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• ffplay does not exit in forked child

  6 septembre 2019, par user12030145

  ffplay  -autoexit does not exit in a forked child

  I need to pipe my application (stdout) to ffplay (stdin). I do this by forking ffplay as a child and using -i pipe:0 as argument.

  #include 
  
  #include 
  
  #include <sys></sys>types.h>
  
  #include <sys></sys>wait.h>
  
  
  
  int main(int argc, const char** argv)
  
  {
  
  int tube[2];
  
  int c;
  
  FILE* f = fopen(argv[1], "rb");
  
  pid_t pid;
  
  if (argc &lt; 2) return -1;
  
  if (pipe(tube))  {
  
      perror("Pipe");
  
      return -1;
  
    }
  
  
  
  // main process cats a .mlp file to stdout, sent to a child ffplay stdin through a pipe
  
  char* const arg[] = {"-i", "pipe:0", "-f", "mlp", "-nodisp", "-autoexit", NULL};
  
  switch (pid = fork())    {
  
              case -1:
  
                  fprintf(stderr,"%s\n", "Could not launch ffplay");
  
                  break;
  
  
  
              case 0:
  
                  close(tube[1]);
  
                  dup2(tube[0], STDIN_FILENO);
  
                  execv("/usr/bin/ffplay", arg);
  
                  fprintf(stderr, "%s\n", "Runtime failure in ffplay child process");
  
                  return -2;
  
  
  
              default:
  
                  close(tube[0]);
  
                  dup2(tube[1], STDOUT_FILENO);
  
          }
  
  
  
  // Here the main process code sending the .mlp file to stdout...
  
  
  
  while ((c = fgetc(f)) != EOF) putchar(c);
  
  
  
  waitpid(pid, NULL, 0);
  
  fclose(f);
  
  
  
  // main never returns
  
  return 0;
  
  }

  The issue is that in this context, ffplay -autoexit never exits (GNU-Linux platform). In a main process, ffplay -autoexit always exits at the end of a media file.
  Is there a pure C workaround without using system, popen or scripting ?
  Is this a feature or a bug of ffplay (I cannot tell) ?

• Child Process will neither complete nor abort in Windows ?

  4 septembre 2014, par Karthikeya Vaidya

  How to make my java parent process wait till child process gets completed. I have tried with runtime.exec and with processBuilder.pb :

  String cmd = "ffmpeg -i input.vob output.mp4" 
  
  Runtime rt = Runtime.getRuntime();
  
  Process proc = rt.exec(cmd); 
  
  proc.waitFor();

  ---

  This works fine with small input file (say less than 10 Mb). If I give larger input file then program will be hanged. Output file will be partially created and file creation will be hanged and control will not return. Even proc.join(10000); did not give any useful result. Here parent process is terminating before child process (ffmpeg) gets completed.

  How to overcome this problem ?

• swscale/ppc/yuv2rgb_altivec : POWER LE support in the macros vec_unh() and vec_unl()

  16 juillet 2015, par Rong Yan

  swscale/ppc/yuv2rgb_altivec : POWER LE support in the macros vec_unh() and vec_unl()
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libswscale/ppc/yuv2rgb_altivec.c