no edit summary
See also: [https://xiph.org/daala/ https://xiph.org/daala/]
== Weekly meetings ==
* 2012 Novemeber 2 - no meeting
* 2012 December 7 - [https://people.xiph.org/~giles/2012/daala_20121207.txt minutes]
= Techniques =
Other components which have been discussed include:
==Techniques applicable to all frame types==
* Using PVQ and energy conservation: see http://jmvalin.ca/video/video_pvq_v3.pdf
==Techniques applicable to inter frames==
** Speculation has been offered that a significant part of MC inaccuracy may be due to blending in a physically incorrect (gamma-corrected) space, though no real conclusions were made. Academic papers on motion compensation accuracy seem to have ignored this issue.
* Timothy has an example code base for a variable partition size blocking-free motion compensation scheme which merges OBMC (overlapped block motion compensation) and CGI (control-grid interpolation) with an interesting prediction/sub-division scheme and whole-frame trellis optimization of motion vectors. (daala-exp)
* Good support for decode side droppable frames?
** Hopefully the referencing structure will be flexible enough to enable this even if it's not an intentional feature.
* Optionally storing a checksum of the expected decoded frame for decoder/encoder mismatch detection.
* Expose the number of referential descendants of a given frame (or even the whole reference DAG) for most efficient allocation of FEC.
** Predict block properties (quantizer, energy, etc.) from MV. (0,0) probably means small delta. Larger MV's may correspond to larger deltas ... although at low shutter speeds large MVs may correlate with reduced overall HF energy.
** Predict delta spectral shape from source block spectral shape. HF/LF ratio of the delta may be correlated with the same ratio in its source blocks. Works well with decode-side fDCT.