Field workflow · SDI contribution
AJA BRIDGE LIVE to Callaba: make the handoff boring
BRIDGE LIVE can encode, decode and transcode in several directions. That range is useful in a facility and dangerous in a rushed setup: it is easy to build a sophisticated pipeline before proving the one boundary that matters. For this job, give the appliance a narrow assignment—take one known SDI program, encode it as MPEG-TS over SRT, open the connection as Caller, and deliver it to a Callaba Listener.
The working arrangement
Media direction: AJA BRIDGE LIVE sends; Callaba receives. Connection roles: BRIDGE LIVE is SRT Caller; Callaba is SRT Listener. Caller does not mean “source” in SRT—it means the side that opens the connection. Keeping those two ideas separate prevents the most common role error.
Create and start the listener first. Then configure one BRIDGE LIVE output, select the physical NIC, match the host, UDP port and any access credentials, and start the pipeline. Do not clone the first channel until Callaba shows a sustained session with picture and the intended audio.
The moving markers represent validation order, not extra delay. With reduced-motion enabled, the diagram remains static.
Start with the name on the appliance, not a remembered specification
AJA’s current BRIDGE LIVE family has two capacity profiles. The workflow on this page fits either one, but the available SDI ports and maximum density are not interchangeable.
BRIDGE LIVE 12G-4
AJA positions this model for up to four bidirectional 12G-SDI UHD channels. For a first contribution test, use one input and one output pipeline. Add the remaining channels only after checking the aggregate encode and network budget.
BRIDGE LIVE 3G-8
AJA positions this model for up to eight bidirectional 3G-SDI HD channels. “Up to eight” is a platform ceiling, not proof that any eight arbitrary codec, raster and processing combinations will fit the same job.
This guide does not cover BRIDGE LIVE IP, AJA’s separate SMPTE ST 2110 I/O product. It also avoids optional NDI, JPEG 2000 and JPEG XS paths. AJA lists those as licensed options; none is required for the direct SRT contribution described here.
Put the running version at the top of the show file
As checked on July 31, 2026, AJA’s current public BRIDGE LIVE software download is v1.18.2, released January 26, 2026, and the current family manual is v1.18r1. That does not make an event-day upgrade a good idea. Record the model, installed version and the manual that matches it; then decide on upgrades during a maintenance window.
The menu path below is therefore version-scoped to the current v1.18r1 manual. If your installed build uses different labels, stop and use its matching AJA manual. A screenshot from another BRIDGE LIVE generation is not an operating contract.
Write the connection contract before opening either interface
A short worksheet is faster than comparing two browser tabs under pressure. Fill it with real production values; the blanks below are deliberate.
| Item | BRIDGE LIVE | Callaba |
|---|---|---|
| Media direction | Output: SDI encode to MPEG-TS over SRT | Input: receive the contribution session |
| SRT role | Caller | Listener |
| Address | Remote Callaba public host or IP | Listener’s reachable public host or IP |
| Port | Chosen destination UDP port | The same open UDP listener port |
| Network | Named physical BRIDGE LIVE NIC | Cloud or host firewall permits that UDP port |
| Identity | Matching Stream ID if the installed build and policy use one | Approved publisher Stream ID or deliberately open guest policy |
| Encryption | Matching passphrase when enabled | The same passphrase and encryption policy |
| Media | Chosen video codec, bitrate, raster and audio mapping | Verify transport, decode, picture and audio separately |
AJA’s current manual says SRT encode and decode are used with MPEG-TS streams. It also documents an SRT overhead allowance above the configured total bitrate for recovery traffic. Include that headroom, audio and transport overhead in the venue uplink budget. SRT can recover loss inside a workable link; it cannot repair a sustained capacity shortfall.
For an interoperability baseline, H.264 video and AAC audio are a sensible first test because AJA lists both and they are widely decoded. They are not universal production settings. Match the raster, frame rate, color profile, audio layout and bitrate to the actual downstream requirements before calling the build complete.
Build the quiet end first: the Callaba Listener
Create one SRT Server resource
Use Callaba’s SRT Server workflow and make it the listener for this contribution. Copy the generated publisher endpoint or record its public host and UDP port. Interface labels may change between releases, so use the current SRT Server guide when a label differs.
Choose access deliberately
In Callaba, publisher and receiver access can be limited by approved Stream IDs or peer IP addresses, or deliberately opened for a guest workflow. For a managed contribution, use an approved identity or address policy. Do not leave guest access on simply to make a rehearsal connect.
Open only the required network path
Permit the selected UDP port in the instance firewall, cloud security group and any upstream network control. Opening TCP on the same number does not open SRT. If the public address is reached through NAT, verify that the mapping terminates at the Callaba listener.
Start the listener and keep its live view open
The receiver must be ready before BRIDGE LIVE calls it. Use the live state for the bring-up; do not depend on a pasted endpoint alone.
Configure one BRIDGE LIVE SRT output
The following field path is verified against AJA’s current v1.18r1 family manual. It deliberately begins inside an already-created output pipeline because source selection and pipeline creation depend on the installed model and the job.
Prove the source before the network output
Select the intended SDI input and confirm the detected format. Check embedded audio at the appliance, not only at the camera. A network test cannot distinguish a silent source from a bad audio map.
Use MPEG-TS over SRT
Choose SRT as the output stream type for the encoded pipeline. AJA’s v1.18r1 manual explicitly limits SRT encode/decode to MPEG-TS streams, so do not carry assumptions from an RTMP, NDI or uncompressed path into this one.
Open the documented destination controls
Stream Destinations → Configure Destinations
In that dialog, set SRT mode to Caller. Enter the remote Callaba Listener address, the matching UDP port, and the physical BRIDGE LIVE NIC that reaches the venue uplink. AJA documents either an IP address or hostname for Caller output. Do not select Loopback for a real contribution path.
Match identity and encryption when those fields are present
AJA’s official v1.16 REST schema documents Caller-side Stream ID and an SRT passphrase; the current family manual also shows these fields in its bonding examples. Treat them as installed-version fields: if they appear in your output configuration, match Callaba exactly. Do not put a production passphrase in screenshots, tickets or the public runbook.
Set the media profile, then account for recovery headroom
Choose the video codec, bitrate and audio map approved for the job. Verify auto-populated source properties instead of assuming they are right. Set SRT overhead according to the measured network and leave enough egress capacity above the total media rate.
Commit and start from the installed build
AJA’s current manual uses save/start controls whose wording varies with pipeline state and whether a restart is required. Use the save or start control shown for the current pipeline state, and schedule any required restart instead of forcing it during a live event.
Three green lights, not one
A connected SRT socket is only the middle of the proof. Work through these boundaries in order; each one has a different owner.
1. Source proof
BRIDGE LIVE sees the expected SDI raster and frame rate. The intended embedded audio channels are active. The encode pipeline is running at the planned rate.
2. Transport proof
Callaba shows a sustained SRT session. Incoming bitrate is plausible for the profile, and live loss and RTT stay inside the latency and capacity budget.
3. Media proof
The Callaba preview decodes, motion is clean, audio is present and in sync, and a short recording plays back before any downstream route is added.
Callaba exposes live operational context, including bitrate, loss and RTT where available. Treat that as a current snapshot, not a durable history or an end-to-end quality score. Save event evidence in the monitoring system your production already uses if you need a post-show record.
Only then expand to multiple channels
Clone the proven AJA pipeline if that is appropriate for the model, then change the SDI source, destination identity and any required port. Keep a simple channel ledger: chassis input, pipeline name, Callaba Stream ID, UDP port, expected bitrate and audio map. A cloned destination that retained the first channel’s identity can look like a network fault while it is actually an addressing collision.
- Start channels one at a time and watch aggregate uplink use.
- Confirm each preview against a visible camera or program identifier.
- Listen to every channel; do not infer audio from picture.
- Run a short recording from every production-critical source.
- Test from the real venue network, not only a bench LAN.
- Export or back up the working AJA pipelines before the show.
Callaba route recovery is another separate design
Callaba’s documented reconnect and route cycling apply to prepared SRT PULL routing hosts. This page uses an AJA Caller pushing into a Callaba Listener, so it does not automatically inherit that PULL behavior. A preferred PULL route change also uses a controlled stop/save/start sequence; it is not an instant or guaranteed hitless switch. Decide whether resilience belongs in AJA bonding, a second contribution source, or a Callaba PULL design—then test the failure you expect.
Troubleshoot the boundary that failed
No SRT session appears
Confirm BRIDGE LIVE Caller and Callaba Listener, then compare the remote host, UDP port and selected AJA NIC. Verify the Callaba listener is running and the firewall allows UDP. If Stream ID or a passphrase is enforced, compare the actual values rather than reusing a saved URL.
The session connects but there is no picture
The network handshake has succeeded. Return to the AJA pipeline: verify the SDI source, MPEG-TS output, video codec and detected format. In Callaba, separate transport state from decode state. Changing the UDP port will not fix an empty or incompatible media payload.
Picture arrives without the right audio
Check which embedded SDI pair enters BRIDGE LIVE, then inspect the pipeline’s channel mapping and audio codec. Watch or listen at the source, at the AJA output and in Callaba. “Audio enabled” is not proof that the intended program pair was mapped.
It works, then breaks up
Compare incoming bitrate, loss and RTT in Callaba with the configured media rate and the venue’s sustained uplink. Leave room for the AJA SRT overhead allowance. Raise receiver latency when measured RTT and jitter require more recovery time; reduce bitrate or fix the path when the link is simply full.
One cloned channel replaces another
Compare pipeline source, destination port and Stream ID. A copied configuration may still identify the first channel. Give every concurrent feed an unambiguous identity and follow the AJA manual’s uniqueness requirements for multiple SRT destinations.
Ingest is healthy but an output fails
If the Callaba session, preview and short recording are good, stop changing BRIDGE LIVE. The remaining fault is downstream—in a restream destination, playback profile, recording target or route. Add those branches one at a time.
After ingest, let the contribution feed do more than one job
Once the AJA session is stable, Callaba can keep the ingest boundary visible while the same received source continues into the production paths you select.
Put it in Multiview
Give operators a shared browser view alongside the live transport state. A preview is confidence monitoring, not a substitute for the source and transport checks above.
Record the received program
Make a short proof clip first, including audio playback. Then apply the storage, retention and naming policy required by the production.
Restream or play it back
Build onward delivery from the proven Callaba input. A destination-specific codec failure should not send the operator back to a healthy AJA ingest.
Compare the AJA family paths
Use the AJA workflow hub when the question is whether BRIDGE LIVE, HELO Plus or another AJA path is the right source device. This page remains the exact-model BRIDGE LIVE procedure.
Operator questions
Can BRIDGE LIVE send SRT directly to Callaba?
Yes. Use an encoded MPEG-TS SRT output, make BRIDGE LIVE the Caller, and make Callaba the Listener. The host, UDP port and any identity or encryption values must agree.
Does Caller mean BRIDGE LIVE must be the media sender?
No. Caller and Listener describe which endpoint opens the SRT connection; sender and receiver describe media direction. In this workflow BRIDGE LIVE happens to be both the media sender and the Caller.
Can I use HEVC instead of H.264?
AJA lists H.265/HEVC support for the BRIDGE LIVE family. Use it only after confirming that every Callaba preview, recording, player and onward destination in the planned chain accepts the chosen profile. H.264 is the cleaner interoperability baseline.
Is v1.18.2 required for SRT?
No. v1.18.2 is the current public release at the verification date, but SRT predates it. Use the manual and release notes that match the installed system; upgrade only through AJA’s documented path and a planned maintenance window.
Can Callaba receive all four or eight channels?
Build each channel as its own identified contribution and size the Callaba deployment and network for the aggregate load. The AJA model’s “up to” channel count does not by itself guarantee capacity in every codec and processing combination.
Can this same box receive a return feed?
BRIDGE LIVE is bidirectional and can decode supported streams back to SDI, but that is a second pipeline and a second operating test. Do not fold return into the contribution proof; give it its own address, role, audio map and failure drill.
Official references used
Device facts, version notes and the security gate were checked against AJA primary sources on July 31, 2026. Callaba behavior was checked against the current public SRT Server page and user guide.
- AJA-SA-2026-002: SRT Protocol Library Vulnerabilities
- AJA BRIDGE LIVE family product page and technical specifications
- AJA BRIDGE LIVE Family Manual v1.18r1
- AJA BRIDGE LIVE Software v1.18.2 download page
- AJA BRIDGE LIVE Family v1.18.2 release notes
- AJA BRIDGE LIVE v1.16 REST API documentation (used only for explicitly version-scoped Stream ID and passphrase fields)
Next step
Bring one BRIDGE LIVE program into a visible SRT workflow
Create the listener, prove one channel end to end, and only then add density. Callaba SRT Server can receive the contribution in the cloud or on your own Linux deployment and continue it into Multiview, recording, restreaming and playback.
