ffmpeg截取视频的特定区域

ffmpeg.exe  -i  "原视频.mp4"  -vf  crop=610:1080:655:0    "原视频_cropped.mp4"

crop=width:height:x:y，其中 width 和 height 表示裁剪后的尺寸，x:y 表示裁剪区域的左上角坐标

ffmpeg一些filter用法

上面的命令截取的是原视频的整个时长，如果可以截取部分时常就好了。


更新改进的bash脚本

#!/bin/bash
for filename in *.mp4; do
        ffmpeg.exe -i "$filename" -ss 10 -y "$(basename "$filename" .mp4)_cut.mp4"
        #ffmpeg.exe -i "$filename"  -vf crop=610:1080:655:0  -ss 10 "$(basename "$filename" .mp4)_cut.mp4"
done

墨卡托投影

UTM投影和Gauss-Krüger投影及其变换实现

自定义坐标系的建立及其坐标变换实现

你常用的海图是这样的

Transverse Mercator projection

Universal Transverse Mercator coordinate system

https://en.wikipedia.org/wiki/Helmert_transformation

http://webhelp.esri.com/arcgisdesktop/9.3/datainterop/mergedProjects/FME_Workbench/geodetictransform/bursa_wolf_transformation.htm

ppm

Helmert.java

spline

样条曲线
    样条曲线是经过一系列给定点的光滑曲线。最初，样条曲线都是借助于物理样条得到的，放样员把富有弹性的细木条（或有机玻璃条），用压铁固定在曲线应该通过的给定型值点处，样条做自然弯曲所绘制出来的曲线就是样条曲线。样条曲线不仅通过各有序型值点，并且在各型值点处的一阶和二阶导数连续，也即该曲线具有连续的、曲率变化均匀的特点。
http://pages.cs.wisc.edu/~deboor/draftspline.html
https://www.autodesk.com/products/fusion-360/blog/sketch-control-point-splines-faq/
http://web.mit.edu/hyperbook/Patrikalakis-Maekawa-Cho/mathe.html

非均匀有理B样条
贝塞尔曲线扫盲

Interpolation-of-an-N-D-curve

dierckx

torrent tracker

Alternative default trackers

https://github.com/rakshasa/rtorrent/issues/471

Resurrecting an ancient thread but I figured this out so I am sharing. Every time a new torrent is added this will add the following tracker to it.

method.set_key=event.download.inserted_new,add_all_trackers001,"d.tracker.insert=\"32\",\"udp://9.rarbg.com:2710/announce\""

You can add more than one too...

method.set_key=event.download.inserted_new,add_all_trackers015,"d.tracker.insert=\"32\",\"http://thetracker.org:80/announce\"" method.set_key=event.download.inserted_new,add_all_trackers016,"d.tracker.insert=\"32\",\"http://torrentsmd.com:8080/announce\"" method.set_key=event.download.inserted_new,add_all_trackers017,"d.tracker.insert=\"32\",\"http://tracker.bittor.pw:1337/announce\""