Spatial scalability support in video encoding and decoding

A device for decoding multi-layer video data, the device comprising:

• a memory configured to store the multi-layer video data;
• and
• one or more processors implemented in circuitry and configured to:
• obtain the multi-layer video data, wherein the multi-layer video data comprises at least a first layer, a second layer, and a third layer;
• determine a layer identification value for the first layer and a layer identification value for the second layer, wherein the layer identification value for the second layer is higher than the layer identification value for the first layer;
• determine a layer identification value for the third layer, wherein the layer identification value for the third layer is higher than the layer identification value for the second layer;
• store decoded pictures of the first layer, decoded pictures of the second layer, and decoded pictures of the third layer in a decoded picture buffer;
• in response to determining that an instantaneous decoding refresh (IDR) picture belongs to the second layer, remove from the decoded picture buffer, all decoded pictures of the second layer and all decoded pictures of the third layer while leaving in the decoded picture buffer all decoded pictures of the first layer;
• and
• after removing from the decoded picture buffer all of the decoded pictures of the second layer and all of the decoded pictures of the third layer, retrieve a copy of a decoded picture of the first layer to predict a block of a current picture of the multi-layer video data.

A computer-readable storage medium storing instructions that when executed by one or more processors cause the one or more processor to:

• obtain the multi-layer video data, wherein the multi-layer video data comprises at least a first layer, a second layer, and a third layer;
• determine a layer identification value for the first layer and a layer identification value for the second layer, wherein the layer identification value for the second layer is higher than the layer identification value for the first layer;
• determine a layer identification value for the third layer, wherein the layer identification value for the third layer is higher than the layer identification value for the second layer;
• store decoded pictures of the first layer, decoded pictures of the second layer, and decoded pictures of the third layer in a decoded picture buffer;
• in response to determining that an instantaneous decoding refresh (IDR) picture belongs to the second layer, remove from the decoded picture buffer, all decoded pictures of the second layer and all decoded pictures of the third layer while leaving in the decoded picture buffer all decoded pictures of the first layer;
• and
• after removing from the decoded picture buffer all of the decoded pictures of the second layer and all of the decoded pictures of the third layer, retrieve a copy of a decoded picture of the first layer to predict a block of a current picture of the multi-layer video data.

An apparatus for decoding multi-layer video data, the apparatus comprising:

• means for obtaining the multi-layer video data, wherein the multi-layer video data comprises at least a first layer, a second layer, and a third layer;
• means for determining a layer identification value for the first layer and a layer identification value for the second layer, wherein the layer identification value for the second layer is higher than the layer identification value for the first layer;
• means for determining a layer identification value for the third layer, wherein the layer identification value for the third layer is higher than the layer identification value for the second layer;
• means for storing decoded pictures of the first layer, decoded pictures of the second layer, and decoded pictures of the third layer in a decoded picture buffer;
• means for removing from the decoded picture buffer, all decoded pictures of the second layer and all decoded pictures of the third layer while leaving in the decoded picture buffer all decoded pictures of the first layer in response to determining that an instantaneous decoding refresh (IDR) picture belongs to the second layer;
• and
• means for retrieving a copy of a decoded picture of the first layer to predict a block of a current picture of the multi-layer video data after removing from the decoded picture buffer all of the decoded pictures of the second layer and all of the decoded pictures of the third layer.