Method and device for processing video signal by using inter prediction
Embodiments of the disclosure provide methods and devices for decoding video signals using inter prediction. According to an embodiment of the disclosure, a method for processing a video signal comprises constructing a reference picture list of a current picture in the video signal and performing a prediction for a current picture by using the reference picture list, wherein constructing the reference picture list comprising, if a first entry of the reference picture list corresponds to a short-term reference picture (STRP), obtaining a picture order count (POC) difference between a picture related to the first entry and another picture, and if a second entry of the reference picture list corresponds to a long-term reference picture (LTRP), obtaining a POC modulo value of a picture related to the second entry. A reference picture list for identifying a picture may be generated in a simplified and effective manner. Thus, the compression performance may be increased, and the computation time may be decreased.
1. A method for decoding a video signal by a device using an inter prediction, comprising:
constructing a reference picture list of a current picture in the video signal; and
performing a prediction for the current picture based on the reference picture list,
wherein constructing the reference picture list comprises:
obtaining a number of entries of the reference picture list; and
performing a reference picture marking for each of entries of the reference picture list as a short-term reference picture (STRP) or a long-term reference picture (LTRP) by the number of entries,
wherein performing the reference picture marking comprises:
based on that a first entry of the reference picture list corresponds to the STRP, obtaining a picture order count (POC) difference between a reference picture related to the first entry and another picture; and
based on that a second entry of the reference picture list corresponds to the LTRP, obtaining a POC modulo value of a picture related to the second entry, and
wherein the number of entries has a maximum value as a maximum required size of a decoded picture buffer plus 14.
2. The method of claim 1 ,
wherein performing the reference picture marking comprises:
obtaining a number of STRP entries and LTRP entries; and
performing a STRP marking by the number of STRP entries, and performing a LTRP marking by the number of LTRP entries.
3. The method of claim 1 ,
wherein constructing the reference picture list comprises:
obtaining a first flag indicating whether an entry of the reference picture list corresponds to the STRP entry; and
determining whether the entry of the reference picture list corresponds to a STRP entry or a LTRP entry based on the first flag.
4. The method of claim 1 ,
wherein the POC difference is an absolute value of a POC of the another picture minus a POC of the reference picture related to the first entry.
5. The method of claim 4 ,
wherein constructing the reference picture list comprises:
based on that the absolute value is greater than 0, obtaining a second flag indicating a sign of the POC difference.
6. A method for encoding a video signal by a device using an inter prediction, comprising:
constructing a reference picture list of a current picture in the video signal; and
encoding code information for constructing the reference picture list,
wherein the code information for constructing the reference picture list comprises a picture order count (POC) difference between a reference picture related to a first entry and another picture in the reference picture list, and a POC modulo of a picture related to a second entry in the reference picture list,
wherein the code information for constructing the reference picture list further comprises a number of entries of the reference picture list, and
wherein the number of entries has a maximum value as a maximum required size of a decoded picture buffer plus 14.
7. The method of claim 6 ,
wherein the code information for constructing the reference picture list further comprises a first flag indicating whether an entry of the reference picture list corresponds to a short-term reference picture (STRP) entry.
8. The method of claim 6 ,
wherein the code information for constructing the reference picture list further comprises a second flag indicating a sign of the POC difference for an entry of which the POC difference is greater than 0.
9. The method of claim 6 ,
wherein the code information for constructing the reference picture list is included in a sequence parameter set (SPS), picture parameter set (PPS), or slice header in a bitstream related to the video signal.
10. An apparatus for decoding the video signal, comprising:
a memory for storing the video signal; and
a processor couple to the memory,
wherein the processor is configured to:
construct a reference picture list of a current picture in the video signal; and
perform a prediction for the current picture based on the reference picture list,
wherein, for constructing the reference picture list, the processor is configured to:
obtain a number of entries of the reference picture list; and
perform a reference picture marking for each of entries of the reference picture list as a short-term reference picture (STRP) or a long-term reference picture (LTRP) by the number of entries,
wherein, for performing the reference picture marking, the processor is configured to:
based on that a first entry of the reference picture list corresponds to the STRP, obtain a picture order count (POC) difference between a reference picture related to the first entry and another picture; and
based on that a second entry of the reference picture list corresponds to the LTRP, obtain a POC modulo value of a reference picture related to the second entry, and
wherein the number of entries has a maximum value as a maximum required size of a decoded picture buffer plus 14.
11. A non-transitory computer-readable medium for storing one or more instructions, the one or more instructions executable by one or more processors to control the video signal processing device to:
construct a reference picture list of a current picture in the video signal; and
perform a prediction for the current picture based on the reference picture list,
wherein, for constructing the reference picture list, the one or more instructions executable by the one or more processors control the video signal processing device to:
obtain a number of entries of the reference picture list; and
perform a reference picture marking for each of entries of the reference picture list as a short-term reference picture (STRP) or a long-term reference picture (LTRP) by the number of entries,
wherein for performing the reference picture marking, the one or more instructions executable by the one or more processors control the video signal processing device to:
based on that a first entry of the reference picture list corresponds to the STRP, obtain a picture order count (POC) difference between a picture related to the first entry and another picture; and
based on that a second entry of the reference picture list corresponds to the LTRP, obtain a POC modulo value of a picture related to the second entry.
12. The method of claim 1 ,
wherein another picture is the current picture based on that the first entry is a first STRP in the reference picture marking, or another picture is a previous STRP in the reference picture list based on that the first entry is not the first STRP in the reference picture marking.
13. The method of claim 6 ,
wherein another picture is the current picture based on that the first entry is a first STRP in the coding information, or another picture is a previous STRP in the reference picture list based on that the first entry is not the first STRP in the coding information.
14. The apparatus of claim 10 ,
wherein another picture is the current picture based on that the first entry is a first STRP in the reference picture marking, or another picture is a previous STRP in the reference picture list based on that the first entry is not the first STRP in the reference picture marking.
15. The medium of claim 11 ,
wherein another picture is the current picture based on that the first entry is a first STRP in the reference picture marking, or another picture is a previous STRP in the reference picture list based on that the first entry is not the first STRP in the reference picture marking.