Degraded network
At protests, the mobile network is often saturated. It is the most common problem, well ahead of a phone being seized. The field phone would rather send something than nothing: a piece of evidence in 480p that was sent is worth more than one in 1080p left on a broken phone. It measures the network every 3 seconds and adjusts the quality of the next segments.
Quality levels
Below 480p, the phone lowers the frame rate first, before reducing the resolution any further: one sharp frame every 200 ms is worth more than a pixel mush at 30 frames per second.
| Level | Frame rate | Video bitrate | Approximate volume |
|---|---|---|---|
| 1080p | 30 fps | 4 Mb/s | 1.8 GB per hour |
| 720p | 30 fps | 2 Mb/s | 900 MB per hour |
| 480p | 30 fps | 1 Mb/s | 450 MB per hour |
| 480p | 15 fps | 500 kb/s | 225 MB per hour |
| 480p | 5 fps | 250 kb/s | 110 MB per hour |
| 360p | 5 fps | 120 kb/s | 54 MB per hour |
| Audio only | 32 kb/s | 15 MB per hour |
When it goes down, when it goes up
The phone goes down one level if more than 12 seconds are waiting in the queue, or if the measured throughput is too low for the current level on two measurements in a row (about 6 seconds). It goes up one level if the queue is almost empty (less than 3 seconds) and the throughput would comfortably allow the next level up on four measurements in a row (about 12 seconds). Going up is slower than going down, to avoid oscillating.
Offline, the phone keeps recording at the current level and builds up a backlog. When the network returns, it drops to the lowest video level (360p at 5 fps) to empty the queue as fast as possible, then goes back up.
Each change is announced by a line on the screen, with no alarm:
Network saturated, switching to audio only to keep sending.
The quality change, resolution or frame rate, happens between two segments. Each segment remains a file that can be played on its own.
The network indicator
| State | Meaning |
|---|---|
| Good | High-quality video, continuous sending |
| Weak | Reduced quality, sending keeps up |
| Saturated | Audio only, the queue is growing |
| Offline | Everything stays in the queue, encrypted |
The send queue
Each segment is encrypted before it enters the queue. Even if the phone is seized with a full queue, its content is unreadable without your key, which the phone does not have.
At most two segments are sent at the same time. If sending fails, it retries with increasing delays. As soon as the server acknowledges receipt, the segment is erased from the phone. The queue survives the page being closed and starts again when it is reopened; it does not survive the browser data being cleared.
What has been sent is safe
The "safe on the server" counter only counts segments whose receipt the server has confirmed. The "waiting to send" counter counts what is still on the phone. Neither is rounded in your favor.
If the phone is destroyed with 40 seconds waiting, those 40 seconds are lost. The server will have no trace of them, and the session timeline will show them as a dated gap, never filled.
What you can do
- Switch to Audio only yourself if the network is bad from the start: the sound of a scene is often decisive and gets through almost anywhere.
- Prefer Photo for a specific detail (badge number, license plate) when video does not get through.
- Keep the page open after stopping until the waiting counter is at zero.
- Turn off Wi-Fi if it is detected but unusable: some phones cling to it instead of using the mobile network.