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Compressed Domain Transcoding |
MPEG has emerged as an industry-wide standard for encoding
video. However MPEG streams are not necessarily well suited for
editing, special effects processing or transmission over
networks. JPEG is a possible alternative but this implies MPEG
streams have to be converted to JPEG ie. transcoded, on a
real-time basis. We have investigated techniques for transcoding
both in the spatial domain and the compressed domain resulting in
the implementation of a publicly available software transcoder.
We found the compressed domain approach to be faster and more
flexible and to offer an additional freedom: the ability to
sacrifice quality for speed. This trade-off is useful in many
real-time applications such as off-line editing and video
gateways. Currently, our compressed domain transcoder provides
speedups ranging from 150% to 300% over the spatial domain
approach. We are about a factor or two away from real-time
performance.
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Paper presenting the various transcoding techniques and detailed
results. [Acrobat]
The latest release of the transcoder. [Download]
Funding for the project is provided under contract N00014-95-1-0799 from the DARPA Information Technology Office. Additional support is provided courtesy of Intel, Xerox, Microsoft and Kodak
This research is supported by DARPA (contract N00014-95-1-0799), Intel, Xerox, Microsoft, and Kodak
