ProRes input to ProRes output video drops a frame every couple seconds

#1

For some reason using high quality ProRes video and upscaling, with it outputting to ProRes as well results in a dropped or repeated frame every second or two resulting in choppy video that is kinda unwatchable. I don’t know if it’s just v1.9.0 but that’s what i’m using.
Audio also gets limited to 96 kbps which makes the audio useless as well which just results in a terrible video other than it looking better.

Please fix this as soon as possible so the program is useable. Thanks

Using an RTX 3070.

#2

i have only used ProRes .mov output by mistake once
and i was shocked
as it exported videos with 80mbit or even 100mbit bitrates

blowing up a small 30min dvd video to 20+ gbyte in 1080p
… imho a complete overkill … what may result in dropped frames on slower systems

until we have settings for the ProRes .mov compression factor, like we have for the .mp4 export,
i will stick to the .mp4 export

comp factor 18 is good for 1080p (FHD)
comp factor 21 is good for 2160p (4K/UHD)

#3

That is the point of ProRes, it’s not intended for sharing and all.
When you encode you get close to loseless compression which allows for you to retain the source quality and also playback high bitrate video much easier. Once I’m ready to share it I will compress it down a bit to reduce the file size so it’s a more manageable size.
Most people aren’t working with ProRes video though so yeah not useful for most. However I want the best possible result. Not so useful if you are working with lower quality or normal quality video. I’m not doing something normal so the higher bitrate when upscaling (for example) just keeps the quality instead of compressing it more e.g 4k generates ~x4 the bitrate, if you used the same bitrate as 1080p it would look worse.

Either way the repeated frames still exist and the low quality audio which makes selecting the option kinda pointless as you would have lost some frames from repeated frames and low quality audio.

VEAI seems to display the video in the program as 23.98 fps when the video is 23.976 which is where I think it is getting duplicated frames from even though the metadata on the output does say 23.976 fps.

Anyway for now i’ll just try to work around it otherwise i’ll have try PNG or TIF then encode if possible.

2 Likes
#4

I am also getting some confusing results with ProRes output though I’m not using ProRes input.

Davinci Resolve and Premiere Pro both report different frame counts than the original. However, when I load the output ProRes file back into VEAI it reports the correct frame count.

I’m upscaling some hybrid DVDs and using Avisynth IVTC to deinterlace, extract variable frame rate time code, and load directly into VEAI. After upscaling I am use Resolve to correct the aspect ratio and do a slight color correction before exporting them for remuxing with the audio and the new timecode. However, since the frame counts don’t match the original, anything muxed from the ProRes files doesn’t sync with the audio.

I too am trying to preserve as much detail as I can before the last h.265 compression.

The only way I’ve been able to ensure the correct frame count is to export to PNG which isn’t the end of the world but much more difficult if I need to move the files, not to mention the time it takes just to delete all those files.

#5

Just a little update on this…

I used ffmpeg to re-encode to mp4 then it would work no problem, I think maybe it is reading the framerate in the metadata wrong or something as 23.98 for example as when I re-encode the ProRes after to mp4 it likes to say 23.98 not 23.976 at least in mpv.

The best way to work around it would be to re-encode as mp4 with 0 for no compression (but I used 5). Then use it in VEAI. I didn’t try re-encode ProRes to ProRes though to see if that would fix any broken things with the file, if it is the file that is the issue.

It didn’t seem to happen in other videos I had but another one did have the same issue so 1/2 chance from the 4 I tested.

Edit:
Re-encoded from ProRes to ProRes and it worked fine after, for some reason there are some issues with the source videos (metadata??) I guess depending on how it VEAI grabs the frame rate or something.

#6

Since it doesn’t support H265 ProRes is a fast high quality output that you can then transcode later. Using H264 for 4k isn’t ideal as the bitrate will be 60-100% higher for the same CRF.

#7

problem with prores with freeze frames is audio tracks - if more than 1 track you have a freeze. Audio track has a 1 or many channels. If track is one no problem - if two or more tracks = freeze on source.

#8

Ah ok I guess I wish I knew that, I would have just done it without sound since I just add the high quality sound back on after. I’ve just been re-encoding my videos so I didn’t have to worry about it. Will try with no audio next time.