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• Getting garbled frames when exporting video to image sequence in FFMPEG

  28 janvier 2018, par film_guy01

  I’m very new to FFMPEG to go easy on me.

  So I’ve just started playing around with ffmpeg but I’m getting some promising results. But I keep getting images like this : https://i.imgur.com/wIMkVoV.jpg which is not what that image it supposed to look like (in case you were uncertain).

  here’s been my command line code :

  ffmpeg -i inputfile.mkv -q:v 1 -r 0.20 outputfile_%04d.jpg

  My input file is a .h264 compressed ultra high definition video saved as .mkv format.

  I’ll get error messages like this :

  [h264 @ 0x7fbccd84ce00] co located POCs unavailable
  
  [h264 @ 0x7fbccd81e200] error while decoding MB 45 61, bytestream -17 drop=406 speed=1.71x    
  
  [h264 @ 0x7fbccd81e200] concealing 17764 DC, 17764 AC, 17764 MV errors in P frame
  
  [h264 @ 0x7fbccd84ce00] co located POCs unavailable
  
  [h264 @ 0x7fbccd814400] reference picture missing during reorder
  
  [h264 @ 0x7fbccd814400] Missing reference picture, default is 65986
  
  [h264 @ 0x7fbccd814400] error while decoding MB 71 100, bytestream -26drop=598 speed=1.79x    
  
  [h264 @ 0x7fbccd814400] concealing 8378 DC, 8378 AC, 8378 MV errors in B frame
  
  [h264 @ 0x7fbccd81dc00] co located POCs unavailable
  
  [h264 @ 0x7fbccd81e200] co located POCs unavailable
  
  [h264 @ 0x7fbccd863200] co located POCs unavailable
  
  [h264 @ 0x7fbccd814400] error while decoding MB 43 116, bytestream -5 drop=710 speed=1.81x   

  Sometimes I get these errors as well, but I’m not sure they’re related.

  [h264 @ 0x7fbcce004c00] Stream #0: not enough frames to estimate rate; consider increasing probesize
  
  [swscaler @ 0x7fbccf0c8000] deprecated pixel format used, make sure you did set range correctly

  Any idea how to fix this problem and get ffmpeg to export the images cleanly ? This would be HUGE if I could figure out how to get this working.

  Thanks !

• lavf : Use wchar functions for filenames on windows for mkdir/rmdir/rename/unlink

  17 novembre 2014, par Martin Storsjö

  lavf : Use wchar functions for filenames on windows for mkdir/rmdir/rename/unlink
  This makes sure that the internal utf8 path names are handled
  
  properly - the normal file handling functions assume path names
  
  are in the native codepage, which isn’t utf8.
  This assumes that the tools outside of lavf don’t use the mkdir
  
  definition. (The tools don’t do the same reading of command line
  
  parameters as wchar either - they probably won’t handle all possible
  
  unicode file parameters properly, but at least work more predictably
  
  if no utf8/wchar conversion is involved.)
  This is moved further down in os_support.h, since windows.h shouldn’t
  
  be included before winsock2.h, while io.h needs to be included before
  
  the manual defines for lseek functions.
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DBH] libavformat/internal.h
  • [DBH] libavformat/os_support.h

• Identification of Frame Type using Xuggle

  1er décembre 2012, par Samveen

  I'm trying to extract just the I-Frames from a video using the Xuggle API. I took the first example from the Xuggle source from here and removing the display code, added the following code snippet to identify the frame type of the current frame :

  //    Decode loop {
  
            if (picture.isComplete()) {
  
                com.xuggle.xuggler.IVideoPicture.PictType type = picture.getPictureType()
  
                if(type == com.xuggle.xuggler.IVideoPicture.PictType.I_TYPE)
  
                    System.out.println("(I-Frame)\n");
  
                else if(type == com.xuggle.xuggler.IVideoPicture.PictType.B_TYPE)
  
                    System.out.println("(B-Frame)\n");
  
                else if(type == com.xuggle.xuggler.IVideoPicture.PictType.P_TYPE)
  
                    System.out.println("(P-Frame)\n");
  
                else if(type == com.xuggle.xuggler.IVideoPicture.PictType.S_TYPE)
  
                    System.out.println("(S-Frame)\n");
  
                else if(type ==com.xuggle.xuggler.IVideoPicture.PictType.DEFAULT_TYPE)
  
                    System.out.println("(Default)\n");
  
                else
  
                    System.out.println("(Other)\n");
  
            }
  
  //    }

  Using this code, I never get an I-Frame in my test video, which by definition of being it being a video is impossible (every video's first frame MUST be an I-Frame) and every frame is identified as

  When I use mplayer to extract the I-Frames from the same video using :

  mplayer video20.mp4 -benchmark -nosound -noaspect -noframedrop -ao null \
  
          -vo png:z=6 -vf framestep=I

  I correctly get a set of I-Frames.

  The number of frames displayed by my code is identical to that extracted by mplayer without the framestep filter

  mplayer video20.mp4 -benchmark -nosound -noaspect -noframedrop -ao null \
  
          -vo png:z=6

  The input video in question is an H264 encoded video.

  My question is that what can I do to correctly get the I-Frames from the video using xuggle

  I picked up the method from Java - Keyframe extraction from a video