pixop-probe-input

Short TSDuck analyze of the pre-Pixop MPEG-TS tap: UDP multicast (or unicast) carrying transport stream before the Pixop enhancement stage. Read-only regarding Pixop configuration; consumes live traffic for a bounded time window.

Default tap matches pixop-flow stage “Ingress → Pixop”: 239.0.0.1:5500 unless overridden in /etc/pixop-live/network.env (TAP_OUT_ADDR, TAP_OUT_PORT).

Usage

pixop-probe-input [-a ADDR] [-p PORT] [-s SECS]
pixop-probe-input -h|--help

Option	Default	Description
`-a`, `--addr`	`TAP_OUT_ADDR` or `239.0.0.1`	UDP bind address
`-p`, `--port`	`TAP_OUT_PORT` or `5500`	UDP port
`-s`, `--secs`	`5`	Capture/analyze duration (seconds)

Argument order: flags only; there is no positional input path.

What changes / what never changes

Changes	Never changes
Nothing on disk (analyze to drop)	Pipeline config, licenses, relay args

Creates a ephemeral Docker container with --network host; does not write TS files (contrast pixop-tap-input).

Preconditions

Requirement	Detail
OS	Appliance guest (AL2023)
Privilege	Re-executes via sudo when not root (Docker + host networking)
`tsduck.env`	`TSDUCK_IMAGE` set to a local digest `…@sha256:…`
Image	`docker image inspect` must succeed; no pull
Traffic	Live TS on the chosen UDP endpoint; idle tap may run until timeout

Typical workflows

Default tap for five seconds:

pixop-probe-input

Longer sample after encoder changes:

pixop-probe-input -s 15

Explicit address when using custom network.env:

pixop-probe-input -a 239.0.0.1 -p 5500 -s 10

After ingress is up but Pixop looks wrong—confirm PID/bitrate at the tap:

tsduckctl status main
pixop-probe-input -s 8
pixop-flow --secs 3

Output interpretation

The script prints a single progress line:

Probing UDP 239.0.0.1:5500 for 5s ...

Then TSDuck analyze --normalized output appears (services, PIDs, bitrates, continuity—whatever the bundled TSDuck version reports). There is no custom Pixop summary or exit-code table in the wrapper: rely on TSDuck’s exit status and stderr for failures.

An idle stream may hit the IP plugin receive timeout (5000 ms in the embedded tsp command) and finish without rich analyze tables—distinguish “no packets” from “analyze error” using whether the pipeline is known to be running (pixop-flow, tsduckctl check).

Privacy and security

Content exposure: Analyze decodes service structure from live broadcast or contribution feeds. Output can reveal program names, PID layouts, and timing—treat logs like sensitive operational data.
No file retention by this tool; safer than pixop-tap-input for quick checks.
Still do not run on production feeds in regulated environments without approval—duplicate UDP consumption is minimal but not zero.
SRT passphrases and keys are not involved (UDP tap only).

Storage and cleanup

No output files. Container is --rm. No manual cleanup.

Common errors

Message	Cause
`ERROR: TSDUCK_IMAGE must be a local immutable digest`	Missing or tag-based image in `tsduck.env`
`ERROR: TSDuck image not present locally`	Image not loaded on appliance
`Unknown arg`	Unsupported flag (exit 2)
Hang / sparse output	No UDP traffic on `ADDR:PORT`

Version note

Available on standard appliance images with TSDuck Docker integration. Candidate builds may differ only in bundled TSDuck analyze fields—not the CLI shape.

pixop-tap-input — write TS capture to disk
pixop-flow — bitrate-only snapshot at five stages
tsduckctl — detect-video-pid for PID commissioning
Monitoring and troubleshooting