b41a6c43da
After a frustrating search for a suitable channel to use for shutdown (tokio::sync:⌚:Receiver and futures::future::Shared<tokio::sync::oneshot::Receiver> didn't look quite right) in which I rethought my life decisions, I finally just made my own (server/base/shutdown.rs). We can easily poll it or wait for it in async or sync contexts. Most importantly, it's convenient; not that it really matters here, but it's also efficient. We now do a slightly better job of propagating a "graceful" shutdown signal, and this channel will give us tools to improve it over time. * Shut down even when writer or syncer operations are stuck. Fixes #117 * Not done yet: streamers should instantly shut down without waiting for a connection attempt or frame or something. I'll probably implement that when removing --rtsp-library=ffmpeg. The code should be cleaner then. * Not done yet: fix a couple places that sleep for up to a second when they could shut down immediately. I just need to do the plumbing for mock clocks to work. I also implemented an immediate shutdown mode, activated by a second signal. I think this will mitigate the streamer wait situation.
Introduction
Moonfire NVR is an open-source security camera network video recorder, started
by Scott Lamb <slamb@slamb.org>. It saves H.264-over-RTSP streams from
IP cameras to disk into a hybrid format: video frames in a directory on
spinning disk, other data in a SQLite3 database on flash. It can construct
.mp4 files for arbitrary time ranges on-the-fly. It does not decode,
analyze, or re-encode video frames, so it requires little CPU. It handles six
1080p/30fps streams on a Raspberry Pi
2, using
less than 10% of the machine's total CPU.
Help wanted to make it great! Please see the contributing guide.
So far, the web interface is basic: a filterable list of video segments, with support for trimming them to arbitrary time ranges. No scrub bar yet. There's also an experimental live view UI.
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There's no support yet for motion detection, no https/TLS support (you'll need a proxy server, as described here), and only a console-based (rather than web-based) configuration UI.
Moonfire NVR is currently at version 0.6.5. Until version 1.0, there will be no compatibility guarantees: configuration and storage formats may change from version to version. There is an upgrade procedure but it is not for the faint of heart.
I hope to add features such as video analytics. In time, we can build a full-featured hobbyist-oriented multi-camera NVR that requires nothing but a cheap machine with a big hard drive. There are many exciting techniques we could use to make this possible:
- avoiding CPU-intensive H.264 encoding in favor of simply continuing to use the camera's already-encoded video streams. Cheap IP cameras these days provide pre-encoded H.264 streams in both "main" (full-sized) and "sub" (lower resolution, compression quality, and/or frame rate) varieties. The "sub" stream is more suitable for fast computer vision work as well as remote/mobile streaming. Disk space these days is quite cheap (with 4 TB drives costing about $100), so we can afford to keep many camera-months of both streams on disk.
- off-loading on-NVR analytics to an inexpensive USB or M.2 neural network accelerator and hardware H.264 decoders.
- taking advantage of on-camera analytics. They're often not as accurate, but they're the best way to stretch very inexpensive NVR machines.
Documentation
- Contributing
- License — GPL-3.0-or-later with GPL-3.0-linking-exception for OpenSSL.
- Change log / release notes.
- Guides
- Design documents
- Wiki has hardware recommendations, notes on several camera models, etc. Please add more!