High quality and optimized file size video recording using directshow.net

0
votes

I am developing a application in c# by using Directshow.NET. I am using a virtual camera which will help to record desktop screen. So my graph is:

Virtual cam --->color space converter --->sample grabber ---> ASF writer.

While coding, I used a custom .prx which I generated by Windows Media Profile Editorand configured into IConfigAsfWriterusing WMCreateProfileManager.

In .prx file Mode is CBR, codec Windows Media Video 9 and frame rate 15fps with 759Kbps video bit rate, but still video looks so blurry. If I increase video bit rate like upto 5Mbps then this blurriness is not coming but increasing bit rate results into large file size (54 seconds of recording file size is 10MB).

I tried another graph using graphEdit virtual cam ---> AVI mux ---> File writer but this also generating large .avi file.

How can i record video without blur effect by keeping minimum file size, for eg. 1 minute of video size up to 2-3 MB? Do i need to use any video compressor?

1
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1 Answers

1
votes

The quality depends on the codec you use, but also on the number of bits per pixel. You can calculate it this way:

bits/pixel = bitrate / (width * height * framerate)

(bitrate in bits/second and framerate is in frames/second)

So if you want to reduce the bitrate without getting blurry video, you also have to reduce the resolution or framerate. That way you keep the number of bits per pixel the same.