Patent ID: 11902544
Assignee: MICROSOFT TECHNOLOGY LICENSING, LLC
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 6:
7. A computer system comprising:
a buffer configured to receive pictures of a video sequence; and
a video encoder configured to perform operations to encode the pictures of the video sequence, thereby producing encoded data in a bitstream, wherein the operations include:
determining a first flag and a second flag that is a separate syntax element from the first flag, the first flag indicating whether source scan type of the pictures of the video sequence is interlaced, and the second flag indicating whether the source scan type of the pictures of the video sequence is progressive, wherein the first flag and the second flag collectively and exclusively indicate one of the following unique states for the source scan type of the pictures of the video sequence: a state indicating that the source scan type of the pictures of the video sequence is interlaced, a state indicating that the source scan type of the pictures of the video sequence is progressive, a state indicating that the source scan type of the pictures of the video sequence is unknown, and a state indicating that the source scan type is independently indicated for each picture of the pictures of the video sequence by a value of a picture-level syntax element that is to be signaled as part of an SEI message or to be inferred;
outputting the first flag and the second flag as part of the encoded data in the bitstream;
determining, for a given picture among the pictures of the video sequence, the value of a given picture-level syntax element that indicates the source scan type of the given picture, the value of the given picture-level syntax element indicating one of the following states: a state indicating that the source scan type of the given picture is interlaced, a state indicating that the source scan type of the given picture is progressive, and a state indicating that the source scan type of the given picture is unknown, wherein, if the given picture-level syntax element is not present in the encoded data in the bitstream, the value of the given picture-level syntax element is to be inferred according to rules that include:
if the first flag and the second flag indicate that the source scan type of the pictures of the video sequence is progressive, inferring the value of the given picture-level syntax element to indicate that the source scan type of the given picture is progressive;
if the first flag and the second flag indicate that the source scan type of the pictures of the video sequence is interlaced, inferring the value of the given picture-level syntax element to indicate that the source scan type of the given picture is interlaced; and
otherwise, inferring the value of the given picture-level syntax element to indicate that the source scan type of the given picture is unknown; and

if the given picture-level syntax element is to be signaled, outputting the given picture-level syntax element as part of the encoded data in the bitstream.