WhipSynth

whipsynth is a synthetic WHIP publisher. It generates audio and video test patterns locally with FFmpeg via the rsmpeg crate and publishes them to a WHIP endpoint without any external media source.

Use cases

• Quickly verify that a WHIP endpoint accepts and forwards streams.
• Load-test a Live777 instance with many concurrent publishers.
• Reproduce codec-specific issues without setting up a real camera or FFmpeg pipeline.

Build

# Build the whipsynth binary (requires FFmpeg development libraries)
cargo build --bin whipsynth --features rsmpeg

Usage

Publish a 640x480 VP8 video-only stream to a WHIP endpoint:

whipsynth -w http://localhost:7777/whip/live

Publish VP8 video + Opus audio:

whipsynth -w http://localhost:7777/whip/live --acodec opus

Publish H.264 with authentication token and run for 60 seconds:

whipsynth -w http://localhost:7777/whip/live \
          -t my-token \
          --vcodec h264 \
          --duration 60

Options

Option	Default	Description
-w, --whip	required	WHIP endpoint URL
-t, --token	none	Bearer token for WHIP authentication
--vcodec	vp8	Video codec: vp8, vp9, h264, h265, av1
--acodec	none	Audio codec: opus, g722 (omit for no audio)
--width	640	Video width in pixels
--height	480	Video height in pixels
--fps	30	Video frame rate
--duration	none	Run for the specified number of seconds, then exit

Load-test mode

whipsynth can spawn multiple concurrent publishers. These options are hidden from the default help because they are mainly used by the test suite:

whipsynth -w http://localhost:7777/whip/live --count 10 --spawn-interval-ms 200

Each session gets a unique URL by appending an index to the last path segment. For example, with --count 3 and base URL /whip/live, the sessions publish to /whip/live-0, /whip/live-1, and /whip/live-2.

Option	Default	Description
--count	1	Number of concurrent WHIP sessions
--spawn-interval-ms	100	Delay between spawning each session

Exit code

• 0: publishing finished normally (duration elapsed or cancelled).
• 1: an error occurred, for example the WHIP endpoint rejected the request or the peer connection failed.