Recording & Storage

How recording is written

SkyView cuts each camera's video into standard MP4 files by time, fixed at 60 seconds per segment. MediaMTX first writes out fMP4 segments; the instant a segment finishes, the runOnRecordSegmentComplete hook fires, and ffmpeg remuxes it in place with -c copy into a standard MP4 with faststart (moov at the head), so every player can seek directly. The on-disk path:

data/recordings/
  <camera_id>/
    2026-05-18_14-30-00.mp4
    2026-05-18_14-31-00.mp4
    2026-05-18_14-32-00.mp4
    ...

Local storage path

Recordings are written to /app/data/recordings (nested mount, can be pointed at a large disk / NAS separately); small state like the database / cookies / logs lives in /app/data, and AI models are bundled in the image rather than in the data directory. For production, always point the recordings directory at a disk with ample capacity, and don't cram it onto the same partition as the system disk — a full recordings disk will keep your server from booting.

# Recommended: mount recordings on a separate large disk / NAS (small state stays in data/)
sudo mkdir -p /mnt/recordings
# One-line script: point --recordings-dir at the large disk
curl -fsSL https://cdn.yun-kan.com/yunkan-install.sh | bash -s -- --recordings-dir /mnt/recordings
# Or nest-mount the recordings volume in a manual docker run
docker run -v $(pwd)/data:/app/data -v /mnt/recordings:/app/data/recordings ...

Retention policy and disk space

Web admin → Settings → Recording retention to enable and configure automatic cleanup (off by default, must be turned on manually). Once on, the two rules below both apply and either one triggers deletion; only archived recordings (uploaded successfully, or local mode) are cleaned, and pending / uploading / failed states are never touched:

• By days: recordings older than the retention days (default 30) → deleted; set 0 = don't trigger by time
• By capacity: when disk usage exceeds the threshold (default 90%) → delete starting from the oldest; set 100 = don't trigger by space

115 Cloud storage (optional)

Asynchronously upload local recordings to 115 Cloud, essentially a "cloud NVR". With instant-upload support, existing recordings don't consume bandwidth.

1. 1

   Scan to log in

   Web admin → 115 → show the QR code and authorize by scanning with the 115 mobile app. SkyView saves the login info encrypted in the data directory.

2. 2

   Choose the target folder

   Create an empty folder in 115 (e.g. "SkyView Recordings"), return to SkyView, and select it as the upload destination

3. 3

   Switch the storage backend

   Settings → Storage → choose 115 → Save. The switch is a hot swap that doesn't restart the process, taking effect on the next upload

4. 4

   Verify it's working

   The Web Admin currently has no upload queue / progress panel. To confirm recordings are uploading, pick any of three ways: ① the Settings → 115 page to check that VIP status and remaining capacity look right; ② the Logs page (sidebar → Logs), select the uploader service on the left to watch each segment's start / finish / failure lines in real time; ③ open the 115 app or website and go into the target folder to see whether new recordings are arriving.

Download / export

The playback page supports "export by time range" — choose a start and end time, and the backend re-encodes and trims it into a single MP4 for the client to download, with frame-level precision on the start/end (<40ms error). It auto-selects hardware: NVIDIA NVENC (50-200x real time, tens of seconds per hour on an RTX) → Intel iGPU VAAPI (25-50x, a minute or two per hour on an N100) → libx264 software encode (1.5-3x, ten-odd minutes per hour). Any tier that fails automatically falls back to the next. All three of Web Admin, Android, and iOS support it.

1. 1

   Open the playback page

   Select the camera and date to export. Drag the timeline near the target range so the center marker lands on that recording segment.

2. 2

   Click the export button

   Web Admin: the ⬇ icon at the far right of the playback control bar; Android / iOS: "Export" to the right of the "Speed" button on the control bar. A range-selection panel pops up, defaulting to the current playback position ±30 seconds.

3. 3

   Adjust the start/end → submit

   Change the start/end times in the panel and it computes the estimated size in real time (1080p H.264 ≈ 250 KB/s). The maximum per export is 1 hour; longer is rejected. Click "Start export".

4. 4

   Watch the progress

   A progress card appears at the bottom-right (Web) / below the control bar (Android/iOS). Web refreshes in real time via SSE; mobile polls every 2 seconds. Once queued, a task usually completes in seconds to tens of seconds (depending on the segment count + whether cloud segments must be pulled from 115).

5. 5

   Download

   Once the progress card turns into a "Download" button, click it: Web downloads directly via the browser; Android uses the system DownloadManager to save to Downloads/SkyView/ with a status-bar notification; iOS opens a ShareSheet to "Save to Files / Photos" or share to WeChat.