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• Real-time video render

  21 août 2014, par Max Grigoriev

  We’re staring a new project where we should be able to modify on the fly video - add text, insert image.
  Project is planing to be written in Java.
  I’m a newbie in video processing so I want to understand.
  What is the best and fast solution to modify video and return to client (web browser).
  I can easy do it using ffmpeg but mp4 is not streamable. And I should write it to file first and then return to client - it’s not fast.
  Maybe my question is very abstract but I should to start from somewhere :)

  Thanks

• How can i convert and compress in real time batch of images to mp4 video file ?

  29 juin 2015, par Brubaker Haim

  In my directory on the hard disk i have many images : screenshot000001.bmp , screenshot000002.bmp....screenshot001200.bmp

  I want to do two things :

  1. For testing using the cmd(Command Prompt) and to compress and convert the images to mp4 video file.

  2. In my program in real time while my program take the screenshots and save them to the hard disk to compress them and build the mp4 video file in real time.

  For the first part i tried to type in cmd :

  ffmpeg -f image2 -i screenshot%d.bmp -vcodec libx264 -b 800k video.avi

  But what i got is two errors :

  [image2 @ 0000000004766380] Could find no file with path ’screenshot%d.bmp’ and
  index in the range 0-4
  screenshot%d.bmp : No such file or directory

  I copied the ffmpeg.exe to the directory where the images are in.
  E :\screenshots

  For the second part this how i’m taking the screenshots in real time :

  A button click event that start a timer :

  private void button1_Click(object sender, EventArgs e)
  
          {
  
              timer1.Start();
  
          }

  Then in the tick event :

      ScreenShot shot = new ScreenShot();
  
      public static int counter = 0;
  
      private void timer1_Tick(object sender, EventArgs e)
  
      {
  
          counter++;
  
          shot.GetScreenShot(@"e:\screenshots\", "screenshot");
  
          if (counter == 1200)
  
          {
  
              timer1.Stop();
  
          }
  
      }

  This line shot.GetScreenShot(@"e :\screenshots\", "screenshot") ; save the screenshots to the hard disk.
  Here after each screenshot save i want to compress and build the mp4 video file in real time.

  I tried this and got errors :

  ffmpeg -f image2 -i screenshot%06d.bmp -vcodec libx264 -b 800k video.avi

  Error message :

  ffmpeg version N-73165-gf1e1730 Copyright (
  
    built with gcc 4.9.2 (GCC)
  
    configuration: --enable-gpl --enable-vers
  
  isynth --enable-bzlib --enable-fontconfig -
  
  le-iconv --enable-libass --enable-libbluray
  
  enable-libdcadec --enable-libfreetype --ena
  
  ibilbc --enable-libmodplug --enable-libmp3l
  
  le-libopencore-amrwb --enable-libopenjpeg -
  
  able-libschroedinger --enable-libsoxr --ena
  
  ble-libtwolame --enable-libvidstab --enable
  
   --enable-libvorbis --enable-libvpx --enabl
  
  e-libx264 --enable-libx265 --enable-libxavs
  
  ble-decklink --enable-zlib
  
    libavutil      54. 27.100 / 54. 27.100
  
    libavcodec     56. 45.100 / 56. 45.100
  
    libavformat    56. 38.102 / 56. 38.102
  
    libavdevice    56.  4.100 / 56.  4.100
  
    libavfilter     5. 18.100 /  5. 18.100
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  2.100 /  1.  2.100
  
    libpostproc    53.  3.100 / 53.  3.100
  
  [bmp @ 0000000002f77ce0] bad magic number
  
      Last message repeated 3 times
  
  [image2 @ 0000000002f76380] decoding for st
  
  [image2 @ 0000000002f76380] Could not find
  
   bmp, none): unspecified size
  
  Consider increasing the value for the 'anal
  
  screenshot%06d.bmp: could not find codec pa
  
  Input #0, image2, from 'screenshot%06d.bmp'
  
    Duration: 00:00:02.88, start: 0.000000, b
  
      Stream #0:0: Video: bmp, none, 25 fps,
  
  Please use -b:a or -b:v, -b is ambiguous
  
  Codec AVOption b (set bitrate (in bits/s))
  
  vi) has not been used for any stream. The m
  
  e (e.g. a video option with no video stream
  
  some encoder which was not actually used fo
  
  Output #0, avi, to 'video.avi':
  
  Output file #0 does not contain any stream

• How can I use FFMPEG to stream an mp4/mov file as its being created in real time ?

  9 janvier 2021, par rrst8

  I was wondering if I could stream an mp4/mov file as it was being created to an RTSP server. Unfortunately, the source where I want to stream from does not have FLV output and so I wanted to know if there was a way I could stream mp4/mov instead.