A picture coding method of the present invention codes a picture signal and a ratio of a number of luminance pixels and a number of chrominance pixels for the picture signal, and then one coding method out of at least two coding methods is selected depending on the ratio. Next, data related to a picture size is coded in accordance with the selected coding method. The data related to the picture size indicates a size of the picture corresponding to the picture signal or an output area, which is a pixel area to be outputted in decoding in a whole pixel area coded in the picture signal coding.

A picture coding method of the present invention codes a picture signal and a ratio of a number of luminance pixels and a number of chrominance pixels for the picture signal, and then one coding method out of at least two coding methods is selected depending on the ratio. Next, data related to a picture size is coded in accordance with the selected coding method. The data related to the picture size indicates a size of the picture corresponding to the picture signal or an output area, which is a pixel area to be outputted in decoding in a whole pixel area coded in the picture signal coding.

A method includes receiving a bit stream, decoding a first frame using the bit stream, determining a scaled first frame using the first frame and a scaling constant, storing the first frame in a first picture buffer at a first index location, and storing the scaled first frame in a second picture buffer at the first index location. Related apparatus, systems, techniques and articles are also described.

A method includes receiving a bit stream, decoding a first frame using the bit stream, determining a scaled first frame using the first frame and a scaling constant, storing the first frame in a first picture buffer at a first index location, and storing the scaled first frame in a second picture buffer at the first index location. Related apparatus, systems, techniques and articles are also described.

An example device for decoding video data includes a memory configured to store video data and one or more processors implemented in circuitry and configured to determine a maximum possible value for a secondary transform syntax element for a block of video data, entropy decode a value for the secondary transform syntax element of the block to form a binarized value representative of the secondary transform for the block, reverse binarize the value for the secondary transform syntax element using a common binarization scheme regardless of the maximum possible value to determine the secondary transform for the block, and inverse-transform transform coefficients of the block using the determined secondary transform.

An example device for decoding video data includes a memory configured to store video data and one or more processors implemented in circuitry and configured to determine a maximum possible value for a secondary transform syntax element for a block of video data, entropy decode a value for the secondary transform syntax element of the block to form a binarized value representative of the secondary transform for the block, reverse binarize the value for the secondary transform syntax element using a common binarization scheme regardless of the maximum possible value to determine the secondary transform for the block, and inverse-transform transform coefficients of the block using the determined secondary transform.

Provided is an encoder including: circuitry; and memory coupled to the circuitry. In operation, the circuitry: performs a mapping process of Luma Mapping with Chroma Scaling (LMCS) for transforming a first pixel value space applied to a luma display image signal into a second pixel value space applied to a luma encoding process signal, using line segments forming a transform curve, each of which corresponds to a different one of sections obtained by partitioning the first pixel value space; and encodes an image, and in the performing of the LMCS, the circuitry determines the transform curve so that among boundary values in the second pixel value space, a first value obtained by dividing a boundary value by a base width defined according to a bit depth of the image is not equal to a second value obtained by dividing another boundary value by the base width.

Provided is an encoder including: circuitry; and memory coupled to the circuitry. In operation, the circuitry: performs a mapping process of Luma Mapping with Chroma Scaling (LMCS) for transforming a first pixel value space applied to a luma display image signal into a second pixel value space applied to a luma encoding process signal, using line segments forming a transform curve, each of which corresponds to a different one of sections obtained by partitioning the first pixel value space; and encodes an image, and in the performing of the LMCS, the circuitry determines the transform curve so that among boundary values in the second pixel value space, a first value obtained by dividing a boundary value by a base width defined according to a bit depth of the image is not equal to a second value obtained by dividing another boundary value by the base width.

An electronic device and a method of operating the same, the electronic device including a first decoder that decodes frames configuring a multimedia file stored in an external storage device; an encoder that encodes decoded frames included in a first decoded file; memory; and a controller that reads the multimedia file from the external storage device, extracts the frames from the read multimedia file, controls the first decoder and the encoder, and controls the memory to store the video thumbnail file output from the encoder.

A video decoding device, in the case where a video of the progressive format is inputted, processes a frame as a picture, in the case where a video of the interlace format is inputted, processes a field as a picture. A video decoding device performs display control corresponding to a format of the both video by analyzing display control information in display control information analyzer. The display control information includes sequence unit display control information which is commonly used in a display process of all pictures that belong to a sequence to be decoded and picture unit display control information which is individually used in a display process of a picture to be decoded. A second code string analyzer acquires each of the sequence unit display control information and the picture unit display control information from an extended information area in units of pictures.