Despite it being cliché, there's truth in the fact that the Internet has made the world a smaller place. Now a new Internet-based technology, Internet Protocol Television (IPTV), is bringing mainland China a little closer for Chinese-Americans by giving them the ability to view the latest movies, TV programs, and a huge inventory of videos from China. Two companies make the entertainment possible - KyLinTV, a Plainview NY-based company that offers the content, (Video-On-Demand (VOD) and TV programs from mainland China), and Beijing Digital TransVideo Technology Co., Ltd. (TransVideo for short), a Beijing, China-based Company that specializes in digital video technologies. TransVideo also supplies the IPTV terminals - otherwise known as Set-Top Boxes (STBs).
KyLinTV provides the videos and multiple TV channels "on demand" to users through its own servers to which the users connect via the Internet. What's more, the IPTV entertainment is presented with extremely high quality as it is based on a new digital video algorithm, H.264 also known as MPEG4-AVC (Advanced Video Coding). H.264 resolves the longstanding quality-versus-bandwidth conundrum by allowing broadcast-quality video to be delivered over the Internet at data rates of less than 1 Mbit/second.
To support the video algorithm, TransVideo chose Blackfin® processors from Analog Devices, Inc. (ADI) because the processors are more than powerful enough to handle the required calculations. But that's not the only reason TransVideo chose ADI. The company said ADI's tools, conferences, and platform-ready designs would speed their product development cycle, a must in this fast-paced consumer market. And with prices starting at $12.95 and $19.95 for the Blackfin ADSP-BF533 and the Blackfin ADSP-BF561 processors respectively, TransVideo felt the price/performance ratio was ideal for their high-volume, mass-market product line.
H.264 otherwise known as MPEG-4 Part 10 or MPEG-4 Advanced Video Coding (AVC) is a high compression digital video CODEC standard. The International Telecommunications Union Video Coding Experts Group (which is responsible for the H.264 nomenclature) wrote it in conjunction with the ISO/IEC Moving Picture Experts Group (which is responsible for the AVC part of the name) as part of a joint effort commonly referred to as the Joint Video Team (JVT). It is not uncommon to call the standard H.264/AVC or AVC/H.264 or H.264/MPEG-4 AVC or MPEG-4/H.264 AVC to stress the common heritage. The goal of the project was to create a standard that provided good video quality at lower bit rates than that of previous video standards without an increase in design complexity.
The standard is an obvious success. H.264 can fit more television programs into a channel bandwidth, deliver quality video over bandwidth-constrained networks, and can even enable a high-definition movie to fit onto a standard DVD. H.264 offers twice the compression of the previous standard MPEG-4 Advanced Simple Profile (ASP). The standard also provides DVD-quality video at less than 1 Mbps and is ideal for full-motion video over wireless, satellite, and ADSL Internet connections or any video application, enabling high-quality video to be distributed over bandwidth-constrained networks cost effectively.
TransVideo's Product Line
Called the Digital Media Device (DMD) 2000, DMD3000, DMD2500, and DMD3500, TransVideo's Blackfin-based line of products support a proprietary CODEC based on the new H.264/MPEG4-AVC standard. The company's IPTV terminals feature support for the H.264 decode format at 25 - 30 frames per second, a 500 - 1,500 Kbps audio bit rate, multiple output and network connections, MP3 stereo, S-Video, and RCA connections. The products also support cable modems, ADSL, Ethernet, and WLAN. All these devices support Video-On-Demand (VOD) and multi-channel broadcast. The DMD3000 and DMD3500 also support downloads.
The devices contain both an MCU for system control tasks and a signal-processing core - a Blackfin ADSP-BF533 processor for the DMD 2000/3000 devices and a Blackfin ADSP-BF561 processor for the DMD 2500/3500 devices.
TransVideo chose Blackfin not only for its price/performance ratio but also for its high quality. The Blackfin ADSP-BF533 processor, which is used inside the DMD 2000/3000, provides the best video quality of 640 x 448 VGA-quality resolution, and television displays using analog signals - over limited bandwidth of 500 - 900 Kbps using the H.264 standard CODEC.
The Blackfin ADSP-BF561 processor, which is used inside the DMD 2500/3500, provides full Digital 1 (D1) capability over limited bandwidth between 1.2 Mbps and 1.5 Mbps. D1 resolution refers to 720 x 576 DVD-quality resolution, which, at 30 fps, requires a 27MB/transfer rate based on the H.264 CODEC standard.
As previously stated, TransVideo chose the Blackfin processor family because of its number-crunching ability, which is more than powerful enough to support the company's high-quality H.264 video application. The Blackfin ADSP-BF533 and the Blackfin ADSP-BF561, a high-performance member of the Blackfin family, were designed specifically to meet the computational demands and power constraints of embedded audio and video applications, delivering breakthrough signal-processing performance and power efficiency with a RISC programming model.
TransVideo also took advantage of Blackfin's memory architecture, particularly the direct memory architecture (DMA) and cache memory. Blackfin views memory as a single unified address space, using 32-bit addresses. All resources, including internal, external, and I/O control registers, occupy separate sections. The Blackfin's DMA controllers provide high bandwidth data movement capability and can perform block transfers of code or data between the internal L1/L2 memories and the external memory spaces. Blackfin's cache memory can also be configured in such a way that the processor and the DMA can independently access it. Fast data transfers, such as these, are quite beneficial to TransVideo's application, as streaming media requires that large blocks of data be transferred to and from processor memory.
To develop its own application software, TransVideo used uClinux, a non-commercial embedded real-time operating system (RTOS), and MiniGUI, a cross-platform Graphics User Interface (GUI) for RTOSes such as uClinux as well as traditional RTOSes. Both are available and supported on Blackfin processors, which made software development much easier for TransVideo.
TransVideo found ADI's assembly language syntax easy to use for both coding and readability, and the architecture, which has been optimized for use in conjunction with the VisualDSP C/C++ compiler, resulted in fast and efficient software implementations. TransVideo said that ADI made it very easy to customize its products because it said ADI has the best development tools, conferences, and platform-ready designs that helped the designers develop the products in a very short period of time. In fact, TransVideo says it was the first company in China to produce a set-top box based on the H.264 standard for commercial use on an IPTV network (July 2004).
For tools, TransVideo used ADI's EZ-KIT Lite Evaluation Kit, which consists of a standalone evaluation board and an evaluation suite of VisualDSP++ to facilitate architecture evaluations via a PC-hosted tool set. TransVideo was able to evaluate ADI's processors as well as simulate, debug, and prototype its application. TransVideo also used ADI's high-performance PCI-based emulator (HPPCI), which consists of a small-shielded pod and cable that allows a non-intrusive debug interface to the JTAG of the Blackfin processor.
The next version of TransVideo's product line, which is sure to include ADI processors, says TransVideo, will support Microsoft's Windows Media Version 9, for high definition TV (HDTV). TransVideo also plans to develop a line of products for video conferencing and video monitors that will use ADI chips. Stay tuned.
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