DCE's Customizations over UPV's Paella Player for Opencast

This is Harvard DCE's Customizations over UPV's' Paella player for Opencast bundle.

DCE Development

Branches and tags

• To add a feature or fix a bug, create a branch off of master. When it is ready to be reviewed and tested, create a pull request from it to master.
• Tags are used to indicate which version of Paella this project is using. When you update the Paella submodule, tag paella-matterhorn with paella + the Paella tag + - + an hudce Matterhorn release version. i.e. paella4.1.18/dceoc1.5.1-1.25.0.

Building

• Run mvn clean install

The OpsWorks runs Maven (mvn ), which reads the pom.xml which tells it to install node and run grunt to build everything. (For local development, you can just install Grunt yourself and run grunt .) server.debug is the default Grunt target because we do not currently minify for production.

Among other things, it:

• installs a local version of node if it is not found globally
• Copies files from the dce-paella-extensions module into node_modules/upv-paella-opencast and various other places (see the [Gruntfile] for details).
• Copies files from build/upv-paella-opencast into build/dce-paella-opencast.
• Also copies files from vendor/... into build.
• Concatenates the .less files together.

How to read the Makefile

Make is a venerable and reliable Unix build tool. The Makefile format lets you specify targets that consist of:

1. Unix commands
2. Dependencies (other targets)

Dependencies

dce-paella-extensions is a dependency that contains DCE-specific Paella changes. paella-engage-ui (polimediaupv/paella-matterhorn.git#...) is a dependency that contains Polimedia UPV Paella Opencast code. browserify supports building the DCE app-src extensions from this repository (extra features, such as routing)

This project uses NPM Shrinkwrap. It installs modules from the npm-shrinkwrap.json file, not the package.json file and will install the exact versions of the dependencies and subdependencies defined in npm-shrinkwrap.json. If you want to update dependencies, you must run npm install --save <module name>@<version> in order to update both package.json and npm-shrinkwrap.json. (<module name> is the name of the dependency module you want to update. For example, dce-paella-extensions.)

player-router handles URL hash-based routing. app-src/index.js is the module within paella-matterhorn that handles webapp functionality external to Paella.

Running locally (Development)

Globally install Grunt and Jshinit:

• Run npm install -g grunt-cli jshint or sudo npm install -g grunt-cli jshint if you cannot write to your global node_modules directory.

Locally install the project dependencies:

• Run npm install

Build the files:

• Run grunt build

If you want to run paella-matterhorn locally without deploying it as a jar within matterhorn (and matterhorn.dce.harvard.edu is currently OK):

• vi test-server.js // change the proxy to your locally running dev matterhorn server
• Run make run-test-server

This will create a server that will serve local copies of files under build/ and will serve a canned episode.json and me.json, but will proxy everything else (like series information) to matterhorn.dce.harvard.edu.

To play a video in the test server, take a URL from production (matterhorn.dce.harvard.edu) and replace the host with localhost:3000. Make sure you use the https protocol.

If you want to run it under http instead of https, you can run the test server with node test-server.js --use-http.

To avoid having to run npm publish and npm install in the dce-paella-extensions local repo, just to see if a change worked in the context of paella-matterhorn, you can:

• From your local dce-paella-extensions project directory, Run npm link (with sudo if your global node_modules is in a place that requires it).
• Run npm link dce-paella-extensions in this directory. Now there will be a symlink-like link to your local dce-paella-extensions project.
• Then, run grunt build.debug in this directory to rebuild the project.

Tests

To run parent frame communcation and player router tests, do:

npm install
vi test-server.js // to point to your locally running matterhorn server
make test-chrome
make test-firefox

This should run the tests in Chrome and Firefox respectively, and in your terminal, you should see the test results.

Much of the code in paella and paella-matterhorn are not covered by tests, so you do need to run locally and poke around to at least make sure you didn't break anything obvious when you make a change.

Non-Paella parts of the project

In app-src, there are modules that get built into app-index.js via Browserify. app-index.js gets pulled into the web page at paella-matterhorn/ui/watch.html.

These modules are Node-style modules that have these basic characteristics:

• All of the code in a module is wrapped in its own JavaScript scope.

• Modules can import other modules with require statements. e.g. In app-src/index.js –

  var setUpParentFrameCommunications = require('./set-up-parent-frame-communications');

Imports a function from the set-up-parent-frame-communications.js module into the index module.

• Properties assigned to modules.exports are available to external modules that require the module.

The app-src/index.js has a function that immediately executes when it's loaded. It is named go.

((function go() {
  setUpParentFrameCommunications(document);
  disableAutoHiding();
  clearDoneUrlCookie();
  router.route();
})());

These are entry points into the four things that the modules in app-src currently do:

• It sets up communications with parent frames. When the player is loaded in an iframe, the player can A) respond to play messages from the parent window and B) can send time update messages to a parent window. Here's an example of that in action.

• Disables auto-hiding of the play controls after the player idles. DCE support and Rebecca Nesson do not find this to be a desirable behavior for students actively watching lectures and taking notes and backing up and rewatching segments. However, it is a core feature of Paella that cannot be disabled via config. Hence, we assign a no-op to paella.player.controls.restartHideTimer.

• If it exists, it clears a cookie named done_url in order to prevent certain authentication problems. I forget specifically which, but Naomi Maekawa will probably remember if you ask her.

• Runs the DCE player-router in order to process the URL and respond to seek requests that are the result of URL changes from either the user or a parent window.

============================ The following are the original UPV Paella Player README

Paella Player for Opencast

This is the Paella player for opencast bundle.

Paella Player

The Paella (pronounce “paeja”) Player is a HTML5 multistream video player capable of playing multiple audio & video streams synchronously and supporting a number of user plugins. It is specially designed for lecture recordings, like Matterhorn Lectures or Polimedia pills.

By using Paella students can view both the lecture hall and the teacher's screen, get info about the lecture (slides, OCR, series videos, footprints) and interact with the lecture (views, comments). Teachers can also soft edit the lecture to set the start and end point or make breaks in the recording.

If you want to use Paella player, but does not have a Matterhorn installation, you can use the standalone version of paella.

Main characteristics

• Multi stream video player
• Based in HTML5 and Javascript
• Resize position/size of video windows while playing
• Play/Pause/30 seconds back controls
• Jump anywhere in the video keeping both tracks in sync
• Jump by clicking on the slide list
• High quality slides while seeking
• Can handle progressive download, pseudostreaming and RTMP streaming servers
• Support of .flv and .mp4 files
• Easily change the relative position of presenter and presentation windows
• Native Fullscreen version
• Embeddable
• “Publish to” buttons for Facebook and Twitter
• Captions support
• Comments (experimental)
• Easy skinning
• Easy install
• Soft Editing features: Trimming and breaks
• Support of Chrome, Firefox, Safari and Internet Explorer 9 an 10 browsers
• Compatible with Opencast Matterhorn 1.4

Build and Install

To build Paella Player for Opencast, please read the documentation.