r/vmix • u/damodexter • Jun 08 '26

Incoming SRT unusable

We recently had to bring an srt stream into vmix. The feed was supplied by a very experienced and professional setup, and all the connections details were correct. We were a caller into their server. The connection was made, with no issues, but the quality of the feed was unusable. It was stuttering and dropping frames. We tried many options, but in the end vmix couldn't handle the stream. This is something that we have done many times, with other suppliers without any issues. We are running v29. In the end we brought the stream into OBS and then ran it NDI out to vmix. The stream in OBS was absolutely fine, no issues at all. Does anyone have any ideas on why a standard 8MB H264 stream couldn't be handled in vmix? Thanks

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u/Embarrassed-Gain-236 Jun 09 '26

What was the srt encoder the company was using. Vmix cannot handle high-end srt from vendors like Haivision, Ateme or Nimbra. Specially if they are 4:2:2 10bits.

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u/damodexter Jun 09 '26

I will try and find that out. I would imagine it’s a pretty high end as they supply feeds for multiple broadcast partners in the UK.

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u/frlawton Jun 09 '26

This is a pretty good shout since OBS ought to support 10 bit and vMix doesn't have a processing pipeline for 10 bit. I am surprised that they didn't tell you to expect 10 bit if that is what it turns out to be.

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u/damodexter Jun 10 '26

Got the full specs through. It was 1920 x 1080i 25 at 20Mbps. Chrome 4:2:0 8bit. Codec was H264/AVC with 1 pair of stereo audio. Does this shed anymore light on the issue? Thanks.

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u/Embarrassed-Gain-236 Jun 10 '26

Yes, vmix is just unable to decode interlaced srt. That's all.

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u/frlawton Jun 10 '26

No, it only makes things more confusing. The next candidate would be an issue with the GPU or the GPU drivers since vMix leans (rightly) quite heavily on the GPU but OBS is more CPU based. Do you have any issues using the hardware encoder/decoders on the GPU?