luma and Chroma sites cannot be
extracted for 16-bit input mode because both Luma and Chroma are sent on the same input clock cycle
and the Ancillary port to the VPDMA VPI is only 8 bits wide.
shows how the planar data regions are stored in DDR. The vertical blanking data is stored in
a set of Planar Buffers. Note that the bottom of the Vertical Ancillary Data from the previous field or frame
is stored in the same buffer as the top of the Vertical Ancillary Data from the current field or frame.
Figure 1-85. Planar Buffer Storage Description