I've had good experience with it too. If you like it, donate to the developer (I did) so he continues to update and fix it.

For x264 it may introduce audio shift. I wish it will be fixed so I could use it for final render as well.

Not sure about x265 and NVEnc, but you should check your results.

Didn't notice any audio shifting when rendering to x265

Perhaps, you should test audio sync? Here's a tool.

https://www.vegascreativesoftware.info/us/forum/audio-sync-comparison-for-various-render-methods--111194/#ca687240

I tried Voukoder Nvenc AVC with a sync testing video and there is no audio shift.

Do you get audio shift with Voukoder but not with Magix AVC Nvenc, is it with all videos?

Actually that is out of sync isn't it. the file vegas created from voukoder has audio 3frames early then the vegascreative re-encoder extends that out to 5-6 frames early

This is original file I used for test and it's sync is correct http://twitch-event-engineering-public.s3.amazonaws.com/sync-footage/Sync-Footage-V1-H264.mp4

Be nice to developers and give links to their products... https://www.voukoder.org/

@Deata what GPU do you have? With my GTX 1050 I'm not seeing any real difference between vegas and voukoder

Be nice to developers and give links to their products... https://www.voukoder.org/

Wasnt sure about the rules to linking to outside of this site.

@Deata what GPU do you have? With my GTX 1050 I'm not seeing any real difference between vegas and voukoder

Rolling with a 1080ti currently

@Deata what GPU do you have? With my GTX 1050 I'm not seeing any real difference between vegas and voukoder

If you download that 60fps audio sync video file encode with voukoder and then bring that encoded file back into vegas. You should see the audio has advanced 3 frames and equivalent to approx 45ms, and then a strange thing happens with the video encoder this website uses. It increases the desync by another 2-3 frames.

The voukoder guy doesn't seem very interested in fixing it as it's a vegas only problem and he works with multiple editors. The sloppy obvious fix is to finish edit and then delay audio by 3frames on the timeline, but surely there's a more elegant fix

If you were to financially support the voukoder project please let him know you're using VegasPro. Now that HappyOtterscripts are charging US$86 for renderplus, the equivalent of voukoder, you can now see how blessed we are to have this free plugin, which will remain free forever. Consider giving to aid in development of the VegasPro plugin, it's a great cause. https://www.voukoder.org/contribute/

It is strange that just a few people discussing this "bug" in voukoder's forum.

Developer might prioritize the issue if others join the discussion there.

The adobe people are so much more active now, to be expected I guess given their numbers, He doesn't have many patreons, we could easily make our VegasPro presence and appreciation known if we were the majority of his patreons

I'm using Voukoder since end of last year, never discovered a sync problem probably because I'm overwhelmed by the great picture quality of the renders.

The 44 msec delay (actually audio is early) is common to all apps that use FFmpeg "under the hood". The same problem exists in Handbrake and despite requests for a "fix" over the years, the issue still remains. The problem "can" be fixed. Since HOS is command line driven, it is very easy to maintain audio sync with the original. There is a "built-in" 44msec adjustment so that renders are correct most of the time. The need for adjusting delay becomes even more pronounced when using hevc sources which can really vary all over the place. For that reason, an audio delay option seemed absolutely necessary and is included in other rendering tools included within HOS.

As an aside, HOS does not use FFmpeg for nvenc renders, but rather an app developed by Rigaya https://github.com/rigaya/NVEnc who at my request, has included an option for adjustment of audio delay. Since he is using pretty much the same FFmpeg libraries, it is apparent that the audio delay issue "can" be addressed internally.

The adobe people are so much more active now, to be expected I guess given their numbers, He doesn't have many patreons, we could easily make our VegasPro presence and appreciation known if we were the majority of his patreons

Though the plugin is in a bit of a trouble when it comes to adobe.

As adobe released their own nvenc renderer with the latest iteration of premiere and its faster then voukoder

The Voukoder encoded audio leads the video. That's a period.

Just to confirm what John just posted, here's a screen grab showing the original, HOS, Voukoder, and Voukoder-corrected.

Here's the very simple command line to do the correction as shown.above.

ffmpeg -y -i <inFile> -itsoffset 0.0444 -i <inFile> -map 0:0 -map 1:1 -c:v copy -c:a copy <outFile>

If there's any interest, I'd be willing to throw together a very simple UI and make it available as a Happy Otter Free Tool.

I don't see any problems at my renders with Voukoder with unsyncing video and audio.
Maybe it is due to the strange framerates a lot of people are using, but with my 25 and 50p I never saw it.
Look what I even did with the 2 rendered files and the result (untitled)

And the latest Voukoder update helps me a lot to be able to get faster rendering with NVENC, a little with AVC and a lot with 4K HEVC

I made a video comparing the rendering of HOS and Voukoder.  

In the rendering of Voukoder there is an audio delay of about 3-5 frames, which corresponds to about 44ms when compared to the original audio.  

In the rendering of HOS, the audio is perfectly synchronized when compared to the original audio. @wwaag you are right again! Great job with HOS!

I hope the Voukoder developer @Vouk will see this post and find a solution to this problem, as Voukoder is also a great coder.

Here's a workaround for the problem which is fairly "user-friendly" and doesn't require knowledge of command lines.

The only requirement is that you have ffmpeg installed and that the executable "ffmpeg.exe" is contained in the user path variable of Environment Variables. It will also work if HOS is installed. There is now a completely Free version of HOS that includes all of the open-source apps such as ffmpeg, avisynth, etc plus the toolbars and a limited set of scripts.

You can download the free standalone app at https://tools4vegas.com/library/

It still might be a bit buggy, so let me know if you have any problems or suggestions for improvement.

Thanks to @joelsonforte.br I discovered a major error in coding, entering 444 ms rather than 44 ms as the default offset correction. You can download the corrected version.

Here are some results using the excellent audio sync footage posted by @Former userIt works a lot better than my old hummer footage.

@wwaag Have you checked how the rendered file behaves when so4 enabled/disabled in VP internal preferences?

I've played with the itsoffset ffmpeg option and found that when so4 enabled (default in VP15+), the audio stream with the start_time added by itsoffset is a bit ahead when the so4 is disabled (default up to VP14).

If I understand correctly, this is another "issue" of the so4 decoder. It does not recognize the audio stream offset correctly.

How to check:

- Put source on timeline (I'm using m2ts from camcorder)

- Render mp4 using ffmpeg with option -itsoffset 0.044 (HOS?) to have start_time != 0

- Open VP, put source and rendered files on timeline and check if audios are in sync.

- Change so4, restart VP and repeat previous step. You should notice slight off-sync.

Holy moly, cant believe i havent stumbled on this piece of software/plugin before.

I seriously recommend downloading voukoder 5 along with its vegas pro plugin, it works just like any other render preset.

The thing is, due to vegas pro nvenc rendering stopping every other second (because the buffer limit is in vegas somehow extremely small) the speed of voukoder 5 is ridiculously fast compared to vegas pro native gpu rendering...

15 minutes of h265 footage took a whopping 3 minutes to re encode!

Also the best thing.. its free.

So yeah, if anyone else is getting frustrated with native gpu rendering stopping every second and then rendering 50 frames and doing the same thing again, i suggest trying this one out!

Voukeder Render is way sharper compared to Magix AAC template. Why Magix render template is horrible? I mean its okey just that the artifacts introduced make it look like a compressed video.