Starting from CourseLab build 130908 audio/video support is re-written to improve playing on iOS/Android devices and modern browsers. There are some limitations and recommendations (based on our experiments).

Audio limitations

iPad/Android (Safari/Chrome/Dolphin/Yandex and Android "The Browser")

1. Audio/video autoplay in most browsers is disabled by default (to prevent user from downloading large files without explicit permission). To allow autoplay user must explicitly click once on audio/video control or corresponding button - next files can be started according to Autoplay attribute.
2. Only one audio file at the time can be played (seems to be changed in newest iOS/Android versions, but it is not the feature to rely on).
3. WAV files cannot be played.

Addition: iOS seems to have the limitation on high MP3 bitrates in browser (in our test 160kbps was the highest played bitrate).

Firefox/Opera on different platforms

Cannot play MP3 (!) due to license limitations, play OGG files instead. Though there are reports that newest Firefox/Opera have support for MP3 we did not succeed in our tests. Firefox on Android has some troubles playing audio, therefore we do not recommend using this combination tfor playing courses with audio.

MIME type

In any case LMS web-server must provide correct audio/video MIME type in response header - otherwise most browsers will ignore this file (exception is Chrome for Windows, which relies on extension more than MIME).

Audio recommendations

1. To allow audio to be played on most platforms/browsers it is recommended to use MP3 as basic format (no more than 160kbps, 44100Hz or less recommended).
2. If Firefox/Opera support is important there is workaround code starting from build 130908 to allow MP3 file to be replaced with OGG file with exactly the same filename (but .ogg extension). I.e. if main MP3 is named sound1.mp3, then fallback OGG file must be sound1.ogg. To add this file into course package please use new Additional files object (from External group). Please note, that there is a lot of free and commercial MP3/OGG converters (apllications and online).
3. Warning. Since audio/video autoplay is disabled by default for web-content on iOS/Android, there will be dialog displayed before modiule starts requesting from user to click on Continue button. After user click this button all next audio can be autostarted. This dialog will be displayed if there is at least one MP3 file in the module.

Please make sure that your LMS web-server provides correct MIME types:

• MP3 - audio/mpeg
• OGG - audio/ogg
• WEBM - audio/webm

Video recommendations

To allow video to be played on most platforms/browsers it is recommended to use MPEG-4 (.mp4). This format is supported on iOS/Android browsers as wel as most desktop browsers (old IE will use Windows Media Player instead). Support for native browser video starts from 130908 build.

Please make sure that your LMS web-server provides correct MIME types: MP4 - video/mp4

Short summary

• Audio: MP3 up to 160kbps + OGG with the same name for Firefox/Opera fallback
• Video: MP4
• Web-server: correct MIME type required for MP3/OGG/MP4