Re-sampling filters for scalable video coding
A layered video coding method is provided that selects data to upsamples from a base layer (BL) to provide to an enhancement (EL) to improved coding efficiency. The method determines a filter to determine an up-sampled value for a first layer for a video, wherein the filter has a set of coefficient values assigned to the filter. The up-sampled value is determined by applying the set of coefficient values to the plurality of sample values. The method then outputs the up-sampled value for use in coding a second enhancement layer (EL) of a higher resolution than the first layer. The up-sampled values may be for the 6/16 and − 6/16 phase offsets.
1. A method comprising:
determining, by a computing device, a filter to determine an up-sampled value for a first layer for a video, wherein the filter has a set of coefficient values of [−1, 3, −9, 47, 31, −10, 4, −1] assigned to the filter;
determining, by the computing device, the up-sampled value by applying the set of coefficient values of [−1, 3, −9, 47, 31, −10, 4, −1] to the plurality of sample values;
outputting, by the computing device, the up-sampled value for use in coding a second layer of a higher resolution than the first layer,
wherein the filter comprises a first filter, the set of coefficient values comprise a first set of coefficient values, and the up-sampled value comprises a first up-sampled value, the method further comprising:
determining a second filter, wherein the second filter has a second set of coefficient values of [−1, 4, −10, 31, 47, −9, 3, −1] assigned for the second filter;
determining a second up-sampled value by applying the second set of coefficient values of [−1, 4, −10, 31, 47, −9, 3, −1] to the plurality of sample values; and
outputting the second up-sampled value for use in coding the second layer of the higher resolution than the first layer.
2. The method of claim 1 , wherein a phase offset for the first filter is a 6/16 phase offset, and wherein a phase offset for the second filter is a − 6/16 phase offset.
3. The method of claim 1 , further comprising:
communicating information for the set of coefficient values from an encoder to a decoder, the information allowing the decoder to determine the set of coefficient values assigned for the filter.
4. The method of claim 3 , wherein communicating comprises:
communicating a first portion of the set of coefficient values from the encoder to the decoder, wherein the decoder determines a second portion of the set of coefficient values based on the first portion of the set of coefficient values.
5. The method of claim 4 , wherein the set of coefficient values are time reversed.
6. The method of claim 3 , wherein the information comprises a flag indicating a method to use to determine the set of coefficient values.
7. The method of claim 3 , wherein the information comprises differences between the set of coefficient values and another set of coefficient values for a different filter.
8. The method of claim 1 , wherein the up-sampled value is used for encoding the second layer.
9. The method of claim 1 , wherein the up-sampled value is used for decoding the second layer.
10. An apparatus comprising:
one or more computer processors; and
a non-transitory computer-readable storage medium comprising instructions, that when executed, control the one or more computer processors to be configured for:
determining, by a computing device, a first filter to determine an up-sampled value for a first layer for a video, wherein the first filter has a set of coefficient values of [−1, 3, −9, 47, 31, −10, 4, −1] assigned to the first filter;
determining, by the computing device, the up-sampled value by applying the set of coefficient values of [−1, 3, −9, 47, 31, −10, 4, −1] to the plurality of sample values;
outputting, by the computing device, the up-sampled value for use in coding a second layer of a higher resolution than the first layer;
determining, by a computing device, a second filter to determine an upsampled value for the first layer for the video, wherein the second filter has a set of coefficient values of [−1, 4, −10, 31, 47, −9, 3, −1] assigned for the second filter; and
determining, by the computing device, the up-sampled value by applying the set of coefficient values of [−1, 4, −10, 31, 47, −9, 3, −1] to the plurality of sample values; and
outputting, by the computing device, the second up-sampled value for use in coding the second layer of the higher resolution than the first layer.
11. The apparatus of claim 10 , wherein a phase offset for the first filter is a 6/16 phase offset, and wherein a phase offset for the second filter is a − 6/16 phase offset.
12. A method comprising:
determining, by a computing device, a filter to determine an up-sampled value for a first layer for a video, wherein the filter has a set of coefficient values of [−1, 3, −9, 47, 31, −10, 4, −1] assigned to the filter;
determining, by the computing device, the up-sampled value by applying the set of coefficient values of [−1, 3, −9, 47, 31, −10, 4, −1] to the plurality of sample values; and
outputting, by the computing device, the up-sampled value for use in coding a second layer of a higher resolution than the first layer.