Implementation of a Vorbis/Theora transcoder for Multiple Description Coding

[vicente-gonzalez-ruiz]

Multiple Description Coding (MDC) is a coding technique that can improve real-time communications in variable-bandwidth transmission contexts. On the other hand, the Multi-Channel Set (MCS) can be used to receive more than one stream simultaneously.

In this scenario, an forward MDC transcoder would input an OGG stream and output so many OGG streams as descriptions. A good starting point can subsample the images using a simple pattern:

+---+---+
| a | b |
+---+---+
| c | d |
+---+---+

if a, b, c and d are neighbor pixels of an image, description (images) A would be formed only by the pixels a, description B only by b pixels and so on.

The inverse MDC transcoder would compose the original resolution of the video using one or more descriptions (missing descriptions should be interpolated).