Syntax and semantics for buffering information to simplify video splicing

A computer system comprising one or more processing units and memory, wherein the computer system implements a video decoder configured to perform operations comprising:

• receiving encoded data in a bitstream for a current decoding unit of a first access unit of a buffering period, the first access unit corresponding to a first picture among pictures of a video sequence, wherein the current decoding unit is a current slice of the first picture;
• and
• decoding the current decoding unit using the encoded data and a coded picture buffer removal delay (“CPBRD”) value for the current decoding unit, including calculating a nominal coded picture buffer (“CPB”) removal time for the current decoding unit relative to a nominal CPB removal time for a last decoding unit of a second access unit of the buffering period, the second access unit corresponding to a second picture among the pictures of the video sequence, wherein the last decoding unit is a last slice of the second picture, and wherein the calculating the nominal CPB removal time for the current decoding unit includes:
• calculating the nominal CPB removal time for the last decoding unit of the second access unit, wherein the nominal CPB removal time for the last decoding unit of the second access unit depends on a nominal CPB removal time for the second access unit, the nominal CPB removal time for the second access unit having been previously calculated based at least in part on a sum of (a) a nominal CPB removal time of a third access unit of the buffering period and (b) a first product of a first clock tick value and a first factor, wherein the first factor depends on a CPBRD value for the second access unit that is signaled as part of a picture timing supplemental enhancement information message for the second access unit;
• calculating a second product of a second clock tick value and a second factor, the second factor depending on the CPBRD value for the current decoding unit;
• and
• adjusting the nominal CPB removal time for the last decoding unit of the second access unit by the second product.

One or more non-transitory computer-readable media having stored thereon encoded data in a bitstream for a current decoding unit of a first access unit of a buffering period, the first access unit corresponding to a first picture among pictures of a video sequence, wherein the current decoding unit is a current slice of the first picture, the encoded data being organized to facilitate decoding of the current decoding unit using the encoded data and a coded picture buffer removal delay (“CPBRD”) value for the current decoding unit with operations comprising calculating a nominal coded picture buffer (“CPB”) removal time for the current decoding unit relative to a nominal CPB removal time for a last decoding unit of a second access unit of the buffering period, the second access unit corresponding to a second picture among the pictures of the video sequence, wherein the last decoding unit is a last slice of the second picture, and wherein the calculating the nominal CPB removal time for the current decoding unit includes:

• calculating the nominal CPB removal time for the last decoding unit of the second access unit, wherein the nominal CPB removal time for the last decoding unit of the second access unit depends on a nominal CPB removal time for the second access unit, the nominal CPB removal time for the second access unit having been previously calculated based at least in part on a sum of (a) a nominal CPB removal time of a third access unit of the buffering period and (b) a first product of a first clock tick value and a first factor, wherein the first factor depends on a CPBRD value for the second access unit that is signaled as part of a picture timing supplemental enhancement information message for the second access unit;
• calculating a second product of a second clock tick value and a second factor, the second factor depending on the CPBRD value for the current decoding unit;
• and
• adjusting the nominal CPB removal time for the last decoding unit of the second access unit by the second product.