How do I reduce the filesize of videos? For some reason, by phone takes giant videos. The worst of these is a 20 minute video that takes up an entire 13 GB. How can I shrink the filesizes of these? They are mp4s encoded in H.264 and MPEG-4 AAC and play at 30 fps.  It's okay if there is reduction in quality.   I tried using avconv to reduce resolution, but even though this outputted a video with smaller dimensions, the size had bizarrely increased.  What is a good way for reducing the sizes of these file?
I would like to convert a Mp4 file in HD into a Mp4 file of lower resolution. Is there any software that can be used for this?
If $a$, $b$, $c$ are the roots of $x^3-6x^2+3x+1=0$, find all possible values of $a^2b+b^2c+c^2a$ Let $a$, $b$, $c$ be the roots of $$x^3 - 6x^2 + 3x + 1 = 0$$ Find all possible values of $a^2 b + b^2 c + c^2 a$. Express all the possible values, in commas.  I've already tried to bash out all the roots, Vieta's Formula, and try to manipulate the equation to become easier to work with. However, Vieta's didn't get me anywhere, and I couldn't find a way to make the equation simpler or anything. Any hints to start this problem? I built a model of multiple linear regression to predict the revenues at the box office of a movie: the variable $Y$ is revenue while the variables $X$ are two: Activity (number of tweets per day) and sentiment (connotation of these tweets).  The problem is that the intercept is not significant. I thought of a possible explanation: the intercept in practice is the value of the variable $Y$ when the variables $X$ assume values of 0; but because of the very strong development of social networks, it is virtually impossible not to have even a tweet (and then a wave of activity) about a movie that just came out, I thought that the significance or not the intercept could be neglected because the assumed value has no meaning in reality (a tweet of 0 would never be satisfied, given the market today). In this way, I consider the intercept a mere constant for the calculation of the line, without worrying about its significance (because in some cases would take negative values, which is impossible for revenues).  The interpretation may be correct? How to install networkx python in QGIS? How to install and how to compile networkx python on QGIS?  I always get an error that no module named networkx in the console of QGIS I copied the file networkx in C:\Program Files\Quantum GIS Lisboa\apps\Python27\Lib\site-packages and there are not change. are the uses of 'bare infinitive' & 'participle' same here? I saw him sing     I saw him singing    In the first example, the verb sing is used as a bare infinitive and in the following one it is exemplified as a present participle. My question is  if both of them are expressing the same meaning? How to make a file executable? How can I make my file so that I can double click on it, and it runs. It is a .sh script, but I also have files that say:  executable (application/x-executable)  in the description of what they are.  I can't run any of these from terminal, or by double clicking.  If possible, I would like a way using either the GUI or a Terminal, but not a combination of the two.  Here is a screenshot of what I see when I right click then go on properties. The file first:    And the shell script here:    NB: I accept that this is a duplicate (I was looking for it, and couldn't find it, so asked + answered it, hoping that I would find it) however, I don't think the question about .desktop files is a duplicate. Tool to confirm Gaussian fit I have a series of (x1,y1) points.  I'm using a 3rd party software tool to which I feed these points. The tool then provides a mechanism for me to get back a series of (x2,y2) points that are on a Gaussian curve that has been fit to the data.  I'd like to confirm that the points I'm getting back are correct (because, frankly, sometimes they don't look like they are.)  What would be an easy on-line or Excel procedure that would allow me to enter the X1, Y1 series and then get back a series of X2, Y2 points, plot both series, and maybe even see the s.d.?  It's been 20+ years since I did any stats, so I'm just "cook-booking" this with no understanding of what I'm trying to do.  EDIT  The is a plot by wavelength, of intensity.  X-axis is the colors of a rainbow, in the familiar ROYGBIV order. The Y-axis is measured intensity of that particular color.   The help page from the vendor is here:    I call the library with each x1, y1 data point.  I then call the method above. I then call the library again with a series of x values (or maybe the x1 series itself), retrieving the y2 values on the fitted curve. I also retrieve the sd of the fit.  EDIT 2  Below is a link to an image of the dataset and Gaussian fit that has me concerned.  I think that the peak of the fitted curve is too low. Root partition size remains same after partition resize with gparted I had resized my root partition from 30gb to 70gb using gparted. But Ubuntu still shows that I have the same old disk size while gparted shows that I acually have 70gb and that the other 40gb is somehow used. How can I fix this?  Output of 'df -h':  Filesystem      Size  Used Avail Use% Mounted on /dev/sda5        30G   16G   13G  55% / none            4.0K     0  4.0K   0% /sys/fs/cgroup udev            1.9G  8.0K  1.9G   1% /dev tmpfs           391M  884K  390M   1% /run none            5.0M     0  5.0M   0% /run/lock none            2.0G  284K  2.0G   1% /run/shm none            100M   48K  100M   1% /run/user /dev/sda6       341G  115G  227G  34% /media/Data /dev/sdb1       932G  459G  474G  50% /media/sidharth/passport   Output of mount:  /dev/sda5 on / type ext4 (rw,errors=remount-ro) proc on /proc type proc (rw,noexec,nosuid,nodev) sysfs on /sys type sysfs (rw,noexec,nosuid,nodev) none on /sys/fs/cgroup type tmpfs (rw) none on /sys/fs/fuse/connections type fusectl (rw) none on /sys/kernel/debug type debugfs (rw) none on /sys/kernel/security type securityfs (rw) udev on /dev type devtmpfs (rw,mode=0755) devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620) tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755) none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880) none on /run/shm type tmpfs (rw,nosuid,nodev) none on /run/user type tmpfs (rw,noexec,nosuid,nodev,size=104857600,mode=0755) /dev/sda6 on /media/Data type fuseblk (rw,nosuid,nodev,allow_other,default_permissions,blksize=4096) binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev) gvfsd-fuse on /run/user/sidharth/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,user=sidharth) /dev/sdb1 on /media/sidharth/passport type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096) Understanding QGIS buffer tool units Is it necessary to dispose System.Timers.Timer if you use one in your application? I am using System.Timers.Timer class in one of the classes in my application. I know that Timer class has Dispose method inherited from the parent Component class that implements IDisposable interface. Instances of the class below are created many times during my application lifecycle; each of them has an instance of Timer class that generates Elapsed events continuously during the class's lifecycle. Should I implement IDisposable interface in the class that uses Timer class to dispose the timer object? (I have seen code that doesn't do this at all). I am afraid that some unmanaged resources will not be freed if I use the class below like this:  SomeClass someClass = new SomeClass(); someClass.DoSomething(); someClass = null;   The class:  using System.Timers;  public class SomeClass {     private Timer m_timer;      public SomeClass()     {                    m_timer = new Timer();         m_timer.Interval = 1000;         m_timer.Elapsed += new ElapsedEventHandler(m_timer_Elapsed);         m_timer.AutoReset = false;         m_timer.Start();                            }      public void DoSomething()     {      }      private void m_timer_Elapsed(object sender, ElapsedEventArgs e)     {         try         {             //Do some task         }         catch (Exception ex)         {             //Ignore         }         finally         {             if (m_timer != null)             {                 //Restart the timer                 m_timer.Enabled = true;             }         }     } } Vertex groups can not be named in blender 2.70 For some reason the name text field doesn't appear for vertex groups in blender 2.70. I tried in 2.69 and it's there and works fine. Was this feature removed in 2.70 or am I missing something? Solving the Kolmogorov forward equation for transition probabilities Let $\lambda \mu &gt; 0$ and let $X$ be a Markov chain on $\{1,2\}$ with generators  $$ Q = \begin{pmatrix} -\mu &amp; \mu \\ \lambda &amp; -\lambda \end{pmatrix}$$  Write down the forward equations and solve them fro the transition probabilities, $p_{i,j}(t), i,j = 1, 2$.  The answers say:  "We have that   $$p_{11}' = -\mu p_{11} + \lambda p_{12}, \, \, \, p_{22}' = -\lambda p_{22} + \mu p_{21}$$  where $p_{12} = 1 - p_{11}$ and $p_{21} = 1 - p_{22}$. Solve these subject to $p_{ij}(t) = \delta_{ij}$, the Kronecker delta, to obtain that the matrix $P_t = \{p_{ij}(t)\}$."  The bits I don't understand are these  1) How do they get those equations in the first place? For example, why have they added $\lambda p_{12}$ when the coefficient for $p_{12} = \mu$?  2) How do you solve these equations? What do you do with that Kronecker delta to solve them? Example of a Borel set that is neither $F_\sigma$ nor $G_\delta$ I'm looking for subset $A$ of $\mathbb R$ such that $A$ is a Borel set but $A$ is neither $F_\sigma$ nor $G_\delta$. Remove Meta Privilege for MSE (only) In Portal, we are promised cake and a party at the end of our tests. However;       we soon discover that the cake is a lie.     Then, at the final scene;       there really is a cake (and my companion cube is waiting for me).   What's the meaning of this?  Was GLADOS not deceiving me? Her comments seem to suggest that;       ...she had the intention of killing me. Was the cake for us (player) and not for the character in the game? What geometric object is given by this equation? What geometric object is given by this equation?  $x^2+y^2+z^2+2xy+2xz+2yz-x-y-z-6=0$  Maple says it's a hyperboloid of one sheet, but is there a way to show it without going the long way by using the principal axis theorem? display only 3 foreach result per row Infinite series $\sum _{n=2}^{\infty } \frac{1}{n \log (n)}$ Recently, I encountered a problem about infinite series. So my question is how to know whether the infinite series $\sum _{n=2}^{\infty } \frac{1}{n \log (n)}$ is convergent? Time taken to hit a pattern of heads and tails in a series of coin-tosses Inspired by Peter Donnelly's talk at , in which he discusses how long it would take for a certain pattern to appear in a series of coin tosses, I created the following script in R. Given two patterns 'hth' and 'htt', it calculates how long it takes (i.e. how many coin tosses) on average before you hit one of these patterns.  coin &lt;- c('h','t')  hit &lt;- function(seq) {     miss &lt;- TRUE     fail &lt;- 3     trp  &lt;- sample(coin,3,replace=T)     while (miss) {         if (all(seq == trp)) {             miss &lt;- FALSE         }         else {             trp &lt;- c(trp[2],trp[3],sample(coin,1,T))             fail &lt;- fail + 1         }     }     return(fail) }  n &lt;- 5000 trials &lt;- data.frame("hth"=rep(NA,n),"htt"=rep(NA,n))  hth &lt;- c('h','t','h') htt &lt;- c('h','t','t')  set.seed(4321) for (i in 1:n) {     trials[i,] &lt;- c(hit(hth),hit(htt))     } summary(trials)   The summary statistics are as follows,        hth             htt          Min.   : 3.00   Min.   : 3.000    1st Qu.: 4.00   1st Qu.: 5.000    Median : 8.00   Median : 7.000    Mean   :10.08   Mean   : 8.014    3rd Qu.:13.00   3rd Qu.:10.000    Max.   :70.00   Max.   :42.000    In the talk it is explained that the average number of coin tosses would be different for the two patterns; as can be seen from my simulation. Despite watching the talk a few times I'm still not quite getting why this would be the case. I understand that 'hth' overlaps itself and intuitively I would think that you would hit 'hth' sooner than 'htt', but this is not the case. I would really appreciate it if someone could explain this to me. How is stock price determined? Is stock price determined only by the last trade that takes place?  For example, if a stock I own is trading at $3.42, and I place a Sell Limit order for $0.00, will the stock price temporarily dip to $0.00?  Likewise, if I place a Buy Limit order for $100.00 for a stock that is trading at $1.23, will the price spike to $100.00?  Is there some sort of "average price" that is reported on the stock ticker?  Thanks for your help in understanding this! If your visa is on an expired passport but still valid, can you still use it with your new passport, or does the old passport have to have a recent expiration date? If so, how do you transfer your visa to your new passport?