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Source diagnostics

"The stream plays but the viewer complains" is the nastiest class of problem: the status is green while the picture falls apart. The Sources tab of the stream page answers what exactly arrives at the input and how evenly. Configuring the sources themselves is on External source and Input failover; this page is about reading the readouts.

The input chain and health

Every input is shown as a card; the active one is marked Active. An input's state is one of six:

  • Working — the input delivers a feed.
  • Ready — a checked backup, ready to take over.
  • Starting — the connection is being made.
  • Degraded — there is a feed, but with violations.
  • Dead — there is no feed.
  • Unchecked — the input has not been reached yet.

The bottom row of the card lists the source problems — what made the input degrade:

  • CC errors over limit — the CC errors limit was exceeded.
  • Bitrate below floor — below Min bitrate (kbit).
  • Bitrate over ceiling — the upper threshold fired.
  • No audio, No video, No frames — a track or the frames do not arrive.
  • No codec config — the track is there but its codec description is not; such a track does not play.

Next to them are the actual readouts: the resolution and bitrate of the active input, a readable fps, Checked ago and Retries. If stats are unavailable or the stream is not running, the readouts are replaced by No data — stats unavailable or the stream is not running.

Source timeline quality

The Source timeline quality chart shows whether the source's time runs evenly:

  • Drift over the range — the divergence between the source clock and the streamer clock accumulated over the range.
  • Window min–max — the spread band within the measurement window.
  • Jitter — the spread between adjacent measurements.

Until history has accumulated it says History is being collected — the first window closes at {time}; if the streamer does not report it, Timeline history is unavailable.

Drift explains slow audio/video desync and growing latency; jitter explains ragged playback while the feed is formally intact.

DTS non-monotonicity

The DTS non-monotonicity chart counts DTS backsteps, ms per minute — the cases where timestamps in the feed went backwards. This is a defect distinct from jitter: it breaks segment assembly and archive recording, not just smoothness.

In the stream list the same thing shows up as the timeline breaks in 24 h column — backsteps and forward dts jumps over a day.

The first value does not appear immediately: No data yet — the counter appears with the first measured minute.

Source errors

The Source errors chart shows the rate in Errors per minute. The first point appears a minute after the start: Collecting data, the first point appears in a minute.

The rate matters more than the total counter: three errors a minute, steadily, is a degrading link, while a thousand errors at once during a source switch is normal.

Input buffer

The Input buffer card is about input pacing ahead of alignment. Four readouts:

  • Depth / target — how much data is in the buffer now and how much it tries to hold.
  • Underruns — how many times the buffer ran dry: the data did not arrive in time.
  • Skips and Skipped — how many times and how much data had to be dropped because the buffer overflowed.

They are read as a pair. Underruns on a shallow buffer mean the source arrives in bursts and the buffer is worth deepening. Skips mean the opposite — the source runs ahead and the excess is dropped.

What next