Hi everyone. Extremely frustrated right now.

So here's what is going on: I get a lot of DroppedFrames in the recorded file and it's causing major issue for me when I am to edit the recorded file in Adobe Premier.

I just recorded a live show. It's about 1 hr 30 minutes long. Now when I am to edit the file I notice that the audio "drift" apart from the video - every 30 seconds or so and I have to manually re-sync the video to match the audio. And it's just a nightmare to deal with this.

Some shows I record has not had this issue at all, while other shows have had tremendous audio/video sync problems. This inconsistency is driving me NUTS and I have not been able to figure it out. I thought i was an issue with my hardware first.

So I want to get to the bottom of it. I just checked the log file for my last recording and I see that out of 190811 total recorded frames I have 4722 DroppedFrames and 100% of those is "DueToSourceFrameRate." So the source (what source?) frame rate is to blame for this.

What is the procedure to avoid dropped frames due to a source that you bring into vMix?

Many clips that I play in the show, have been edited and then exported in to the same framerate as the vMix project: 29.97, but not all. Some clips I play have not been exported by me and I've just imported them into vMix "as is." I haven't checked all of them so I don't know what frame rate they have. Do they have to match?

Here are my questions:

1. Do I need to convert/transcode/render EVERY SINGLE CLIP that I want to play in vMix, to match the project frame rate - to avoid this issue? (Is this the issue?)
2. If one (or several) of my 5 camera sources have a different frame rate (or even interlaced even for example), than my vMix project, can this cause the dropped frames?
3. What about NDI/vMix desktop capture. If my vMix project is 29.97 and I have a NDI/desktop capture input that is at 15 frames per second, will this be an issue? Can this cause DroppedFrames in the recorded file?
4. What if I have a source that has a different frame rate - and say I can't change it - How does vMix handle this?

I'm kinda embarrassed that I have not been paying attention to this before to be honest. From everything that I've been reading about and experimenting with in Vmix, I have not come across good instructions on a standard file convention that should be implemented to match frame rates, before you record/stream a show.

So, is there any kind of rigorous procedure that should I adopt, in order to avoid this in the future?

Would a transcoding feature in vMix be something that would "fix" this issue? Tricaster has this I believe. In order to avoid that a few clips, with different frame rate, create an unbearable situation later when you are to edit the file that you've recorded.

Thank you for any help I can get on this. I do not want to go through this torture of an editing job again.

Thanks sinc747

My settings

vMix version 18.0.0.65 x 64
vMix Project preset I use: HD 1080 29.97

These are my recording settings:

I'm running an external audio mixer, hence the audio delay to compensate


Specs on my computer:

OS Name Microsoft Windows 10 Pro
Version 10.0.14393 Build 14393
OS Manufacturer Microsoft Corporation
System Name RENDER
System Manufacturer ASUS
System Model All Series
System Type x64-based PC
System SKU All
Processor Intel(R) Xeon(R) CPU E5-1650 v3 @ 3.50GHz, 3501 Mhz, 6 Core(s), 12 Logical Processor(s)
BIOS Version/Date American Megatrends Inc. 2001, 9/30/2015
SMBIOS Version 2.8
Embedded Controller Version 255.255
BIOS Mode Legacy
BaseBoard Manufacturer ASUSTeK COMPUTER INC.
BaseBoard Model Not Available
BaseBoard Name Base Board
Platform Role Desktop
Secure Boot State Unsupported
PCR7 Configuration Binding Not Possible
Windows Directory C:\WINDOWS
System Directory C:\WINDOWS\system32
Boot Device \Device\HarddiskVolume1
Locale Sweden
Hardware Abstraction Layer Version = "10.0.14393.206"
User Name RENDER\Ragnvald
Time Zone GMT+1
Installed Physical Memory (RAM) 64.0 GB
Total Physical Memory 63.9 GB
Available Physical Memory 60.1 GB
Total Virtual Memory 73.4 GB
Available Virtual Memory 69.3 GB
Page File Space 9.50 GB
Page File C:\pagefile.sys
Hyper-V - VM Monitor Mode Extensions Yes
Hyper-V - Second Level Address Translation Extensions Yes
Hyper-V - Virtualization Enabled in Firmware Yes
Hyper-V - Data Execution Protection Yes

Graphics card: NVIDIA GeForce GTX 980 Ti
Audio interface: Audient ID4

Let me know if there are some specs or settings that I'm missing. Thanks so much again for helping guys.

How many hard drives, type and which one is being used to record vMix files to?

DWAM: What is a WM instance? A Virtual Machine? This is not something I have set up no, but I'm not sure if it's running or not. How do I find out? And how might it related to my problem?

SportsNetUSA.net: I record to a Samsung SSD 850 PRO 512GB, then once i've recorded I move the file to two different HDD's.

Ittaidv: Yes, I record to mp4. I can try that but I think the problem is that there are dropped frames in the files already before importing it into Premier. So I don't think these can be restored, even if I transcode it with handbrake? The frames will be lost and the audio/video will drift apart anyway. I really don't want to record to avi (too large files) and WMV sucks. I see mp4 as my only viable option.

Thanks guys. Trying to get to the bottom of what frame rate I need on my input sources to avoid the issue. Unless it's a codec issue.

Hi,

On a recording, DueToSourceFrameRate drops are usually due to the graphics card being unable to keep up for some reason.
The 980 Ti is certainly powerful enough, so not sure why this would be happening.

Can you confirm if the Render Time in vMix is high while recording?
I have seen on rare occasions dropped frames and high render time as a result of the graphics card not being installed in the correct slot in the PC.
This can be confirmed by checking the bus interface in the free GPU-Z software:

https://www.techpowerup.com/gpuz/

Make sure it is at least PCI-E 2.0 x8

If that doesn't help, can you confirm the number and type of inputs you were using in vMix including the capture card vendor and model?

Thanks,

Martin
vMix

Ragnvald, maybe not on the spot - but

The Yuan High-Tech SC510N4 HDMI can as far as I recall it only capture up to 1080 50i (or maybe 60i - not 50p/60p).

I have also noticed that if you have an Input with this card, and no source connected, there are besides a lot of "dropped frames" (i.e. none captured at all) an extra burden on the render time. Removing the unused input helps.

Run a test recording and keep an eye on the "Render Time" down the bottom of vMix.
If this is consistently high (>25ms or so) then you will start to have dropped frames in the recording.

Video files with different frame rates should not impact the recording, though adding additional inputs could increase the load of the system.

If the render time is high, try removing inputs until you find the source.
I have heard of issues with older Yuan cards on XEON or X99 based systems, so the first suggestion would be to test to see if
you still have the same problem with no inputs from the Yuan card added to vMix.

Hope this helps.

Regards,

Martin
vMix