Webcasting to tablets and phones

Frank Carmona Control-Room (Live Production), Encoding, HTTP Streaming, Mobile

webcaStudio HLS compatible webcasts



WebcaStudio can stream live and on-demand presentations to PC, MAC, and Linux and now also to HLS compatible devices.

HLS stands for Http Live Streaming, and is Apple’s proprietary version of a HTTP streaming protocol. HLS became a temporary de-facto standard whilst open initiatives for a standard HTTP protocol were still under development.  In future webcaStudio versions the video player will be compatible with different HTTP streaming protocols too.

HLS compatible devices are iPAD and some Android devices. In the case of the latter ones the functionality is not always optimal for live events whilst they normally work fine with on-demand contents.

In the case of iPhones the choice of the webcaStudio platform is to stream Audio and Slides.


Setting up your account for HLS

In order to enable HLS streaming in webcaStudio you have to contact Vancast and we will upgrade your account and webcast templates for this purpose.


Operating HLS compatible events

Once your account has been upgraded, you will notice several changes in the user interface:

  1. Event Management > Edit > Contents >   …. In this page you will find a new content item named “slideshowshtml5”. An explanation on how this works is decribed below in this document.
  2. When accessing the “ControlRoom” to manage a live event you will be asked whether you want your event to be compatible for iOS devices or not. In the case where you tick the checkbox you will be prompted to select two different bitrate qualities for your video and audio streams. Never use a higher bitrate than the one you will choose on the RTMP encoder later.
  3. On the main event management page you will find a new menu item called “transcoders”, where you can monitor your transcoders.


Managing Slides for HLS compatible devices

CASE 1: Using JPEG files for the slides

This case is compatible with HLS directly.

CASE 2: Using SWF converted powerpoints

In the case where you use powerpoints converted to SWF files using iSpring you must use the “slideshowshtml5” content item to upload a .jpg version of the slides suitable for HLS compatible devices.

The procedure is:

  1. Upload an SWF file to the “slideshows” content tab, then a new folder with the exact same name of the uploaded file will be automatically created in the equivalent location under the “slideshowshtml5” contents tab.


  1. Then, upload a jpg group of slides into that folder. This can be done using the “save as” option in powerpoint. Remember to tick the “Rename PowerPoint produced JPG “ check box in order to correctly organize the numbering of the slides. [powerpoint will create the files like slide1, slide2, … slide11, slide12. and you need them to be slide001, slide002…slide011, slide012…in order to work fine in webcaStudio]


Publishing your content in order to create an On-demand version

Two things must be considered:

1.- You must upload the video file in .mp4 format.

If, as an outcome of a live event, you have a .f4v recorded version of your video you must convert it to .mp4 format:

In order to convert your video to mp4 you can use ffmpeg software:

Find below two sample scripts using ffmpeg:

ffmpeg.exe -i input.f4v -c copy -moveflags faststart output.mp4

This script only performs transmuxing (no transcoding)

ffmpeg.exe -i input.f4v -b:v 400k -ss  00:10:50 -moveflags faststart output.mp4

This script forces transcoding the video to a bitrate of 400kbps and also cuts 10 minutes and 50 seconds from the input video

2.- When your live event was streamed in different languages simultaneously

In case you have an event in more than one language that used the left & right audio tracks of a single channel to stream those different languages live, you must convert your original video twice, one for each language. If you’re in this situation please request specific support from Vancast. We will teach you how to do this.