Blackmagic Streaming Encoder 4K integration
Turn a 12G-SDI program output into an observable SRT contribution
Blackmagic Streaming Encoder 4K is a compact hardware bridge between a professional SDI program and an IP receiver. It can encode H.264 or H.265, stream HD or Ultra HD up to 2160p60 over SRT, and use a custom destination loaded through Blackmagic Streaming Setup. In this workflow Callaba receives that outbound contribution, shows whether media is arriving, and makes the accepted feed available to monitoring, recording, or routing.
The reliable first test
Feed the encoder with one known-good 12G-SDI source, create one Callaba SRT Listener, and configure one custom SRT destination for that listener. Start with a media profile every required downstream system can decode. Prove moving picture and audio in Callaba before enabling a second network route, multiple destinations, automation, or a new codec.
The Streaming Encoder 4K is an originating encoder in this design. Blackmagic’s public product material supports outbound streaming to custom SRT services; it does not establish the unit as a general SRT Listener or Rendezvous endpoint. Keep Callaba as the listening side for the baseline workflow.
The moving patterns distinguish baseband input from the encoded SRT leg. They do not depict measured frame timing, bitrate, or network latency. Motion is removed for reduced-motion users.
Use the hardware characteristics that matter to the workflow
The 12G-SDI input accepts professional HD and Ultra HD program formats, with standards conversion available in the appliance. The product can stream up to 2160p60 and carries embedded SDI audio; the technical specification lists 16 embedded input channels. Confirm which audio pair or program is actually selected for the stream rather than assuming that every input channel is present downstream.
H.264 offers the broadest interoperability. H.265 can reduce bandwidth for comparable image quality and is valuable for UHD contribution, but every decoder, recorder, player, and onward destination must support the chosen profile. Make the codec decision for the whole path, not solely from the encoder’s capability list.
Source timecode is useful when recordings or downstream systems need to relate the contribution to the production clock. Verify the timecode at the SDI input and again at the system that consumes it. A visible clock on an encoder display does not prove that the required metadata survived the complete path.
Choose the network without calling it bonding
Ethernet is the normal fixed-network connection. Blackmagic also supports mobile data by connecting a compatible phone through USB-C. That provides another way for the appliance to reach the internet; it does not combine several carriers into one bonded contribution and does not prove automatic failover between two independent paths.
If the production needs a backup route, design it explicitly. Record which network is primary, how the alternative is activated, whether the SRT session reconnects, and who verifies the program after a change. Test the same failure that the plan is expected to survive. Two cables or two internet labels are not useful redundancy when they share the same switch, power source, phone, or upstream provider.
Map the Blackmagic controls to the receiving contract
| Control | Decision | Acceptance check |
|---|---|---|
| SDI input and stream standard | Use the raster and frame rate required by the production; do not change standards during the first network test. | Input is locked and the encoded output has the expected size and frame cadence. |
| Codec | H.264 for widest compatibility, or H.265 after every downstream stage has been verified. | Callaba preview or recording decodes the expected codec with motion and audio. |
| Custom service | Load a service definition built with Blackmagic’s current Streaming XML schema. | The service appears in Blackmagic Streaming Setup and points only to the intended event destination. |
| Server | The reachable Callaba SRT Listener host and UDP port. | The network allows outbound UDP from the encoder and inbound traffic to the listener. |
| Passphrase | Use the matching SRT secret only when encryption is enabled on both ends. | The session connects after the same value is entered; the secret is absent from public screenshots. |
| Network | Ethernet or a deliberately tested phone data connection. | The selected route remains stable for the full rehearsal and recovers as documented. |
Configure one custom SRT destination
- Prove the source. Connect the SDI program and confirm picture, embedded audio, format, and timecode where required using the encoder’s local monitoring.
- Prepare Callaba. Create and start one SRT Listener. Record its reachable host, UDP port, and encryption policy, then apply matching cloud and host firewall rules.
- Use current Blackmagic software. Connect to the appliance with Blackmagic Streaming Setup. Load a custom streaming configuration produced with the official Streaming XML File Format for the installed software generation.
- Select the custom service. Enter or select the intended Callaba server, choose the approved codec and stream standard, and enter the matching passphrase if the receiving policy uses one.
- Start streaming. Confirm that the encoder reports the output active and Callaba shows a sustained SRT session with plausible incoming bitrate.
- Decode the program. Place the feed in one Multiview tile or make a short recording. Watch representative motion, listen to the intended audio, and inspect sync.
Do not publish a guessed XML fragment for a third-party service. Blackmagic maintains a separate format specification, and supported elements can change. Build the file from that specification and the actual Callaba destination, then keep the accepted file with the event configuration.
Acceptance test for a production feed
- Baseband: stable 12G-SDI lock, expected raster/frame rate, correct audio program, and valid timecode where used.
- Encoder: intended H.264 or H.265 profile, HD/UHD standard, custom service, and network route.
- Transport: established SRT session and sustained bitrate on both the encoder and Callaba side.
- Decoded proof: several minutes of motion, audio, and sync in Multiview or a Callaba recording.
- Reconnect: stop and restart the stream, then interrupt and restore the chosen network in a controlled rehearsal.
- Recording: play a captured segment from the beginning and near the end; confirm duration, picture, audio, and expected time relationship.
- Backup: if mobile data is part of the plan, activate it exactly as the operator will during the event and record the observed interruption.
Troubleshoot the part that has not been proved
The custom service is missing
Confirm the XML file follows Blackmagic’s current schema and was loaded into the intended appliance. Reopen Streaming Setup and verify the service appears before investigating Callaba.
No SRT connection
Check the listener address and UDP port, outbound venue policy, inbound firewall, and matching passphrase. Keep Callaba running as Listener; do not switch modes based on an unrelated SRT tutorial.
Connected, but no decoded picture
Return to SDI input lock and codec selection. Confirm Callaba receives sustained bitrate, then compare the selected H.264/H.265 profile with the downstream decoder and recording path.
Audio is missing or wrong
Verify embedded audio at the SDI source and the program selection used by the encoder. Listen after decode; an input meter alone cannot prove the intended channels reached Callaba.
UHD is unstable
Measure the actual encoded rate and network headroom, then test the same path in a simpler profile. Separate a capacity fault from SRT recovery and decoder compatibility.
Phone tether does not recover the show
Confirm the phone has service, data permission, power, and a tested USB connection. Document whether selecting or reconnecting that route is manual; it is not a bonded path.
Official references
- Blackmagic Streaming Processors product page — device role, 12G-SDI, HD/UHD formats, codecs, monitoring, and network options.
- Blackmagic Streaming Encoder 4K technical specifications — connections, supported standards, audio, and streaming capabilities.
- Blackmagic Streaming Processors manual — current installation and operating instructions.
- Blackmagic Streaming XML File Format — authoritative custom-service format.
Match all menu labels and custom-service fields to the installed Blackmagic software and current official manual before the production rehearsal.
Receive the SDI program where transport and media are both visible
Create one Callaba listener, send the Blackmagic custom SRT output to it, and accept the workflow only after the decoded program and reconnection behavior have been observed.
Prepare the Callaba SRT receiver