Coding least significant bits of picture order count values identifying long-term reference pictures

A video encoding device for encoding video data, the video encoding device comprising:

• means for determining, for a current picture of the video data, a long term reference picture to be used when encoding at least a portion of a current picture of the video data;
• means for determining a number of bits to be used to represent one or more least significant bits of a picture order count value that directly identifies the long-term reference picture;
• specifying, in a bitstream representative of an encoded version of the video data, the one or more least significant bits of the picture order count value using the determined number of bits,
• means for determining whether to specify, in the bitstream, one or more most significant bits of a delta of the picture order count value directly identifying the long-term reference picture and a picture order count value directly identifying the current picture;
• means for specifying, based on the determination of whether to specify the one or more most significant bits, the one or more most significant bits in a slice header of the bitstream;
• and
• means for encoding at least the portion of the current picture using the long-term reference picture.

A non-transitory computer-readable storage medium having stored thereon instructions that, when executed, cause one or more processors of a video encoding device to:

• determine, for a current picture of video data, a long term reference picture to be used when encoding at least a portion of a current picture of the video data;
• determine a number of bits to be used to represent one or more least significant bits of a picture order count value that directly identifies the long-term reference picture;
• specify, in a bitstream representative of an encoded version of the video data, the one or more least significant bits of the picture order count value using the determined number of bits;
• determine whether to specify, in the bitstream, one or more most significant bits of a delta of the picture order count value directly identifying the long-term reference picture and a picture order count value directly identifying the current picture;
• based on the determination of whether to specify the one or more most significant bits, specify the one or more most significant bits in a slice header of the bitstream;
• and
• encode at least the portion of the current picture using the long-term reference picture.

A method of decoding encoded video data, the method comprising:

• determining, for a current picture of the encoded video data, a number of bits used to represent one or more least significant bits of the picture order count value that directly identifies a long-term reference picture to be used when decoding at least a portion of the current picture;
• parsing the determined number of bits from a bitstream representative of the encoded video data, wherein the parsed determined number of bits represents the one or more least significant bits of the picture order count value that directly identifies the long-term reference picture;
• determining whether one or more most significant bits of a delta of the picture order count value directly identifying the long term reference picture and a picture order count value directly identifying the current picture are specified in a slice header of the bitstream;
• based on the determination of whether the one or more most significant bits are specified, parsing the one or more most significant bits from the slice header of the bitstream;
• retrieving the long-term reference picture from a decoded picture buffer based on one or more of the least significant bits and the one or more most significant bits;
• and
• decoding at least the portion of the current picture using the retrieved long-term reference picture.

A video decoding device for decoding encoded video data, the video decoding device comprising:

• a memory configured to store a current picture of the encoded video data;
• and
• one or more processors configured to determine, for the current picture, a number of bits used to represent one or more least significant bits of the picture order count value that directly identifies a long-term reference picture to be used when decoding at least a portion of the current picture, parse the determined number of bits from a bitstream representative of the encoded video data, wherein the parsed determined number of bits represents the one or more least significant bits of the picture order count value that directly identifies the long-term reference picture, determine whether one or more most significant bits of a delta of the picture order count value directly identifying the long term reference picture and a picture order count value directly identifying the current picture are specified in a slice header of the bitstream, based on the determination of whether the one or more most significant bits are specified, parse the one or more most significant bits from the slice header of the bitstream, retrieve the long-term reference picture from a decoded picture buffer based on one or more of the least significant bits and the one or more most significant bits, and decode at least the portion of the current picture using the retrieved long-term reference picture.

A video decoding device for decoding encoded video data, the video decoding device comprising:

• means for determining, for a current picture of the encoded video data, a number of bits used to represent one or more least significant bits of the picture order count value that directly identifies a long-term reference picture to be used when decoding at least a portion of the current picture;
• means for parsing the determined number of bits from a bitstream representative of the encoded video data, wherein the parsed determined number of bits represents the one or more least significant bits of the picture order count value that directly identifies the long-term reference picture;
• means for determining whether one or more most significant bits of a delta of the picture order count value directly identifying the long term reference picture and a picture order count value directly identifying the current picture are specified in a slice header of the bitstream;
• means for parsing, based on the determination of whether the one or more most significant bits are specified, the one or more most significant bits from the slice header of the bitstream;
• means for retrieving the long-term reference picture from a decoded picture buffer based on one or more of the least significant bits and the one or more most significant bits;
• and
• means for decoding at least the portion of the current picture using the retrieved long-term reference picture.

A non-transitory computer-readable storage medium having stored thereon instructions that, when executed, cause one or more processor of a video decoding device to:

• determine, for a current picture of the encoded video data, a number of bits used to represent one or more least significant bits of the picture order count value that directly identifies a long-term reference picture to be used when decoding at least a portion of the current picture;
• parse the determined number of bits from a bitstream representative of the encoded video data, wherein the parsed determined number of bits represents the one or more least significant bits of the picture order count value that directly identifies the long-term reference picture;
• determine whether one or more most significant bits of a delta of the picture order count value directly identifying the long term reference picture and a picture order count value directly identifying the current picture are specified in a slice header of the bitstream;
• based on the determination of whether the one or more most significant bits are specified, parse the one or more most significant bits from the slice header of the bitstream;
• retrieve the long-term reference picture from a decoded picture buffer based on one or more of the least significant bits and the one or more most significant bits;
• and
• decode at least the portion of the current picture using the retrieved long-term reference picture.