Introduction

Moonfire NVR is an open-source security camera network video recorder, started by Scott Lamb slamb@slamb.org. Currently it is basic: it saves H.264-over-RTSP streams from IP cameras to disk as .mp4 files and provides a simple HTTP interface for listing and viewing fixed-length segments of video. It does not decode, analyze, or re-encode video frames, so it requires little CPU. It handles six 720p/15fps streams on a Raspberry Pi 2, using roughly 5% of the machine's total CPU.

This is version 0.1, the initial release. Until version 1.0, there will be no compatibility guarantees: configuration and storage formats may change from version to version.

I hope to add features such as salient motion detection. It's way too early to make promises, but it seems possible to build a full-featured hobbyist-oriented multi-camera NVR that requires nothing but a cheap machine with a big hard drive. I welcome help; see Getting help and getting involved below. 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 3 TB drives costing about $100), so we can afford to keep many camera-months of both streams on disk.
• decoding and analyzing only select "key" video frames (see wikipedia.
• off-loading expensive work to a GPU. Even the Raspberry Pi has a surprisingly powerful GPU.
• using HTTP Live Streaming rather than requiring custom browser plug-ins.
• taking advantage of cameras' built-in motion detection. This is the most obvious way to reduce motion detection CPU. It's a last resort because these cheap cameras' proprietary algorithms are awful compared to those described on changedetection.net. Cameras have high false-positive and false-negative rates, are hard to experiment with (as opposed to rerunning against saved video files), and don't provide any information beyond if motion exceeded the threshold or not.

Downloading

See the github page (in case you're not reading this text there already). You can download the bleeding edge version from the command line via git:

$ git clone https://github.com/scottlamb/moonfire-nvr.git

Building from source

There are no binary packages of Moonfire NVR available yet, so it must be built from source. It requires several packages to build:

• CMake version 3.1.0 or higher.
• a C++11 compiler, such as gcc 4.7 or higher.
• ffmpeg, including libavutil, libavcodec (to inspect H.264 frames), and libavformat (to connect to RTSP servers and write .mp4 files). Note ffmpeg versions older than 55.1.101, along with all versions of the competing project libav, does not support socket timeouts for RTSP. For reliable reconnections on error, it's strongly recommended to use ffmpeg >= 55.1.101.
• libevent 2.1, for the built-in HTTP server. (This might be replaced with the more full-featured nghttp2 in the future.) Unfortunately, the libevent 2.0 bundled with current Debian releases is unsuitable.
• gflags, for command line flag parsing.
• glog, for debug logging.
• gperftools, for debugging.
• googletest, for automated testing. This will be automatically downloaded during the build process, so it's not necessary to install it beforehand.
• re2, for parsing with regular expressions.
• libuuid from (util-linux)[https://en.wikipedia.org/wiki/Util-linux].
• SQLite3.

On Ubuntu 15.10 or Raspbian Jessie, the following command will install most pre-requisites (see also the Build-Depends field in debian/control):

$ sudo apt-get install \
               build-essential \
               cmake \
               libavcodec-dev \
               libavformat-dev \
               libavutil-dev \
               libgflags-dev \
               libgoogle-glog-dev \
               libgoogle-perftools-dev \
               libjsoncpp-dev \
               libre2-dev \
               sqlite3 \
               libsqlite3-dev \
               pkgconf \
               uuid-runtime \
               uuid-dev

libevent 2.1 will have to be installed from source. In the future, this dependency may be replaced or support may be added for automatically building libevent in-tree to avoid the inconvenience.

uuid-runtime is only necessary if you wish to use the uuid command to generate uuids for your cameras (see below). If you obtain them elsewhere, you can skip this package.

You can continue to follow the build/install instructions below for a manual build and install, or alternatively you can run the prep script called prep.sh.

$ cd moonfire-nvr
$ ./prep.sh

The script will take the following command line options, should you need them:

• -E: Forcibly purge all existing libevent packages. You would only do this if there is some apparent conflict (see remarks about building libevent from source).
• -f: Force a build even if the binary appears to be installed. This can be useful on repeat builds.
• -S: Skip updating and installing dependencies through apt-get. This too can be useful on repeated builds.

You can edit variables at the start of the script to influence names and directories, but defaults should suffice in most cases. For details refer to the script itself. We will mention just one option, needed when you follow the suggestion to separate database and samples between flash storage and a hard disk. If you have the hard disk mounted on, lets say /media/nvr, and you want to store the video samples inside a directory named samples there, you would set:

SAMPLES_DIR=/media/nvr/samples

The script will perform all necessary steps to leave you with a fully built, installed moonfire-nvr binary and (running) system service. The only thing you'll have to do manually is add your camera configuration(s) to the database. Alternatively, before running the script, you can create a file named cameras.sql in the same directory as the prep.sh script and it will be automatically included for you. For instructions, you can skip to "Camera configuration and hard disk mounting".

Once prerequisites are installed, Moonfire NVR can be built as follows:

$ mkdir build
$ cd build
$ cmake ..
$ make
$ sudo make install

Alternatively, if you do have a sufficiently new apt-installed libevent installed, you may be able to prepare a .deb package:

$ sudo apt-get install devscripts dh-systemd
$ debuild -us -uc

Further configuration

Moonfire NVR should be run under a dedicated user. It keeps two kinds of state:

• a SQLite database, typically <1 GiB. It should be stored on flash if available.
• the "sample file directory", which holds the actual samples/frames of H.264 video. This should be quite large and typically is stored on a hard drive.

Both are intended to be accessed only by Moonfire NVR itself. However, the interface for adding new cameras is not yet written, so you will have to manually create the database and insert cameras with the sqlite3 command line tool prior to starting Moonfire NVR.

Manual commands would look something like this:

$ sudo addgroup --system moonfire-nvr
$ sudo adduser --system moonfire-nvr --home /var/lib/moonfire-nvr
$ sudo mkdir /var/lib/moonfire-nvr
$ sudo -u moonfire-nvr -H mkdir db sample
$ sudo -u moonfire-nvr sqlite3 ~moonfire-nvr/db/db < path/to/schema.sql

Camera configuration and hard drive mounting

If a dedicated hard drive is available, set up the mount point:

$ sudo vim /etc/fstab
$ sudo mount /var/lib/moonfire-nvr/sample

Once setup is complete, it is time to add camera configurations to the database. However, the interface for adding new cameras is not yet written, so you will have to manually insert cameras configurations with the sqlite3 command line tool prior to starting Moonfire NVR.

Before setting up a camera, it may be helpful to test settings with the ffmpeg command line tool:

$ ffmpeg \
      -i "rtsp://admin:12345@192.168.1.101:554/Streaming/Channels/1" \
      -c copy \
      -map 0:0 \
      -rtsp_transport tcp \
      -flags:v +global_header \
      test.mp4

Once you have a working ffmpeg command line, insert the camera config as follows. See the schema SQL file's comments for more information. Note that the sum of retain_bytes for all cameras combined should be somewhat less than the available bytes on the sample file directory's filesystem, as the currently-writing sample files are not included in this sum. Be sure also to subtract out the filesystem's reserve for root (typically 5%).

In the following example, we generate a uuid which is then later used to uniquely identify this camera. Thus, you will generate a new one for each camera you insert using this method.

$ uuidgen | sed -e 's/-//g'
b47f48706d91414591cd6c931bf836b4
$ sudo -u moonfire-nvr sqlite3 ~moonfire-nvr/db/db
sqlite3> insert into camera (
    ...>     uuid, short_name, description, host, username, password,
    ...>     main_rtsp_path, sub_rtsp_path, retain_bytes) values (
    ...>     X'b47f48706d91414591cd6c931bf836b4', 'driveway',
    ...>     'Longer description of this camera', '192.168.1.101',
    ...>     'admin', '12345', '/Streaming/Channels/1',
    ...>     '/Streaming/Channels/2', 104857600);
sqlite3> ^D

Using automatic camera configuration inclusion with prep.sh

Not withstanding the instructions above, you can also prepare a file named cameras.sql before you run the prep.sh script. The format of this file should be something like in the example below for two cameras (SQL gives you lots of freedom in the use of blank space and newlines, so this is formatted for easy reading, and editing, and does not have to be altered in formatting, but can if you wish and know what you are doing):

insert into camera (
		uuid,
		short_name, description,
		host, username, password,
		main_rtsp_path, sub_rtsp_path,
		retain_bytes
	)
	values
	(
		X'1c944181b8074b8083eb579c8e194451',
		'Front Left', 'Front Left Driveway',
		'192.168.1.41',
		'admin', 'secret',
		'/Streaming/Channels/1', '/Streaming/Channels/2',
		346870912000
	),
	(
		X'da5921f493ac4279aafe68e69e174026',
		'Front Right', 'Front Right Driveway',
		'192.168.1.42',
		'admin', 'secret',
		'/Streaming/Channels/1', '/Streaming/Channels/2',
		346870912000
	);

You'll still have to find the correct rtsp paths, usernames and passwords, and set retained byte counts, as explained above.

System Service

Moonfire NVR can be run as a systemd service. If you used prep.sh this has been done for you. If not, Create /etc/systemd/system/moonfire-nvr.service:

[Unit]
Description=Moonfire NVR
After=network-online.target

[Service]
ExecStart=/usr/local/bin/moonfire-nvr \
    --sample_file_dir=/var/lib/moonfire-nvr/sample \
    --db_dir=/var/lib/moonfire-nvr/db \
    --http_port=8080
Type=simple
User=moonfire-nvr
Nice=-20
Restart=on-abnormal
CPUAccounting=true
MemoryAccounting=true
BlockIOAccounting=true

[Install]
WantedBy=multi-user.target

Note that the HTTP port currently has no authentication; it should not be directly exposed to the Internet.

Complete the installation through systemctl commands:

$ sudo systemctl daemon-reload
$ sudo systemctl start moonfire-nvr.service
$ sudo systemctl status moonfire-nvr.service
$ sudo systemctl enable moonfire-nvr.service

See the systemd documentation for more information. The manual pages for systemd.service and systemctl may be of particular interest.

Troubleshooting

While Moonfire NVR is running, logs will be written to /tmp/moonfire-nvr.INFO. Also available will be /tmp/moonfire-nvr.WARNING and /tmp/moonfire-nvr.ERROR. These latter to contain only warning or more serious messages, respectively only error messages.

Getting help and getting involved

Please email the moonfire-nvr-users mailing list with questions, bug reports, feature requests, or just to say you love/hate the software and why.

I'd welcome help with testing, development (in C++, JavaScript, and HTML), user interface/graphic design, and documentation. Please email the mailing list if interested. Patches are welcome, but I encourage you to discuss large changes on the mailing list first to save effort.

C++ code should be written using C++11 features, should follow the Google C++ style guide for consistency, and should be automatically tested where practical. But don't worry about this too much; I'm much happier to work with you to refine a rough draft patch than never see your contribution at all!

License

This file is part of Moonfire NVR, a security camera digital video recorder. Copyright (C) 2016 Scott Lamb slamb@slamb.org

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

In addition, as a special exception, the copyright holders give permission to link the code of portions of this program with the OpenSSL library under certain conditions as described in each individual source file, and distribute linked combinations including the two.

You must obey the GNU General Public License in all respects for all of the code used other than OpenSSL. If you modify file(s) with this exception, you may extend this exception to your version of the file(s), but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version. If you delete this exception statement from all source files in the program, then also delete it here.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.