Table of Contents
Video Content Status
The following are the details of present video formats and details across the app.
| Location | Format | Resolution | BitRate(Max.) | Playback Method | |
|---|---|---|---|---|---|
| My learning - Course Player | mp4 | 900×506 | 640kbps | Flash streaming | This fallsback to 640×680 and 512kbps video if no 900×506 video present |
| FileBox Player | mp4 | 640×480 | 512kbps | Flash streaming | |
| Content Creation/content picker | mp4 | 640×480 | 512kbps | Flash streaming | |
| Blog | mp4 | 640×480 | 512kbps | Flash streaming | |
| Homepage | mp4 | 576×324 | 512kbps | Flash streaming | |
| Ipad(Whole app except homepage) | mp4(HLS) | 640×480 | 512kbps | HTTP Live streaming | |
| Ipad(homepage) | mp4(HLS) | 576×324 | 512kbps | HTTP Live streaming |
Note -
- all the videos are resized keeping the aspect ratio. Which means the video with is changed to the targetted width and target height is computed without changing the aspect ratio of the video.
- All the videos play with progressive download when streaming does not work.
Bit Rate calculation and importance
Bit rate is decided based on some trials on multiple videos and also following some suggestions on the web. 640kbs is actually very near to HD 720p and provides a very good quality of the video on course player. 640kbps is reasonable considering the average internet speeds across the world. If we go with too high bandwidth there is a risk of loosing the smooth streaming experience for users with low network speeds.
Apart from course player, remaining places have videos with max bandwidth of 512 kbps which seems to be very much fine so far for us.
References
http://www.longtailvideo.com/support/jw-player/28838/mp4-video-encoding/
http://www.adobe.com/devnet/adobe-media-server/articles/dynstream_live/popup.html
Future Work
1) Right now course player is 16:9 but content player and etc. are 4:3 in terms of widthxheight ratio. This can be standardized to 4:3. How ever this is not going to be a major concern for us as we always resize videos keeping the aspect ratio.
2) For course player, implement adaptive streaming or HD plugin for jwplayer 5. As we anyway have 512kbps and 640kbps videos for course player, this helps to address low bandwidth users and users seeking HD videos both.
Adaptive streaming - This automatically detects user's bandwidth and plays the videos which suit the quality. But this is not supported with red5/jwplayer combination.
HD Plugin - This is an option for the user to turn HD video on or off himself. Also when user switches to video automatically higher bit rate video is smoothly played.
(Ex - http://www.longtailvideo.com/support/jw-player/28838/mp4-video-encoding/ This needs to be figured out for jwplayer5)
