Update README.md

[ahsandar]

Added the additional library dependencies required to use JavaCV in a SBT based project

[saudet]

Great! Could add the dependencies for FFmpeg, etc, etc as well? Thanks!

[jpsacha]

Platform, like linux-x86, can be determined automatically using code shown here. Maybe worth creating a simple SBT plugin to avoid cutting and pasting, it is 19 lines :)

[saudet]

@jpsacha Instead of that code, do you know if it is possible with sbt to call Loader.getPlatform() directly as a "maven-plugin"? With Maven, AFAIK, it's not possible, but if we can with sbt, it could help provide a nicer workaround.

[jpsacha]

SBT can call anything that can be added to its classpath, so it could be possible to call Loader.getPlatform() that way. Not sure if it can access a "maven-plugin", will need to check on that.

[jpsacha]

@saudet What exactly javacpp "maven-plugin" do?

[saudet]

I'm not sure myself, maybe nothing. sbt seems to treat "jar" artifacts differently from "maven-plugin" ones, unlike Maven itself. It's just a keyword required to indicate to Maven to look up for classes implementing the Mojo interface, which is BuildMojo in JavaCPP's case.

[jpsacha]

I modified javacv-examples to use javacpp to determine platform in build.sbt:

val platform = org.bytedeco.javacpp.Loader.getPlatform

To make it work javacpp needs to be added to build.sbt classpath. It is done in project/plugins.sbt:

classpathTypes += "maven-plugin"
libraryDependencies += "org.bytedeco" % "javacpp" % "0.11"

[saudet]

Great 👍 Thanks! BTW, do you know if it's possible to get the dependencies of JavaCV so we can loop over that and add the platform specific dependencies as well?

[jpsacha]

If you just want to add dependency on specific preset libraries you could use in build.sbt som ething like this:

// Platform classifier for native library dependencies
val platform = org.bytedeco.javacpp.Loader.getPlatform
// Libraries with native dependencies
val bytedecoPresetLibs = Seq(
  // library names and versions
  "opencv" -> "2.4.11-0.11",
  "flycapture" -> "2.7.3.19-0.11"
).flatMap { case (lib, ver) =>
  Seq(
    // Add both: dependency and its native binaries for the current `platform`
    "org.bytedeco.javacpp-presets" % lib % ver,
    "org.bytedeco.javacpp-presets" % lib % ver classifier platform
  )
}

libraryDependencies ++= Seq(
  "org.bytedeco" % "javacpp" % javacppVersion,
  "org.bytedeco" % "javacv" % javacppVersion,
  "org.scala-lang.modules" %% "scala-swing" % "1.0.1",
  "junit" % "junit" % "4.12" % "test",
  "com.novocode" % "junit-interface" % "0.11" % "test"
) ++ bytedecoPresetLibs

It is also possible to automatically determine all "org.bytedeco.javacpp-presets" libraries from "javacv" dependencies and add platform classifier to each. I will need to think how to actually do it. Though that will possibly add large amount of unneeded dependencies to the project.

[saudet]

Yes, I realize it would add a lot of unneeded dependencies. I am just hoping to have something like that as a sample build file, because we can't do it the Maven way. :) There is no hurry, so take your time! Thanks

[saudet]

Hi, any updates on this?

[ahsandar]

not yet , haven't had time to work on it yet

[saudet]

Closing as this is no longer required with the "platform artifacts". We just need to add a dependency on "javacv-platform" or "opencv-platform", for example, which in turn depend on binaries for all platforms. This works not only with Maven, but with Gradle and sbt as well.