pts | 易学教程

倾斜目标检测RRPN （Arbitrary-Oriented Scene Text Detection via Rotation Proposals）

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RRPN可以采用一阶段的目标检测流程或二阶段的目标检测流程（Faster RCNN）一阶段的目标检测只需要计算RRPN IOU, 不需要ROI pooling，两阶段的需要计算RRPN IOU和RRPN pooling 1.RRPN中的IOU计算 (1)给定预测框和标注框的中心点坐标和宽高，角度。即region1和region2包含5个元素，（cx,cy,w,h,angle） float computeRectIoU(T const * const region1, T const * const region2) (2) 根据region得到4个端点的（x,y）坐标，共8个值，得到rect_pts1，rect_pts2。注意：倾斜框需要考虑角度的影响 convert_region_to_pts(region1, rect_pts1); convert_region_to_pts(region2, rect_pts2); template <typename T> __DEVICE__ inline void convert_region_to_pts(T const * const roi, T * pts) { T cx = roi[0]; T cy = roi[1]; T w = roi[2]; T h = roi[3]; T angle = deg2rad(roi[4]

How is flv format contained in RTMP?

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问题 I'm using wireshark to inspect the packets but I'm confused by how exactly flv format is followed in RTMP streaming. FLV doc specifies the tag to be: tag type, datasize, timestamp, timestampExtended, streamID, VideoTagHeader, but I'm getting [fmt] [timestamp 2000] [body size], [typeID (tag type)] [stream ID] 04 00 07 d0 00 00 2c 09 01 00 00 00 When streaming, does the FLV timestamp just use the RTMP timestamp? and therefore doesn't follow the big-endian format but rather use the RTMP extended

CSP2019 游记

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先自我介绍一下，我就是那个 $day1\ t1$ 没有 $A$ 掉的菜鸡。 Day 0 为了在 $CSP2019$ 之前改完 $NOIP2018$ ，早上 $7$ 点多起床改 $\lceil$ 填数游戏 $\rfloor$ 。由于太菜（太颓），改到中午 $11$ 点多。下午去试机，到的时候离结束只剩 $10\ min$ 了，敲完 $a+b$ 跑路。不知道为什么，好像就我这个考场试机结束得特别早。晚上考前例行吃汉堡。然后翻了翻近期模拟赛的题。发现当时做不出来的现在还是做不出来，当时看懂题解的现在已经看不懂了。玩到快 $12$ 点才睡。 Day 1 在闹钟响之前醒来。定了 $6:30$ 的闹钟，大概 $5:40$ 就醒了。 $8:30$ 比赛开始。 $T1$ 人口普查题，几分钟就搞定了。开始看 $T2$ ，发现自己不知道怎么求 $\lceil$ 以 $u$ 为结尾的最短的合法括号序列 $\rfloor$ 。花了好长时间编了一个奇怪的 $O(n)$ 做法，非常幸运地被第二个样例 $hack$ 了。然后好像已经快 $10:00$ 了。想起去年的 $day\ 1$ ， $10:00$ 的时候已经切完 $2$ 题了，然后心态就崩了。在绝望之中编了一个 \(O(n

Points (PTS) in flash game

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问题 A friend to me made a flash game for my website. The game makes a request to /game/p00ints.php with the points in $_POST['points']. But, a hacker can easy find out how to get more points I guess, so, how can my friend or I fix this security hole? Best regards, Erik Persson 回答1: The way to fix this is have all the point calculation on the server and have the client send raw input (e.g. hold left arrow key 1 second, enter key press, hold left mouse button 2 seconds, etc.). Even then, attackers

Points (PTS) in flash game

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Can the ffmpeg av libs return an accurate PTS?

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问题 I'm working with an mpeg stream that uses a IBBP... GOP sequence. The (DTS,PTS) values returned for the first 4 AVPackets are as follows: I=(0,3) B=(1,1) B=(2,2) P=(3,6) The PTS on the I frame looks like it is legit, but then the PTS on the B frames cannot be right, since the B frames shouldn't be displayed before the I frame as their PTS values indicate. I've also tried decoding the packets and using the pts value in the resulting AVFrame, put that PTS is always set to zero. Is there any way

What to do when last_pts > current_pts using ffmpeg libs (C++)

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问题 Im having some hard time figuring out where to find about this.. Im building a simple recorder to learn about this video compression universe and Im facing some weird behaviors.. Before all I need to explain the scenario... Its very simple... everytime I call av_read_frame( input_context, input_packet ) I save the pts into the last_pts variable... So... Whats bothering me is the fact that about 10% of my calls to av_read_frame I get input_packet.pts > last_pts Resulting in a error message

sshpass throwing error 'Failed to get a pseudo terminal: Success'

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问题 I am trying to run the sshpass tool to automate an sftp action. On another server, the command works, but on this server it just returns one line of error mesage. Here is the command I am using: sshpass -p Password sftp Uname@Host And I get the error: Failed to get a pseudo terminal: Success I've tried it with lots of different hosts and as the root user, and I can sftp in without a problem so I am pretty sure it is either a sshpass or pseudo terminal issue. I don't know a whole lot about

pts & pcr values limit in mpegts?

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问题 As I know PCR stored in 42bits and PTS stored in 33bits in mpegts container So, Max value for PCR is 2^42 = 4398046511104 Max value for PTS is 2^33 = 8589934592 PCR (sec) = 4398046511104 / 27 000 000 Hz = 162890,6 seconds (45 hours) PTS (sec) = 8589934592 / 90 000 Hz = 95443,7 seconds (26,5 hours) So, what I must to do, if PTS or PCR reach one of this max values ? This can be happening in iptv for continuous stream 回答1: Just let it overflow and continue to write the low 33 bits. The demuxer

Calculate PTS before frame encoding in FFmpeg

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问题 How to calculate correct PTS value for frame before encoding in FFmpeg C API? For encoding I'm using function avcodec_encode_video2 and then write it by av_interleaved_write_frame . I found some formulas, but no one of them doesn't work. In doxygen example they are using frame->pts = 0; for (;;) { // encode & write frame // ... frame->pts += av_rescale_q(1, video_st->codec->time_base, video_st->time_base); } This blog says that formula must be like this: (1 / FPS) * sample rate * frame number