Systems and methods for signaling picture order count values for pictures included in coded video
View Patent ↗Some embodiments include a method of signaling picture count information for decoding video pictures. The method sends a picture order count (POC) most significant bit (MSB) first flag indicating that a picture order count most significant bit second flag is present. The method sends the POC MSB second flag to indicate whether a POC MSB cycle element is present. When a value of the POC MSB present flag is true, the method sends the POC MSB element specifying a value of a POC MSB cycle.
1. A method of signaling picture count information for decoding video pictures, the method including:
sending a picture order count (POC) most significant bit (MSB) first flag indicating that a picture order count most significant bit second flag is present;
sending the POC MSB second flag to indicate whether a POC MSB cycle element is present; and
when a value of the POC MSB second flag is true, sending the POC MSB cycle element specifying a value of a POC MSB cycle,
wherein said flags and cycle element are for use by a decoder to decode the video picture,
wherein the value of the POC MSB cycle is used by the decoder to compute a POC MSB value that combined with a POC least significant bit (LSB) value produces a POC value used for decoding the first video picture,
wherein a length of the POC LSB value is based on a maximum POC LSB minus four value.
2. The method of claim 1 , wherein sending the POC MSB first flag comprises sending the POC MSB first flag as a sequence parameter for a sequence of video pictures.
3. The method of claim 2 , wherein the sequence parameter is included in the sequence parameter set (SPS) header associated with the sequence of video pictures.
4. The method of claim 3 , wherein the SPS header is specified in an SPS Raw Byte Sequence Payload (RBSP) syntax for the sequence of video pictures.
5. The method of claim 3 , wherein the POC MSB second flag and the POC MSB cycle element are associated with a video picture in the sequence of video pictures.
6. The method of claim 1 , wherein the POC MSB second flag is a POC MSB present flag.
7. The method of claim 6 , wherein when the value of the POC MSB present flag is false, the POC MSB cycle element specifying a value of the POC MSB cycle is not sent.
8. The method of claim 1 , wherein the POC MSB second flag is associated with a first video picture.
9. The method of claim 8 further comprising:
sending another POC MSB second flag that is associated with a second video picture and that indicates that a POC MSB cycle element is not present; and
foregoing sending the POC MSB cycle element for decoding blocks of the second video picture.
10. The method of claim 1 , wherein the POC MSB cycle element is a variable-length element, wherein a length of the POC MSB cycle element is based on a value of at least one other element.