Re-sampling with phase offset adjustment for luma and chroma to select filters in scalable video coding

A system for coding scalable video with a base layer and an enhancement layer having a higher resolution than the base layer, the system comprising:

• (a) an upsampling unit receiving base layer samples as an input to an upsampling process, so as to enable more efficient coding of the enhancement layer, wherein the upsampling unit is capable of:
• (b) selecting input base layer samples;
• (c) filtering the selected input base layer samples prior to upsampling using an automatically selected set of at least one filter chosen from a plurality of available filters;
• (d) wherein an input to an encoder for the base layer is downsampled from a full resolution signal, wherein a first phase offset is generated to select at least one of the filters used in the upsampling process, and
• (e) wherein at least one of a luma phase offset and a chroma phase offset in downsampling is used to determine the first phase offset;
• (f) further comprising only one selected from:
• (i) wherein the luma phase offset and the chroma phase offset are determined only for column filtering and not determined based upon row filtering;
• (ii) wherein the luma phase offset and the chroma phase offset are determined only for row filtering and not determined based upon column filtering.