Hi all,

I recently downloaded a Trial version of vMix to test with for switching over from OBS/Wirecast, and while most of everything seems to be working great, I'm having trouble with getting the correct frame rates to stream.

For my test streams, I have everything in vMix set to 24 fps: "FILM 24p" for the Master Frame Rate (indicated by "1080p24" in the lower left green box), "FILM 24p" in each of the inputs for the cameras, and 24fps for each of the capture devices, and cameras themselves. However, in streaming to YouTube, I noticed the video would stutter throughout. Checking the stats of the stream, it says I'm streaming at 30fps. After closing the stream, I downloaded the YouTube video file and confirmed that it is in fact 30fps (30.0 YUV 420 8 bit, to be exact). Just as a sanity check, I conducted a test in OBS with the same settings/hardware/cameras, and YouTube indicates that the OBS stream is 24fps (which is correct). Everything looks fine and smooth in that version. Going back to vMix, I fed it some 24fps pre-recorded media, just to get around the issue of potential hardware and camera setting issues, and it still streams to YouTube at 30fps. Lastly, I recorded the feed locally on my computer's hard drive, and that one is 24fps and smooth. Only the stream is 30fps, which is incorrect.

Are there some other frame rate settings I'm missing other than the Master Frame Rate? The stream settings only cover resolution and bitrate, and not frame rate, so I assume it just uses the Master Frame Rate. But just to cover my bases, the streaming settings I'm using are the following:

FFMPEG H264 at 5 Mbps, 720p, AAC audio at 128 kbps
Source: Output 1; Profile: Baseline, Level: 3.1, Preset: Very Fast

Additionally, I'm using vMix Trial - 23.0.0.54 x64 on Windows 7 64-bit SP1.

I've searched the software manual and Google/Forums, and cannot find any more detail regarding frame rate mismatches on streaming. Any help on this would be much appreciated. I'd like to make the full switch to vMix, but I'll need to resolve some of these technical hurdles first.

That's what I thought at first too. However, I did the test in OBS, same settings, and YouTube correctly sees the stream as 24fps. But I did check, just in case, and YouTube's guides indicate that it supports a large range of frame rates, bit rates, etc and has recommended settings - which I followed. I'm not sure how to further troubleshoot on the platform, which is why I'm focused on vMix itself.

I'm using a custom RTMP setting, entering the stream server URL and stream key. However, my understanding is either a preset or custom RTMP settings shouldn't have an impact on the server-side receiving frame rate for the video feed. Is there something that would do otherwise?