Lessons Learned Through Recording VCR and Video Game Footage With Two Different PC Recording Devices
This article looks at VCR and video game footage recorded with two different USB recording devices, the USBAV-191 ADS Tech Video Xpress (now discontinued) and the DIAMOND ATI Theater™ HD 750 USB TV Tuner. Although the Video Xpress does a decent job, it has two problems:
With these problems in mind, I decided to get the ATI Theater HD 750 for the following three reasons:
JVC HR-VP782U VCR Footage
From looking at VCR footage recorded with the Video Xpress and the ATI Theater HD 750, we learn a valuable lesson, which is:
To demonstrate this concept, here is VCR footage captured by the Video Xpress:
Next, here is the same VCR footage captured by the ATI Theater HD 750:
Although it is not immediately obvious, the ATI Theater HD 750 is recording 4 rows below the Video Xpress. This becomes more apparent when the "CH 2" segments are lined up next to each other. The picture below has the Video Xpress on the left and the ATI Theater HD 750 on the right, with the red at the top and bottom signifying the area that each recording device is missing. I also placed a red line to show that the "CH 2" information does in fact line up with the correct placement:
Ice Hockey Footage
From the 1988 Nintendo Entertainment System (NES) game Ice Hockey, we learn that:
There are three video screenshots that lead to these conclusions. The first is Ice Hockey being played on the actual NES and recorded by the Video Xpress, the next is Ice Hockey being played on the actual NES and recorded by the ATI Theater HD 750, and the last is Ice Hockey being played on the Wii via Wii's Virtual Console service and recorded by the Video Xpress. I have separated these pictures with green bars so it is easier to see the borders. Also, the increased sharpness of the Wii is in large part due to the Wii's S-Video connection, something the NES lacks. Finally, if you know your American history, you should be able to notice a mess-up on the part of the designers of the game Ice Hockey:
Before getting into the PAR issues, let's take a closer look at the number of rows. The picture below basically confirms what I say in the beginning of this section about rows. The red shows the areas that the recording devices are missing while the orange shows the part of the image that the Wii is not outputting. In order to make the comparison image less wide, I reduced the width of the pictures by half and cut out the middle:
Next, let's move on to the issue of PAR. According to the Overscan article on the Nesdev Wiki, the NES generated a 256x240 picture with an 8:7 PAR and borders on the sides, and these borders used the background color (thus explaining why the NES Ice Hockey pictures have white borders) . The 256x240 picture with an 8:7 PAR means that the active video area (i.e. the video area minus the black and white borders) should be 644x480 when shown with a 10:11 PAR. The math for this is shown below:
8/7 * 256 * 2 * 11/10
As it so happens, cropping out the black and white borders from the NES footage with the previous picture in mind reveals a picture that is 644x480. Thus, the NES is correctly using a 10:11 PAR. However, if we crop out the black borders from Ice Hockey being played on the Wii, we are left with a 669x456 picture. As the Ice Hockey comparison picture shows, the Wii is not doing any vertical stretching. Instead, the Wii is simply using horizontal stretching, and therefore the picture is too wide. How wide? Ironically enough, the Wii's Virtual Console seems to use the opposite PAR of the NES generated graphics before they reach the TV, which would be 7:8. This because both 10/11 * 644 and 7/8 * 669 come out to about the same number, 585.
Super Smash Bros. Brawl (SSBB) & Perfect Dark Footage
From the 2008 Wii game SSBB and the 2010 Xbox 360 version of 2000 Nintendo 64 (N64) game Perfect Dark, we learn that:
First, let's look at a screenshot of SSBB recorded by the Video Xpress followed by another screenshot of SSBB recorded by the ATI Theater HD 750:
As you can see, the ATI Theater HD 750 is once again recording 4 rows below the Video Xpress. The 4 rows located below the Video Xpress recording area are black. This, combined with the fact that this is video generated in more modern times (i.e. not 1988), strongly suggests that the SSBB video has a height of 480 rows. This would, in turn, further imply that Video Xpress is recording in the "correct" area while the ATI Theater HD 750 is recording in an "incorrect" area. However, looking at some footage of the Xbox 360 remake of Perfect Dark throws this notion out the window. First is a screenshot of Perfect Dark taken with the Video Xpress, followed by a screenshot of Perfect Dark taken with the ATI Theater HD 750:
The Video Xpress has two black rows at the top while the ATI Theater HD 750 has two black rows at the bottom. This means that, in terms of positioning, the Xbox 360 is generating video placed between the Video Xpress and the ATI Theater HD 750, so both recording devices fail to capture the entire 480-row picture. This is illustrated by the picture below (the Video Xpress is on the left and a flipped version of the ATI Theater HD 750 picture is on the right):
How to Eliminate or Reduce Picture Row Loss
As the previous screenshots have shown, there is a good chance that recording 525-line video with a 704x480 or 720x480 resolution will result in losing some picture rows, either due to the picture having up to 486 rows (though this typically only the case for older analog footage) or having the recording area misaligned with the video area. So, what to do? There are basically two possible solutions: record with a 720x486 resolution or adjust the positioning of the recording area.
First, let's start with the best possible solution, which is to record with a 720x486 resolution. One such series of PC recording devices that do this are the Intensity products from the company Blackmagic Design    . The key problem, however, is the price - the Intensity products start at $199 . Unfortunately, there does not appear to be cheaper devices that will record the full 720x486 resolution. Hopefully, if this article gets popular enough, manufacturers of cheaper devices will add support for 720x486 in their devices as well.
The next possible solution is to adjust the positioning of the recording area, although you'll still end up losing up to 6 rows if the video you are recording has more than 480 rows. This is possible if you use the BT8x8 Tweaker tool within VirtualDub. To understand the problem with this approach, you have to understand exactly what the BT8x8 Tweaker tool does. Basically, certain PC video recording devices used one of the BT8x8 chips. These chips became widespread, enabling people to gain a greater understanding of how they worked and thus the creation of the BT8x8 Tweaker . That being said, the major problem with the BT8x8 Tweaker is that the BT8x8 chips are only found in older PCI devices . PCI devices do not work in laptops and some newer desktops that lack a PCI card slot. Additionally, since PCI devices are older, certain PCI devices might have problems with the versions of Windows past Windows XP.
1. Audio preview issues with ATI Theater HD 750 USB. Apr. 27, 2010 5:57 PM. virtualdub.org.
2. Overscan. Nesdev Wiki.
3. Intensity. ©Blackmagic Design Pty. Ltd. 2012.
4. Thread started by el g00g on Feb. 5, 2010 7:34 PM GMT -6. Blackmagic Intensity Pro issues when recording from xbox 360: Audio and video problem. Powered by All-streaming-media.com; 2006-2011.
5. Thread started by kauri on Nov. 7, 2011 8:25 PM GMT -5. Blackmagic Intensity Pro - NTSC Captured File Not Recognised at Interlaced?. VideoHelp.com Forum.
6. Thread started by VirtualDubFan on Dec. 3, 2011 4:55 PM GMT +1. VHS: Here's How I Convert Theatrical Material, Your Comments?. Doom9 Forum.
7. Products. ©Blackmagic Design Pty. Ltd. 2012.
8. Version4Team. BT8x8 Tweaker. June 12, 2004. Doom9.org.
9. Bttv devices (bt848, bt878). Jan. 22, 2012 6:53 AM. LinuxTVWiki.