In Vegas Pro 15 build 323 Steam (and I believe in the previous build as well) there is a bug: deinterlacing the SD footage while upscaling to HD and changing the FPS causes unacceptable visual bugs in the output file. Please read the description below.
Task: to deinterlace and upscale the interlaced legacy AVI DV 50i SD footage to 1080 24p.
System: PC Win10, Intel i7, 16G Ram, Nvidia Geforce GTX 1070, UHD 4K desktop resolution.
Footage: standard SD AVI DV PAL 576 50i (i.e. 25 fps interlaced), previously captured from DV tapes with the older versions of Sony Vegas Pro.
Vegas Pro preferences: Video -> GPU acceleration of video processing = Nvidia GTX 1070.
Project properties: 1920x1080 progressive, 24.000 fps, pixel format 8 bit (or 32 bit full range - same glitch), full resolution rendering quality - Best, motion blur - Gaussian, deinterlace method - Blend Fields or Smart Adaptive (I don't use Interpolate as it makes the picture too pixelated), resample mode - any of them (Smart Resample, Force Resample or Disable Resample - tried them all, and they don't fix the bug).
The properties of the SD footage/media in Vegas Pro are standard PAL DV defaults with field order "Lower field first", "Use project resample mode", playback rate = 1.00, undersample rate = 1.0, reduce interlace flicker = On or Off (doesn't affect the bug). There are no video FX used in the media, events, tracks or project.
Then I render the footage to any 1080 24p codec/format and always get the following bug:
- with "Blend Fields" deinterlace method: every 0,5 second or so the picture switches to blurry and then back to normal, and then again and again for the whole length of the video;
- with "Smart Adaptive" deinterlace method: every 0,5 second or so the top half of the picture shifts a few pixels up and down, up and down all the time for the whole length of the video.
With both of these glitches the output file is useless.
I tried different formats/codecs with 1080 24p - Magix Prores, AVC, Intel Hevc etc. - the result was always the same with that glitch.
This glitch is also noticeable without rendering, just in the full-screen video preview of the timeline with best full settings. So I assume it has nothing to do with the codec.
This glitch is also present when using the MPEG2 SD PAL 576 50i footage for upscaling to 1080 24p the same way and the bugs on the screen are the same as with AVI DV PAL.
I used to do exactly the same upscaling of the SD DV PAL 50i footage to 1080 24p (and "Blend Fields" deinterlacing method) on the old versions of Sony Vegas Pro and it always worked fine. So this is a sort of a newly introduced glitch. As I have lot's of legacy SD DV footage which I'm still using in HD projects, that's a serious issue for me. I believe for the other Vegas users it may be important too. There always will be a need for the old archive SD interlaced footage in the HD or 4K progressive projects (for example, in the documentaries). I hope that this bug can be fixed in the next build of Vegas Pro 15 Steam. Thank you.