Using videos with multiple audio-tracks

We recently added a learning module to our application, which includes a
collection of short videos. Initial feedback have been positive and
specific videos are being played frequently in the communities. The only
significant limitation is that we only recorded Spanish language audio
initially, while most of the CHWs and people in the communities speak one
of several Mayan languages as their first language.

In previous CommCare applications we used the built-in translations support
to deliver both Spanish and Mayan audio recordings (text is always
displayed in Spanish, the audio file path was the only difference between
the translations). We started running into scalability issues as the
number of Mayan languages increased (e.g. our xforms became very big).

For videos, our preferred design is to produce videos with multiple audio
tracks and only use a single CommCare language translation (ie Spanish).

We created a prototype using MKVToolNix
https://www.bunkus.org/videotools/mkvtoolnix/downloads.html to produce a
multi language Video and the Android VLC player to play it. After
installing VLC, the user is given the option to use it when launching a
video from CommCare. It seems relatively easy to switch between languages
in the VLC player itself, although our testing has been limited so far.

We would be very interested to receive feedback about this general design,
and also about the specific applications are we evaluating (ie. MKVToolsNix
and VLC player).

Thanks, Ray

ยทยทยท -- Ray Brunsting, CTO, Tula Foundation / tula.org