Layer characteristic signaling in multi-layered coding
A signaling of at least one characteristic for layers of a multi-layered video signal such as, for example, for each layer the indication of dependent layers to which the respective layer directly relates via inter-layer prediction, or the signaling of the afore-mentioned second inter-dependency syntax structure, is described. A maximum syntax element is signaled within the multi-layered video signal to indicate a maximally used value of an extension layer-ID field of the packets of the multi-layered video signal, the scope of the maximum syntax element being, for example, a predetermined portion of the multi-layered video signal extending, for example, across several portions of the multi-layered video signal. Accordingly, it is feasible for devices such as decoders or network elements receiving the multi-layered video signal to gain, for a relatively large predetermined portion of the multi-layered video signal, knowledge about the actually consumed portion of the possible domain of possible values.
1. A device comprising:
a video encoder configured to encode a video into a multi-layered video signal based on inter-layer prediction, wherein the multi-layered video signal includes information representing prediction residual and is composed of a sequence of packets each of which comprises a layer identification syntax element structure composed of a base layer-ID field and an extension layer-ID field; and
a layer identification extender configured to:
insert, for a predetermined portion of the multi-layered video signal comprising a plurality of packets, a maximum syntax element into the multi-layered video signal, the maximum syntax element indicating a maximum value of the extension layer-ID field of the plurality of packets, determine a maximum number of layers within the predetermined portion of the multi-layered video signal based on the maximum value of the extension layer-ID field, and determine at least one characteristic for each of the maximum number of layers based on a layer characterizing syntax portion of the multi-layered video signal, wherein the video encoder is configured to encode the video into the multi-layered video signal based on the layer characterizing syntax portion.
2. The device according to claim 1 , wherein the multi-layered video signal has the video material coded thereinto as multiple different layers using inter-layer prediction such that any layer inter-layer predicted from another layer adds one or more of:
further views;
depth information;
alpha blending information;
color component information;
spatial resolution refinement; and
SNR resolution refinement.
3. The device according to claim 1 , wherein the packets include data representing at least one of NAL units, slices, tiles and pictures, and the predetermined portion represents a coded video sequence, or a group of pictures.
4. The device according to claim 1 , wherein the layer identification extender is configured to derive a bit length of the extension layer-ID field using the maximum value of the extension layer-ID field.
5. The device according to claim 4 , wherein the layer identification extender is configured to derive the bit length of the extension layer-ID field by rounding up the logarithm to base 2 of the maximum value of the extension layer-ID field.
6. The device according to claim 1 , wherein the characteristic of a layer of the maximum number of layers relates to an inter-layer prediction dependency of that layer to any other of the maximum number of layers.
7. The device according to claim 1 , wherein the layer identification extender is configured to acquire a bit length of the extension layer-ID field from an explicit signaling in the multi-layered video signal, wherein the maximum syntax element indicates the maximum value of the extension layer-ID field in units of one.
8. The device according to claim 1 , wherein the layer identification extender is configured to determine the layer ID for the respective packet based on the layer identification syntax element structure by concatenating the base layer-ID field and extension layer-ID field.
9. The device according to claim 1 , further comprising a network element configured to discard packets of the multi-layered video signal based on the characteristic determined for each layer.
10. The device according to claim 1 , wherein the extension layer-ID field has a bit length equal to n signaled within the multi-layered video signal, and the maximum syntax element indicates the maximum value of the extension layer-ID field in units smaller than (n−1) 2 .
11. A method comprising:
encoding a video into a multi-layered video signal based on inter-layer prediction, wherein the multi-layered video signal includes information representing prediction residual and is composed of a sequence of packets each of which comprises a layer identification syntax element structure composed of a base layer-ID field and an extension layer-ID field;
inserting, for a predetermined portion of the multi-layered video signal comprising a plurality of packets, a maximum syntax element into the multi-layered video signal, the maximum syntax element indicating a maximum value of the extension layer-ID field of the plurality of packets;
determining a maximum number of layers within the predetermined portion of the multi-layered video signal based on the maximum value of the extension layer-ID field;
determining at least one characteristic for each of the maximum number of layers based on a layer characterizing syntax portion of the multi-layered video signal, wherein encoding the video into the multi-layered video signal is further based on the layer characterizing syntax portion.
12. The method according to claim 11 , wherein the multi-layered video signal has the video material coded thereinto as multiple different layers using inter-layer prediction such that any layer inter-layer predicted from another layer adds one or more of further views;
depth information;
alpha blending information;
color component information;
spatial resolution refinement; and
SNR resolution refinement.
13. The method according to claim 11 , wherein the packets include data representing at least one of NAL units, slices, tiles and pictures, and the predetermined portion represents a coded video sequence or a group of pictures.
14. The method according to claim 11 , further comprising deriving a bit length of the extension layer-ID field using the maximum value of the extension layer-ID field.
15. The method according to claim 11 , further comprising deriving the bit length of the extension layer-ID field by rounding up the logarithm to base 2 of the maximum value of the extension layer-ID field.
16. The method according to claim 11 , wherein the characteristic of a layer of the maximum number of layers relates to an inter-layer prediction dependency of that layer to any other of the maximum number of layers.
17. The method according to claim 11 , further comprising acquiring a bit length of the extension layer-ID field from an explicit signaling in the multi-layered video signal, wherein the maximum syntax element indicates the maximum value of the extension layer-ID field in units of one.
18. The method according to claim 11 , wherein the determining the layer ID for the respective packet based on the layer identification syntax element structure includes concatenating the base layer-ID field and extension layer-ID field.
19. The method according to claim 11 , wherein the extension layer-ID field has a bit length equal to n signaled within the multi-layered video signal, and the maximum syntax element indicates the maximum value of the extension layer-ID field in units smaller than (n−1) 2 .
20. A non-transitory digital storage medium having computer-readable code stored thereon to perform, when said storage medium is run by a computer, a method according to claim 11 .