Recherche avancée

Sur d’autres sites (8037)

• How to use prebuilt FFmpeg in Android Studio

  26 mai 2016, par vxh.viet

  I’m sure this is a very basic question but since this is the my first time messing around with the NDK, a lot of thing is still very unclear to me.

  Use case :

  • I’m trying to develop a video scrubbing feature so fast and accurate frame seeking is crucial. I’ve tried most of the available players out there but the performance is still not up to my demand. That’s why I’m going down the FFmpeg route.

  • Basically, what I’m looking for is FFmpeg input seeking. I’ve tried WrtingMinds’ ffmpeg-android-java. However it is a file based implementation which means the out.jpg need to be written to external memory and read back which has a big hit on performance (roughly 1000 milliseconds for 1 seek).

  • That’s why I’m trying to built my own FFmpeg player to do the input seeking in JNI and push back the byte[] to be displayed in Java.

  Question : After a lot of struggling with the NDK, I’ve managed to set it up and successfully calling the JNI method from my Java code. The structure is as below :

  MyApp
  
    -app
  
    -MyFFmpegPlayer
  
      -build
  
      -libs
  
      -src
  
        -main
  
          -java
  
            -com.example.myffmpegplayer
  
              +HelloJNI.java
  
          -jni
  
            +MyFFmpegPlayer.c

  After some fail attempt to build FFmpeg on Windows, I’ve decided to use WritingMinds prebuilt FFmpeg. However, after extraction they just come up as plain ffmpeg files (not .so file) so I don’t really know how to use these.

  It would be a great gratitude, if someone can just chime in and give me a good starting point for my next step.

  Thank you so much for your time.

• Using ffmpeg with Visual Studio 2013 and C

  19 juin 2016, par user5000935

  I’m try
  main.c
  av_register_all() ;

  AVFormatContext *pFormatCtx = NULL;
  
  
  
  // Open video file
  
  if (avformat_open_input(&pFormatCtx, argv[1], NULL, NULL) != 0)
  
      return -1; // Couldn't open file
  
  
  
  if (avformat_find_stream_info(pFormatCtx, NULL) < 0)
  
      return -1; // Couldn't find stream information
  
  }

  • I’ve added the include (C :\ffmpeg\include) directory to my C/C++ > General > Additional Include Directories ;
  • I’ve added
    I’m using "Zeranoe FFmpeg Build Version : git-5911eeb (2015-10-08)". I tried both 32/64bits versions as said in another question here in SO.

  These are the errors I’m getting :

  Error   3   error C2143: syntax error : missing ';' before '{'  c:\ffmpeg\include\libavutil\error.h 110 1   FFMpeg Test
  
  Error   6   error C2143: syntax error : missing ';' before '{'  c:\ffmpeg\include\libavutil\mem.h   94  1   FFMpeg Test
  
  Error   9   error C2143: syntax error : missing ';' before '{'  c:\ffmpeg\include\libavutil\mem.h   229 1   FFMpeg Test
  
  Error   12  error C2143: syntax error : missing ';' before '{'  c:\ffmpeg\include\libavutil\mem.h   338 1   FFMpeg Test
  
  Error   15  error C2143: syntax error : missing ';' before '{'  c:\ffmpeg\include\libavutil\rational.h  54  1   FFMpeg Test
  
  Error   18  error C21in formal parameter list   c:\ffmpeg\include\libavutil\mem.h   338 1   FFMpeg Test
  
  Error   20  error C2085: 'av_q2d' : not in formal parameter list    c:\ffmpeg\include\libavutil\rational.h  80  1   FFMpeg Test
  
  Error   8   error C2085: 'av_mallocz_array' : not in formal parameter list  c:\ffmpeg\include\libavuormal parameter list    c:\ffmpeg\include\libavutil\rational.h  54  1   FFMpeg Test

• Can't link FFmpeg in Visual Studio 2013

  22 février 2016, par Sir DrinksCoffeeALot

  I’m struggling with this for past 3-4 days with barely any progress. I’ve downloaded "dev" and "shared" archives and extracted them. "Dev" archive has .lib and .h files and "Shared" has .dll files needed for running app. These are the steps that i’ve done linking-wise :

  Project -> Properties -> Configuration Properties -> VC++ Directories -> Include Directories -> ...\ dev\ include

  Project -> Properties -> Configuration Properties -> VC++ Directories -> Library Directories -> ...\ dev\ lib

  Project -> Properties -> Configuration Properties -> C/C++ -> General -> Additional Include Directories -> ...\ dev\ include

  Project -> Properties -> Configuration Properties -> Linker -> General -> Additional Library Directories -> ...\ dev\ lib

  Project -> Properties -> Configuration Properties -> Linker -> Input -> Additional Dependencies -> avcodec.lib ... swscale.lib

  And when i try to build it i get following error :

  Error 1 error LNK2019: unresolved external symbol _avcodec_register_all referenced in function _main...

  I have no idea why,somehow .lib are not getting linked or something or i’ve done something wrong. It’s getting really frustrating and ffmpeg is crucial in project that i’m working on, basicly i can’t do anything without it. So please if someone could point me in right direction i would aprreciate it very much.

  This is the example that im trying to build.

  #include 
  
  extern "C"
  
  {
  
  
  
  #include "libavcodec\avcodec.h"
  
  }
  
  
  
  
  
  #pragma comment(lib, "avcodec.lib")
  
  
  
  int main()
  
  {
  
      printf("Trying avcodec_register_all... ");
  
      avcodec_register_all();
  
      printf("Done.\n");
  
      return 0;
  
  }

  Thank you in advance.