DVD versus PC-DVD..............
Can a PC outperform a DVD player?
August 20, 1997
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Electronic Buyers' News via Individual Inc. : After several years of cross-industry cooperation between consumer electronics companies, computer manufacturers, and the entertainment industry, DVD has arrived. Because DVD disks can be played on a consumer player or on a desktop/notebook computer, DVD can be called a convergence medium.
Consumers are apt to compare the playback capabilities of a commercial DVD player and a PC. The PC can deliver a knockout punch with a solution that combines PC interactivity with the quality audio and video of the DVD format.
If PC manufacturers compromise this objective, end users will give up their PCs in favor of the relatively less-expensive (below $500) consumer DVD players for watching movies.
The challenge for DVD OEMs is to deliver crisp, better-than-TV-quality video and CD-quality sound. For audio, this means 16-bit, CD-quality digital audio with true surround sound. For video, DVDs require true video playing at 30 frames/s without loss of frames and an absence of any visual artifacts or video flaws.
DVD players achieve this quality by decoding MPEG-2 video and AC-3 audio in hardware. The same can be done in the PC, but some suggest it can also be done in software.
Software decoding is not proven, and it would require extremely fast CPUs (300 MHz) and a new generation of video-graphics accelerators with 8-Mbyte frame buffers. These are hid- den costs, and perhaps the greatest cost is the risk of compromising video/audio quality with loss of frames, jerky motion, unusual sound, or loss of audio/video synchronization. Users will not accept this, as they expect more from their PCs.
A sure way to deliver stunning video playback in PCs is to use dedicated DVD/MPEG-2 decoder hardware or a combination of hardware/software decoders to deliver crisp, high-quality audio and video. It is clear that the majority of the load is in the processing of the MPEG-2 video stream. At 30 frames/s, this means 20 Mbytes/s of digital video data needs to be displayed in a video window without affecting other normal PC desktop activities.
In parallel, AC-3 digital audio encoded audio data needs to be sent to the sound device. Also, any activity, such as menu display, navigation control, inter-activity, and user input, has to be processed in parallel.
Hardware DVD-decoding solutions free up the processor to handle other essential tasks, such as 3-D graphics and running several applications simultaneously. A mainstream PC designed with hardware DVD MPEG-2 playback is able to offer a well- balanced system in which the added DVD MPEG-2 design complements the features of the overall PC subsystem rather than saturating the system's performance.
The DVD decoder is typically a PCI card that handles (at least) MPEG-2 video decoding in hardware. Some cards decode AC-3 in hardware, but this task can easily be done in software with any 133-MHz processor. A hybrid solution helps reduce the cost of the decoder without compromising the quality of playback.
A number of companies have started to introduce DVD decoders as described above. Sigma Designs Inc.'s solutions, for example, combine a hardware video decoder with software AC-3 audio decoding and come with complete DVD decryption, navigation, and control software.
DVD has opened a new era in digital video technology, and the PC is at the center of the convergence between consumer entertainment and PC-based interactivity. To dominate this market, the PC must outperform the consumer DVD players by delivering uncompromising video and audio quality.
-Prem Talreja is vice president of marketing for Sigma Designs Inc., Fremont, Calif.
Copyright (c) 1997 CMP Media Inc.
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I may have posted this previously -- it looks familiar. |
