WhepProbe

whepprobe is a diagnostic tool similar to ffprobe for WHEP endpoints. It subscribes to a WHEP stream and verifies that the stream is reachable and that its media can be decoded with FFmpeg via the rsmpeg crate. It decodes VP8, VP9, H.264, H.265 and AV1 video, plus Opus, G.722, PCMU and PCMA audio. Video-only streams keep the original success semantics; whenever audio RTP is received, at least one audio frame must also decode successfully.

For browser-based playback verification, see WhepWright.

Get it

whepprobe is included in the all-in-one live777-all image:

docker run --rm --network host ghcr.io/binbat/live777-all:latest \
  whepprobe -w http://localhost:7777/whep/live

The image's built-in smoke-test command uses whepprobe for its WHEP verification step — see Getting Started.

Build

# Requires FFmpeg development libraries
cargo build --bin whepprobe --features rsmpeg

AV1 software decoding requires an FFmpeg build with libdav1d or libaom enabled. The probe prefers those decoders over FFmpeg's hardware-oriented native AV1 decoder.

Usage

Probe a WHEP endpoint:

whepprobe -w http://localhost:7777/whep/live

Specify the expected codec and timeout:

whepprobe -w http://localhost:7777/whep/live --codec h264 --timeout 60

Get JSON output for scripts or CI:

whepprobe -w http://localhost:7777/whep/live --output json

Options

Option	Default	Description
-w, --whep	required	WHEP endpoint URL
-t, --token	none	Bearer token for WHEP authentication
-v	warn	Increase verbosity (-v info, -vv debug, -vvv trace)
--codec	auto-detect	Expected video codec: vp8, vp9, h264, h265, av1. The rsmpeg backend auto-detects the codec from the WHEP session, so this option only affects the reported result.
--sprop-params	none	H.265 sprop parameters (sprop-vps=...;sprop-sps=...;sprop-pps=...)
--decode-duration	5	Seconds to decode after the WHEP session connects, limited by the remaining --timeout budget (2 seconds are reserved for cleanup).
--output	human	Output format: human, json
--timeout	30	Overall timeout in seconds
--ice-server	none	ICE server for gathering, repeatable; format <url>[,<username>[,<credential>]]. Defaults to none — host candidates only (WHIP/WHEP endpoints advertise their own ICE servers via Link headers)

JSON audio fields

Every report contains audio_frame_count, audio_sample_rate and audio_channels, including failure reports and streams without audio. Their zero values mean that no audio frame was decoded. For a successfully decoded track they report the decoded frame count, actual sample rate (G.722 is 16,000 Hz even though its RTP clock is 8,000 Hz) and channel count.

Exit code

• 0: WHEP connected and video was decoded; if audio RTP was received, audio was decoded too.
• 1: probe failed or an error occurred.

Core library

The probe logic lives in livetwo::probe and can be reused by integration tests or other Rust tools:

use cli::Codec;
use livetwo::probe::{ProbeBackend, ProbeConfig};
use livetwo::probe::rsmpeg::RsmpegProbe;

// RsmpegProbe requires `livetwo` to be built with the `rsmpeg` feature.
let config = ProbeConfig {
    whep_url: "http://localhost:7777/whep/live".to_string(),
    video_codec: Some(Codec::Vp8),
    ..Default::default()
};

let result = RsmpegProbe::default().probe(&config).await?;
assert!(result.success);