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A method to support random access of background frames in ps stream and streaming media

A random access, streaming media technology, applied in the field of video codec system layer, can solve problems such as low efficiency

Active Publication Date: 2019-01-11
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

If you want to find the code stream of the recently decoded background frame, you need to search back in the code stream byte by byte until you find the starting point of the background frame code stream, which requires a very high cost and is very inefficient

Method used

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  • A method to support random access of background frames in ps stream and streaming media
  • A method to support random access of background frames in ps stream and streaming media
  • A method to support random access of background frames in ps stream and streaming media

Examples

Experimental program
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Effect test

Embodiment 1

[0027] figure 1 It is a flow chart of a random access method for a PS stream provided by an embodiment of the present invention. The PS stream random access method provided in this embodiment includes:

[0028] Step 1, point the file pointer to the corresponding position in the PS stream file at the time point of random access, and record this position as the starting position;

[0029] Specifically, a possible situation is that when a user chooses to randomly access a video at a certain time point, he first roughly points the pointer to a certain position in the file according to the time point. A possible method is that the length of the PS stream video is 90 minutes, the user wants to randomly access the video at the 45-minute moment. At this point, at first point the file pointer to the middle position (45 / 90=0.5) of the file, then search for packet elementary stream (PES) packets near this position, parse the PES packet to obtain PTS (presentation_time_stamp) informatio...

Embodiment 2

[0039] figure 2 It is a schematic diagram of a scene sample box in a streaming media file. The streaming media file scene sample box described in this embodiment includes:

[0040] The scene sample box includes sample numbers of scene frames (scene samples) in the entire streaming media file. Specifically, the size indicates the number of bytes of the box; the type of the box is Scene sample box; the version indicates the version of the box; the value of the flag is 0 here; the number of entries indicates the number of Scenesample; each Scenesample corresponds to a background frame The serial number of the sample.

[0041] One possible situation is to scan the ES (element stream) stream file when making a streaming media file. If a background frame is scanned, write the sample number of the background frame into the table in the scene sample box and record the background frame The serial number of the sample.

Embodiment 3

[0043] image 3 It is a schematic flow diagram of a method for performing random access in streaming media files. The method for random accessing streaming media files provided in this embodiment includes:

[0044] Step 1, determine the sample number at a given time;

[0045] Specifically, given a time point, get the time corresponding to this video, assuming that the corresponding video time is 600. Through the time to sample box, we get the duration of the sample is 40, so we need to find the 600th / 40=15+1=16 samples.

[0046] Step 2, check the sync sample box to find the key frame sample after the sample number, which is recorded as sample1;

[0047] Specifically, the sample sequence number of each key frame (S frame in the background frame technology) is recorded in the sync sample box. Find the sample value that is greater than the minimum sample number of the sample in step 1 among these serial numbers, and this key frame sample is recorded as sample1.

[0048] Step...

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Abstract

The invention discloses a method supporting random background frame access in a PS flow and streaming media. The method comprises steps that, on one hand, when random access of the PS flow occurs, a program stream catalog in the PS flow is firstly searched, a needed background frame is found according to notes of the background frames (G / GB frames) and a frame (an S frame) only taking the background frames as reference in the program stream catalog, and then decoding is carried out; on the other hand, in a streaming media file, scene sample box is added to indicate a sample sequence number of the background frames, when a video is decoded, when random access occurs, the background frames are found according to the scene sample box, and then subsequent decoding is further carried out. The method solves a problem that a random access point image and a subsequent image can not be normally decoded in the background frame coding technology when random access occurs.

Description

technical field [0001] The invention relates to video codec system layer technology, in particular to a PS stream random access, stream media file format and random access method in video codec. Background technique [0002] In video coding technology, the redundancy of video information in time and space is eliminated by using prediction in time domain and space domain. Inter-frame prediction technology is a technology commonly used in the field of video coding and decoding. Inter-frame prediction takes advantage of the fact that the information contained in the encoded frame and the current frame has great redundancy. Using motion estimation, it can greatly compress the video. [0003] However, for a class of video with a fixed camera (such as surveillance video, video conferencing, etc.), there are some characteristics different from conventional video. Mainly include: there are a large number of static backgrounds; fixed scenes with various scene contents; long video t...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04N21/8547H04N21/845H04N19/58H04N19/70
Inventor 虞露邵振江
Owner ZHEJIANG UNIV