Video decoding method and apparatus using the same
A video decoding method according to an embodiment of the present invention may include determining a type of a filter to be applied to a first-layer picture which a second-layer picture as a decoding target refers to; determining a filtering target of the first-layer picture to which the filter is applied; filtering the filtering target based on the type of the filter; and adding the filtered first-layer picture to a second-layer reference picture list. Accordingly, the video decoding method and an apparatus using the same may reduce a prediction error in an upper layer and enhance encoding efficiency.
1. A video decoding method supporting a plurality of layers, the method performed by a video decoding apparatus and comprising:
resampling a picture of a reference layer referenced by a picture of a current layer based on a size of the picture of the current layer;
adding the resampled picture of the reference layer to a reference picture list of the current layer as an inter-layer reference picture;
generating a prediction block of a current picture in the current layer by referencing at least one among a plurality of reference pictures included in the reference picture list; and
generating a reconstructed block of the current picture in the current layer using the prediction block;
wherein when the reference picture list includes a long-term reference picture which belongs to the current layer, the inter-layer reference picture is added to the reference picture list before the long-term reference picture,
wherein the inter-layer reference picture is added to the reference picture list as being marked as a long-term reference picture,
wherein motion information used for the inter prediction is derived by using motion information of at least one of temporal and spatial neighboring blocks of a current block to be decoded, and
wherein the temporal neighboring block is an external block located outside of a block present at a position spatially corresponding to the current block, within a reference picture included in the reference picture list.
2. The video decoding method of claim 1 ,
wherein when the reference picture list includes a short-term reference picture which belongs to the current layer, the inter-layer reference picture is added to the reference picture list after the short-term reference picture.
3. A video encoding method supporting a plurality of layers, the method performed by a video encoding apparatus and comprising:
resampling a picture of a reference layer referenced by a picture of a current layer based on a size of the picture of the current layer;
adding the resampled picture of the reference layer to a reference picture list of the current layer as an inter-layer reference picture;
generating a prediction block of a current picture in the current layer by referencing at least one among a plurality of reference pictures included in the reference picture list; and
generating a reconstructed block of the current picture in the current layer using the prediction block;
wherein when the reference picture list includes a long-term reference picture which belongs to the current layer, the inter-layer reference picture is added to the reference picture list before the long-term reference picture,
wherein the inter-layer reference picture is added to the reference picture list as being marked as a long-term reference picture,
wherein motion information used for the inter prediction is encoded by using motion information of at least one of temporal and spatial neighboring blocks of a current block to be encoded, and
wherein the temporal neighboring block is an external block located outside of a block present at a position spatially corresponding to the current block, within a reference picture included in the reference picture list.
4. The video encoding method of claim 3 ,
wherein when the reference picture list includes a short-term reference picture which belongs to the current layer, the inter-layer reference picture is added to the reference picture list after the short-term reference picture.
5. A non-transitory computer-readable medium storing a bitstream generated by a video encoding method, the video encoding method comprising:
resampling a picture of a reference layer referenced by a picture of a current layer based on a size of the picture of the current layer;
adding the resampled picture of the reference layer to a reference picture list of the current layer as an inter-layer reference picture; generating a prediction block of a current picture in the current layer by referencing at least one among a plurality of reference pictures included in the reference picture list; and
generating a reconstructed block of the current picture in the current layer using the prediction block;
wherein when the reference picture list includes a long-term reference picture which belongs to the current layer, the inter-layer reference picture is added to the reference picture list before the long-term reference picture,
wherein the inter-layer reference picture is added to the reference picture list as being marked as a long-term reference picture,
wherein motion information used for the inter prediction is encoded by using motion information of at least one of temporal and spatial neighboring blocks of a current block to be encoded, and
wherein the temporal neighboring block is an external block located outside of a block present at a position spatially corresponding to the current block, within a reference picture included in the reference picture list.