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| Unofficial VirtualDub Support Forums > Advanced Video Processing > Keeping Sharpness From 50 Fps To 25 Fps |
| Posted by: Fredd Feb 11 2003, 12:39 PM |
| Hello all, I a few words, my problem is to get a sharp image from a 50 fps source converted to 25 fps (MPEG files). I work with MJPEG files, PAL, 704*576. To get rid of interlacing artefacts, I usually use Gunnar Thalin's "area based" deinterlacer, but I came across www.100fps.com and, as Virtualdub can load MJPEG files and split their fields, I tried working from 50 fps files. Then I use the bob filter, and resize (precise bicubic) to 352*288 (also used in the case where I use Gunnar's filter). I exported a test file in AVI @50fps: a pure pleasure to watch! But converted to MPEG, it will revert back to 25 fps and what's annoying, the overall quality gets blurred. I got sharper results from the original file with the area based deinterlacer (maybe TMPGenc keeps one image out of two). The advantage with 50 fps was speed, I found the overall process much faster (around 20 fps) than working on the original file @25 fps and the smart deinterlacer I applied (around... 6fps). The 50 fps file looks sharp... I don't know if it's just an impression but I'd like to keep this sharpness. So... Is there a way to merge 2 frames into 1 to get 25 fps, instead of decimating? |
| Posted by: jcsston Feb 11 2003, 06:05 PM |
| MPEG-1 video can be 50fps, so you can keep the original rate. But if you're creating a VCD you will need to reduce the frame rate for compatibility. |
| Posted by: minion Feb 12 2003, 10:14 PM |
| One thing I can tell you is you can not use tmpgenc to Properly convert the 50FPS to 25FPS By Just setting the Frame rate to 25fps, you would have to set the Frame rate to "50fps(25fps Internal)" or Better would be to use AVISynth to Change the Frame rate then Frame serve to Tmpgenc... |