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• ffmpeg crashing on my ec2 linux

  19 décembre 2016, par Alex Bollbach

  I have a node script that has the line :

  execSync('ffmpeg -loglevel panic -i ${path} -acodec copy -f segment -segment_time 10 -vcodec copy -reset_timestamps 1 -map 0 ./tmp/%d.ts');

  Basically, I’m splitting a given video into 10 second segments. This works on my development machine where I have ffmpeg installed :

  However, when I push the code to my ec2 instance (running the linux AMI), I get this crash :

  Error: Command failed: ffmpeg -loglevel panic -i ../test11.mp4 -acodec copy -f segment -segment_time 10 -vcodec copy -reset_timestamps 1 -map 0 ./tmp/%d.ts

  I have checked that all the files and directories exist and are organized correctly in both cases. The only thing I’ve deduced is that the ffmpeg versions vary between machines, so :

  (developement-Machine)$ ffmpeg -version

  (developement-Machine)$ ffmpeg version 3.0.2 Copyright (c) 2000-2016 the FFmpeg developers

  (ec2)$ ffmpeg -version

  (ec2)$ ffmpeg version N-61041-g52a2138

  Is it the case that the ffmpeg version issues are the culprit here and if so how can I get them in sync ? Locally I simply used Homebrew to install ffmpeg. On the ec2, I’ve used YUM as a package manager to install node and npm before but it isn’t trivial to install ffmpeg. I’ve tried to wget the static builds on ffmpeg sites but after un-taring them I get a directory of directories and I’m not sure how to proceed. The original ffmpeg I installed on my ec2 was here (http://ffmpeg.gusari.org/static/64bit/ffmpeg.static.64bit.2014-02-16.tar.gz)

  Either way I am making no progress and I could spend the next 6 hours figuring out what is going on in my linux shell. So I realize this question is a bit unfocused but is the crash likely an ffmpeg version ? and if so, how can I install the local version I have of ffmpeg on my production ec2 server ?

• Native function in Vitamio

  1er août 2014, par hclee

  I am now looking the code beind the Vitamio (media framework) cause I want to know what API does it use to retrieve the buffer percentage/download rate and how it interect with the android OS to retrieve other information about the streaming video.

  But I realized that it does use some native functions which enable it use some code written in C/C++ language.

  I try to investigate on the C++ code but I don’t know where are they.
  I guessed they are stored inside the res/raw/librarm.so.
  I unzipped the file but all I can find is some machine code but what I want is the implementation of the native function.

  For example, I want to know the implementation of the following function :

  public native int getVideoTrack() ; // What is this function for ? What does it mean by the track
  // number of a straming video ?

  or

  private static native boolean loadFFmpeg_native(String ffmpegPath) ;

  and when will this function be called :

  private static void postEventFromNative(Object mediaplayer_ref, int what, int arg1, int arg2, Object obj)

  Do anyone know where can I investigate the implementation of such native function.
  It should be some C++ code but I don’t want machine code...

  I went to
  https://www.vitamio.org/en/2013/Tutorial_0509/13.html

  but they didn’t have the thing that I want

  Thanks in advance !!!

• How would I dynamically link FFmpeg in a C# Project for use with FFMpegCore ?

  15 octobre 2024, par liamliam

  So far, I have FFMpegCore working in my project with a ffmpeg.exe dropped into the project directory. This works, but for LGPL license compliance FFmpeg requires dynamic linking :
  
Use dynamic linking (on windows, this means linking to dlls) for linking with FFmpeg libraries..

  


  While I understand the basic concept of dynamic vs static linking, my problem is likely a misunderstanding of how .dlls work and how they apply to C# and .NET.
  
Would it be possible to compile ffmpeg into a single .dll that could be accessed by FFMpegCore cross-platform ? From what I can gather in the source, FFMpegCore looks for an ffmpeg or ffmpeg.exe file in its configuration path.

  


  Is it possible to have .NET dynamically link FFmpeg and expose it to libraries for use or is that a complete misunderstanding and would I then need a wrapper library with different capabilities ?

  


  I've attempted to find the answer in the relevant documentation, but I found none for this specific use of either library. I suspect my problem might be a fundamental misunderstanding of how these tools work and work together.
My ideal result would be using FFMpegCore with an FFmpeg.dll that works cross-platform instead of the .exe.

  


  Edit 1 : @taratect's answer and graphic sent me down a path that cleared up quite a bit about exes and dlls. .Net compiles source code down to platform agnostic Intermediate Language in the form of a .dll or .exe(completely different to C++ variants of these files), which is executed by the Common Language Runtime using a Just In Time compiler to convert that Intermediate Language to Machine Code that can be run on the specific platform .Net is installed on. C++(FFmpeg) compiles directly to platform specific Machine Code (as shown in the graphic), confusingly in the form of a .dll or .exe (on Windows). .Net can indeed load and run machine code unmanaged by Common Language Runtime, since everything is run as Machine Code by the end, however memory and other complexities must then be managed by me, which seems to be what FFMpegCore does in wrapping the executable. I might still be confused/incorrect on some of this, unmanaged code is beyond my understanding so far.
This does more or less confirm that FFMpegCore probably can't be expected to use FFmpeg in the way I hoped and a better workaround might be having the user just supply an FFmpeg source or implement a downloader as part of installation so that I don't have to redistribute it at all.