VOD Howto

Getting Started

To get started streaming your VOD with ScaleEngine, all you need is video files, an FTP client, and a web browser.

Make sure your files are encoded as h.264 video, with either AAC or MP3 audio. Main or high profile is recommended.

Uploading your Files

You will need an FTP client. We send a setup email when your account is ready. This email contains the specific storage server name where you will upload your content. Login with your ScaleEngine account name and password. Be sure that you upload to the "vod" directory, and make sure the content has completely uploaded before you play anything. If you wait for the file browser to update (about 20 minutes), this will not be an issue for you.

Generating .smil files

If you have multiple renditions of the same VOD asset, you will want to generate a ".smil" file. A smil file contains a list of the different renditions, allowing the player to select between them.

We provide a utility called smilgen that will generate a smil file that you can use in the embed generator. To use smilgen, you need encoded versions of your content with a predictable naming convention. Generally, appending the frame size or bitrate to the end of the filename is best, i.e. file_1080.mp4, file_720.mp4, file_480.mp4, and file_360.mp4.

Log in to your storage account over ssh, cd into your vod directory and run the utility as follows. We have (for example) video_720.mp4 and video_480.mp4

[demo@sestore99 ~/vod]$ smilgen -o video.smil  video*

Using the File Browser

The Control Panel On-Demand File Browser page shows each video file with details.

A double click on any selection takes you to a player page with Embed code.

New content takes about 20 minutes to get indexed. Note that you must rename files that you re-upload. Our caching system will not update files that you have re-uploaded, unless you rename them as well.

Getting your Player

From the embed generator page you can access the file browser and add any indexed item (content or smil manifest) to the embed generator template.

Optimizing your VOD

Normally, for VOD you want long keyframe intervals for higher efficency, but the keyframe frequency also affects how quickly video will start. Video can only start on a keyframe, which contains all the data a player needs to start showing the video to the viewer. For short videos, or cases where it's important not to have long load times (like marketing videos) you may want to experiment with shorter keyframes.

With modern streaming protocols, such as HLS and MPEG-Dash, the user has to fetch an entire chunk before they can start playing video. Chunks can only be split on a keyframe, so if your video is encoded with 2 second keyframes, the viewer will have to load 2 seconds of video before they can start playing.

At the expense of file size, setting a frequent keyframe rate means video starts faster. If you only send a keyframe every 5 seconds, your viewers will have to load a 5 second chunk before video can start; however the resolution will be better at a lower bitrate, as more of the data is available to describe changes in the video. If you send a keyframe every second or two, your start time will improve, but you will need to increase bitrate to have the same quality.