I'm thinking of extracting the "best" parts of my home video files. Why? Because my videos has a lot uninteresting footage that I don't need wasting disk space.  I thought I'd use -ss and -t to specify the part I want, and -codec copy. Example:   ffmpeg -i iphone4sFullVideo.mov -ss 00:00:10 -t 10 -codec copy iphone4sGoodPart.mp4   I have of course tested this and know this creates a new file with a length of 10 seconds that plays in vlc.  With doing this I think I am getting no loss in quality, and being able to use the mp4-video in a GUI video editor (like Adobe Premiere Elements) later. I was planning to do this with my video files from different phones and camcorders. I got .mts, .mov and .mp4.   My question is kind of advice seeking. Is what I'm thinking of stupid? Will my files be ok after copying a part to an mp4 container?
I am using ffmpeg to cut out a section of a large file like this: ffmpeg -i input.wmv -ss 60 -t 60 -acodec copy -vcodec copy output.wmv  The -ss part works fine but the -t is ignored. It correctly removes the initial specified seconds specified with -ss but then keeps going to the end of the input with the copy. Is there a way to use ffmpeg to cut off the end of a video without recoding it?
Please provide a Moderators table in the Data Explorer Volume of bounded region between sphere and a plane Why do diamonds shine? I have always wondered why diamonds shine. Can anyone tell me why? Subsetting matrices Is a clean install better than upgrading? Can you restore log file backups to a mirror database after failure? Purely a theoretical question as I've been considering possible DR scenarios...  In this scenario:   The link between a principle and a mirror server becomes unavailable for a period of time (e.g. network outage) Incremental log backups are still being taken during this time Then the principle database fails and is unrecoverable   Is it possible to restore the incremental log backups onto the mirror to bring it up to date and back online, or would you need to start from scratch with a restore of a full backup?  Depending on the size of the database the difference could be hours of downtime so it would be nice to know.  I'm predominantly interested in SQL Server 2008 R2 and 2012 but other people may be interested in other versions if there's a difference. amsalpha-like bibtex style with manual labels Why was Enterprise on a five-year mission in TOS? There is a small difference between intro texts in TOS:     Space: the final frontier. These are the voyages of the starship Enterprise. Its five-year mission: to explore strange new worlds, to seek out new life and new civilizations, to boldly go where no man has gone before.   and in TNG:     Space: the final frontier. These are the voyages of the starship Enterprise. Its continuing mission: to explore strange new worlds, to seek out new life and new civilizations, to boldly go where no one has gone before.   (emphasis mine)  It's pretty obvious that no man was changed to no one to include women. But, is there any explanation why was five-year changed to continuing? Also, why was it a five-year mission at all?  My only assumptions are:   Gene Roddenberry hoped to get funding to run the show for 5 seasons. Gene Roddenberry just made up a number without any special meaning. Gene Roddenberry was a .   Is there any official explanation, in universe or not? What is __init__.py for? What is __init__.py for in a Python source directory? How can I vertically align entries in my acronyms' list? I use the Glossaries package to generate it. Here is MWE:  % !TeX program = xelatex % !TeX encoding = utf-8 % !TeX spellcheck = ru_RU  \documentclass[12pt, a4paper]{article}  \usepackage{polyglossia} \setdefaultlanguage{russian} \setmainfont[Ligatures=TeX]{Times New Roman}  \usepackage[xindy={glsnumbers=false}, nonumberlist, nopostdot, nogroupskip]{glossaries} %\setglossarystyle{super} % uncomment for style "super" \makeglossaries  \begin{document}  \newacronym{bam}{ДАП}{Двунаправленная Ассоциативная Память} \newacronym{ai}{ИИ}{Искусственный Интеллект} \newacronym{am}{АП}{Ассоциативная Память} \newacronym{ann}{ИНС}{Искусственная Нейронная Сеть} \newacronym{an}{ИН}{Искусственный Нейрон} \newacronym{it}{ИТ}{Информационные Технологии} \glsaddall  \printglossaries  \end{document}   With the default style I have the following:  As you can see, the long names are not vertically aligned. What I want can be achieved with the    \setglossarystyle{super}   But it this case, short names lose the BOLDness, some small horizontal indent appears and the spacing between lines becomes smaller:  where RED is some extra indent, which I don't need. Thank you for your answers! Can I uninstall and reinstall Ubuntu Software Center? PhD without previous academic degree: truth or myth? Linear Matrix Inequality of a matrix $T$ with $\| T \|_2 < \rho$ Assume $T \in \mathbb{R}^{d\times d}$. Let $\rho(T)$ be the spectral radius of $T$ and $\rho \ge 0$. Prove that  $\rho(T) &lt; \rho$ if and only if there exists a $P \succ 0$ satisfying $T^TPT - \rho^2 P \prec 0$.  I can prove the Necessity: If $P = I$, for any $x \in \mathbb{R}^d$,   \begin{equation} x^T T^T P T x - \rho^2 x^T P x = \| Tx \|^2 - \rho^2 \| x\|^2 &lt; 0 \end{equation} so $T^T PT - \rho^2 P \prec 0$  I get stuck in proving the Sufficiency. Assume $f:\mathbb R\rightarrow  {\mathbb R} $ is Lebesgue integrable, prove $\sum_{n\in\mathbb N } f(x+n)$ converges for almost everywhere x. This is a question discussed with friends. Thanks I've got the new Canon Pixma MG 3150 and so far, I can't seem to find a driver anywhere. I do have the CD for both Windows and Mac, but this doesn't help me, as I have Ubuntu 11.10. I'd prefer to have it running on the wifi.  I'm really new to this, so I need for you to explain this to me as basically as possible. Counter example for $(A \times B) \cap (C \times D) = (A \cap C ) \times (B \cap D)$ Is it possible to dual boot two OS's at the same time? I'm doing some exercises on Apostol's calculus, on the floor function. Now, he doesn't give an explicit definition of $[x]$, so I'm going with this one:     DEFINITION Given  $x\in \Bbb R$, the integer part of $x$ is the unique $z\in \Bbb Z$ such that $$z\leq x &lt; z+1$$ and we denote it by $[x]$.   Now he asks to prove some basic things about it, such as: if $n\in \Bbb Z$, then $[x+n]=[x]+n$  So I proved it like this: Let $z=[x+n]$ and $z'=[x]$. Then we have that  $$z\leq x+n&lt;z+1$$  $$z'\leq x&lt;z'+1$$  Then $$z'+n\leq x+n&lt;z'+n+1$$  But since $z'$ is an integer, so is $z'+n$. Since $z$ is unique, it must be that $z'+n=z$.  However, this doesn't seem to get me anywhere to prove that  $$\left[ {2x} \right] = \left[ x \right] + \left[ {x + \frac{1}{2}} \right]$$  in and in general that   $$\left[ {nx} \right] = \sum\limits_{k = 0}^{n - 1} {\left[ {x + \frac{k}{n}} \right]} $$  Obviously one could do an informal proof thinking about "the carries", but that's not the idea, let alone how tedious it would be. Maybe there is some easier or clearer characterization of $[x]$ in terms of $x$ to work this out.  Another property is $$[-x]=\begin{cases}-[x]\text{ ; if }x\in \Bbb Z \cr-[x]-1 \text{ ; otherwise}\end{cases}$$  I argue: if $x\in\Bbb Z$, it is clear $[x]=x$. Then $-[x]=-x$, and $-[x]\in \Bbb Z$ so $[-[x]]=-[x]=[-x]$. For the other, I guess one could say:  $$n \leqslant x &lt; n + 1 \Rightarrow  - n - 1 &lt; x \leqslant -n$$  and since $x$ is not an integer, this should be the same as $$ - n - 1 \leqslant -x &lt; -n$$  $$ - n - 1 \leqslant -x &lt; (-n-1)+1$$  So $[-x]=-[x]-1$ Complex towers: $i^{i^{i^{...}}}$ comparing the first column of two files and printing the entire row of the second file if the first columns match I have two files in these formats:   file1 :  air smell hand dude road cat   file 2:   air,4,21,01,13,3,2 smell,21,4,2,5,6 dude,1,31,42,1 road,1,4,2,1,4 cat,1,5,6,3,1 hand,1,4,2,1,6 mouse,1,3,5,6,2   what I want to do is print the entire row of file 2, if the first string in column 1 of file 2 is found in file 1, and I want to keep the order of file 1.   expected output:   air,4,21,01,13,3,2 smell,21,4,2,5,6 hand,1,4,2,1,6 dude,1,31,42,1 road,1,4,2,1,4 cat,1,5,6,3,1