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Video decoders target security surveillance apps

San Jose, Calif. — Techwell, Inc. unveiled two, four-channel NTSC/PAL video decoders with integrated audio analog-to-digital (A/D) converters, and a Motion Joint Photographic Experts Group (MJPEG) compression controller for multichannel digital video recorders (DVRs) for security surveillance applications.

Extending Techwell's TW2800 family of security ICs, the pin-to-pin compatible TW2815 and TW2816 four-channel video decoders convert analog composite video signals to digital component YCbCR data for standalone and PC-based DVR security applications.

The TW2815 also includes audio codecs and combined with the new TW2700 four-channel compression controller provide a scalable, end-to-end MJPEG DVR solution, said David Nam, Techwell's vice president of sales and marketing.

The TW2815 and TW2816 include four integrated analog anti-aliasing filters, 10-bit, CMOS-based A/D converters, and high-performance adaptive 4H comb filters for all NTSC/PAL standards.

Both ICs provide simultaneous four channel Full D1 and CIF time-multiplexed outputs with 54 MHz, and both operate at an ultra low level of power (typically 480 milliwatts to 500 mW). In addition, the TW2815 offers four integrated audio A/D converters, an audio digital-to-analog (D/A) converter, multichannel audio mixed analog output, and support for a standard I2S interface for record output and playback input.

The TW2700 is a real-time four-channel video compression controller for security applications that can compress and decompress four full-size video data streams simultaneously, Nam said.

Features include four ITU-R BT.656 compatible video input ports; an independent compression engine for each channel with a proprietary algorithm; support for triplex operations, simultaneous recording, playback and network connection; and support for up to sixteen channels through cascade mode.

The pin-to-pin compatible TW2815 and TW2816 are priced at $12.00 and $10.00, respectively, in 10,000-piece quantities, and come in a 100-pin, TQFP package. The devices are currently sampling with production slated for Q2.Click here for the TW2815 data sheet. Click here for the TW2816 data sheet.

The TW2700, priced at $25.00 in same quantities, uses a 256-pin, PQFP package. The device will begin sampling in Q2, and will go into full production in Q3. Click here for the TW2700 data sheet.

Techwell Inc. , 1-408-435-3888, www.Techwellinc.com.

This product trio is said to represent the first end-to-end semiconductor solution in the security surveillance market — combining audio A/D converters with MJPEG compression. The chips were developed in response to demand for crystal sharp images in security applications.

“These devices enable superior displays in embedded digital video recorders, PC-based DVRs, networked video recorders and multiplexers,” said Tom Krause, Techwell's director of business development. Techwell's security surveillance products integrate the functions required to display, store and transport analog video signals from security surveillance cameras. “By integrating multiple video decoders into a single semiconductor, we are able to receive and decode analog video signals from multiple cameras into a standard digital format — while also saving considerable power consumption,” he said.

The TW2700 video compression controller — combined with the TW2815 or TW2816 video decoders enables a complete end-to-end MJPEG DVR system that can scale from 4 channels up to 16 channels.

Furthermore, combining the TW2815 decoder and the TW2700 controller enables a two-chip solution versus up to 11 separate chips to perform the same functions — four NTSC/PAL video decoders, four audio A/D converters, one multiplexer, one MJPEG codec, and one NTSC/PAL encoder, according to Krause.

The TW2815 and TW2816 include proprietary adaptive 4H comb filters that were developed by Techwell. These filters are typically used in NTSC/PAL video decoders. The filter limits common artifacts like horizontal crawling dots, vertical dangling dots, and cross color.

The TW2815 and TW2816 devices are Techwell's third generation 4-1 video decoders. The first generation (TW2804) came out in 2003, and the second generation (TW2814) emerged in 2005. Before the TW2804, only single-channel video decoders were available, Krause said. The TW2815 is Techwell's first decoder chip to integrate audio functions.

The TW2815 is a 4-in-1 NTSC/PAL video decoder with integrated audio A/D converter and audio D/A converter. This chip receives analog video and audio signals from a video surveillance camera and converts those signals into digital formats to send to the TW2700 or a third party compression chip, whether it be MJPEG, MPEG2, MPEG4, or H.264.

Techwell's latest generation video decoders boast improved comb filter performance for better image quality and less artifacts, significantly lower power consumption (from 1 watt to 500 mW), a smaller form factor (124-pin QFP versus a 100-pin QFP), integrated audio, and a 54-MHz output.

The TW2700 is a video compression codec, i.e. MJPEG compression and de-compression. It also multiplexes or combines multiple video signals into one signal and has a variety of I/O support like Ethernet and IDE for hard drives.

The RISC-based controller is also a first for Techwell. Up until now, Techwell has focused on the front end of DVRs, i.e. the video decoders and multiplexer blocks. “Now, we are starting to address the compression codec segment,” Krause said.

Techwell's customers are demanding more end-to-end solutions including decoding, multiplexing, compression, networking and display technology. Over time, the company's goal is to provide chip solutions that can address customer's needs across all of these technologies, Krause said.

 
 
See related TW2815 block diagram

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