Axis Ab

Malte Johansson

Mattias Pettersson

Fredrik Pihl

Björn Völcker

Alexander Toresson

Axel Jonsson

Mattias X Pettersson

A system for handling bandwidth shortage for transmission of encoded video frames. In a sending device, a long term reference frame which indicates bandwidth shortage is created. During a first time period, the reference frame is sent to the receiving device for storage. During a subsequent second time period, bandwidth shortage is determined in the sending device, wherein the bandwidth during the second time period is insufficient if the encoded video frames are encoded according to an encoding principle used at times without bandwidth shortage. During the second time period, inter encoded frames referencing the long term reference frame are sent, wherein each frame includes encoded blocks, and at least a subset of the blocks of the inter encoded frames are empty blocks such that the bit rate of the inter encoded frames is lower or equal to the bandwidth during the second time period.

Method and device for handling bandwidth shortage in relation to transmission of video frames

A computer implemented method for controlling a transmission of a video stream is provided. The method comprises estimating a number of bits for a group of pictures, GOP, of the video stream to be transmitted, setting a latency requirement for the transmission of the video stream, determining an average minimum video bitrate across the GOP based on the estimated number of bits and a time corresponding to a time period represented by a duration of the GOP, for video frames in the GOP setting an output bitrate for transmission of a video frame based on the latency requirement and the average minimum video bitrate, and transmitting the video frame using the output bitrate.

Methods and devices for controlling a transmission of a video stream

A method for adding at least one additional image frame to a stream of encoded image frames, the stream of encoded image frames comprising image frames encoded by an encoder. An event relating to at least one of: i) a change of operation state of a sender of the stream of encoded image frames, or ii) a change of connection state between the sender and a receiver is detected. Depending on the type of the detected event, the at least one additional image frame is provided. Each at least one additional image frame comprises a reference to a preceding image frame and codes a predetermined visual change relative to the preceding image frame. The predetermined visual change is indicative of the type of the detected event. The at least one additional image frame is added to the stream of encoded image frames to obtain a combined stream of image frames.

System and method for adding one additional image frame or a sequence of additional image frames to a stream of encoded image frames

There is provided an image pipeline and a method therein for intra-coding an image frame. The image pipeline comprises a processing part followed by an encoding part supporting a plurality of intra-prediction modes used for intra-coding image frames. The method comprises receiving an image frame and for at least one block of pixel values in the image frame: predicting pixel values of the at least one block of pixel values using an intra-prediction mode supported by the encoding part and updating the image frame by adjusting at least one pixel value within the at least one block of pixel values so as to reduce a residual between the at least one pixel value and a corresponding predicted pixel value. Further, the method comprises intra-coding the updated image frame using at least one out of the plurality of intra-prediction modes.

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Lund, Sweden

Malte Johansson