The picture stutters or breaks up

Symptom

The stream looks bad — stutters, freezes, or a blocky/broken picture — and it's not obvious whether the problem is the network, the phone or camera, or Stream itself.

Cause

The receiving box (stream_door_admin.py) tracks the incoming feed's real bitrate and frame rate per session, exposed live in the panel next to the preview. Two genuinely different failure modes produce visually similar symptoms, and the bitrate readout is what tells them apart:

• Bitrate dips at the same moment the picture stutters → the uplink is the bottleneck. The encoder is sending less data because the connection can't carry more.
• Bitrate holds steady and the picture still breaks up → the device is the problem — heat throttling, a failing camera, or bad codec settings, not the network.

How to check

• Watch the bitrate number in the panel while the problem is happening, not after — it's a live per-session reading, not a summary.
• A steady drop in reported bitrate with no recovery points at the encoder's own adaptive-bitrate logic reacting to a real network problem — check the connection, not the phone.
• A broken picture with rock-steady bitrate is not a network problem — check the device: let it cool down, try a different camera, or lower the encoder's own quality setting rather than relying on the network to fix it.
• This reading is about the incoming feed only. What each platform's own viewers experience adds that platform's own buffering delay on top, and that part isn't something the bitrate chip — or Stream — can diagnose or control.

What's next

Camera and device issues — what happens when the source itself, not the network, is the problem.