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• VideoReader decodes different Frame counts on different computers

  7 février 2014, par vishal

  I have a large video clip of .avi format(approx 1 hour in length). I read the file using VideoReader in Matlab. Surprisingly the number of frames I get on two different computers vary. Below are my system details along with the number of frames I get.

  System 1 :
  OS : Windows 8.1 (x64)
  Matlab Version : 2013b
  Media Package installed : (default, didn't install anything separately. VLC Player is also there on the PC)
  Number of frames decoded in Video : 119391

  System 2 :
  OS : Windows 7 (x64)
  Matlab Version : 2013b
  Media Package installed : ffMpeg
  Number of frames decoded in Video : 119653

  It appears the difference in frame counts is because of different codecs being used in the two cases ?

  How can I align the H264 decoder versions in the two cases ? In case I install ffmpeg on System 1, how do I configure Matlab to use that particular decoding library.

  And also I would like to know why two different codecs should yield different number of frames on decoding the same video clip !!

• Android FFMpeg guardian project IOException : Permission Denied

  30 décembre 2016, par sector11

  I have cloned compiled ffmpeg binary from here https://github.com/guardianproject/android-ffmpeg and using in android project reference from here https://github.com/guardianproject/android-ffmpeg-java

  But i am not able to get -version command output as it is saying Caused by: java.io.IOException: Permission denied

  Error Logs as follow :

  Permission changed now
  
  12-30 02:30:20.083 3765-3765/in.ashish29agre.ffmpeg I/System.out: Permission changed now
  
  12-30 02:30:20.083 3765-3765/in.ashish29agre.ffmpeg I/System.out: Binary path: /data/data/in.ashish29agre.ffmpeg/app_bin/ffmpeg
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg I/TestActivity: Progress: -version 
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err: java.io.IOException: Error running exec(). Command: [-version] Working Directory: /data/data/in.ashish29agre.ffmpeg/app_bin Environment: [ANDROID_ROOT=/system, LOOP_MOUNTPOINT=/mnt/obb, ANDROID_BOOTLOGO=1, LD_LIBRARY_PATH=/vendor/lib:/system/lib, EXTERNAL_STORAGE=/storage/sdcard, ANDROID_SOCKET_zygote=9, ANDROID_DATA=/data, PATH=/sbin:/vendor/bin:/system/sbin:/system/bin:/system/xbin, ANDROID_ASSETS=/system/app, ASEC_MOUNTPOINT=/mnt/asec, BOOTCLASSPATH=/system/framework/core.jar:/system/framework/conscrypt.jar:/system/framework/okhttp.jar:/system/framework/core-junit.jar:/system/framework/bouncycastle.jar:/system/framework/ext.jar:/system/framework/framework.jar:/system/framework/framework2.jar:/system/framework/telephony-common.jar:/system/framework/voip-common.jar:/system/framework/mms-common.jar:/system/framework/android.policy.jar:/system/framework/services.jar:/system/framework/apache-xml.jar:/system/framework/webviewchromium.jar, ANDROID_PROPERTY_WORKSPACE=8,0, ANDROID_STORAGE=/storage]
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at java.lang.ProcessManager.exec(ProcessManager.java:211)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at java.lang.ProcessBuilder.start(ProcessBuilder.java:195)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at org.ffmpeg.android.FfmpegController.execProcess(FfmpegController.java:137)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at org.ffmpeg.android.FfmpegController.execFFMPEG(FfmpegController.java:101)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at org.ffmpeg.android.FfmpegController.execFFMPEG(FfmpegController.java:111)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at in.ashish29agre.ffmpeg.TestActivity.onResume(TestActivity.java:37)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1192)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at android.app.Activity.performResume(Activity.java:5310)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2778)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2817)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2250)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at android.app.ActivityThread.access$800(ActivityThread.java:135)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:102)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at android.os.Looper.loop(Looper.java:136)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:5017)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at java.lang.reflect.Method.invokeNative(Native Method)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at java.lang.reflect.Method.invoke(Method.java:515)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at dalvik.system.NativeStart.main(Native Method)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err: Caused by: java.io.IOException: Permission denied
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at java.lang.ProcessManager.exec(Native Method)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:     at java.lang.ProcessManager.exec(ProcessManager.java:209)
  
  12-30 02:30:20.093 3765-3765/in.ashish29agre.ffmpeg W/System.err:   ... 20 more

  My Activity code is as follows :

  @Override
  
      protected void onResume() {
  
          super.onResume();
  
          File fileTmp = getCacheDir();
  
          File fileAppRoot = new File(getApplicationInfo().dataDir);
  
          List<string> commands = new ArrayList&lt;>();
  
          commands.add("-version");
  
          try {
  
              FfmpegController ffmpegController = new FfmpegController(this, fileAppRoot);
  
              ffmpegController.installBinaries(this, true);
  
              System.out.println("Binary path: " + ffmpegController.getBinaryPath());
  
  
  
              ffmpegController.execFFMPEG(commands, new ShellUtils.ShellCallback() {
  
                  @Override
  
                  public void shellOut(String shellLine) {
  
                      logger.info("Progress: " + shellLine);
  
  
  
                  }
  
  
  
                  @Override
  
                  public void processComplete(int exitValue) {
  
                      logger.info("Process complete");
  
                  }
  
              });
  
          } catch (IOException e) {
  
              e.printStackTrace();
  
          } catch (InterruptedException e) {
  
              e.printStackTrace();
  
          }
  
      }
  
  </string>

  Just to make sure that i added permission of reading and writing external storage in manifest here is AndroidManifest.xml

  <?xml version="1.0" encoding="utf-8"?>
  
  <manifest package="in.test.ffmpeg">
  
  
  
      
  
      
  
  
  
      <application>
  
          <activity>
  
              
  
                  <action></action>
  
  
  
                  <category></category>
  
              
  
          </activity>
  
      </application>
  
  
  
  </manifest>

• screen recorder by using accord.net

  12 juin 2020, par mohammad

  I tried to creat screen recorder by ussing accord.ffmpeg when run project it show this error :

  



  


  An unhandled exception of type 'System.AccessViolationException' occurred in Accord.Video.FFMPEG.dll
 Additional information : Attempted to read or write protected memory. This is often an indication that other memory is corrupt

  


  



  At line :

  



  FileWriter.WriteAudioFrame(e.Signal.RawData);


  



  Full Code :

  



  using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using Accord;
using Accord.Video;
using Accord.Video.FFMPEG;
using System.Diagnostics;
using System.Threading;
using Accord.DirectSound;
using Accord.Audio;
using System.IO;
namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        VideoFileWriter FileWriter;
        Stopwatch stopwatch = new Stopwatch();
        AudioCaptureDevice audioDevice;
        int frameTime;
        int totalTime;
        Thread recorderTherad;
        bool start;

        /// diemntion of screen
        int x = 1280;
        int y = 800;

        private void button1_Click(object sender, EventArgs e)
        {
            //Start recorder

            AudioDeviceInfo info = null;
            var adc = new AudioDeviceCollection(AudioDeviceCategory.Capture);
            foreach (var ad in adc)
            {
                string desc = ad.Description;
                if (desc.IndexOf("Audio") > -1)
                {
                    info = ad;
                }
            }
            if (info == null)
            {
                audioDevice = new AudioCaptureDevice();
            }
            else
            {
                audioDevice = new AudioCaptureDevice(info);
            }

            audioDevice.NewFrame += AudioDevice_NewFrame;
            audioDevice.Format = SampleFormat.Format16Bit;



            FileWriter = new VideoFileWriter();
            FileWriter.Open(@"d:\nn.mp4",x,y,10,VideoCodec.MPEG4  ,1000000,AudioCodec.MP3  ,320000,audioDevice.SampleRate ,audioDevice.Channels  );

            recorderTherad = new Thread(delegate () { recorder(); });
            start = true;
            audioDevice.Start();
            recorderTherad.Start();
        }

        private void recorder()
        {
            stopwatch.Start();
            while (start == true)
            {
             Bitmap bitmap = new Bitmap(x, y);
                using (Graphics g = Graphics.FromImage(bitmap))
                { g.CopyFromScreen(new System.Drawing.Point(0, 0), System.Drawing.Point.Empty, new Size(x, y)); }

                stopwatch.Stop();
                frameTime = Convert.ToInt32(stopwatch.ElapsedMilliseconds);
                stopwatch.Restart();

                //if time of get screen shoot > 100 msec
                if (frameTime > 100)
                {
                    totalTime += frameTime;
                    TimeSpan d = new TimeSpan(0, 0, 0, 0, totalTime);
                    FileWriter.WriteVideoFrame(bitmap, d);
                    bitmap.Dispose();
                }
                else
                {
                    totalTime += 100;
                    TimeSpan d = new TimeSpan(0, 0, 0, 0, totalTime);
                    FileWriter.WriteVideoFrame(bitmap, d);
                    bitmap.Dispose();
                    Thread.Sleep(100 - frameTime);
                }
            }
        }
        private void AudioDevice_NewFrame(object sender, Accord.Audio.NewFrameEventArgs e)
        {
                FileWriter.WriteAudioFrame(e.Signal.RawData);
        }

        private void button2_Click(object sender, EventArgs e)
        {
            audioDevice .Stop();
            start = false;
            recorderTherad.Abort();
            FileWriter.Close();
            FileWriter.Dispose();
            audioDevice.Dispose();
        }
    }
}