Capture tips

Software environment

Use Windows 2000/XP and NTFS volumes. It gives you the following advantages:

• The NTFS file system and iuVCR allow you to create .avi files of any size Under the FAT32 file system no file can exceed 4 GB in size. 
• WDM drivers are handled much more efficiently.  
• Strict priority management reduces frame loss. 

An update to DirectX 9.0 or higher is also recommended.

Color format choice

16-bit YUY2 or YVUV are strictly recommended for capture. First, these formats are "native" for color representation in both TV broadcast and video signal digitizing chips. For instance, the popular bt848/878 chip digitizer output returns YUY2, and all the other color formats (such as RGB16, RGB24, and YUV12) are derived from YUY2 as a result of conversion in bt8x8. So, there's no need to apply RGB24, as it carries no additional color information and takes 1.5 more storage volume.

Compression codec choice

The best quality can be achieved in an uncompressed video stream. But a minute of an uncompressed video may take up to 768x576x2x25x60~=1.2 GB, and the data stream is approx. 20Mb/sec. Not every system is able to process such a high amount of data. That's why video is already being compressed at the capture stage. To obtain quality results, special codecs for real time capture are recommended. These compression ratio of these codecs isn't high (approx. 2-32), but it is enough to reduce system requirements and retain picture quality. These are some of the most popular of these codecs:

• PICVideo MJPEG compressor (http://www.jpg.com). A very fast codec with a quickly changeable compression ratio. Compression is lossy and some quality loss occurs. The picture quality gets noticeably poor at high compression ratios.
• Huffyuv Lossless Video Codec ( http://neuron2.net/www.math.berkeley.edu/benrg/huffyuv.html ) Huffyuv is a very fast, lossless free codec .
• Alparysoft Lossless Video Codec (http://www.alparysoft.com) Another good lossless free codec.

After you're finished with the capture, you will need to edit and finalize compressing your video using a codec like MPEG4 using the VirtualDUB utility (www.virtualdub.org).

Additional filters and plug-ins for iuVCR

Can be found at http://vlafy.iulabs.com It is Vladimir Filippov's page. He is multimedia software developer and just iuVCR user.

Drivers for bt848/878-based cards

Many of the WDM drivers for bt848/878-based cards have numerous limitations under Windows 2000/XP. Visit www.iulabs.com  to find multipurpose improved WDM drivers for bt848/878-based cards. If you see your card in the compatibility list published on the site, it is recommended that you download and install the drivers. Alternative drivers can be located here at http://btwincap.sourceforge.net 

Coming over the mistiming

If you can see a significant audio/video streams mistiming in your recorded file, try applying this options set, as shown here:

Notes on filters application

To crop frame edges, you can apply the "iuLab Video Crop" filter supplied with iuVCR. If the frame color format is YUY2 / YUYV, X1 and X2 parameters are required to be multiples of 4.

Image sequence capture

iuVCR has the capability of capturing a video stream into a sequence of static images in .bmp or .jpeg format. Choose a special "[BMP] Capture to images" mode from the codecs list under the "Video" tab to activate it.