50 results about "Frame synchronization (video)" patented technology

A method of playing a compressed digital video sequence, comprising steps comprising attributing to each frame a display duration determined as a function of a playing speed set point, and at each period of a frame synchronization signal: if a display duration cumulative value is equal to or greater than a threshold value corresponding to the period of the synchronization signal, playing a previously acquired decoded frame and decreasing the cumulative value of the threshold value; and if the present cumulative value is less than the threshold value, acquiring a new decoded frame and adding the display duration attributed to the newly acquired frame to the cumulative value, until the cumulative value is equal to or greater than the threshold value, playing a last decoded frame acquired and decreasing the cumulative value of the threshold value.

The invention discloses a digital KVM (Keyboard, Video and Mouse) switcher oriented screen video compression method. The method comprises the steps of (1), inputting a frame of screen video data; (2), writing frame header information of a current video frame in a stream; (3), obtaining an uncoded chrominance component sub-frame from the current video frame; (4), obtaining an uncoded data block from a current chrominance component sub-frame; (5), calculating coding information and reconstruction data of a current block under various candidate coding modes, and selecting a final coding mode; (6), writing the coding information of the current block in the stream; (7), repeating the steps (4) to (6); (8), carrying out byte alignment to the stream written in the current video frame; (9), repeating the steps (3) to (8); and (10), carrying out frame synchronization header escape on the stream generated by the current video frame. According to the method, under the limited calculation complexity, the overall and peak data volume of the video stream of the screen can be effectively reduced; moreover, the high reconstruction video quality is ensured.

The invention provides a cloud director multi-machine inter-position frame synchronization method, which comprises the following steps of: when a stream pushing end is initialized, carrying out time synchronization on the stream pushing end and an NTP server; after time synchronization, obtaining a difference value between the local time and NTP time, and recording the difference value as a clockdifference value; in view that during collection, the collection timestamp is the sum of the local time and the clock difference value, enabling the timestamp to correspond to NTP time to serve as unified reference time of synchronization; when the cloud director directs, performing frame synchronization sorting according to the timestamp of the stream pushing end; and when all the audio and videoframes participating in synchronization are synchronized according to the timestamp, rendering the audio and video frames by a renderer. The invention also provides a cloud director multi-machine inter-position frame synchronization system. Through time synchronization and frame synchronization mechanisms, inter-camera audio and video synchronization during cloud director processing is realized.Even if a network fluctuates, the error between cameras can be reduced to be within one frame. Frame synchronization can be realized between any cameras.

The invention discloses a display signal synchronization method and a conversion device. The method comprises the steps that a video access interface receives an input video signal transmitted by a video signal source, and an input time sequence detection module detects a time sequence parameter of the video input signal to judge whether the time sequence parameter of the input video signal is a time sequence parameter of display equipment or not and judge whether synchronous operation of the method can be carried out or not; on the occasion that an external video signal source outputs a self-contained frame synchronization signal and data; and the time delay control module outputs a trigger signal with controllable time delay to the display output time sequence generator, and the displayframe synchronization signal output by the display output time sequence generator has controllable time delay relative to the frame synchronization signal of the video source, so that the output videosignal is output to the display equipment for display according to the output time sequence. Compared with the traditional technology in which a DRAM (Dynamic Random Access Memory) and other memoriesare needed to cache video data, the method only needs very small on-chip cache, and only brings time delay of on-chip cache and display processing.

The invention discloses a method and a device for constructing a virtual video based on an FPGA, a storage medium and equipment. The method comprises the following steps: the FPGA firstly obtaining pixel values of pixel points in a foreground of each frame of image in a to-be-matted video and opaqueness values of the foreground; inputting the pixel value of the pixel point in the foreground, the opacity value of the foreground and the virtual background into a cache DDR; performing frame synchronization through DDR, obtaining a synchronization result; then obtaining a target image frame by frame from the synchronization result, taking each pixel point in the target image as a to-be-synthesized point, and further converting the to-be-synthesized point according to a pixel value and an opacity value of the to-be-synthesized point so as to obtain a corresponding pixel point of the to-be-synthesized point in a virtual video. Visibly, according to the embodiment of the invention, the construction of the virtual interactive video is realized through pure FPGA hardware, and the same clock period is ensured in all calculation processes, so that the constructed virtual video can be better in real-time performance and relatively small in delay (only 1-2 frames).

The invention relates to a multi-node net signal scheduling method based on SDI (Serial Digital Interface) video and audio signals, belongs to the technical field of video and audio signal processing, does not need to additionally add equipment, greatly reduces the cost, can improve the utilization rate of a built-in keying system of a switching station with low utilization rate at the current stage, and is convenient to manage. The detection and judgment of the frame synchronization process are further refined, so that misjudgment of the detection and judgment is avoided; in the pilot run stage of the scheme, the superiority of the scheme is reduced due to the misjudgment phenomenon for many times, so that the detailed verification link needs to be designed, and corresponding parameters need to be set according to historical data judged by the frame synchronization signal. Due to the existence of the program BUG for judging the frame synchronization signal, two independent operation units need to be designed, and misjudgment caused by the program BUG problem under the condition of extremely few programs can be effectively avoided.

The technical scheme of the invention provides an unmanned vehicle monitoring system and method, and the system comprises a multi-path image obtaining device which synchronously obtains multi-path environment image data of an unmanned vehicle, and synchronously transmits the multi-path environment image data; the vehicle-end video processing unit is configured to receive the multi-channel environment image data, perform synchronous format conversion on the multi-channel environment image data to convert the multi-channel environment image data into format data, perform synchronous coding conversion on the format data to convert the format data into multi-channel video stream data, synchronize the multi-channel video stream data, package the multi-channel video stream data, and send the multi-channel video stream data to the vehicle-end video processing unit; sending the packaged multi-channel video stream data to a cloud server; and the monitoring end video processing unit receives the packaged multi-channel video stream data sent by the cloud server, unpacks the packaged multi-channel video stream data, and displays the unpacked multi-channel video stream data through a terminal display device. According to the system and the method, the monitoring video with complete frame synchronization can be obtained at the monitoring end.

The invention provides a display system and method for video synchronization of multiple spliced display screens. The system comprises a display card, at least one splicing control device and a display screen. The display card comprises a signal output port and a frame difference controller. The splicing control device comprises read-write cache module and a splicing control module, and the framedifference controller and the read-write cache modules are in mutual communication control through control lines. According to the invention, existing hardware equipment is utilized; position information state exchange between a display card and frames of different splicing control devices is carried out through a control signal line of an HDMI or DisplayPort in an idle state; closed-loop cooperative control is formed through the frame difference controller of the display card, the splicing control module of the splicing control device and a control line in a video transmission cable, and video frame synchronization of the multiple splicing screens is achieved; and the frame output adjusting capability of the display card and the adjusting capability of the splicing screen control device are fully utilized to carry out closed-loop frame synchronization control, and the effect is better than the effect of carrying out unidirectional frame synchronization only by virtue of the display card.

The invention is suitable for the technical field of video transmission, and provides a method for dynamically adjusting a video time sequence, which comprises an AVERAGEINPUT module, a CALDELTA module, a CALADJUST module and a refdtimeGEN module. An AVERAGEINPUT module, wherein the AVERAGEINPUT module is used for calculating the number of clocks between two adjacent VSyncins through an output clock or a display clock; and a CALDELTA module. According to the scheme, Vsync, (frame synchronization or field synchronization signals) and Hsync (line synchronization signals) of video signals are used for sampling and calculating time sequence drift, the PLL thought is used for reference, output is locked at a fixed time sequence, a transmission clock is not needed, a frame buffer is not needed either, and the system complexity and the system cost can be reduced.

The invention provides a method for synchronizing video frames in a multi-view live broadcast scene. The method comprises the following steps: setting a shared PTS; when each player renders the video,the PTS of the video frame to be rendered currently is compared with the shared PTS, and when the PTS is smaller than the shared PTS, the video frame is not rendered, otherwise, the video frame is rendered normally; and when the player does not render the video, starting a frame chasing mode, and sequentially skipping all the video frames of which the PTS is smaller than the shared PTS until thePTS of the video frames is greater than or equal to the shared PTS. According to the invention, the synchronization time delay can be reduced to the frame level, the ultra-low frame synchronization time delay is achieved, the consistency of the playing progress of multiple paths of multi-view video streams can be ensured, and the accuracy of video synchronization is greatly improved.

The embodiment of the invention provides a signal processing unit and method, an acceleration unit, electronic equipment and a system on chip, the signal processing unit is used for processing video data transmitted to a digital video interface, and the signal processing unit comprises a control unit and a pulse generation unit; the control unit is used for acquiring configuration information for multi-exposure video data, and the multi-exposure video data comprises at least two kinds of image frames corresponding to different exposure times; the pulse generation unit is used for receiving the multi-exposure video data and generating at least one frame synchronization pulse on a first frame synchronization signal included in the multi-exposure video data according to a row effective signal and configuration information included in the multi-exposure video data so as to obtain a second frame synchronization signal, and enabling the second frame synchronization signal to comprise a frame synchronization pulse corresponding to each image frame in the multi-exposure video data, and sending the second frame synchronization signal to the digital video interface. According to the scheme, the applicability of the signal processing unit can be improved.

The invention discloses a video synchronous display method and system. The method is based on the method provided by the invention. When synchronous verification of the spliced screen is carried out,output frame synchronization of the video segmentation equipment is judged through rectangular stripes which diffuse outwards from a central point at a constant speed and are continuously circulated.The method is simpler and more intuitive, and can be easily judged only by human eyes, and when frames are asynchronous, the dislocation difference of stable movement exists at the splicing position of each display screen, so that not only is the mode of adding a timestamp or a frame stamp into a video avoided, but also the frame synchronization verification time of a user or a worker is reduced.

The invention discloses a video frame synchronization method and device between multiple head-mounted devices, a head-mounted device and a computer readable storage medium. The method comprises the steps that a main head-mounted device processes a target video according to a preset rule to obtain video synchronization information; the video synchronization information comprises a target video frame of a video currently played by the main head-mounted device; and the video synchronization information is sent to the slave head-mounted device which is successfully interconnected and paired with the master head-mounted device, so that the slave head-mounted device judges whether a current video frame currently played by the slave head-mounted device is consistent with the target video frame according to the video synchronization information: if not, updating the current video frame to the target video frame, and carrying out video playing on the updated current video frame. According to the invention, video frame synchronization between the slave head-mounted device and the master head-mounted device can be realized in the use process, so that the user experience in the film watching process of a user is higher.

The invention relates to a synchronization method and system for a plurality of 4K-resolution video processors, which synchronize the plurality of 4K video processors through 2K synchronization signals, so when pictures output by the 4K video processors are spliced or sent to next-level equipment, frame synchronization can be kept, and the phenomena of wrong frames, tearing and the like between images are avoided.

The invention discloses an image sample data set construction method and device based on dynamic panoramic image reconstruction and terminal equipment. Comprising the steps of performing video recording on a sampling scene by using a camera group; performing frame synchronization on the plurality of recorded videos to form a frame group; calculating the mutual relation among the plurality of camera images at the same time, and laminating the camera images into a panoramic image of the frame; when sampling is needed, calculating a visual angle point position corresponding to an observation point according to needs, and performing complete sample collection on a target by traversing each frame of the panoramic video and the visual angle point of the target needing sample collection on each frame, so that a data set of the target is obtained; performing the operation on any target once, so that sample pictures of all scenes possibly required by the target can be obtained, so that the complete picture set of the target sample can be collected in a short time.