Slice level intra block copy and other video coding improvements

1. A method for decoding video data, the method comprising:

receiving a first slice of a current picture of the video data;

receiving a syntax element indicating a number of reference pictures in a reference picture list for the first slice of the video data;

determining that an intra block copy (IBC) mode is enabled for the first slice; and

determining that the number of reference pictures in the reference picture list is equal to 1:

determining that information associated with modification of the reference picture list is not signaled in the video data;

responsive to the number of reference pictures in the reference picture list being equal to 1, the determination that the IBC mode is enabled for the first slice, and the determination that information associated with modification of the reference picture list is not signaled in the video data, adding the current picture comprising the first slice to the reference picture list during construction of the reference picture list.

2. The method of claim 1 , further comprising:

responsive to the determination that the number of reference pictures in the reference picture list is the value equal to 1, adding the current picture comprising the first slice as a first entry in the reference picture list.

3. The method of claim 1 , further comprising:

receiving a second slice of a current picture of the video data;

parsing an IBC syntax element to determine that an IBC mode is enabled for the second slice;

parsing a slice type syntax element associated with the second slice to determine that the second slice is an I slice;

decoding the second slice as an I slice, wherein decoding the second slice as an I slice comprises decoding all blocks of the second slice using at least one intra prediction coding mode,

wherein the IBC syntax element comprises a curr_pic_as_ref_enabled_flag syntax element, and wherein parsing the IBC syntax element to determine that the IBC mode is enabled for the second slice comprises determining the value of the curr_pic_as_ref_enabled_flag syntax element is equal to 1.

4. The method of claim 3 , wherein decoding the second slice as an I slice comprises decoding blocks of the second slice using only intra prediction.

5. The method of claim 3 , wherein decoding the second slice as an I slice comprises decoding blocks of the second slice without using an inter prediction mode and without using the IBC mode.

6. The method of claim 3 , wherein the slice type syntax element comprises a slice_type syntax element, and wherein parsing the slice type syntax element associated with the second slice to determine the second slice is an I slice comprises determining the value of the slice_type syntax element is equal to 2.

7. A device for decoding video data, the device comprising:

a memory configured to store the video data; and

one or more processors configured to:

receive a first slice of a current picture of the video data;

receive a syntax element indicating a number of reference pictures in a reference picture list for the first slice of the video data;

determine that an intra block copy (IBC) mode is enabled for the first slice;

determine that the number of reference pictures in the reference picture list is equal to 1;

determine that information associated with modification of the reference picture list is not signaled in the video data; and

responsive to the number of reference pictures in the reference picture list being equal to 1, the determination that the IBC mode is enabled for the first slice, and the determination that information associated with modification of the reference picture list is not signaled in the video data, add the current picture comprising the first slice to the reference picture list during construction of the reference picture list.

8. The device of claim 7 , wherein the one or more processors are further configured to:

responsive to the determination that the number of reference pictures in the reference picture list is the value equal to 1, add the current picture comprising the first slice as a first entry in the reference picture list.

9. The device of claim 7 , wherein the one or more processors are further configured to:

receive a second slice of a current picture of the video data;

parse an IBC syntax element to determine that an IBC mode is enabled for the second slice;

parse a slice type syntax element associated with the second slice to determine that the second slice is an I slice;

decode the second slice as an I slice, wherein to decode the second slice as an I slice, the one or more processors are further configured to decode all blocks of the second slice using at least one intra prediction coding mode,

wherein the IBC syntax element comprises a curr_pic_as_ref_enabled_flag syntax element, and wherein to parse the IBC syntax element to determine that the IBC mode is enabled for the second slice, the one or more processors are further configured to determine the value of the curr_pic_as_ref_enabled_flag syntax element is equal to 1.

10. The device of claim 9 , wherein to decode the second slice as an I slice, the one or more processors are further configured to decode blocks of the second slice using only intra prediction.

11. The device of claim 9 , wherein to decodes the second slice as an I slice, the one or more processors are further configured to decode blocks of the second slice without using an inter prediction mode and without using the IBC mode.

12. The device of claim 9 , wherein the slice type syntax element comprises a slice_type syntax element, and wherein to parse the slice type syntax element associated with the second slice to determine the second slice is an I slice, the one or more processors are further configured to determine the value of the slice_type syntax element is equal to 2.

13. The device of claim 7 , wherein the device comprises at least one of:

an integrated circuit;

a microprocessor; or

a wireless communication device that comprises a receiver configured to receive encoded video data.

14. An apparatus for decoding video data, the apparatus comprising:

means for receiving a first slice of a current picture of the video data;

means for receiving a syntax element indicating a number of reference pictures in a reference picture list for the first slice of the video data;

means for determining that an intra block copy (IBC) mode is enabled for the first slice;

means for determining that the number of reference pictures in the reference picture list is equal to 1;

means for determining that information associated with modification of the reference picture list is not signaled in the video data; and

means for adding the current picture comprising the slice to the reference picture list during construction of the reference picture list responsive to the number of reference pictures in the reference picture list being equal to 1, the determination that the IBC mode is enabled for the first slice, and the determination that information associated with modification of the reference picture list is not signaled in the video data.

15. The apparatus of claim 14 , further comprising:

responsive to the determination that the number of reference pictures in the reference picture list is the value equal to 1, means for adding the current picture comprising the first slice as a first entry in the reference picture list.

16. The apparatus of claim 14 , further comprising:

means for receiving a second slice of a current picture of the video data;

means for parsing an IBC syntax element to determine that an IBC mode is enabled for the second slice;

means for parsing a slice type syntax element associated with the second slice to determine that the second slice is an I slice;

means for decoding the second slice as an I slice, wherein the means for decoding the second slice as an I slice comprises means for decoding all blocks of the second slice using at least one intra prediction coding mode,

wherein the IBC syntax element comprises a curr_pic_as_ref_enabled_flag syntax element, and wherein the means for parsing the IBC syntax element to determine that the IBC mode is enabled for the second slice comprises means for determining the value of the curr_pic_as_ref_enabled_flag syntax element is equal to 1.

17. A non-transitory, computer readable storage medium storing instructions that when executed by one or more processors cause the one or more processors to:

receive a first slice of a current picture of the video data;

receive a syntax element indicating a number of reference pictures in a reference picture list for the first slice of the video data;

determine that an intra block copy (IBC) mode is enabled for the first slice;

determine that the number of reference pictures in the reference picture list is equal to 1;

determine that information associated with modification of the reference picture list is not signaled in the video data; and

responsive to the number of reference pictures in the reference picture list being equal to 1, the determination that the IBC mode is enabled for the first slice, and the determination that information associated with modification of the reference picture list is not signaled in the video data, add the current picture comprising the first slice to the reference picture list during construction of the reference picture list.

18. The non-transitory, computer readable storage medium of claim 17 , further storing instructions that when executed by one or more processors cause the one or more processors to:

responsive to the determination that the number of reference pictures in the reference picture list is the value equal to 1, add the current picture comprising the first slice as a first entry in the reference picture list.

19. The non-transitory, computer readable storage medium of claim 17 , further storing instructions that when executed by the one or more processors cause the one or more processors to:

receive a second slice of the video data;

parse an IBC syntax element to determine that an IBC mode is enabled for the second slice;

parse a slice type syntax element associated with the second slice to determine that the second slice is an I slice;

decode the second slice as an I slice, wherein to decode the second slice as an I slice, the one or more processors decode all blocks of the second slice using at least one intra prediction coding mode,

wherein the IBC syntax element comprises a curr_pic_as_ref_enabled_flag syntax element, and wherein to parse the IBC syntax element to determine that the IBC mode is enabled for the second slice, the instructions cause the one or more processors to determine the value of the curr_pic_as_ref_enabled_flag syntax element is equal to 1.