Video documents: Difference between revisions

Latest revision as of 15:19, 1 December 2016

This page is in development and will eventually contain information about supporting Video and Audio documents in EPrints.

Related Pages[edit]

Video Transcoding by EPrints/FFMPEG[edit]

Summary of video codec support on browsers: http://videojs.com/html5-video-support/ By default, EPrints performs the following tasks when generating "thumbnails" for videos, using FFMPEG:

generate an image thumbnail
transcode video to ogg container
transcode video to mp4 container

Video Document Integration[edit]

Should the video player be integrated as an iframe embed code, document "preview" link, or embedded directly on the abstract page? Most recent version of EdShare generates a video player directly on the abstract page, rather than a popup "preview" window as in Kultur plugin. It is also possible to embed a video player (typically with an iframe) to stream content from another site, like YouTube and Vimeo.

Video Players[edit]

Depositors can upload video documents. Since EPrints 3.3, there is a flowplayer in EPrints, under /lib/static/. However, EPrints does not embed any video player as a "preview" thumbnail or on the abstract page. To generate a video player for a document in EPrints, the Kultur plugin (http://files.eprints.org/773/) can be used to extend the preview with a video player.

Video.js Integration[edit]

One solution is to integrate video.js with EPrints. Following these instructions: http://videojs.com/getting-started/ Integration involves adding the following to the <head> of the template (globally, in /archives/ARCHIVEID/cfg/lang/LANGID/templates/default.xml)

<link href="http://vjs.zencdn.net/5.11.7/video-js.css" rel="stylesheet"/>
<!-- If you'd like to support IE8 -->
<script src="http://vjs.zencdn.net/ie8/1.1.2/videojs-ie8.min.js"></script>

and the following right before the last closing </body> tag:

<script src="http://vjs.zencdn.net/5.11.7/video.js"></script>

Video player[edit]

Generating the video player can be done in eprint_render.pl, as follows:

#TN - render a video player for video documents
my $type = "";
my $videoDiv = $session->make_element( "div" );
$type = $doc->get_type;		
if ($type eq "video"){
	my $video_preview_image = $doc->thumbnail_url("preview");
	my $videomimetype_1="video/mp4";
	my $video_preview_1 = $doc->thumbnail_url("video_mp4");
	my $videomimetype_2="video/ogg";
	my $video_preview_2 = $doc->thumbnail_url("video_ogg");

	if ($video_preview_1 || $video_preview_2){
   		my $videoDivID = "my-video".$doc->get_id;
		my $videoplayer = $session->make_element( "video", id=>$videoDivID, class=>"video-js", controls=>"", preload=>"auto", poster=>$video_preview_image, 'data-setup'=>"{}" );
		if ($video_preview_1){
			my $source_1 = $session->make_element ("source", src=>$video_preview_1, type=>$videomimetype_1);
			$videoplayer->appendChild( $source_1 );
			}
		if ($video_preview_2){
			my $source_2 = $session->make_element ("source", src=>$video_preview_2, type=>$videomimetype_2);
			$videoplayer->appendChild( $source_2 );
			}
		my $nojsP = $session->make_element ("p", class=>"vjs-no-js");
		my $nojstext = "To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video";
		$nojsP->appendChild( $session->make_text( $nojstext) );
		$videoplayer->appendChild( $nojsP );
		$videoDiv->appendChild($videoplayer);
	}		
}
#$videoDiv now holds the video player, and can be added to the page with appendChild($videoDiv)

Audio player[edit]

Similarly, video-js can be used to render audio player using video-js. Note that audio does not have an image preview, so you can use a default blank image, for example:

#TN - render an audio player for audio documents
my $type = "";
my $audioDiv = $session->make_element( "div" );
$type = $doc->get_type;		
if ($type eq "audio"){
	my $audiomimetype_1="audio/mp4";
	my $audio_preview_1 = $doc->thumbnail_url("audio_mp4");
	my $audiomimetype_2="audio/ogg";
	my $audio_preview_2 = $doc->thumbnail_url("audio_ogg");
        my $audio_preview_image = "/images/default-audio-poster.png";
 
	if ($audio_preview_1 || $audio_preview_2){
   		my $audioDivID = "my-audio".$doc->get_id;
		my $audioplayer = $session->make_element( "audio", id=>$audioDivID, class=>"video-js", controls=>"", preload=>"auto", poster=>$audio_preview_image, 'data-setup'=>"{}" );
		if ($audio_preview_1){
			my $source_1 = $session->make_element ("source", src=>$audio_preview_1, type=>$audiomimetype_1);
			$audioplayer->appendChild( $source_1 );
			}
		if ($audio_preview_2){
			my $source_2 = $session->make_element ("source", src=>$audio_preview_2, type=>$audiomimetype_2);
			$audioplayer->appendChild( $source_2 );
			}
		my $nojsP = $session->make_element ("p", class=>"vjs-no-js");
		my $nojstext = "To view this audio please enable JavaScript, and consider upgrading to a web browser that supports HTML5 audio";
		$nojsP->appendChild( $session->make_text( $nojstext) );
		$audioplayer->appendChild( $nojsP );
		$audioDiv->appendChild($audioplayer);
	}		
}
#$audioDiv now holds the audio player, and can be added to the page with appendChild($audioDiv)

Server Settings[edit]

The following file should contain a path to ffmpeg and ffprobe:

   /opt/eprints3/lib/syscfg.d/executables.pl

ffmpeg should be installed on the server. On some servers (Ubuntu), 'libx264' needs to be installed for the H264 codec.

@@ Line 41: / Line 41: @@
 </source>
-===Video player===
+====Video player====
 Generating the video player can be done in eprint_render.pl, as follows:
@@ Line 78: / Line 78: @@
 </source>
-===Audio player Integration===
+====Audio player====
 Similarly, video-js can be used to render audio player using video-js.  Note that audio does not have an image preview, so you can use a default blank image, for example: