harvid -- HTTP Ardour Video Daemon

Harvid decodes still images from movie files and serves them via HTTP.

Its intended use-case is to efficiently provide frame-accurate data and act as second level cache for rendering the video-timeline in Ardour.

Download

Apart from the source-code and packages from your linux-distributor, binaries are available for OSX, Windows and Linux at http://x42.github.com/harvid/ .

Usage

Harvid is a standalone HTTP server, all interaction takes place via HTTP. After launching it, simply point a web-browser at http://localhost:1554/

The OSX bundle and window installer come with a shortcut link to launch the server. On Linux or with the OSX package, harvid is usually started from a terminal by simply typing harvid<enter>.

Harvid can also be run directly from the source folder without installing it. Get its build-dependencies (see below), run

make
./src/harvid

When used from ardour, ardour will automatically start the server when you open a video. Ardour searches $PATH or asks your for where it can find harvid. The easiest way is to simply run:

sudo make install

Harvid can be launched as system-service (daemonized, chroot, chuid, syslog), and listen on specific interfaces only in case you do not want to expose access to your movie-collection. However, is no per request access control.

For available options see harvid --help or the included man page which is also available online at http://x42.github.com/harvid/harvid.1.html

Build-dependencies

ffmpeg is used to decode the movie. The source code should be compatible and compile with libav.

For encoding images, libpng and libjpeg are required.

Internals

Harvid is highly concurrent makes use of all available CPUs. It will spawn multiple decoder processes, keep them available for a reasonable time and also cache the video-decoder's output for recurring requests.

The cache-size is variable only limited by available memory. All images are served from the cache, so even if you are not planning to use the built-in frame cache, the cache-size defines the minimum number of concurrent connections.

Interface

The HTTP request interface is documented on the homepage of the server itself: http://localhost:1554/

The default request-handler will respond to /?file=PATH&frame=NUMBER requests. Optionally &w=NUM and &h=NUM can be used to alter the geometry and &format=FMT to request specific pixel-formats and/or encodings.

/index[/PATH] allows to get a list of available files - either as tree or as flat-list with the ?flatindex=1 as recursive list of the server's docroot.

/info?file=PATH returns information about the video-file.

Furthermore there are built-in request handlers for status-information, server-version and configuration as well as admin-tasks such as flushing the cache or closing decoders.

The &format=FMT also applies for information requests with HTML, JSON, CSV and plain text as available formatting options.