Hi folks,

I’m using a Blackmagic DeckLink Mini Recorder 4K in my desktop PC to record video over HDMI. I am focused for the moment on recording 4K HDR input, which the Blackmagic card is capable of recording. It comes with the Blackmagic Media Express software for recording, which is a very basic Windows application that simply allows you to record with some basic settings from what I can tell.

In the Media Express settings, the “File Format” options are:

AVI 8-bit YUV
AVI 10-bit YUV
AVI 10-bit RGB
AVI Motion JPEG
QuickTime Uncompressed 8-bit YUV
QuickTime Uncompressed 10-bit YUV
QuickTime Uncompressed 10-bit RGB
DPX 10-Bit RGB

The recording works fine in terms of capturing the video and audio and saving to the desktop’s internal SSD. The problem has been trying to get HDR to work. The only file formats that seem to capture and playback HDR are the QuickTime options listed above. The others (I haven’t tested DPX) are washed out SDR (input is sending HDR). The QuickTime files on the other hand though are prohibitively massive ultimately leading to full storage or a crash (1 Gbit/second bit rate) and the input is not anywhere near this bitrate.

The AVI Motion JPEG option seems to be the only option that saves files in a reasonable/functional size (~100 mbit/second bitrate) but does not save with HDR. The Blackmagic card purportedly works with other recording software, and so far I have tried OBS, which works but does not record HDR.

I’m basically trying to figure out if there is a way/software that will record the 4K HDR input but in a reasonable/functional size. Any ideas?

Thanks!