Method for signaling a step-wise temporal sub-layer access sample

1 . A method for encoding a picture, the method comprising:

encoding a step-wise temporal sub-layer access (STSA) sample grouping that allows determining when to switch to a new temporal layer based on the STSA sample grouping,

wherein the STSA sample grouping is a group of STSA samples, the STSA sample grouping comprises a next STSA upswitching distance parameter and a next STSA sample distance parameter, wherein the next STSA upswitching distance parameter is different from the next STSA sample distance parameter, wherein the next STSA sample distance parameter indicates a distance of a next temporal layer switching point in a current temporal layer, wherein the next STSA upswitching distance parameter indicates a distance of a next temporal layer up switching point in a temporal layer higher than the current temporal layer, and wherein a network access layer (NAL) unit type indicates whether a picture is a STSA picture; and

wherein encoding the picture includes a transformation step and quantization step to produce transformed and quantized coefficients.

2 . The method of claim 1 , wherein the group of STSA samples are grouped in a sample group description box (SGPD).

3 . The method of claim 1 , wherein the STSA sample grouping comprises a type temporal switching access (TSA) flag.

4 . The method of claim 3 , wherein the type TSA flag value indicates if a sample in the STSA sample grouping is a TSA sample or a STSA sample.

5 . The method of claim 1 , wherein a STSA picture provides temporal layer switching functionality to a temporal layer to which the STSA picture belongs.

6 . The method of claim 1 , wherein the STSA sample grouping is included in an ISO base media file.

7 . A method of transmitting a bitstream of an encoded picture, wherein the picture has been encoded by:

encoding a bitstream including a step-wise temporal sub-layer access (STSA) sample grouping that allows determining when to switch to a new temporal layer,

wherein the STSA sample grouping is a group of STSA samples, wherein the STSA sample grouping comprises a next STSA upswitching distance parameter and a next STSA sample distance parameter, wherein the next STSA upswitching distance parameter is different from the next STSA sample distance parameter, wherein the next STSA sample distance parameter indicates a distance of a next temporal layer switching point in a current temporal layer, wherein the next STSA upswitching distance parameter indicates a distance of a next temporal layer up switching point in a temporal layer higher than the current temporal layer, and wherein a network access layer (NAL) unit type indicates whether a picture is a STSA picture; and

wherein encoding the picture includes a transformation step and quantization step to produce transformed and quantized coefficients.

8 . The method of claim 7 , wherein the group of STSA samples are grouped in a sample group description box (SGPD).

9 . The method of claim 7 , STSA sample grouping comprises a type temporal switching access (TSA) flag.

10 . The method of claim 9 , wherein the type TSA flag value indicates if a sample in the STSA sample grouping is a TSA sample or a STSA sample.

11 . The method of claim 7 , wherein a STSA picture provides temporal layer switching functionality to a temporal layer to which the STSA picture belongs.

12 . The method of claim 7 , wherein the STSA sample grouping is included in an ISO base media file.

13 . A method for decoding a picture, the method comprising:

receiving an audio-visual bitstream;

obtaining a step-wise temporal sublayer access (STSA) sample grouping;

decoding the STSA sample grouping; and

determining when to switch to a new temporal layer based on the STSA sample grouping, wherein the STSA sample grouping is a group of STSA samples, wherein the STSA sample grouping comprises a next STSA upswitching distance parameter and a next STSA sample distance parameter, wherein the next STSA upswitching distance parameter is different from the next STSA sample distance parameter, wherein the next STSA sample distance parameter indicates a distance of a next temporal layer switching point in a current temporal layer, wherein the next STSA upswitching distance parameter indicates a distance of a next temporal layer up switching point in a temporal layer higher than the current temporal layer, and wherein a network access layer (NAL) unit type indicates whether a picture is a STSA picture; and

wherein decoding the picture includes an inverse quantized and inverse transformation step to produce a decoded residual signal.