Video Doorbell

A video doorbell system provides added security by transferring outside video and audio to an indoor display or speaker. At the heart of this system is the DM3xx family of low-power processors. Live video display without video encoding (for compression or storage) can be implemented roughly less than 100mW total system power consumption. Even with full video encoding, less than 400mW total system power consumption.

The core subsystem includes:

Processor - Performs the processing of video, handles audio processing, and controls the user interface.

Video Compression - If video and audio needs to be transferred through a network, the MPEG4 encoder of the DM355 and H.264 encoder of the DM365 are perfect to reduce video data sent through the network. Video compression is also important for storage into HDD or SD/MMC card. H.264 provides smaller compressed video than MPEG4.

Video Processing - The image processing capability of the VPFE of the DM355 and DM335 allows for a cheaper image sensor and lens module. The DM365 has an even more advanced video quality tuning feature than DM335 or DM355, thus reducing total system cost. CMOS and CCD sensors are supported.

Video Display - In the case of connecting directly to a LCD or TV display from the main processor, no video compression is required; the Video Processing Front End (VPFE) for video quality tuning and Video Processing Back End (VPBE) for LCD or TV display are sufficient. The DM335 is a good fit under this scenario. The VPBE, which is included in all DM335, DM355, and DM365 DSPs, can also generate composite video output for analog TVs and has the capability to make a decent menu with live video.

Connectivity - Allows the user to transmit data via an Ethernet connection. The DM335 and DM355 both require external Ethernet part while the DM365 has internal EMAC.

Audio - A video doorbell requires two audio codecs; one for the outside and another for inside. The DM335 and DM355 require external audio codecs for audio input/output, while the DM365 has one mono audio codec built-in. External audio codecs can be connected to the DM335, DM355 and DM365 processors via the McBSP bus.

Memory - Stores executing code, data/parameters, video and sound. DDR2 memory can be used with the DM335, DM355 and DM365 processors.

Power Conversion - Converts the input power from the AC/DC wall adaptor or Power Over Ethernet (PoE) to run various functional blocks.