DivX promises better image quality, smoother video (via better performance), and improved battery life. Ultimately, each claim comes with its own caveat.
Technically, DivX wins in image quality, but it’s marginal. According to our PSNR analysis in MatLab, you get, at best, a 5% bump in image quality. However, 1080p video from YouTube is relatively low bit rate when compared to what you get from a Blu-ray movie. And when you're working on a small screen, the whole image quality issue is a wash. In the end, performance is what really matters.
In general, there are two ways to decode video.
- Use the GPU's dedicated video decode logic
- Use the CPU via a software decoder
They’re efficient, in that order, with regard to power consumption and battery life. On our Brazos-based motherboard, Adobe Flash Player is able to offload more of its video processing workload to AMD's UVD3 fixed-function hardware. This is something not possible on older systems and most netbooks, such as our Mini 1012.
The GMA 3150 (Atom N450) only supports MPEG-2 decoding, as Intel didn't fully support H.264 decoding until the GMA 4500MHD. Whether or not a given configuration offers hardware-accelerated decoding turns out to be the key here. On a system equipped with GPU-based hardware acceleration, Adobe reigns king. On older systems like the GMA 3150, which are forced to rely on CPU-based software decoding, DivX offers a superior experience.
When it comes to battery life, DivX's video engine appears to help here as well. But it's not a complete win. DivX still requires you install Adobe Flash Player, which it relies on to identify the Flash video container before it's passed to the DivX HiQ plug-in. This causes additional processing overhead. Whenever you go to a DivX HiQ-supported Web site, the browser loads the DivX plug-in after Flash. The chart above shows what happens when you open a YouTube video. With DivX HiQ installed, there’s a spike in CPU usage because it's loaded as a secondary plug-in. In practical terms, the amount of battery life you potentially save is very small. In many cases, that processing overhead negates any power savings attributable to DivX Plus Web Player.
At the end of the day, if you can't get good Flash performance from Adobe's Flash Player, DivX has an alternative of sorts. However, be aware that claims of better battery life and cooler laptops don't hold up, especially if you already have a new laptop capable of hardware-accelerated H.264 decoding.
It's also worth mentioning that we encountered more browser crashes and poorer system response when we played video through the DivX Plus Web Player. Nevertheless, it's impressive to see completely fluid (30 FPS) 720p YouTube video on our Atom N450-based netbook, which couldn't achieve that level of performance using Adobe's Flash Player. If that's the boat you find yourself in, then DivX has an answer.