Method and device for video decoding

A video decoding device, used for decoding a transform block of a video image, wherein the transform block is divided into a plurality of sub-blocks, and each sub-block comprises a plurality of decoding positions arranged in rows and columns, and the device comprises:

• index conversion means, configured to convert a first block index of at least one decoding position of the transform block in a first scanning order into a second block index in a second scanning order, wherein the second scanning order is different from the first scanning order;
• decoding means, configured to perform residual decoding on the plurality of sub-blocks of the transform block according to the first scanning order;
• and
• a plurality of buffers, configured to store residual information of one or more decoding positions that have been decoded,
• wherein the decoding means comprises:
• a residual decoding unit, configured to perform residual decoding on residual information of each decoding position in a sub-block currently decoded according to the first scanning order based on residual information that is of one or more decoding positions that have been decoded in the transform block and that is stored in a plurality of preset buffers;
• and
• a residual information updating unit, configured to update the residual information of the decoding positions stored in the plurality of buffers according to residual information of at least a part of decoded decoding positions.