Blackmagic Forum

What software is there that's recommended for multi channel video recording. I have the new HDMI quad decklink and apparently the video express doesn't offer multi channel recording via the decklink. I called and they were unable to give me any guidance other than they can't help me with that.

The only free solution to this that I found was running several instances of FFMPEG at once, with NVENC and blackmagic opts enabled in the build.

There are some commercial software options for this. On the Mac, there is Softron MovieRecorder which can record up to 16 video channels:
https://softron.tv/products/movierecorder

On Windows, VMix has a Multicorder option which can record up to 4 channels on its Pro and 4K editions:
https://www.vmix.com/help17/index.htm?MultiCorder.html

And Metus Ingest also supports multi-channel recording (up to 16 channels depending on the recording codec used):
https://www.metus.com/metus-ingest/

One issue to keep in mind, is that depending on the computer hardware and recording codec used, it is pretty easy to overwhelm the system when attempting multi-channel recording, in which case it wouldn't be able to keep pace with the incoming video and would start to drop frames.

I'd imagine four HD streams is probably doable on some systems, but four 4K streams gets trickier, especially 4K at higher frame rates (50 or 60 fps).

Wow some expensive options out there. I will look into FFMPEG and maybe write an app... ugh!

Try OBS

RikshaDriver wrote:Try OBS

I don't believe that OBS supports recording multiple sources/scenes separately. Several people have requested it on their forum. It may be coming in the future, but it's not present currently. You can run multiple instances of OBS in parallel, if you like, but that's basically the same as just using FFMPEG in commandline.

https://ideas.obsproject.com/posts/41/m ... eo-outputs

https://obsproject.com/forum/threads/mu ... ing.96984/

https://obsproject.com/forum/threads/my ... age.96129/

https://obsproject.com/forum/threads/ab ... es.125431/

https://obsproject.com/forum/threads/re ... nu.122793/

bis01005 wrote:Wow some expensive options out there. I will look into FFMPEG and maybe write an app... ugh!

You can use FfmpegGUI, might be easier than writing a batch script - https://www.videohelp.com/software/FFmpegGUI-2

Or

AnotherGUI (have not tried this) - https://www.stuudio.ee/anothergui/documentation.html

You may run into issues with timing of the start/stop though, so I eventually went with a bash script. I don't have access to the studio computer right now but I will provide it here if I can get my hands on it.



If you are recording multiple videos at once to MP4, you will need a new-ish NVIDIA GPU so that you can use the NVENC encoder (up to 3 video streams simultaneously). Otherwise you are sure to max out your CPU using x264.

You would need to have multiple instances of OBS running

The code needs to be refactored a bit and should be adapted to your particular hardware, but this might be a useful starting point -

https://pastebin.com/U012aJkj