Intro
Wikipedia wrote:
Serial digital interface (SDI) is a family of digital video interfaces first standardized by SMPTE (The Society of Motion Picture and Television Engineers) in 1989. ... These standards are used for transmission of uncompressed, unencrypted digital video signals (optionally including embedded audio and time code) within television facilities. ... The various serial digital interface standards all use (one or more) coaxial cables with BNC connectors, with a nominal impedance of 75 ohms.
HAVOC SDI gear
- Two cheap noname HDMI to SDI converters from AliExpress
- One cheap noname SDI to HDMI converter from AliExpress
- 2 × 20 meters of 75 ohm coax cable with BNC plugs for SDI
- some RCA-BNC plugs that allow using consumer cables designed for composite analog SD video
Possible scenarios with the above gear
These scenarios define the word- far as farther than what usual HDMI cables can reach (typically around 3 meters) and
- beamer as either the beamer itself or a port in which we can plug our HDMI gear into
- Both voctomix sources being far from the voctomix PC
- a 20-meter cable connects each source with the voctomix PC
- an HDMI to SDI converter is put at each source (camera and slides)
- the coax cables are connected to the SDI inputs of the DeckLink cards in the voctomix PC
- however: the beamer must be near either the slides source or the voctomix PC
- One voctomix source is far from the voctomix PC, and the beamer is far from both the voctomix PC and the slides source
- one 20-meter cable connects the far source with the voctomix PC
- an HDMI to SDI converter is put at the far source (camera or slides)
- this coax cable is connected to the SDI input of the DeckLink card in the voctomix PC
- the slides signal is split either at the source or at the voctomix PC (whichever is closer to the beamer)
- the split signal is connected to the other HDMI to SDI converter
- the output of the SDI to HDMI converter is connected to the beamer
- the other coax cable connects the HDMI ports of these latter two converters
