Recherche avancée

Sur d’autres sites (7408)

• Windows Pipes STDIN and STDOUT Parent Child proc communication IPC FFMPEG

  15 octobre 2018, par Evren Bingøl

  I am writing a simple WINDOWS app which demonstrates piping,

  I pass byte size data down to child proc, increment the value and send the char size data back to parent and loop until it reaches MAX_CHAR
  Pretty much demonstration of "i++" with IPC.

  Parent Process

  while(i<256){
  
      bSuccess = WriteFile(g_hChildStd_IN_Wr, chBuf, sizeof(char), &dwWritten, NULL);
  
      bSuccess = ReadFile(g_hChildStd_OUT_Rd, chBuf, sizeof(char), &dwRead, NULL); // IF THERE IS NO FFLUSH IT BLOCKS
  
  }

  And in Child

  while (i<256){
  
          byte data=0;
  
          fread(&data, sizeof(char), 1, stdout);
  
          data++;
  
          fwrite(&data, sizeof(char), 1, stdout);
  
          //fflush(stdout); IF I DO NOT HAVE THIS  PARENT BLOCKS ON READ
  
  }

  First of all if I do not FFLUSH child proc stdout, the parent blocks on reading child’s stdout.

  How can one run this code without having to fflush child’s stdout.

  Closing the pipe after child’s first write is not an option as it is in a loop and needs to execute 256 times.

  more generically I want the child to write N bytes to parent, parent read that N bytes do something and write back to child another N bytes and child does something with that N bytes and write to parent N bytes. This happens M times.

  thing is I can not use fflush because my final goal is to use a child process that is not implemented by me.

  My final goal is to pipe data to FFMPEG encode the data and read back from the stdin and do this over and over again with out having to fork a new FFMPEG process for each image frame but rather fork one instance of FFMPEG and pipe data in and read data out from it. And since I did not implement ffmpeg and I can not change the source code.

  thanks

  Thanks

• Anomalie #4187 (Fermé) : Connecté en Anglais (langue principale français) pas de bouton pour ajout...

  8 février 2021, par cedric -

  Et je ferme ici car le bug ne concerne pas SVP mais extraire_multi, et donc on traite le problème dans

  #4189

• Can't play MP4 after download

  14 août 2018, par joe

  I am using a downloader program in Firefox to download videos playing in Firefox. Most of the time final MP4 is playable. But sometimes I get MP4 file that looks good(shows file size) but shows no length of video in file explorer.

  I get this error log.

  Could not get information from media 'ESPN 2 (HD) Live Stream Channel' from file 'C:\Download\dwHelper\ESPN 2 (HD) Live Stream Channel.mp4'. The file might be corrupted.
  
  
  
  {
  
      "file": "C:\\Download\\dwHelper\\ESPN 2 (HD) Live Stream Channel.mp4",
  
      "stat": {
  
          "dev": 3831878042,
  
          "mode": 33206,
  
          "nlink": 1,
  
          "uid": 0,
  
          "gid": 0,
  
          "rdev": 0,
  
          "ino": 9007199254752056,
  
          "size": 610722524,
  
          "atimeMs": 1534241605017.09,
  
          "mtimeMs": 1534241604156.685,
  
          "ctimeMs": 1534241604426.08,
  
          "birthtimeMs": 1534237675494.6475,
  
          "atime": "2018-08-14T10:13:25.017Z",
  
          "mtime": "2018-08-14T10:13:24.157Z",
  
          "ctime": "2018-08-14T10:13:24.426Z",
  
          "birthtime": "2018-08-14T09:07:55.495Z"
  
      }
  
  }
  
  Exit code: 1
  
  ffprobe version n4.0-1-gdc49a24-vdhcoapp Copyright (c) 2007-2018 the FFmpeg developers

  built with gcc 5.3.1 (GCC) 20160211

  configuration : —cross-prefix=x86_64-w64-mingw32- —sysroot=/usr/x86_64-w64-mingw32/ —extra-ldflags=-static-libgcc —target-os=mingw32 —arch=x86_64 —prefix=/home/mig/vdhcoapp/converter/src-build/win/64/converter-build —extra-version=vdhcoapp —extra-cflags=-I/home/mig/vdhcoapp/converter/src-build/win/64/deps/include —extra-ldflags=’-static-libgcc -L/home/mig/vdhcoapp/converter/src-build/win/64/deps/lib -L/home/mig/vdhcoapp/converter/src-build/win/64/zlib’ —extra-libs=-lpthread —pkg-config=/usr/bin/x86_64-w64-mingw32-pkg-config —enable-shared —enable-gpl —enable-pthreads —disable-w32threads —enable-libmp3lame —enable-libopenjpeg —enable-libopus —enable-libtheora —enable-libvorbis —enable-libvpx —enable-libwebp —enable-libx265 —enable-libxvid —enable-libx264 —enable-avresample —disable-doc

  libavutil 56. 14.100 / 56. 14.100

  libavcodec 58. 18.100 / 58. 18.100

  libavformat 58. 12.100 / 58. 12.100

  libavdevice 58. 3.100 / 58. 3.100

  libavfilter 7. 16.100 / 7. 16.100

  libavresample 4. 0. 0 / 4. 0. 0

  libswscale 5. 1.100 / 5. 1.100

  libswresample 3. 1.100 / 3. 1.100

  libpostproc 55. 1.100 / 55. 1.100

  [mov,mp4,m4a,3gp,3g2,mj2 @ 00000000024c3900] moov atom not found

  C :\Download\dwHelper\ESPN 2 (HD) Live Stream Channel.mp4 : Invalid data found when processing input

  It looks like moov atom is missing thus can’t aggregate PART file into final playable MP4.

  I understand that during download, PART file is created. Then later PART is aggregated into final MP4.

  So question is how can I make this MP4 to play ?
  or is it impossible to play cus moov atom was not properly downloaded ?

  Any thoughts ?
  Thanks