Hardware vs. Software for Desktop DVD Playback
In the showdown between software and hardware DVD decoding, software has taken a commanding lead, despite its flaws, according to DVD experts. Early on, there were a number of integration issues with hardware players, notes Blaine Graboyes, founder and creative director of Zuma Digital. For example, the Toshiba Tecra—a first-generation DVD laptop that used software decoding—flashed a bright magenta before playing, due to an initialization issue with Direct Show, he says. "Processor speed seemed to be the key," he says. "I think Intel pushed software hard so they could sell more and faster processors to OEMs and then consumers." Quality issues still exist, even at the high end of software decoding, generally jumping and stuttering at random moments, he says, adding, "It would take some wicked advanced testing to figure out if the issue was software, hardware, encoding, authoring, disc issues, etc."
Zuma uses software decoding on all demo and sales systems (powerDVD on Dell Inspirons, HP OmniBooks, and Compaq Presarios). "We rarely get anything other than jaws dropping at the quality," Graboyes notes. "Once in a while some picky guy will say, ‘hey it stutters,' or whatever, but generally people are so impressed with PC DVD quality they do not even notice or care about the issues."
Zuma sells a software product called ActiveDVD that includes DVD in PowerPoint. Zuma recommends the use of PowerDVD, a 650mHz+ machine, with 128MB RAM, 8MB VRAM, and a 4X or higher DVD drive. Although software decoding will work at 400mHz, Graboyes says, he considers 650mHz a more realistic baseline for quality playback. Graboyes recommends Dell systems because they seem to be rugged, and the company has good support. "One of the big issues we find is software support on OEMs' Web sites," he says. "If you cannot tweak the latest and greatest drivers, then software playback will suffer greatly."
The benefits of hardware versus software decoding solutions depend on the target audience and application, according to Michael Ory, director of digital services at Crush Digital Video. He considers the ability to output the signal to an NTSC monitor to be one of the major benefits of hardware decoding. "Hardware decoding is also non-CPU-dependent, which means it can work on lower-end computers and/or when you have a CPU-intensive application which is running along with your DVD decoder," Ory says. "Software decoders require the majority of the CPU load in order to display smoothly."
He points to compatibility with DirectX drivers as the biggest plus with software decoders. "This gives you the most flexibility and power to embed DVD video into other applications such as HTML browsers, PowerPoint, Director, or custom software," Ory says. In his experience, Pentium II, 500mHz is the minimum speed required for software decoding to work correctly. Chris Armbrust of Marin Digital says computer requirements depend on your needs. "If you really want to use your computer when watching a DVD, get a hardware decoder," he says. "Otherwise, the software decoder on the Pentium II/III 300+mHz machines is very workable."
The other factor that goes into whether a software decoder will work is the bitrate of the encode. "We have created DVD titles that worked with 250mHz Pentium IIs," Armbrust says. "We had to encode at 3mbps, but it looked good and played back just fine." With Windows, system operation is sluggish but still works when a DVD is going, Armbrust says; and with Mac OS, you usually only have one thing going at a time anyway. His company mainly works with clients whose projects are running from DVD-R, and he recommends at least a 300+mHz Pentium II under Windows 98, NT, or Win2k. He says Mac OS 9+ with DVD Player 2.1 seems to work fine as long as it's a G3 with a minimum speed of 300mHz.
According to Armbrust, DVD-ROM drives are improving but too many still have problems with DVD-R (particularly the 4.7GB version). "As far as specific hardware, I actually tell people to try to get a Sony or a Pioneer drive," he adds. "Pioneer DVD-ROM drives work with DVD-R and they are widely OEM'd. Others may work, but I know that these two will not cause problems."
From a system integrator's perspective, software decoding is preferable because it's less expensive and offers greater flexibility, says Mike Evangelist, Apple's senior DVD product line manager. "Everybody always wanted to use software, but it wasn't practical" with slower processors, he says. "Now, it is."
DVD decoding in Apple computers is primarily software-based, but hardware is used to speed the display of video, Evangelist explains. "When cost is no object, and people don't have to worry about taking up slots, then in some sense hardware is better," he says.
Since software decoding relies on the main CPU, playback can be affected if another program is running, but users aren't usually doing anything else when watching DVDs, Evangelist says. The authoring professionals agree that the rise of software decoding is a big positive for the desktop DVD market. "Software decoders are easier to write customized software for, so the quality of software which is DVD-enabled should grow rapidly," Ory predicts. "Of course, the negative aspect is that people who have older, slower machines and try to watch DVD may be turned off by the poor playback quality. However, any machine sold today easily has enough horsepower to display DVD flawlessly with software decoding."