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• Working a mac application that needs to encode video [closed]

  9 février 2013, par Anand

  I am pretty new to xcode world. I am looking for a Tutorial to help me out to create a mac osx xcode project that encodes one format of video to other.
  For example the app will take and avi file and convert it to mp4.
  I see that ffmpeg and other libraries are available but none i am aware of how to use them in a xcode project.
  I am looking for a very very simple form of http://handbrake.fr/ mac application.

  A link to - simple step by step explanation of how to use a simple dylib file would do.

• How I can use Runtime.getRuntime.exec with ffmpeg library in Android ?

  24 février 2015, par beni

  I’m trying to establish the correct rotation in my recorded video because in some devices the setOrientationHint method doesn’ work becuase in some video players may choose to ignore the compostion matrix in a video during playback, Android Documentation.

  So, I’ve decided to use the ffmpeg library. I’m develop a test for the app. In Ubuntu, I download this library and execute the configure and make to obtain the ffmpeg executable, I copy this executable to the DCIM folder in the sdcard, the same for a video what I’ve recorded for my camera recorder app. So, in the DCIM folder, I have the ffmpeg executable and a video.

  I created a test project and in the onCreate method, I’ve include :

  try {
  
  
  
  Process p= Runtime.getRuntime().exec("chmod 777 /mnt/sdcard/beni/ffmpeg");
  
  p.waitFor();
  
  
  
  p = Runtime.getRuntime().exec("/mnt/sdcard/beni/ffmpeg -i /mnt/sdcard/beni/f.mp4 -vf \"transpose=1\" -r 24 -sameq /mnt/sdcard/beni/f2.mp4");
  
  p.waitFor();
  
  
  
  BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));  
  
  String line = null;  
  
  while ((line = in.readLine()) != null) {  
  
      System.out.println(line);  
  
  }  
  
  
  
  
  
  
  
  
  
  } catch (IOException e) {
  
      e.printStackTrace();
  
  } catch (InterruptedException e) {
  
  e.printStackTrace();
  
  }

  but I have the following warning :

  09-13 13:14:03.547: W/System.err(7782): java.io.IOException: Error running exec(). Command: [/mnt/sdcard/beni/ffmpeg, -i, /mnt/sdcard/beni/f.mp4, -vf, "transpose=1", -r, 24, -sameq, /mnt/sdcard/beni/f2.mp4] Working Directory: null Environment: null
  
  09-13 13:14:03.547: W/System.err(7782):     at java.lang.ProcessManager.exec(ProcessManager.java:224)
  
  09-13 13:14:03.547: W/System.err(7782):     at java.lang.Runtime.exec(Runtime.java:189)
  
  09-13 13:14:03.547: W/System.err(7782):     at java.lang.Runtime.exec(Runtime.java:275)
  
  09-13 13:14:03.547: W/System.err(7782):     at java.lang.Runtime.exec(Runtime.java:210)
  
  09-13 13:14:03.547: W/System.err(7782):     at com.example.prueba.MainActivity.onCreate(MainActivity.java:22)
  
  09-13 13:14:03.547: W/System.err(7782):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
  
  09-13 13:14:03.547: W/System.err(7782):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1623)
  
  09-13 13:14:03.547: W/System.err(7782):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1675)
  
  09-13 13:14:03.547: W/System.err(7782):     at android.app.ActivityThread.access$1500(ActivityThread.java:121)
  
  09-13 13:14:03.547: W/System.err(7782):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:943)
  
  09-13 13:14:03.547: W/System.err(7782):     at android.os.Handler.dispatchMessage(Handler.java:99)
  
  09-13 13:14:03.547: W/System.err(7782):     at android.os.Looper.loop(Looper.java:138)
  
  09-13 13:14:03.547: W/System.err(7782):     at android.app.ActivityThread.main(ActivityThread.java:3701)
  
  09-13 13:14:03.547: W/System.err(7782):     at java.lang.reflect.Method.invokeNative(Native Method)
  
  09-13 13:14:03.547: W/System.err(7782):     at java.lang.reflect.Method.invoke(Method.java:507)
  
  09-13 13:14:03.547: W/System.err(7782):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:878)
  
  09-13 13:14:03.547: W/System.err(7782):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:636)
  
  09-13 13:14:03.547: W/System.err(7782):     at dalvik.system.NativeStart.main(Native Method)
  
  09-13 13:14:03.547: W/System.err(7782): Caused by: java.io.IOException: Permission denied
  
  09-13 13:14:03.547: W/System.err(7782):     at java.lang.ProcessManager.exec(Native Method)
  
  09-13 13:14:03.547: W/System.err(7782):     at java.lang.ProcessManager.exec(ProcessManager.java:222)
  
  09-13 13:14:03.547: W/System.err(7782):     ... 17 more

  Is this code right ? Or I’ve done something wrong.

• ffmpeg conversion command to output to h.264 for iPad

  23 juin 2016, par janet-PCF

  I’m looking for a good (general) conversion command that will convert any input file to h.264 sized for the iPad.

  Currently I have this command that works, that was adapted from robert.swain

  With presets :

  $ ffmpeg -i INPUT -acodec aac -ab 160000 -s 1024x768 -vcodec libx264 \
  
           -vpre slow -vpre ipod640 -b 1200kb -threads 0 -f mp4 OUTPUT.mp4

  Long form, no presets :

  $ ffmpeg -i INPUT -acodec aac -ab 160000 -s 1024x768 -vcodec libx264 \
  
           -coder 1 -flags +loop -cmp +chroma \
  
           -partitions +parti8x8+parti4x4+partp8x8+partb8x8 -me_method umh \
  
           -subq 8 -me_range 16 -g 250 -keyint_min 25 -sc_threshold 40 \
  
           -i_qfactor 0.71 -b_strategy 2 -qcomp 0.6 -qmin 10 -qmax 51 -qdiff 4 \
  
           -bf 3 -refs 5 -directpred 3 -trellis 1 \
  
           -flags2 +bpyramid+mixed_refs+wpred+dct8x8+fastpskip -wpredp 2 \
  
           -rc_lookahead 50 -coder 0 -bf 0 -refs 1 -flags2 -wpred-dct8x8 \
  
           -level 30 -maxrate 10000000 -bufsize 10000000 -wpredp 0 -b 1200k \
  
           -threads 0 -f mp4 OUTPUT.mp4

  Note : I’m skipping the aspect ratio because we handle that in the program, and we only resize it if the input resolution is greater than the output resolution.

  If there’s any suggestions for improvement, we are looking to balance speed, quality and conversion time.