DVD players are the fastest-selling new consumer-electronics product in history, and they have quickly become commodities. Remarkably, you can buy a decent DVD player today for $40, tax included. Yet the format's success has led to an incredible diversity among players, which keeps the category interesting and keeps us busy. At CNET, we test everything from bare-bones models to tricked-out audiophile decks that cost more than most televisions. Naturally, different types of players must be tested differently. Below, you'll find our basic testing procedures as well as how we handle more exotic DVD players.

Test environment

Experience in testing DVD players is a prerequisite for all of our testers. For audio-centric DVD players, both an audio specialist and a video specialist contribute to the testing.

We don't use a single reference TV at CNET to test DVD players. Instead, we use high-definition, professionally calibrated monitors that are being tested for CNET's television reviews. For DVD-player testing, the TVs are hooked directly to the player using Belkin and Monster component-video cables, S-Video cables, and composite-video cables. For DVI-equipped DVD players, we use a Samsung DVI cable.

Our primary test equipment consists of a suite of DVDs, CDs, and other discs that test the DVD player's image quality and disc compatibility. They include:

• Video Essentials DVD
• Digital Video Essentials DVD
• Avia Guide to Home Theater DVD
• Video2000 patterns from Genesis/Faroudja DVD
• Star Trek: Insurrection opening pan for 2:3 pull-down detection and anamorphic downconversion

We also test disc compatibility by seeing if the player can read the following formats: DVD-R, DVD-RW, DVD+R, DVD+RW, DVD-RAM, Video CD (VCD), CD-R, CD-RW, and Enhanced CD. 

We use different media authored by different DVD and CD recorders, and we test at least two discs for each format. If the player can handle MP3, MPEG-4, WMA, WMV 9.0, DivX, or JPEG discs, we test with at least two varieties of these file formats.

Standard tests

Most of our tests use the player's component-video output, since it's the highest-quality output found on many DVD players. It's also the only output capable of passing a progressive-scan signal. We also look at composite and S-Video outputs, but only to make sure they have no obvious flaws.

Resolution

We use the 200-TVL resolution pattern from Avia to determine whether a DVD player can deliver all 500 lines of resolution permitted by the DVD format. We also note whether the test's 6.75MHz pattern shows up.

2:3 pull-down (sometimes referred to as 3:2 pull-down)

This test applies only to progressive-scan DVD players. We evaluate how well a player detects and compensates for the 2:3 pull-down cadence required to convert 24fps film-based movies to 30fps video. We look at the opening pan of Star Trek: Insurrection as well as various test patterns from the Genesis/Faroudjia Video2000 disc.

Anamorphic downconversion

We set the DVD player to 4:3 pan-and-scan mode and look at the same section of Star Trek: Insurrection, this time evaluating how well the player downconverts anamorphic discs for display on standard 4:3 televisions. We look for undulating lines and jagged edges; a player will score better in this test if the picture looks softer and less distorted by the conversion.

Video-based processing

This test applies only to progressive-scan DVD players. Many DVDs are video-based (for example, 30fps programs shot "live on tape") as opposed to film-based, so we also evaluate how a player converts the video-based source to progressive-scan format. The principal test is the waving flag from Video Essentials, which shows jagged edges of varying severity depending on how well the player handles video-based discs. We also look at a variety of material from the Video2000 disc.

Black-and-white clipping

We test whether a player can output blacker-than-black and whiter-than-white signals using the reverse gray ramps pattern from Digital Video Essentials. This test assures that a player can handle the full dynamic range of video present on the disc.

Endurance

We subject every DVD player to a stress test by placing it in Chapter Repeat mode and leaving it on overnight, sometimes for more than one night. This stresses the drive mechanism by making it go over the same area hundreds of times. If a player fails this test, we note it in the review.

Specialized tests

Depending on the type of player we're evaluating, various other tests are required. Here's a brief rundown of the most common specialized tests.

JPEG reading

To test a player's ability to read JPEG images, we measure how long it takes the player to go from one image to the next in a slide show, how it treats different image sizes and aspect ratios, whether it can rotate images, and how easily the user can utilize a player's photo-playback functionality.

MP3/WMA playback

With a number of audio discs using different authoring methods, we test how well a player handles different types of files, whether it can play files at random, how it displays filenames, and how easily the user can utilize its music-playback functionality.

DVI

If a DVD player has a DVI output, we'll connect it to the appropriate display, namely a fixed-pixel display with a native resolution that exactly matches the output of the DVD player. We also perform the above-mentioned component-video tests using the DVI output and note any image-quality differences between the two.

Networking

Networked DVD players are becoming more common and require a separate series of tests. We connect the player to a wired network and, if appropriate, to a wireless one as well. We then subject the player to situations that test real-world usability, streaming a variety of audio, video, and image files over the network and noting whether the player can stream the media across the network without stuttering.