Recherche avancée

Sur d’autres sites (3846)

• Revision 6ce718eb18 : Merge "End of orientation zero group experiment" into experimental

  22 avril 2013, par Deb Mukherjee

  Changed Paths : Modify /vp9/decoder/vp9_decodframe.c Modify /vp9/encoder/vp9_encodemb.c Modify /vp9/encoder/vp9_rdopt.c Merge "End of orientation zero group experiment" into experimental

• Ffmpeg only receives a piece of information from the pipe

  4 juillet 2017, par Maxim Fedorov

  First of all - my english is not very good, i`m sorry for that.

  I use ffmpeg from c# to convert images to video. To interact with ffmpeg, I use pipes.

  public async Task ExecuteCommand(
  
          string arguments,
  
          Action<namedpipeserverstream> sendDataUsingPipe)
  
      {
  
          var inStream = new NamedPipeServerStream(
  
              "from_ffmpeg",
  
              PipeDirection.In,
  
              1,
  
              PipeTransmissionMode.Byte,
  
              PipeOptions.Asynchronous,
  
              PipeBufferSize,
  
              PipeBufferSize);
  
  
  
          var outStream = new NamedPipeServerStream(
  
              "to_ffmpeg",
  
              PipeDirection.Out,
  
              1,
  
              PipeTransmissionMode.Byte,
  
              PipeOptions.Asynchronous,
  
              PipeBufferSize,
  
              PipeBufferSize);
  
  
  
          var waitInConnectionTask = inStream.WaitForConnectionAsync();
  
          var waitOutConnectionTask = outStream.WaitForConnectionAsync();
  
  
  
          byte[] byteData;
  
  
  
          using (inStream)
  
          using (outStream)
  
          using (var inStreamReader = new StreamReader(inStream))
  
          using (var process = new Process())
  
          {
  
              process.StartInfo = new ProcessStartInfo
  
              {
  
                  RedirectStandardOutput = true,
  
                  RedirectStandardError = true,
  
                  RedirectStandardInput = true,
  
                  FileName = PathToFfmpeg,
  
                  Arguments = arguments,
  
                  UseShellExecute = false,
  
                  CreateNoWindow = true
  
              };
  
  
  
              process.Start();
  
  
  
              await waitOutConnectionTask;
  
  
  
              sendDataUsingPipe.Invoke(outStream);
  
  
  
              outStream.Disconnect();
  
              outStream.Close();
  
  
  
              await waitInConnectionTask;
  
  
  
              var logTask = Task.Run(() => process.StandardError.ReadToEnd());
  
              var dataBuf = ReadAll(inStream);
  
  
  
              var shouldBeEmpty = inStreamReader.ReadToEnd();
  
              if (!string.IsNullOrEmpty(shouldBeEmpty))
  
                  throw new Exception();
  
  
  
              var processExitTask = Task.Run(() => process.WaitForExit());
  
              await Task.WhenAny(logTask, processExitTask);
  
              var log = logTask.Result;
  
  
  
              byteData = dataBuf;
  
  
  
              process.Close();
  
              inStream.Disconnect();
  
              inStream.Close();
  
          }
  
  
  
          return byteData;
  
      }
  
  </namedpipeserverstream>

  Action "sendDataUsingPipe" looks like

  Action<namedpipeserverstream> sendDataUsingPipe = stream =>
  
          {
  
              foreach (var imageBytes in data)
  
              {
  
                  using (var image = Image.FromStream(new MemoryStream(imageBytes)))
  
                  {
  
                      image.Save(stream, ImageFormat.Jpeg);
  
                  }
  
              }
  
          };
  
  </namedpipeserverstream>

  When I send 10/20/30 images (regardless of the size) ffmpeg processes everything.
  When I needed to transfer 600/700 / .. images, then in the ffmpeg log I see that it only received 189-192, and in the video there are also only 189-192 images.
  There are no errors in the logs or exceptions in the code.

  What could be the reason for this behavior ?

• Libavcodec "the procedure entry point for av_frame_alloc could not be located" error in Visual Studio 2017 C++ project

  25 novembre 2019, par Aves

  I am trying to use libavcodec from ffmpeg library in C++ with Visual Studio 2017 Community. I downloaded the latest x64 dev and shared builds from zeranoe (version 20171217), set up include directories and additional libraries in Visual Studio for x64 build, added DLL files from shared package to my PATH.

  This is my sample test code :

  extern "C" {
  
  #include 
  
  }
  
  int main() {
  
      avcodec_register_all();
  
      AVFrame *pAvFrame = av_frame_alloc();
  
      av_frame_free(&pAvFrame);
  
      return 0;
  
  }

  The code compiles without problems but when I run the application I see a dialogue window with error message "the procedure entry point for av_frame_alloc could not be located in DLL" (actual message is not in English, this is the translated version).

  I tried to set Linker->Optimization->References to /OPT:NOREF as it was advised in the similar questions but it did not help.

  Dependency walker shows that av_frame_alloc is exported, "Entry Point" is not bound. A little bit strange is that av_frame_alloc is displayed in both avcodec-58.dll (as red) and avutil-56.dll (as green). Maybe the reason is that the application is trying to get this function from avcodec instead of avutil, but I’m not sure, since I did not check the source code of these libraries.

  So the question is how to set up such a simple FFMPEG-based C++ project in VS2017, where I’m wrong ?

  UPD. 1.

  Linker flags : /OUT :"C :\work\code\TestFfmpeg\x64\Release\TestFfmpeg.exe" /MANIFEST /NXCOMPAT /PDB :"C :\work\code\TestFfmpeg\x64\Release\TestFfmpeg.pdb" /DYNAMICBASE "c :\work\dev\ffmpeg-20171217-387ee1d-win64-dev\lib*.lib" "kernel32.lib" "user32.lib" "gdi32.lib" "winspool.lib" "comdlg32.lib" "advapi32.lib" "shell32.lib" "ole32.lib" "oleaut32.lib" "uuid.lib" "odbc32.lib" "odbccp32.lib" /DEBUG:FULL /MACHINE:X64 /OPT:NOREF /PGD :"C :\work\code\TestFfmpeg\x64\Release\TestFfmpeg.pgd" /MANIFESTUAC :"level=’asInvoker’ uiAccess=’false’" /ManifestFile :"x64\Release\TestFfmpeg.exe.intermediate.manifest" /OPT:ICF /ERRORREPORT:PROMPT /NOLOGO /TLBID:1