公开(公告)号：US20240163456A1

公开(公告)日：2024-05-16

申请号：US18503393

申请日：2023-11-07

Applicant: Axis AB

Inventor： Viktor Edpalm ,  Johan Palmaeus ,  Alexander Toresson

IPC: H04N19/159 ,  H04N19/172 ,  H04N19/177

CPC classification number: H04N19/159 ,  H04N19/172 ,  H04N19/177

Abstract: An improved method of managing encoded image frames in a data buffer is presented. Encoded image frames are buffered, for example in a pre-event buffer, in such a way that all stored, e.g., buffered, encoded image frames can be retrieved from the data buffer as a decodable video sequence and such that only those encoded image frames needed for obtaining a decodable video sequence having a pre-defined recording time may be stored in the data buffer. This may be referred to as pruning the data buffer in such a way that all stored encoded image frames can be retrieved from the data buffer as a decodable video sequence having a pre-defined recording time. Thereby, only the encoded image frames needed for generating the video sequence may be stored in the data buffer. Consequently, no extra space for storage of an extra GOP is needed in the data buffer.

公开(公告)号：US11178401B2

公开(公告)日：2021-11-16

申请号：US16863245

申请日：2020-04-30

Applicant: Axis AB

Inventor： Xing Danielsson Fan ,  Viktor Edpalm ,  Alexander Toresson

IPC: H04N19/146 ,  H04N19/126 ,  H04N19/179 ,  H04N19/196

Abstract: A method of controlling output bitrate of a video encoder encoding a video sequence comprises: setting an allowable average bitrate, gathering encoding data by encoding video during a first time period and for each of a plurality of time intervals, storing a respective output bitrate, and a quantisation parameter used for encoding during the respective time interval. For each time interval, the output bitrate is normalised by calculating a corresponding normalised bitrate estimated for a predetermined nominal quantisation parameter as a function of the output bitrate and the quantisation parameter. An average normalised bitrate is calculated by averaging the normalised bitrates of the plurality of time intervals. A new quantisation parameter is calculated based on a comparison of the average normalised bitrate and the allowable average bitrate. The video sequence is encoded using the new quantisation parameter during a second time period subsequent to the first time period.

公开(公告)号：US10574996B2

公开(公告)日：2020-02-25

申请号：US15960176

申请日：2018-04-23

Applicant: AXIS AB

Inventor： Viktor Edpalm ,  Alexander Toresson ,  Alexandre Martins

IPC: H04N19/146 ,  H04N19/114 ,  H04N19/124 ,  H04N19/40 ,  H04N19/61 ,  H04N19/179 ,  H04N19/169

Abstract: A method of controlling output bitrate of a video encoder encoding a video sequence. The method comprises setting a long-term bit budget for a time period of at least one day for output of the video encoder, and determining a first allowable bitrate based on the long-term bit budget. The method further comprises determining an instantaneous bit restriction for output of the video encoder, and determining a second allowable bitrate based on the instantaneous bit restriction. Output bitrate is controlled based on the first allowable bitrate and the second allowable bitrate, such that the long-term bit budget, the first allowable bitrate and the second allowable bitrate are complied with. The method may be performed in a non-transitory computer-readable medium having instruction stored thereon. The method may also be performed by a bitrate controller. The bitrate controller may be found in a camera and a network video recorder.

公开(公告)号：US20200007883A1

公开(公告)日：2020-01-02

申请号：US16452431

申请日：2019-06-25

Applicant: Axis AB

Inventor： Alexander Toresson

IPC: H04N19/46 ,  H04N19/107 ,  H04N19/16 ,  H04N5/272

Abstract: Encoding video data comprises receiving an image sequence comprising first and second input image frames, adding an overlay, thereby generating first and second generated image frames, and encoding a video stream containing output image frames with and without overlay. The first input image frame is encoded as an intra-frame to form a first output image frame. The second input image frame is encoded as an inter-frame with reference to the first output image frame to form a second output image frame. The generated image frames are encoded as inter-frames with reference to the first and second output image frames to form first and second overlaid output image frames. A first part of the second generated image frame is encoded with reference to the first overlaid output image frame, and a second part of the second generated image frame is encoded with reference to the second output image frame.