Use Windows 2000/XP and NTFS volumes. It gives you the following advantages:
An update to DirectX 8.1 is also recommended.
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.
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:
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).
MPEG4 codecs such as DivX (www.divx.com) are not recommended for ôon-the-flyö video capture because theyÆre not designed for capturing high quality video in real time. They are best suited to ôrecord-watch-deleteö purposes, as the quality is quite mediocre.
The author has used the following routine to get video clips of acceptable quality:
1. Video is captured in 768x576xYUY2x25fps format, using PicVideo MJPEG codec, quality 19 and PCM 44100x16bit mono sound.
2. Then the following processing is implemented in the Virtual DUB utility: these filters are applied successively: - Static noise reduction (or SmartDeinterlace) - Resize to 512x384 (a slight crop may be applied if necessary) - Smart smoother (optional)
3. Finally, the sound is recoded into ADPCM or MP3
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.
If you can see a significant audio/video streams mistiming in your recorded
file, try applying this options set, as shown here:
| 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.
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Real time deinterlacing is possible using the Dscaler DirectShow filter:
http://sourceforge.net/project/showfiles.php?group_id=7420&release_id=61078
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.