Application Programs and Systems - Heterogeneous Multicore Processor Technologies for Embedded Systems - page 209

Processing unit Memory

MPEG-2 video stream
Frame buffer of decoding data
(YrCbCr x4)

MPEG-2 video
decoding

VPU

Frame buffer of captured image
(YrCbCr x1)

Frame buffer of decoded data
(YrCbCr x1)
Frame buffer of scaled data
(YrCbCr x1)

720

Video image
scaling

VEU

480

1024

Frame buffer of graphics
(YrCbCr x1)
Frame buffer of synthesized data
(YrCbCr x1)

Image-graphics
synthesis

BEU

768

1024

768

Image output to
DVI

Display

LCDC

Memory area dedicated for uITRON
Memory area shared by both uITRON and Linux

Data transfer

Fig. 6.37 Data fl ow of uITRON system and utilized hardware IP cores

6.4.1 Implementation of Main Functions

The system on uITRON plays back motion pictures, carries out the image scaling
and synthesis, and outputs the image to a monitor, which are the main functions of
the video image search. Figure 6.37 illustrates the data flow of the system on uITRON.
It also shows the utilized hardware IP cores. The VPU that decodes video streams
supports multiple video codecs such as H.264, MPEG-2, and MPEG-4. The codec
used by the system is MPEG-2. The VEU reads an image placed on the specified area
of the memory, enlarges/reduces the size of the image, and writes it to the specified
area of the memory. The BEU reads three images placed on the specified areas of the
memory, blends the three images, and writes them to the specified areas. The imple-
mented system uses BEU's blending of two images. The LCDC reads an image on
the specified area of the memory and transmits it to a display device. The system uses
a DVI interface for the transmission.
The implementation details of the five main functions on the uITRON system are
described as follows:

1. MPEG-2 decoding
2. Still-image capturing
3. Image scaling
4. Video image and graphics synthesizing
5. Output image controlling