[MPlayer-cygwin] slave mode + windows frontend

[Rémy Bertot]

Hi,

I'm currently trying to use mplayer in slave mode in order to build a 
windows frontend. I don't manage to make the basis of this frontend to 
work (basicly the stuff that CreatProcess and CreatePipe, then link the 
stdin/stdout of Mplayer and the console), since the commands i'm sending 
to mplayer (even if it's well displayed on stdout) don't seem to be 
received by mplayer.

While looking for a solution, I realised that the slave mode was not 
working under 'cmd' but just with msys. When I launch mplayer from the 
classic DOS cmd, the video is working, but the commands I type in the 
shell don't work. In fact the strings (like 'pause\n') seems to be 
stored only in the cmd buffer, since they appear right after the prompt 
when I quit mplayer.

I tried this under the last precompiled version of mplayer, and one that 
I compiled myself. Is that normal, or did I skip something during the 
compilation or in the command line (mplayer.exe -slave -idle -quiet 
mymovie.avi)? Does it affect the program I'm writting or is it something 
different? Here is the source code of the small app (hugely inspired by 
createprocess tutorials), if it helps.

Thanks a lot!
RB


//----------- START ------------
#include <windows.h>
#include <stdio.h>
#include <conio.h>
#include <string.h>
#pragma hdrstop

void ErrorMessage(char *str)  //display detailed error info
{
  LPVOID msg;
  FormatMessage(
    FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
    NULL,
    GetLastError(),
    MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
    (LPTSTR) &msg,
    0,
    NULL
  );
  printf("%s: %s\n",str,msg);
  LocalFree(msg);
}

#define INFO_BUFFER_SIZE 32767
#define bzero(a) memset(a,0,sizeof(a)) //easier -- shortcut

int main(VOID)
{
  char buf[1024];                           //i/o buffer
  STARTUPINFO si;
  SECURITY_ATTRIBUTES sa;
  SECURITY_DESCRIPTOR sd;               //security information for pipes
  PROCESS_INFORMATION pi;
  HANDLE newstdin,newstdout,read_stdout,write_stdin;  //pipe handles

  ZeroMemory( &si, sizeof(si) );
  si.cb = sizeof(si);
  ZeroMemory( &pi, sizeof(pi) );

  sa.lpSecurityDescriptor = NULL;
  sa.nLength = sizeof(SECURITY_ATTRIBUTES);
  sa.bInheritHandle = true;         //allow inheritable handles

  if (!CreatePipe(&newstdin,&write_stdin,&sa,0))   //create stdin pipe
  {
    ErrorMessage("CreatePipe");
    getch();
    return 0;
  }
  if (!CreatePipe(&read_stdout,&newstdout,&sa,0))  //create stdout pipe
  {
    ErrorMessage("CreatePipe");
    getch();
    CloseHandle(newstdin);
    CloseHandle(write_stdin);
    return 0;
  }

  GetStartupInfo(&si);      //set startupinfo for the spawned process

/*
*  The dwFlags member tells CreateProcess how to make the process.
*  STARTF_USESTDHANDLES validates the hStd* members. STARTF_USESHOWWINDOW
*  validates the wShowWindow member.
*/
  si.dwFlags = STARTF_USESTDHANDLES|STARTF_USESHOWWINDOW;
  si.wShowWindow = SW_HIDE;
  si.hStdOutput = newstdout;
  si.hStdError = newstdout;     //set the new handles for the child process
  si.hStdInput = newstdin;
  //char app_args[] = "";
  //char app_spawn[] = "C:\\WINDOWS\\system32\\cmd.exe";
  char app_spawn[] = "D:\\Prog\\v0\\mplayer\\mplayer.exe";
  char app_args[] = "-slave -idle -quiet 
D:\\Prog\\MediaRythmo\\v0\\0004.avi";
 
  //spawn the child process
  if (!CreateProcess(app_spawn,app_args,NULL,NULL,TRUE,0,NULL,NULL,&si,&pi))
  {
    ErrorMessage("CreateProcess");
    getch();
    CloseHandle(newstdin);
    CloseHandle(newstdout);
    CloseHandle(read_stdout);
    CloseHandle(write_stdin);
    return 0;
  }

  unsigned long exit=0;  //process exit code
  unsigned long bread;   //bytes read
  unsigned long avail;   //bytes available

  bzero(buf);
  for(;;)      //main program loop
  {
    GetExitCodeProcess(pi.hProcess,&exit);      //while the process is 
running
    if (exit != STILL_ACTIVE)
      break;
    PeekNamedPipe(read_stdout,buf,1023,&bread,&avail,NULL);
    //check to see if there is any data to read from stdout
    if (bread != 0)
    {
      bzero(buf);
      if (avail > 1023)
      {
        while (bread >= 1023)
        {
          ReadFile(read_stdout,buf,1023,&bread,NULL);  //read the stdout 
pipe
          printf("%s",buf);
          bzero(buf);
        }
      }
      else {
        ReadFile(read_stdout,buf,1023,&bread,NULL);
        printf("%s",buf);
      }
    }
    if (kbhit())      //check for user input.
    {
      bzero(buf);
      *buf = (char)getche();
      //printf("%c",*buf);
      WriteFile(write_stdin,buf,1,&bread,NULL); //send it to stdin
      if (*buf == '\r') {
        *buf = '\n';
        printf("%c",*buf);
        WriteFile(write_stdin,buf,1,&bread,NULL); //send an extra 
newline char,
                                                  //if necessary
      }
    }
  }

  // Close process and thread handles.
  CloseHandle( pi.hProcess );
  CloseHandle( pi.hThread );
  CloseHandle(newstdin);            //clean stuff up
  CloseHandle(newstdout);
  CloseHandle(read_stdout);
  CloseHandle(write_stdin);
}

//----------- STOP -------------