Recherche avancée

Sur d’autres sites (6317)

• Remove the instance of native library from app using dlclose(Android NDK)

  7 septembre 2012, par mirroredAbstraction

  I have compiled FFmpeg library using NDK and use it to trim videos and get thumbnails from a video in my app, so basically I have ffmpeg.so and video-trimmer.so libraries up and running.

  The problem however is strange, the trim or getThumbnail operations are successful but just one time i.e. the first time and the operations fail the second time. However it is successful the third time, I googled it and got two similar posts on SO related to my problem

  POST 1 :

  POST 2 :

  Interestingly they suggest the same solution and I am unable to solve the issue being a naive in C programming language.

  Here is what I have done

  void Java_com_example_demo_natives_LibraryLoader_loadTrimmerLibrary(JNIEnv* env, jclass class, jstring libffmpeg_path, jstring inputFile, jstring outFile,
  
          jstring startTime, jstring length)
  
  {
  
          const char* path;
  
          void* handle;
  
          int *(*Java_com_example_demo_natives_VideoTrimmer_trim)(JNIEnv *, jclass, jstring, jstring, jstring, jstring);
  
  
  
          path = (*env)->GetStringUTFChars(env, libffmpeg_path, 0);
  
  
  
          handle = dlopen(path, RTLD_LAZY);
  
  
  
          Java_com_example_demo_natives_VideoTrimmer_trim = dlsym(handle, "Java_com_example_demo_natives_VideoTrimmer_trim");
  
          (*Java_com_example_demo_natives_VideoTrimmer_trim)(env, class, inputFile, outFile, startTime, length);
  
  
  
          (*env)->ReleaseStringUTFChars(env, libffmpeg_path, path);
  
  
  
          dlclose(handle);
  
  }

  Despite of calling dlclose the library instance still exists in memory, what I am doing wrong here ?

  I come to know that library instance still exists because when I load the libraries again in some other activity the error message says library already exists in CL.

  I want to get rid of the instance of that library from memory, please help...

• Cutting video based on audio training data

  28 février 2018, par TheVCodes

  I essentially want to cut a pre-recorded video based on a bunch of
  training data of a certain sound. Any idea where I could find good documentation of this ?

  Example : Cut a PUBG video from when gunshots are heard in the video to 30 seconds ahead of the the beginning of the cut.

  How it could help : It could help make simple video editing tasks faster.

  Anywhere you think I could get help with this ?

  Note : I’m new, so correct me if anything is wrong with this post

• Any working example recording a (e.g. rtsp) stream to a local MP4 file with ffmpeg/libav ?

  15 novembre 2017, par ggs

  I’m looking for a working and not-out-dated script how to record an e.g. rtsp input stream to a local file (mp4) with ffmpeg/libav. If you could point me to one or post one, many thanks in advance. I’m searching for many hours and I haven’t got any experience with this topic.

  A lot of examples, libs, etc. are outdated, but I want to use ffmpeg >= v3.3.

  Any special things I have to consider (when compiling ffmpeg, or when saving local file to iOS device) ?