Recherche avancée

Sur d’autres sites (10449)

• Anomalie #2472 : Compagnon : un bug dans un des boutons de fermeture

  2 janvier 2012, par Johan .

  Je reproduis le bug sur 3 serveurs : SPIP 3.0.0-beta SVN [18865] (ou 18866)

  en local : asus AMD 94 (PHP Version 5.3.3-7+squeeze3)

  en local : toshiba intel (PHP Version 5.3.3-7+squeeze3)

  en prod : Linux 2.6.26-2-amd64 (PHP Version 5.2.17-0.dotdeb.0) Aucun plugin, rien dans mes_options.php (...)

• Synchronization between camera video and inertial sensor data

  14 janvier 2013, par Dima Bobby

  I need to :

  write an Android real-time data logging application employing camera video and polling other sensor (accelerometer, gyro, compass) data at high rates e.g. 50 Hz and writing this information into file. As these data will later be used for navigation, precise synchronization between different data is extremely important.

  What I have done :

  implemented sensor polling in native code, so that less Java execution overhead is employed. Nonetheless, camera encoding is still in Java, for this I tried MediaRecorder and MediaCodec. In both cases data from inertial sensors and camera are not synchronized between each other, there is a varying delay of about 400ms and this is inacceptible. Moreover, I am pretty sure that encoding is HW accelerated. Now, to reach my goal I am considering about going for native implementation of video encoding using either OpenCV or FFMPEG (native code is expected to be more efficient).

  EDIT : I have even tried saving the image uncompressed as pgm file, but this way the image data get really huge in size and the FPS is really low, so we are losing data. I suspect that file writing process is the bottleneck in this case. Is there an efficient way to save raw data to file achieving high FPS ?

  Any hints what I should go for to achieve my goal ? I am using Android Jelly Bean with Asus Transformer TF700 Infinity.

  Regards,
  Dmitriy

• Error FFmpeg in Android

  19 novembre 2013, par Mark

  I'm using FrameGrabber to load a video from sdcard and perform some image processing operation. I followed the tutorial at JavaCV site to load javacc and ffmpeg.
  Currently, to run the application, I'm using my tablet (Asus TF 101G with Android version 4.0.3) connected to my pc and it works fine. But if I try to run the same application in another device (e.g. Nexus with Android 4.1.2) I get these errors :

  02-01 16:51:54.687: E/AndroidRuntime(2839): FATAL EXCEPTION: main
  
  02-01 16:51:54.687: E/AndroidRuntime(2839): java.lang.ExceptionInInitializerError
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at com.googlecode.javacv.FFmpegFrameGrabber.<init>(FFmpegFrameGrabber.java:104)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at com.example.com.uniud.avires.MainActivity.onCreate(MainActivity.java:92)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at android.app.Activity.performCreate(Activity.java:5008)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at android.app.ActivityThread.access$600(ActivityThread.java:130)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at android.os.Handler.dispatchMessage(Handler.java:99)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at android.os.Looper.loop(Looper.java:137)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at android.app.ActivityThread.main(ActivityThread.java:4745)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at java.lang.reflect.Method.invokeNative(Native Method)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at java.lang.reflect.Method.invoke(Method.java:511)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at dalvik.system.NativeStart.main(Native Method)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839): Caused by: java.lang.ExceptionInInitializerError
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at java.lang.Class.classForName(Native Method)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at java.lang.Class.forName(Class.java:217)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at com.googlecode.javacpp.Loader.load(Loader.java:338)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at com.googlecode.javacv.cpp.avcodec.<clinit>(avcodec.java:86)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     ... 16 more
  
  02-01 16:51:54.687: E/AndroidRuntime(2839): Caused by: java.lang.UnsatisfiedLinkError: Cannot load library: link_image[1891]: 26325 could not load needed library &#39;libavutil.so&#39; for &#39;libjniavutil.so&#39; (load_library[1093]: Library &#39;libavutil.so&#39; not found)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at java.lang.Runtime.load(Runtime.java:340)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at java.lang.System.load(System.java:521)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at com.googlecode.javacpp.Loader.loadLibrary(Loader.java:422)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at com.googlecode.javacpp.Loader.load(Loader.java:372)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at com.googlecode.javacpp.Loader.load(Loader.java:319)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     at com.googlecode.javacv.cpp.avutil.<clinit>(avutil.java:75)
  
  02-01 16:51:54.687: E/AndroidRuntime(2839):     ... 20 more
  
  </clinit></clinit></init>

  Any suggestion please ?

  I want to attach also my Android.mk file

  LOCAL_PATH := $(call my-dir)
  
  include $(CLEAR_VARS)
  
  OPENCV_LIB_TYPE:=STATIC
  
  include C:/Users/Marco/Desktop/new_ADT/adt-bundle-windows-x86_64/OpenCV-2.4.3.2-android-sdk/sdk/native/jni/OpenCV.mk
  
  OPENCV_INSTALL_MODULES:=on
  
  #OPENCV_CAMERA_MODULES:=on
  
  LOCAL_MODULE    := udmodule
  
  LOCAL_SRC_FILES := udjni.cpp
  
  LOCAL_LDLIBS +=  -llog -ldl
  
  include $(BUILD_SHARED_LIBRARY)

  and my Apllication.mk file

  APP_STL := gnustl_static
  
  APP_CPPFLAGS := -frtti -fexceptions
  
  APP_ABI := armeabi armeabi-v7a 
  
  #APP_ABI := all
  
  APP_PLATFORM := android-8

  Any suggestion ?
  Thanks

  Also I tried to change the application.mk file in this way but with no results :

  APP_STL := gnustl_static
  
  APP_CPPFLAGS := -frtti -fexceptions
  
  APP_ABI := armeabi
  
  LOCAL_CFLAGS += -march=armv7-a -mfloat-abi=softfp -mfpu=vfp -mfpu=neon
  
  LOCAL_LDLIBS += -Wl,--fix-cortex-a8
  
  APP_PLATFORM := android-8