LG GX500 Service Manual page 31

3. TECHNICAL BRIEF
GX500 Operational Description
The audio recording is performed on the DSP (GSM AMR CODEC). Multiplexing of audio and video streams
is performed by the ARM.
• View Finding during Video Encoding: During video recording the user needs to see what is being
recorded. Therefore, the captured frames are not only encoded but also transferred to the display interface.
If only every second frame from the camera is used for encoding, viewfinding is possible without
burdening the CPU. However, if each frame from the camera has to be encoded, due to low camera frame
rate, the YCbCr4:2:2 to YCbCr4:4:4 color conversion and further downscaling is performed by SW.
Picture rotation and overlay has to be done in SW in any case.
• Storage: Compressed H.263 or MPEG-4 videos can be stored on an MMC/SD, a Flash or a PC.
• Viewing: De-multiplexing of audio and video streams is performed by the ARM. The H.263 or MPEG-4
decoding is also done by SW on the ARM and then the frames are transferred to the display interface.
Audio decoding (GSM-AMR) is done on the DSP.
The audio/video synchronization is done by time stamp feedback from the DSP to the ARM.
• Sending/Receiving: H.263 or MPEG-4 videos can be sent/received as MMS (E-GPRS), as e-mail or
downloaded from the internet.
Higher Multimedia Performance
If higher multimedia performance is required, an external multimedia IC can be connected to
S-GOLDradio because it contains a multimedia IC interface module. The camera and display interface
TM
pins are used in a multiplex mode to connect an external multimedia IC to the S-GOLDradio
IC interface module. The display and camera are connected to the multimedia IC, which contains functions
(in HW and/or SW) to process still images and video data. This configuration is intended for higher-end
graphics features (for example, high quality video streaming, video conferencing, hardware-assisted 2D/3D
graphics functions, etc.).
3.2.2.2 External Devices connected to memory interface
Table 3-6 Memory interface
Device
NAND FLASH
SDRAM
LGE Internal Use Only
LG Electronics
Name
K5D1H12ACC-A075
K5D1H12ACC-A075
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Maker Remark
SAMSUNG 1G(64Mx16) NAND
SAMSUNG 512M(16Mx16) SDRAM
Copyright © 2010 LG Electronics. Inc. All right reserved.
Revision A
multimedia
TM
Only for training and service purposes
LGE Property