Can't render with constant bitrate?

[sealilly]

Trying to render as AVC but the "Variable" drop down is greyed out? My online platform is suggesting I use constant bitrate since when THEY process, my video/audio often comes out of sync.

[Davidk]

Despite the 'preferred' format, most users don't realise that on-line platforms like Youtube re-render an upload to a format that's specialised for fast download for any subsequent viewer. And if you watch the upload processing, that's a message displayed (for a short time) at the very end of the upload action. So even tho you have a good render at your end, it does not mean that 'issues' with it on the on-line platform are yours.
That said, to use the on-line service you will have to adapt. Since the format is going to be re-rendered (dumbed down is what I'd call it), find one in your render list that will fit the on-line platform spec and render to that. A certain amount of trial and error likely to be involved here.

[lata]

Most video formats will use a variable data rate, Mpeg2 will allow for variable data rates although only standard definition not HD
Are you referring to rendering to AVC.H264 this will produce a motion transport stream video m2t
I thought Mpeg4 would the preferred video type for the online platform, I assume that is not YouTube.
Of course your original videos should influence your choice of output format.

Even so I would not have thought the Data rate being variable would influence the audio sync, if you were referring to a variable frame rate then that may be a different matter.

What are the properties of your original video clips?
If they were recorded using a Variable Frame Rate, note Frame Rate then that could cause issues.

[sealilly]

Thanks for replies. here is full story in case it helps: I Live Stream funerals and use Boxcast as platform. I add a wireless audio recorder to lectern to improve audio for the recorded version. After funeral, I do a light edit, clip unneeded footage, add smooth transitions, and use the recorded audio for the eulogy. Camera files are of course always cleaner too. Boxcast allows me to replace the live stream version with this edited version to the same link. Live viewers view the "raw" version, but recorded viewers view the "edited" version. Client also receives a copy on USB. Unfortunately, here is the hiccup; often times when i upload my edited video which is perfectly in sync, once they process, the audio becomes out of sync and of course looks horrible when you can see the speakers lips way out of whack.When I first asked Boxcast, they said to keep the file size low, under 5gb. It seemed to work by compressing with handbrake but it happened again at 2.8gb. I asked again and got below reply. I also attached my typical render specs.

"Hi Darryn,
Streaming to other platforms wouldn't be an apples to apples comparison as we transcode videos to support hls playback. One thing that helps with a/v getting out of sync is to make sure you are setting a constant bitrate and framerate instead of variable when rendering your videos. Try that next time you are editing a video."

This is a screen grab of my typical render:

[lata]

Thanks for the details which helps to understand your process
Can you view the properties of the original video file and properties of the sound file.
Provide details here
Pay attention to the audio rates for both video and sound file maybe 48000hz.
If different you may have to change settings during recordings.

You are best to render to the same properties as your original videos, yes you may need to reduce the data rate to control the file size, this will reduce quality although I doubt that will be noticeable.

[sealilly]

Thanks for quick reply. I hope below is what you mean, this is the properties of the files from camera. I actually thought I was filming 29.97 but this indicates 60?? Any advice would be great, I am off to a funeral now and will be thrilled to try anything later today

[lata]

I assume you have a separate Sound file, can you view those properties
From Video studio right click the sound clip for properties, view the Audio rate hopefully its the same as the video rate at 48000hz.