Converting interlaced 25fps video to smooth 50fps in Vegas

[Wayne Waag]

You have a couple of options. First, there is a plug-in for Vegas (Yadif-yet another deinterlace filter). Just search “yadif for vegas”. In my view, it certainly works better than either the blend or interpolate de-interlacers included in Vegas. I’ve used it on a few occasions for 1080 60i footage in a 1080 60P project. Second, is the use of QTGMC, a bob de-interlace Avisynth filter. You would have to install and learn to use Avisynth, in conjunction with Virtualdub. The learning curve is a bit steep, but the results are much better. I routinely use QTGMC when doing restoration work with older 8mm or Hi8 video. My suggestion would be to first try the Yadif plug-in. As I recall, it is applied as a Media Fx, and you must also set the de-interlace method to None. If you’re not happy, prepare to spend some time learning Avisynth. Good luck.

wwaag

[Lachlan Wisdom]

Thanks for the reply, I’ll look into the yadif plug-in now. I watched some footage with the Yadif (2x) deinterlace mode in VLC and it looks great, hopefully I can get some results like these.

EDIT: Upon reading the description of the plug-in and also testing, it appears the plug-in is unable to get the (2x) effect I want. I may need to look into Avisynth!

[Jaroslav Bouma]

Hello, as I understand you, you have 25i material, which you would like to use as 50p video (no speed change). It is possible without any deinterlacing, because in 25i video you have 50 video fields per second which you need to convert (or “switch”) to 50 video frames per second. In Vegas Pro 12 I use this procedure:
Project properties are:
field order: progressive scan
frame rate: 50 fps
deinterlace method: interpolate fields
media properties (need to set in every video file used in timeline):
* force resample (no smart resaple, no disable resmple)
* field order – upper field first (or for lower field first set for lower field firt material, ofcourse)
It works for me, every video frame is clear, no blurred frames. I use this also when I need to view 25i material not frame by frame but field by field (in this case I temporarily set the project and media properties to values shown above)
Hope this will help. Jaroslav

[Pete Baratta]

Hi Jaroslav,

I also have 50i video. I tried your method to convert to 50fps and the video plays clear on the preview screen. Is there any way to render out to the same results and, if so, what would be the render settings. Thanks, Pete.

[Jaroslav Bouma]

Hi Pete,
first of all, I assume that if I am talking about 25i and you are talking about 50i, we are talking about the same thing – 25 fps interlaced video (50 video fields = 25 video frames per second) This video is placed into 50 fps progressive project according to process I described above. Then the only thing is choose output format which is capable to handle 50 progressive frames per sec. I usually render to .mp4 AVC format. I found that MainConcept AVC/AAC codec doesn´t allow me to choice 50fps while Sony AVC/MVC does, so I use this one. (field order None-progressive, frame rate 50fps and bitrate according to required size/quality of output file).
Jaroslav

[Pete Baratta]

Hello again Jaroslav,

Thanks for the info. I shall give it a try.

[Marcel Gächter]

Thank you very much for your rendering advices in this thread. They helped me a lot (:

[Cedric Divang]

> Project properties are:
> field order: progressive scan
> frame rate: 50 fps
> deinterlace method: interpolate fields
> force resample

Hey Jaroslav, I don’t know if you will read this but I just want to thank you for your AWESOME guide on how to convert 1080i25 to high quality 1080p50 without deinterlacing ! I wish I read your message earlier, it would have saved me from making hundreds of meh quality deinterlaced 1080p25 videos 🙁 Now, I use your technique and render to 1080p50 with Lagarith, then I reencode the huge file to x265 with Handrake. The final video is low size and VERY HIGH quality.

Thanks again Jaroslav !