Concept for picture/video data streams allowing efficient reducibility or efficient random access
A video data stream is rendered reducible in a manner so that the reduction leads to a restriction of pictures of the reduced video data stream to merely a predetermined subarea of the pictures of the original video data stream and in a manner so that transcoding, such as re-quantization, may be avoided and a conformance of the reduced video data stream relative to the codec underlying the original video data stream be maintained. This is achieved by providing the video data stream with information including an indication of the predetermined subarea and replacement indices for redirecting the indices included by the payload portion so as to refer to, and/or replacement parameters for adjusting the first set of coding parameter settings so as to result in, a second set of coding parameter settings.
1. A non-transitory digital storage medium storing a data stream having a picture encoded thereinto, the data stream comprising
displacing information which indicates for a set of at least one predetermined subregion of the picture a displacement of the set of at least one predetermined subregion within a target picture area, wherein the displacing information comprises
a count of the predetermined subregions within the set of at least one predetermined subregions of the picture;
size parameters defining a size of the target picture area, and
for each predetermined subregion of the set of at least one predetermined subregion of the picture,
a width, a height, a top sample row and a left-most sample column of the respective predetermined subregion in the target region and
a further width, a further height, a further top sample row and a further left-most sample column of the respective predetermined region within the picture,
wherein the data stream further comprises a default filling information which indicates a default filling using which a portion of the target picture area is to be filled which is not covered by any of the set of at least one predetermined subregion of the picture displaced according to the displacing information.
2. The non-transitory digital storage medium according to claim 1 , wherein the set of at least one subregion of the picture is a subset of a gapless and overlap-free spatial partitioning of the picture into an array of subregions.
3. The non-transitory digital storage medium according to claim 1 , wherein the displacing information comprises
for each predetermined subregion of the set of at least one predetermined subregion of the picture,
information on a rotation and information on a mirroring when mapping the respective predetermined subregion between the target region and the picture.
4. The non-transitory digital storage medium according to claim 3 , wherein the data stream has a sequence of pictures encoded thereinto, wherein the displacing information is valid for the sequence of pictures.
5. The non-transitory digital storage medium according to claim 4 , wherein the target picture area represents a cubic projection of a panoramic scene.