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• Running ffmpeg as library in android

  4 février 2014, par szakal

  I've got a simple task to do. I need to merge set of pictures into a video using ffmpeg working in android environment.

  After over a week fighting with different tutorials and examples explaining how to run compile ffmpeg I have, let's say, middle success. I've finally compiled ffmpeg for android.

  I followed this example :
  https://github.com/appunite/AndroidFFmpeg
  which worked best for me.

  As a result of building ffmpeg a have following directory structure :

  [Project]/jni/ffmpeg-build/armeabi-v7a/libffmpeg.so
  
  [Project]/jni/ffmpeg-build/armeabi/libffmpeg.so
  
  [Project]/jni/ffmpeg-build/mips/libffmpeg.so
  
  [Project]/jni/ffmpeg-build/x86/libffmpeg.so

  I also followed the ndk examples so I have running c code from java :

  #include 
  
  #include 
  
  #include 
  
  #include 
  
  #include     
  
  #include <android></android>log.h>    
  
  #include 
  
  #include 
  
  
  
  bool initted = false;    
  
  static JavaVM *sVm;
  
  
  
  jstring Java_com_example_hellojni_HelloJni_stringFromJNI(JNIEnv* env, jobject thiz) {
  
  
  
      char **argv;
  
      char *cmd;
  
      int argc;
  
  
  
  //  cmd = "ffmpeg -version";
  
  //  argv = parsedargs(cmd, &amp;argc);
  
  //  ffmpeg(argc, argv);
  
  
  
      return (*env)->NewStringUTF(env, "Hello from JNI !");
  
  
  
  }

  My question is how to run function from ffmpeg from my "hello-jni" c-file. I've read I need to write a wrapper over ffmpeg which my hello-jni is intended to be.

  Here is my Android.mk which probably is importat part to achieve my goal, but honestly I don't understand some lines set in this file. Or simply I don't know how to make things work.

  LOCAL_PATH := $(call my-dir)
  
  
  
  include $(CLEAR_VARS)
  
  LOCAL_MODULE := ffmpeg-prebuilt
  
  LOCAL_SRC_FILES := ffmpeg-build/$(TARGET_ARCH_ABI)/libffmpeg.so
  
  LOCAL_EXPORT_C_INCLUDES := ffmpeg-build/$(TARGET_ARCH_ABI)/include
  
  LOCAL_EXPORT_LDLIBS := ffmpeg-build/$(TARGET_ARCH_ABI)/libffmpeg.so
  
  LOCAL_PRELINK_MODULE := true
  
  include $(PREBUILT_SHARED_LIBRARY)
  
  
  
  
  
  include $(CLEAR_VARS)
  
  LOCAL_ALLOW_UNDEFINED_SYMBOLS=true
  
  LOCAL_MODULE    := hello-jni
  
  LOCAL_SRC_FILES := hello-jni.c
  
  LOCAL_C_INCLUDES := $(LOCAL_PATH)/ffmpeg-build/$(TARGET_ARCH_ABI)/include
  
  LOCAL_SHARED_LIBRARY := ffmpeg-prebuilt
  
  #LOCAL_CFLAGS += -g -Iffmpeg-prebuilt -Ihello-jni -Wno-deprecated-declarations 
  
  #LOCAL_LDLIBS += -llog -lz -landroid ffmpeg-build/$(TARGET_ARCH_ABI)/libffmpeg.so 
  
  
  
  include $(BUILD_SHARED_LIBRARY)

  One more thing. I've found an example how to wrap ffmpeg's main function. It'd be the easiest way to use ffmpeg for me sinse I don't know ffmpeg's api and I hope it's possible to run ffmpeg this way :
  Can FFmpeg be used as a library, instead of a standalone program ?

  To sum up, I think my problems are due to completely lack of c/c++ knowledge at all, especially how to use run any function from .so library.

  I hope someone can help me :).

• Split video on android via ffmpeg

  27 septembre 2016, par Lior

  I have tried to use ffmpeg to split video,
  by adding compile 'org.bytedeco:javacv:1.+'and
  compile 'org.bytedeco.javacpp-presets:ffmpeg:3.1.2-1.2:android-arm' to my gradle file i got all of *.os files which is JNI wrap of all ffmpeg library to my android project .

  According ffmpeg wiki there is option to split the video but how i deal with command like ffmpeg -ss 00:22:30 -i Mononoke.Hime.mkv -ss 00:00:30 -frames:v 1 out3.jpg in android.

  I hope for some help if someone delt with splitting video file on android before, Thanks.

• FFmpeg tee muxer

  14 février 2013, par deed02392

  I'm trying to use the Tee muxer recently introduced to FFmpeg, to both output a stream over UDP and render the output in an SDL window.

  This is because I want to measure latency in my live broadcast system between the input to FFmpeg and its output (i.e. the encoding process latency).

  Can anyone explain how to use it properly ? This is what I have tried :

  ffmpeg -re -i ......\sample_ipod.m4v -f tee "[f=mpegts]udp ://127.0.0.1:1233|[f=sdl]foo"

  I understood this should result in an output stream to UDP and that I could specify additional formats by enclosing like [f=sdl] to mean -f sdl. Then because the sdl muxer requires an argument (the window title) I provided this in the same way the example gives for the stream.

  Hope some FFmpeg expert can shed some light on this. I've even scanned the code that adds the Tee muxer to no avail.