A temporal sequence of pictures is generated in a method for encoding of a first video stream. To do so, a synchronization signal can be used, which can be derived from a second video stream independently of the first video stream. Alternatively, the encoding of a second video stream independent of the first video stream can be based on the same principle as for the encoding of the first video stream.

A method of decoding a coded video bitstream implemented by a video decoder is provided. The method includes the video decoder receiving the coded video bitstream, the coded video bitstream containing a gradual decoding refresh (GDR) flag corresponding to a coded video sequence (CVS); determining, by the video decoder, whether a GDR picture is present in the CVS based on a value of the GDR flag; initiating, by the video decoder, decoding of the CVS at the GDR picture when the value of the GDR flag indicates that the GDR picture is present; and generating, by the video decoder, an image according to the CVS as decoded. A corresponding method of encoding implemented by a video encoder is also disclosed.

A method of decoding a coded video bitstream implemented by a video decoder is provided. The method includes the video decoder receiving the coded video bitstream, the coded video bitstream containing a gradual decoding refresh (GDR) flag corresponding to a coded video sequence (CVS); determining, by the video decoder, whether a GDR picture is present in the CVS based on a value of the GDR flag; initiating, by the video decoder, decoding of the CVS at the GDR picture when the value of the GDR flag indicates that the GDR picture is present; and generating, by the video decoder, an image according to the CVS as decoded. A corresponding method of encoding implemented by a video encoder is also disclosed.

A video decoding method performed by a video decoding apparatus according to the present document comprises: parsing number information about the number of slices for which height is explicitly signaled in a tile of a current picture from a bitstream; parsing height information about the height of the slices for which height is explicitly signaled from the bitstream based on the number information; and decoding the current picture based on the number information and the height information.

A video decoding method performed by a video decoding apparatus according to the present document comprises: parsing number information about the number of slices for which height is explicitly signaled in a tile of a current picture from a bitstream; parsing height information about the height of the slices for which height is explicitly signaled from the bitstream based on the number information; and decoding the current picture based on the number information and the height information.

In an image decoding method performed by a decoding device according to the present disclosure, whether the number of slices included in the current picture is 1 is determined on the basis of a flag pertaining to whether or not sub-picture information is present, and a flag pertaining to whether a sub-picture includes a single slice.

Non-transform blocks of video content may be coded by selectively changing a scanning order. In some implementations, an encoder or decoder may perform a scanning process on a block according to a scanning order. When the block has not been transformed, the encoder or decoder may selectively change the scanning order to a different order. For example, if the block is associated with a particular type of prediction, the scanning order may be changed to a different order. In another example, if the non-transform block has a size that is smaller than a predetermined size, the scanning order may be changed to a different order.

Non-transform blocks of video content may be coded by selectively changing a scanning order. In some implementations, an encoder or decoder may perform a scanning process on a block according to a scanning order. When the block has not been transformed, the encoder or decoder may selectively change the scanning order to a different order. For example, if the block is associated with a particular type of prediction, the scanning order may be changed to a different order. In another example, if the non-transform block has a size that is smaller than a predetermined size, the scanning order may be changed to a different order.

A mechanism is provided that implements video coding and decoding such that only a specific partial image region on a screen can be independently decoded. A video decoding apparatus (31) according to an aspect of the present invention configures, in intra prediction, inter prediction, loop filter processing, or the like, a partial image region in a picture, handles a region outside the partial image region in a similar manner to a region outside the picture, and does not apply such restriction to a non-partial image region other than the partial image region in the picture.

A mechanism is provided that implements video coding and decoding such that only a specific partial image region on a screen can be independently decoded. A video decoding apparatus (31) according to an aspect of the present invention configures, in intra prediction, inter prediction, loop filter processing, or the like, a partial image region in a picture, handles a region outside the partial image region in a similar manner to a region outside the picture, and does not apply such restriction to a non-partial image region other than the partial image region in the picture.