Dear vMix Team,

First of all, thank you for the amazing software you’ve created. I’ve been using vMix 4K in a professional multi-camera 4K production environment and it’s a vital part of our studio workflow.

However, I’d like to respectfully bring up an issue we’ve been facing when recording in MP4 format using the Multicorder feature, especially when editing later in DaVinci Resolve Studio 20.

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⚠️ The Problem:

When recording ISO feeds in MP4 via Multicorder, we consistently face audio/video sync issues and minor stutters or frame skips when importing these files into DaVinci Resolve.

These files play fine in standard media players. But inside DaVinci — which we use as our main editing platform — there are noticeable sync issues and timeline instability.

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🔬 What We’ve Tested:
• Tested on multiple projects and timelines (with and without proxies).
• Recorded in MOV: no issues.
• Recorded from OBS Studio: no issues.
• Recorded via vMix AVI (default format): playback is smoother, but DaVinci Resolve has long-standing issues with AVI files, making them unreliable for editing.
• We also contacted the DaVinci team via forums. Their technical feedback was clear: “The problem is not on DaVinci’s side; it is how the MP4 file is being encoded by vMix Multicorder.”

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🖥️ My Studio Setup:
• CPU: AMD Ryzen 9
• Motherboard: MSI Prestige X570
• RAM: 128 GB DDR4
• SSD (recording): 4x Samsung 990 Pro NVMe Gen4
• GPU: AMD Radeon Pro VII
• Capture Card: Blackmagic 4K HDMI (4 Inputs)
• Audio Interface: Zoom PodTrak P8 (via USB)
• Editing Platform: DaVinci Resolve Studio 20
• OS: Windows 11 Pro (Fully Updated)
• Cameras: Fuji X-H2S and X-H2 (HDMI 4K Clean Feed)

This is a high-performance system built specifically for 4K video workflows. After exhaustive testing, the only bottleneck appears to be the MP4 encoding inside vMix Multicorder.

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🙏 Friendly Request:

We kindly ask the vMix team to review the current MP4 codec used in the Multicorder module, or give us alternative codec options that are more compatible with editing software such as DaVinci Resolve.

At the moment, the lack of a smooth MP4 workflow causes production delays and increases the risk of sync errors, especially when handling multiple ISO recordings.

We are not requesting major changes — just a codec refinement or a reliable alternative codec for those of us using DaVinci (and other NLEs) in 4K professional setups.

I’m also more than willing to send test files or collaborate with your engineering team if it helps speed up this improvement.

Thank you for your incredible work. We truly admire what vMix has built — and just want to help make it even more bulletproof for editors like us.

Warm regards,
Sérgio Cardoso
Host of Verdade no Ar Podcast
📍 Boca Raton, FL
🎥 Multi-cam 4K Studio – vMix + DaVinci Resolve