GNOME Bugzilla – Bug 519484
User choice of video codec compression algorithms
Last modified: 2008-04-03 14:22:39 UTC
The ability to select between a variety of video compression algorithms is desirable for accessibility. On the user interface, a choice of Video compression methods is offered. This replicates the same functionality as of choosing between the different Audio codecs currently available in Ekiga. Within the same codec family such as h.263+, there may be different compression algorithms such as a Sign Language optimised H.263 encoder, a Football match H.263 profile, etc ... So choosing encoding profiles would result in better quality images for the purpose of the communication. Another example is the stream that would come from a powerpoint presentation. Other requirements include the ability to abstract from standard/base-line codecs limitations such as high resolution pictures and high bandwidths.
There are several ways the user can influence the video transmission: - codec selection - bitrate selection - temporal spacial trade off (i.e. if he/she prefers frame rate or quality), not supported by theora. With these 3 settings, enough generalized freedom to influence video transmission is offered in my opinion. TSTO allows the user to set up a minimum quality, possibly leading to the dropping of frames in order to keep the bitrate limit. Optional features of a specific codec are negotiated automatically with the other endpoint to the best commonly supported set of parameters. The proposed profiles are unfeasible since - they are codec specific (e.g. no adjustable settings exists for theora, etc) - nobody will provide them - enough freedom to adjust video transmission already exists. In case there is the need for parameters for a specific situation I would be happy to give my advice.