Abstract:
Exemplary embodiments include systems and methods for coding a video comprising a plurality of pictures including a current picture, a first reference picture, and a second reference picture, where each picture includes a plurality of blocks. In one method, for at least a current block in the current picture, a number of available bi-prediction weights is determined based at least in part on a temporal layer and/or a quantization parameter of the current picture. From among available bi-prediction weights a pair of weights are identified. Using the identified weights, the current block is then predicted as a weighted sum of a first reference block in the first reference picture and a second reference block in the second reference picture. Encoding techniques are also described for efficient searching and selection of a pair of bi-prediction weights to use for prediction of a block.
Abstract:
L'invention concerne un procédé et un dispositif de décodage d'un signal de données codées représentatif d'une séquence vidéo multi-vues représentative d'une vidéo omnidirectionnelle, la séquence vidéo multi-vues comprenant au moins une première vue et une deuxième vue. Des paramètres permettant d'obtenir (61 ) une matrice homographique représentative de la transformation d'un plan de la deuxième vue vers un plan de la première vue, sont lus (60) dans le signal. Une image de la deuxième vue comprend une zone dite active comprenant des pixels qui lorsque lesdits pixels sont projetés via la matrice homographique sur une image de la première vue, sont compris dans l'image de la première vue. Une image de la deuxième vue est décodée (62) par la génération (620) d'une image de référence comprenant des valeurs de pixels déterminées à partir de pixels précédemment reconstruits d'une image de la première vue et de la matrice homographique, et pour au moins un bloc de l'image de la deuxième vue, l'image de référence générée est comprise dans ladite liste d'images de référence lorsque ledit bloc appartient (622) à la zone active. Ledit bloc est reconstruit (625) à partir d'une image de référence indiquée par un index lu (621 ) dans le signal de données.
Abstract:
A motion-field based reference frame is rendered that can be used to perform a prediction process for a first frame of a video sequence to be predicted. A first reference frame from the video sequence for forward inter prediction of the first frame is determined, as is a second reference frame from the video sequence for backward inter prediction of the first frame. A respective motion field determined for blocks of the first frame is used to determine parameters forming an affine homographic model. A current block of a reconstructed reference frame is rendered at a co-located position within a motion field-based reference frame by applying the affine homographic model to the current block. An affine homographic model may be determined for each reconstructed reference frame block to render the motion-field based reference frame.
Abstract:
There is provided a method of encoding video using motion compensation, the method comprising determining a motion vector that defines a transformation from a reference picture, the method comprising using bi-prediction encoding referencing a first and second list of references (L0, L1). The method is characterized in that the first reference list includes a reference created by applying a first weighting to a first picture, and the second reference list includes a reference created by applying a second weighting to said first picture.
Abstract:
본 발명에 따른 영상 복호화 방법은, 큐브 맵 형태로 근사되는 360도 영상을 2차원 영상으로 변환하는 단계, 상기 2차원 영상에 포함된 복수의 페이스들을 재배열하여, 직사각형 형태의 투영 영상을 생성하는 단계, 및 상기 투영 영상에 대한 복호화를 수행하는 단계를 포함할 수 있다.
Abstract:
본 발명에 따른 영상 복호화 방법은, 페이스간 예측이 허용되는지 여부를 결정하는 단계, 상기 페이스간 예측이 허용되는지 여부에 따라, 현재 블록의 참조 픽처 리스트를 구성하는 단계, 및 상기 참조 픽처 리스트를 이용하여, 상기 현재 블록에 대한 인터 예측을 수행하는 단계를 포함할 수 있다.
Abstract:
In general, this disclosure described techniques for pruning a list of motion vector prediction candidates based on picture order count (POC) values. A video coding device may be configured to generate the list of motion vector prediction candidates for a prediction unit (PU) of video data. The video coding device may prune a first motion vector prediction candidate from the list of motion vector prediction candidates when a POC value for a reference picture identified by the first motion vector prediction candidate is equal to a second POC value of a reference picture identified by a second motion vector prediction candidate in the list of motion vector prediction candidates. The video coding device may code the PU using the pruned list.
Abstract:
A method (20) is disclosed performed in an encoder (40) for encoding video pictures into a video bit stream, the method (20) comprising: obtaining (21) a transformed version (2'; 12', 13') of a reference picture (2; 12, 13), by using a geometric transformation comprising at least one of: scaling, rotation, shearing, reflection, and projection; performing (22) a matching procedure at least once, the matching procedure comprising matching a reference matching area (6; 15, 16) of the reference picture (2; 12, 13) to a matching area (4; 16, 15) of a second picture (1; 13, 12) and matching a reference matching area (6'; 15', 16') of the transformed version (2'; 12', 13') to the matching area (4; 16, 15) of the second picture (1; 13, 12); and encoding (23) a block (3; 14) of the current picture (1; 11) by selecting for the block (3; 14) a first prediction area (5; 15, 16) based on the reference matching area (6; 15, 16) or a second prediction area (5'; 15', 16') based on the transformed reference matching area (6'; 15', 16'), wherein the first and second prediction areas at least partly overlap the respective reference matching areas (6; 6'; 15, 16, 15', 16') and wherein the prediction area having lowest matching error to a corresponding matching area (4; 15, 16) of the second picture (1; 13, 12) is selected as prediction for the block. A corresponding method (30) in a decoder (50) is disclosed, and encoder (40), decoder (50), computer programs and computer program products.
Abstract:
A transmitting device for generating a plurality of encoded portions of a video to be transmitted to a receiving device over a network configured to: receive an error message over a feedback channel from the receiving device indicating at least one of said plurality of encoded portions that has been lost at the receiving device; encode a recovery portion responsive to said receiving said error message; and transmit said recovery portion to the receiving device over said network; wherein said error message includes information pertaining to a decoded portion successfully decoded at the receiving device and said recovery portion is encoded relative to said decoded portion.
Abstract:
A transmitting device for generating a plurality of encoded portions of a video to be transmitted to a receiving device over a network configured to: receive an error message over a feedback channel from the receiving device indicating at least one of said plurality of encoded portions that has been lost at the receiving device; encode a recovery portion responsive to said receiving said error message; and transmit said recovery portion to the receiving device over said network; wherein said error message includes information pertaining to a decoded portion successfully decoded at the receiving device and said recovery portion is encoded relative to said decoded portion.