I have the following plot:
    
    import matplotlib.pyplot as plt

    fig2 = plt.figure()
    ax3 = fig2.add_subplot(2,1,1)
    ax4 = fig2.add_subplot(2,1,2)
    ax4.loglog(x1, y1)
    ax3.loglog(x2, y2)
    ax3.set_ylabel(&#39;hello&#39;)


I want to be able to create axes labels and titles not just for each of the two subplots, but also common labels that span both subplots.  For example, since both plots have identical axes, I only need one set of x and y- axes labels.  I do want different titles for each subplot though.

I tried a few things but none of them worked right

pyplot common axes labels for subplots

I&#39;ll explain by example:

Elvis Operator (?: )

&gt; The &quot;Elvis operator&quot; is a shortening
&gt; of Java&#39;s ternary operator. One
&gt; instance of where this is handy is for
&gt; returning a &#39;sensible default&#39; value
&gt; if an expression resolves to false or
&gt; null. A simple example might look like
&gt; this:

    def gender = user.male ? &quot;male&quot; : &quot;female&quot;  //traditional ternary operator usage
    
    def displayName = user.name ?: &quot;Anonymous&quot;  //more compact Elvis operator

&gt; Safe Navigation Operator (?.)
&gt; 
&gt; The Safe Navigation operator is used
&gt; to avoid a NullPointerException.
&gt; Typically when you have a reference to
&gt; an object you might need to verify
&gt; that it is not null before accessing
&gt; methods or properties of the object.
&gt; To avoid this, the safe navigation
&gt; operator will simply return null
&gt; instead of throwing an exception, like
&gt; so:

    def user = User.find( &quot;admin&quot; )           //this might be null if &#39;admin&#39; does not exist
    def streetName = user?.address?.street    //streetName will be null if user or user.address is null - no NPE thrown


Is there a null-coalescing (Elvis) operator or safe navigation operator in javascript?

I&#39;m trying to use `Gstreamer`&#39;s &lt;a href=&quot;http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer-editing-services/html/index.html&quot;&gt;GStreamer Editing Services&lt;/a&gt; to `concatenate` 2 videos, and to have a `transition` between the two.

This command, which joins 2 segments of the videos together without a transition, works fine:

    ges-launch-0.10 vshort01.mov 0 5 vshort02.mov 5 5 -r -o file:///tmp/foo.mov

Here is the output from it:

    $ ges-launch-0.10 vshort01.mov 0 5 vshort02.mov 5 5 -r -o file:///tmp/foo.mov
    save_path: (null)
    load_path: (null)
    Adding file:///home/rory/vshort01.mov inpoint:0:00:00.000000000 duration:0:00:05.000000000
    Adding file:///home/rory/vshort02.mov inpoint:0:00:05.000000000 duration:0:00:05.000000000
    Done

If I try to have a short `transition` between the 2 videos with this command, it just hangs.

    ges-launch-0.10 vshort01.mov 0 5 +transition crossfade 2 vshort02.mov 5 5 -r -o file:///tmp/foo.mov

The output, I get is this:

    save_path: (null)
    load_path: (null)
    Adding file:///home/rory/vshort01.mov inpoint:0:00:00.000000000 duration:0:00:05.000000000
    Adding &lt;transition:crossfade&gt; duration 0:00:02.000000000
    Adding file:///home/rory/vshort02.mov inpoint:0:00:05.000000000 duration:0:00:05.000000000

And there it hangs. The file ``/tmp/foo.mov`` stays at 0 bytes, with no CPU activity.

&gt; I am using package ``ges0.10-tools`` version 0.10.1-1 on ubuntu 11.04 natty. I have tried a freshly built version of gst-editing-services
&gt; from a git clone today ``c2668d058501513b734c8a8013a5e78c817712bb``

I tried without the ``-r -o …`` options (i.e. telling `ges-launch` to display the video, not render it to a file), and the same problems occurred. With the ``+transitition``, the window opens (to show the video) showing the first frame of the first video. But the video doesn&#39;t play, and there is no CPU usage etc.

How do I get it to make a file and transition between them?

GStreamer Editing Services freezes when transitions are added

I'm trying to use <code>Gstreamer</code>'s <a href="<a href=" http:="" gstreamer.freedesktop.org="" data="" doc="" gstreamer="" head="" gstreamer-editing-services="" html="" index.html&#x26;quot;&#x26;gt;gstreamer&#x22;="">http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer-editing-services/html/index.html">GStreamer</a> Editing Services to <code>concatenate</code> 2 videos, and to have a <code>transition</code> between the two.
This command, which joins 2 segments of the videos together without a transition, works fine:
<pre><code class="hljs language-perl">ges-launch-0.10 vshort01.mov 0 5 vshort02.mov 5 5 -r -o file:///tmp/foo.mov
</code></pre>
Here is the output from it:
<pre><code class="hljs language-ruby">$ ges-launch-0.10 vshort01.mov 0 5 vshort02.mov 5 5 -r -o file:///tmp/foo.mov
save_path: (null)
load_path: (null)
Adding file:///home/rory/vshort01.mov inpoint:0:00:00.000000000 duration:0:00:05.000000000
Adding file:///home/rory/vshort02.mov inpoint:0:00:05.000000000 duration:0:00:05.000000000
Done
</code></pre>
If I try to have a short <code>transition</code> between the 2 videos with this command, it just hangs.
<pre><code class="hljs language-perl">ges-launch-0.10 vshort01.mov 0 5 +transition crossfade 2 vshort02.mov 5 5 -r -o file:///tmp/foo.mov
</code></pre>
The output, I get is this:
<pre><code class="hljs language-csharp">save_path: (null)
load_path: (null)
Adding file:///home/rory/vshort01.mov inpoint:0:00:00.000000000 duration:0:00:05.000000000
Adding &#x3C;transition:crossfade> duration 0:00:02.000000000
Adding file:///home/rory/vshort02.mov inpoint:0:00:05.000000000 duration:0:00:05.000000000
</code></pre>
And there it hangs. The file <code>/tmp/foo.mov</code> stays at 0 bytes, with no CPU activity.
> I am using package <code>ges0.10-tools</code> version 0.10.1-1 on ubuntu 11.04 natty. I have tried a freshly built version of gst-editing-services
> from a git clone today <code>c2668d058501513b734c8a8013a5e78c817712bb</code>
I tried without the <code>-r -o …</code> options (i.e. telling <code>ges-launch</code> to display the video, not render it to a file), and the same problems occurred. With the <code>+transitition</code>, the window opens (to show the video) showing the first frame of the first video. But the video doesn't play, and there is no CPU usage etc.
How do I get it to make a file and transition between them?

I want to write a little iOS video client and have to use HTTP Live Streaming. The videos come from a Wowza Media Server which supports HTTP Live Streaming, so the server-side implementation is not my problem.
I have already watch the WWDC videos and read the Apple documentation about HTTP Live Streaming. 

But there is nowhere explained how to play back the videos on an iOS device. In a WWDC-talk was mentioned that there are 3 possibilities to display the videos:

 - UIWebView 
 - MPMoviePlayerController
 - AVPlayerItem

Which one is the best?

And how can I read out the video-URL&#39;s from a HTML-Page like these, which become provided by the server?

    &lt;html&gt;
    &lt;head&gt;
        &lt;title&gt;HTTP Live Streaming Example&lt;/title&gt;
    &lt;/head&gt;
    &lt;body&gt;
        &lt;video
            src=&quot;http://devimages.apple.com/iphone/samples/bipbop/bipbopall.m3u8&quot;
            height=&quot;300&quot; width=&quot;400&quot;
        &gt;
        &lt;/video&gt;
    &lt;/body&gt;
    &lt;/html&gt;
(Source: [Apple HTTP Live Streaming Overview][1])

I really don&#39;t know where to start with coding...Maybe somebody know better example code than the annoying &quot;Stitched Stream Player&quot; or can write a little tutorial.


  [1]: https://developer.apple.com/library/archive/documentation/NetworkingInternet/Conceptual/StreamingMediaGuide/DeployingHTTPLiveStreaming/DeployingHTTPLiveStreaming.html#//apple_ref/doc/uid/TP40008332-CH2-DontLinkElementID_29

Implementation of HTTP Live Streaming in iOS

I&#39;ve looked through a couple of questions to find out if an HTML5 element is playing, but can&#39;t find the answer. I&#39;ve looked at the W3 documentation and it has an event named &quot;playing&quot; but I can&#39;t seem to get it to work.

This is my current code:

    var stream = document.getElementsByTagName(&#39;video&#39;);
    
    function pauseStream() {
      if (stream.playing) {
        for (var i = 0; i &lt; stream.length; i++) {
          stream[i].pause();
          $(&quot;body &gt; header&quot;).addClass(&quot;paused_note&quot;);
          $(&quot;.paused_note&quot;).text(&quot;Stream Paused&quot;);
          $(&#39;.paused_note&#39;).css(&quot;opacity&quot;, &quot;1&quot;);
        }
      }
    }

Detect if HTML5 Video element is playing

I want to achieve the following.

    &lt;video src=&quot;file:///Users/username/folder/video.webm&quot;&gt;
    &lt;/video&gt;

The intent is that the user will be able to select a file from his/her hard drive.

And the reason for not uploading is of course transmission costs and storage quota. There will be no reason to save the file.

Is it possible?

Play local (hard-drive) video file with HTML5 video tag?

Can anyone suggest how I embed a youtube channel into a webpage - I am getting conflicting information from various sites, ideally using the custom player if possible? thanks

How to embed a YouTube channel into a webpage

Like many people already seem to have (there are several threads on this subject here) I am looking for ways to create video from a sequence of images.

I want to implement my functionality in C#!

Here is what I wan&#39;t to do:

    /*Pseudo code*/
    void CreateVideo(List&lt;Image&gt; imageSequence, long durationOfEachImageMs, string outputVideoFileName, string outputFormat)
    {
        // Info: imageSequence.Count will be &gt; 30 000 images
        // Info: durationOfEachImageMs will be &lt; 300 ms
    
        if (outputFormat = &quot;mpeg&quot;)
        {
        }
        else if (outputFormat = &quot;avi&quot;)
        {      
        }
        else
        {
        }
        
        //Save video file do disk
    }

I know there&#39;s a project called **Splicer** (http://splicer.codeplex.com/) but I can&#39;t find suitable documentation or clear examples that I can follow ([these][1] are the examples that I found).
 
The closest I want to do, which I find here on CodePlex is this:
https://stackoverflow.com/questions/251467/how-can-i-create-a-video-from-a-directory-of-images-in-c

I have also read a few threads about **ffmpeg** (for example this: https://stackoverflow.com/questions/1707516/c-sharp-and-ffmpeg-preferably-without-shell-commands and this: https://stackoverflow.com/questions/3275865/convert-image-sequence-using-ffmpeg) but I find no one to help me with my problem and I don&#39;t think **ffmpeg**-command-line-style is the best solution for me (because of the amount of images).


I believe that I can use the **Splicer**-project in some way (?). 

In my case, it is about about &gt; 30 000 images where each image should be displayed for about 200 ms (in the videostream that I want to create). 

(What the video is about? Plants growing ...)

Can anyone help me complete my function?


  [1]: http://www.codeplex.com/Splicer/Wiki/View.aspx?title=News%20Feeds&amp;referringTitle=Home

Image sequence to video stream?

I apparently have a `redis-server` instance running because when I try to start a new server by entering `redis-server`, I&#39;m greeted with the following:

    Opening port: bind: Address already in use

I can&#39;t figure out how to stop this server and start a new one.

Is there any command I can append to `redis-server` when I&#39;m typing in the CLI?

My OS is Ubuntu 10.04.

How can I stop redis-server?

I recently tried to set a test server up with Apache. The site must run under domain `www.mytest.com`. I always get a `403 Forbidden` error. I am on Ubuntu 10.10 server edition. The doc root is under dir `/var/www`. The following are my settings:

**Content of /var/www**

    ls -l /var/www/

    total 12
    drwxr-xr-x 2 root root 4096 2011-08-04 11:26 mytest.com
    -rwxr-xr-x 1 root root 177 2011-07-25 16:10 index.html


**Content of the host file on the server (with IP 192.168.2.5)**

    cat /etc/hosts

    127.0.0.1 localhost 
    127.0.1.1 americano
    192.168.2.5 americano.mytest.com www.mytest.com

    # The following lines are desirable for IPv6 capable hosts
    ::1 localhost ip6-localhost ip6-loopback
    fe00::0 ip6-localnet
    ff00::0 ip6-mcastprefix
    ff02::1 ip6-allnodes
    ff02::2 ip6-allrouters

**Site config**

    &lt;VirtualHost *&gt;
    ServerAdmin admin@mytest.com
    ServerName www.mytest.com
    ServerAlias mytest.com
    
    DocumentRoot &quot;/var/www/mytest.com&quot;
    
    ErrorLog /var/log/apache2/mytest-error_log
    CustomLog /var/log/apache2/mytest-access_log combined
    
    #
    # This should be changed to whatever you set DocumentRoot to.
    #
    &lt;Directory &quot;/var/www/mytest.com&quot;&gt;
    Options -Indexes FollowSymLinks
    AllowOverride None
    
    Order allow,deny
    Allow from all
    &lt;/Directory&gt;
    &lt;/VirtualHost&gt;

I have no `.htaccess` file in my doc root. The permissions are set correctly (readable by www-data).

If I type in the IP address from my desktop, the site shows up correctly. I changed the hosts file on my desktop to point `www.mytest.com` to the server&#39;s IP. When I use it, I get `403`. Since many functions of this site are sitename-sensitive, I have to be able to access the site by the domain name.

Another funky thing is, even if all log files are created properly, they have no information regarding this error.

I am stuck. Can anybody help?

Apache VirtualHost 403 Forbidden

In Ubuntu I normally install both but what are the differences between the client and server for MySQL. 

As a bonus, when a new statement mentions that it needs MySQL 5.x does it mean the client, the server or both.  For example this link https://dev.mysql.com/doc/refman/5.7/en/json-search-functions.html mentions that it need 5.7.x for it to support json_extract, does this mean the client, server or both need to be 5.7.x

What is the difference between MySQL Server and MySQL Client

Where can (can I ?) find .deb packages for the latest versions of Node.js ?

If not, and because it&#39;s a project that progresses very fast, what is the easiest way to keep up with the releases of Node.js ?

 - Adding some PPA and it will be updated when there&#39;s a new package ?
 - ./configure &amp;&amp; make &amp;&amp; ln -s ./node /usr/bin/node ?
 - Some other way you know and I can&#39;t imagine but hopefully you will share ?

How to keep up with the latest versions of Node.js in Ubuntu? PPA? Compiling?

I&#39;d need a program to be run every time I start up my Ubuntu Linux. So I&#39;d need to add it to my startup programs list. Just one problem: I&#39;d need to do it via the terminal.





Automatically run a program on startup under Linux Ubuntu

I need to convert a bunch of video files using FFmpeg. I run a Bash file that converts all the files nicely, however there is a problem if a file converted is not in 16:9 format.

As I am fixing the size of the screen to -s 720x400, if the aspect ratio of the original is 4:3, FFmpeg creates a 16:9 output file, screwing up the aspect ratio.

Is there a setting that allows setting an aspect ratio as the main parameter, with size being adjusted (for example, by fixing an X or Y dimension only)?


Maintaining aspect ratio with FFmpeg

I tried the following command to extract audio from video:

    ffmpeg -i Sample.avi -vn -ar 44100 -ac 2 -ab 192k -f mp3 Sample.mp3

but I get the following output

    libavutil     50.15. 1 / 50.15. 1
    libavcodec    52.72. 2 / 52.72. 2
    libavformat   52.64. 2 / 52.64. 2
    libavdevice   52. 2. 0 / 52. 2. 0
    libavfilter    1.19. 0 /  1.19. 0
    libswscale     0.11. 0 /  0.11. 0
    libpostproc   51. 2. 0 / 51. 2. 0
    SamplE.avi: Invalid data found when processing input

Can anyone help, please?


How can I extract audio from video with ffmpeg?

I have two videos of the same exact length, and I would like to use ffmpeg to stack them into one video file.

How can I do this?

Vertically or horizontally stack (mosaic) several videos using ffmpeg?

I wanted to decode video frames without using an extractor. So I just tried a small sample, where I use media extractor but I don&#39;t do `extractor.readsample()` to copy the bitstream data into the input buffer instead I use FFmpeg parser, inside JNI, where I memcopy the video frames into the input byte buffers and then queued the input buffer. 

But when I call `decoder.dequeueOutputBuffer(info, 10000)`:
- It returns `MediaCodec.INFO_TRY_AGAIN_LATER`
- While it works fine if I use `extractor.readsample()`

**Java Side:**

    import java.io.File;
    import java.io.FileNotFoundException;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.nio.ByteBuffer;
    
    import android.app.Activity;
    import android.media.MediaCodec;
    import android.media.MediaCodec.BufferInfo;
    import android.media.MediaExtractor;
    import android.media.MediaFormat;
    import android.os.Bundle;
    import android.os.Environment;
    import android.util.Log;
    import android.view.Surface;
    import android.view.SurfaceHolder;
    import android.view.SurfaceView;
    
    public class VideoBrowser extends Activity implements SurfaceHolder.Callback {
        private static final String SAMPLE = Environment.getExternalStorageDirectory() + &quot;/obama.mp4&quot;;
        private PlayerThread mPlayer = null;
        private static native &lt; jintArray &gt; int AVinitializecntxt(String strl, jintArray arr);
        private native int AVREADVIDEO(byte[] array);
        public int FLAG = 0;
        public int jk = 0;
        File f1;
        FileOutputStream f;

        static {
            Log.i(&quot;ABCD&quot;, &quot;BEFORE&quot;);
            System.loadLibrary(&quot;ffmpeg&quot;);
            System.loadLibrary(&quot;ffmpeg-test-jni&quot;);
            Log.i(&quot;ABCD&quot;, &quot;Success&quot;);
        }

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            SurfaceView sv = new SurfaceView(this);
            sv.getHolder().addCallback(this);
            setContentView(sv);
            int val;
            int[] array = new int[6];
            int END_OF_FILE = 0;
            int aud_stream = 0;
            int vid_stream = 0;
            String urlString = &quot;/mnt/sdcard/obama.mp4&quot;;
            f1 = new File(&quot;/mnt/sdcard/t.h264&quot;);
            try {
                f = new FileOutputStream(f1);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
            // This is where I call the function to initialize the ffmpeg inside JNI
            val = AVinitializecntxt(urlString, array);
            FLAG = val;
            Log.i(&quot;ABCD&quot;, &quot;FLAG : &quot; + FLAG + val);
        }

        protected void onDestroy() {
            super.onDestroy();
        }
    
        @Override
        public void surfaceCreated(SurfaceHolder holder) {}
    
        @Override
        public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
            if (mPlayer == null) {
                mPlayer = new PlayerThread(holder.getSurface());
                mPlayer.start();
            }
        }

        @Override
        public void surfaceDestroyed(SurfaceHolder holder) {
            if (mPlayer != null) {
                mPlayer.interrupt();
            }
        }

        private class PlayerThread extends Thread {
            private MediaExtractor extractor;
            private MediaCodec decoder;
            private Surface surface;
            // private VideoPlayer VideoPlayerAPIInterfaceClass = new VideoPlayer();

            public PlayerThread(Surface surface) {
                this.surface = surface;
            }

            @Override
            public void run() {
                if (FLAG == 1) {
                    extractor = new MediaExtractor();
                    extractor.setDataSource(SAMPLE);
                    for (int i = 0; i &lt; extractor.getTrackCount(); i++) {
                        MediaFormat format = extractor.getTrackFormat(i);
                        String mime = format.getString(MediaFormat.KEY_MIME);
                        if (mime.startsWith(&quot;video/&quot;)) {
                            extractor.selectTrack(i);
                            decoder = MediaCodec.createDecoderByType(&quot;video/avc&quot;);
                            // Log.i(&quot;ABCD&quot;, &quot;MIME : &quot; + mime);
                            decoder.configure(format, surface, null, 0);
                            break;
                        }
                    }

                    if (decoder == null) {
                        Log.e(&quot;DecodeActivity&quot;, &quot;Can&#39;t find video info!&quot;);
                        return;
                    }

                    decoder.start();

                    ByteBuffer[] inputBuffers = decoder.getInputBuffers();
                    ByteBuffer[] outputBuffers = decoder.getOutputBuffers();
                    BufferInfo info = new BufferInfo();
                    boolean isEOS = false;
                    long startMs = System.currentTimeMillis();
                    int outIndex1 = -1;

                    while (outIndex1 &lt; 0) {
                        outIndex1 = decoder.dequeueOutputBuffer(info, 10000);
                        Log.i(&quot;ABCD&quot;, &quot;etgeuieoy&quot;);
                    }

                    while (!Thread.interrupted()) {
                        if (!isEOS) {
                            int inIndex = decoder.dequeueInputBuffer(10000);
                            if (inIndex &gt;= 0) {
                                ByteBuffer buffer = inputBuffers[inIndex];
                                // int sampleSize = extractor.readSampleData(buffer, 0);
                                byte[] bytes = new byte[buffer.capacity()];
                                // This is where we call JNI function to memcopy the encoded bitstream into the input buffer
                                int sampleSize = [b] AVREADVIDEO[/b](bytes);
                                buffer.clear(); buffer.put(bytes, 0, sampleSize);
                                if (sampleSize &lt; 0) {
                                // We shouldn&#39;t stop the playback at this point, just pass the EOS
                                // flag to decoder, we will get it again from the
                                // dequeueOutputBuffer
                                // Log.d(&quot;DecodeActivity&quot;, &quot;InputBuffer BUFFER_FLAG_END_OF_STREAM&quot;);
                                    decoder.queueInputBuffer(inIndex, 0, 0, 0, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
                                    isEOS = true;
                                } else {
                                    decoder.queueInputBuffer(inIndex, 0, sampleSize, 0, 0);
                                    extractor.advance();
                                }
                             }
                         }
                         int outIndex = decoder.dequeueOutputBuffer(info, 10000);
                         switch (outIndex) {
                            case MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED:
                                Log.d(&quot;DecodeActivity&quot;, &quot;INFO_OUTPUT_BUFFERS_CHANGED&quot;);
                                outputBuffers = decoder.getOutputBuffers();
                                break;
                            case MediaCodec.INFO_OUTPUT_FORMAT_CHANGED:
                                 Log.d(&quot;DecodeActivity&quot;, &quot;New format &quot; + decoder.getOutputFormat());
                                 break;
                            case MediaCodec.INFO_TRY_AGAIN_LATER:
                                 Log.d(&quot;DecodeActivity&quot;, &quot;dequeueOutputBuffer timed out!&quot;);
                                 break;
                           default:
                                ByteBuffer buffer = outputBuffers[outIndex];
                                Log.v(&quot;DecodeActivity&quot;, &quot;We can&#39;t use this buffer but render it due to the API limit, &quot; + buffer);
                                // We use a very simple clock to keep the video FPS, or the video
                                // playback will be too fast
                                while (info.presentationTimeUs / 1000 &gt; System.currentTimeMillis() - startMs) {
                                    try {
                                        sleep(10);
                                    } catch (InterruptedException e) {
                                        e.printStackTrace();
                                        break;
                                    }
                                }
                                //	Log.i(&quot;ABCD&quot;, &quot;RELEASING OUTPUT BUFFER&quot;);
                                decoder.releaseOutputBuffer(outIndex, true);
                                //decoder.releaseOutputBuffer(outIndex, false);
                                break;
                            }

                            // All decoded frames have been rendered, we can stop playing now
                            if ((info.flags &amp; MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
                                Log.d(&quot;DecodeActivity&quot;, &quot;OutputBuffer BUFFER_FLAG_END_OF_STREAM&quot;);
                                break;
                            }
                        }
    
                        decoder.stop();
                        decoder.release();
                        extractor.release();
                    }
                }
            }
        }
    }

JNI Side:

    JNIEXPORT jint JNICALL
    Java_com_alldigital_videoplayer_VideoBrowser_AVREADVIDEO(JNIEnv * pEnv, 
        jobject pObj, jbyteArray array) {
    
        AV_ctxt * avctxt = &amp; aud_vid_ctxt;
        jbyte * buf = ( * pEnv) - &gt; GetByteArrayElements(pEnv, array, NULL);
        if (buf == NULL) {
            LOGERR(10, &quot;AVVIDEOREAD&quot;, &quot;Bytes null&quot;);
        }

        AVPacket * packet;
        packet = av_malloc(sizeof(AVPacket));
        av_init_packet(packet);
        int avread_res = av_read_frame(avctxt - &gt; gFormatCtx, packet);
        int size = packet - &gt; size;
        if (avread_res &gt;= 0) {
            if (packet - &gt; stream_index == avctxt - &gt; gVideoStreamIndex) {
                // packet-&gt;size,packet-&gt;
                if (NULL == memcpy(buf,(char * ) packet - &gt; data, packet - &gt; size))
                    LOGERR(10, &quot;AV_AUDIO_DECODE&quot;, &quot;memcpy for audio buffer failed&quot;);
                }
            }
            ( * pEnv) - &gt; ReleaseByteArrayElements(pEnv, array, buf, 0);
            av_free_packet(packet);
            packet = NULL;
            return size;
        }
    }

Even though I am copying the encoded data of each frame through FFmpeg without calling extractor, I am getting this outputbuffer timeout issue - why?

Unable to do low-level decoding of video on Android 4.2 without using media extractor

I have a web page, which (among other things) needs to extract a specific frame from a user-uploaded video.  The user seeks to a particular part of a .mp4 in the player, then clicks a button, and an ajax call gets fired off to a php script which takes the .mp4, and the exact time from the video, and uses that to extract a &quot;thumbnail&quot; frame.

My current solution is using the php `exec` command:

`exec(&quot;ffmpeg -i $videoPath -ss $timeOffset -vframes 1 $jpgOutputPath&quot;);`

...which works just great, except it&#39;s as slow as molasses.  My guess is that ffmpeg is a little too much for the job, and I might be able to do better by utilizing the underlying libraries or something... however I have zero idea how to do that.

Ideally I don&#39;t want to have to install anything that requires a real &quot;installation process&quot;... i.e., dropping an executable into the folder with my web app is fine, but I&#39;d rather not have to actually run an installer.  Also, the solution should be able to run on mac, linux and windows (though linux is the top priority).

What can I do to speed this process up?

Thanks.

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