Recording your inputs
Input Rec records the inputs you choose to their own files, each exactly as it arrived (its own size, frame rate and sound, before crop, colour, effects or gain), so you have the raw material to re-edit a show afterwards. This is separate from recording Program, which is the switched, composited result.
Arm your inputs
Open the Input Recording window, behind its gear icon beside Input Rec, and choose which inputs to record. Only NDI, network stream, USB capture, Blackmagic, audio and Window inputs can be armed.
How many you can arm
How many inputs you can record at once depends on your Mac, not on InterDirector: every armed input is encoded and written to disk at the same time as everything else your Show is already doing, and a slower Mac, or a slower disk, runs out of room to do that sooner than a faster one. There is no fixed number: try what you plan to run before a real show, on the same Mac and the same disk you will use for it.
For many inputs, record in ProRes. HEVC and H.264 share one encoder with the stream, replay and Program’s recording: on an M4 Pro MacBook Pro, three 1080p50 inputs in HEVC keep up beside a stream, replay and Program recording. ProRes has an encoder of its own, and on the same Mac more than twenty 1080p50 inputs kept up with nothing else dropping a frame. What limits ProRes is the disk: eight 1080p50 inputs in ProRes 422 Proxy write about 75 MB a second, 270 GB an hour, and about twice that in LT. Record to your Mac’s own SSD or a Thunderbolt SSD, not a spinning disk or a USB stick.
For NDI inputs, use a wired network. A full-quality 1080p NDI source is more than 100 Mbit/s, so eight of them fill a gigabit connection. Use a 2.5 or 10 gigabit Ethernet adapter for that many, and never Wi-Fi.
If the recorders cannot keep up, Input Rec turns amber and names the input that is behind, the same way the Stream button does for a struggling destination. The fix is to arm fewer inputs, record in ProRes, or record to a faster disk.
Start it
Press Input Rec to start every armed input recording together, into one new folder named for your Show and the moment, in the same place as your Show file by default (or elsewhere, if you choose a folder yourself). An input with a picture is written as a movie, in HEVC, H.264 or ProRes, with its own sound; an input with sound alone is written as a WAV.
Next
Recording Program, for the switched result, and NDI, Blackmagic and the external display for the other ways Program can leave your Mac.