One of the commonly asked questions we receive is why there are black bars when you watch video on a portable device. To explain this, there are a few things that we need to explain first.

DVD video has a fixed resolution.  To ensure DVDs play on even the first generation of DVD players, a DVD movie has to be created using the official standard. If it is not created in such a way that it is compliant with the standard, not all DVD players can play the DVD.

Because the DVD standard was initially created when wide-screen at home was still in its early stage, the DVD standard was based on 4:3 video content. An original movie or TV show would fill the screen completely on a classic, standard-definition TV. However, wide-screen became more mainstream, and to stay compliant with the DVD standard, wide-screen movies received black padding to fit within the DVD specifications.

Unlike most conversion utilities, DVD Catalyst automatically removes the embedded borders from the video, which improves the video quality. The black borders are actually part of the video, and when these are not removed, they will take up valuable space.

With the black bars removed, the video portion that is left does not have a common screen resolution anymore, and the actual size depends on the actual movie as well. There are a few different aspect ratios (the width of the actual widescreen movie) which greatly affect this. In addition. the video player screen also affect the amount of video that fills the screen.

This all sounds complicated, but lets use some pictures to see what this looks like.

This shows an example of Apple’s iPod Video (5G) with a widescreen video. The iPod uses a 4:3 screen aspect ratio, which is the same for many other devices, such as the most Zen and Zune devices. The black borders of the actual video have been removed, but when you play the video on your device, it will stillshow black borders.

The reason for this is that the video is scaled to fit within the device screen size, without changing the look of the video.

The next example shows a Sony PSP with a widscreen video. The PSP has an actual widescreen screen, which is similar to Apple’s iPhone and iPod Touch, as well as the newer Blackberry models and many more devices. The video fills the screen a lot more, but it still shows a bit of borders on top and bottom.

OK, so how do we make movies full-screen?

There are a few ways of doing this. The thing to keep in mind is that there will be a loss of something, either quality or part of the video itself.

1. Both video player devices in the screen shots have a “zoom” function (many other players have this as well). This will remove the black borders, by zooming in, and hiding the sides.

This is the recommended option, because you can decide if you want to watch the movie in it’s full glory (and accept the black borders) or watch the movie full screen. You can even switch back and forth.

2. DVD Catalyst 3 has a “remove black bars from device” option in Global Settings. This will remove black bars from the video, and if needed cut off parts of the sides of the video to make it full screen. Using this will make any movie or show full screen on any device, regardless the screen size or the video size. If you convert a widescreen movie for a non-widescreen device, it will cut off the sides, and if you convert a non-wide screen video for a wide-screen device, it will cut off the top and bottom a bit. Depending on the movie you can loose quite a bit of the video. For example using this option with a very wide Star Wars movie on a 4:3 device, you can loose more than half of the actual video. While movies and TV shows almost always keep the main plot in the center of the video, you will loose things that happen on the sides. If you convert for a Square-screen device, you will loose even more video.

3. DVD Catalyst 3 has a”Full screen stretch” option in Global Settings, which will remove the black bars, and stretch the video to make it full screen. The problem with this is that depending on the video size, people might appear to be taller and skinnier than usual.

So, if you are wondering why DVD Catalyst 3 shows it’s converting at a different screensize than the one you selected, the above should give you some insight on this.