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• How can low frame rate video be made to look more smooth ?

  14 décembre 2016, par d3pd

  I am trying to clean up a video that was recorded in 2003 in low-light conditions on what was possibly a cameraphone. The video has been cleaned up somewhat (cropped, logos removed and stabilized), but it remains quite jerky, due in large part to its low frame rate. What are some tricks that might clean up the video in this regard ? I feel that I am asking for something a bit like tweening in flash animations, but for pixels, whereby additional frames are generated using nearby frames of the video. Does such a trick exist ? Is there another way to approach this problem ?

  To reproduce the video processing so far, take the following steps :

  # get video
  
  wget http://www.anwarweb.net/saddamdown.wmv
  
  # crop
  
  ffmpeg -i saddamdown.wmv -filter:v "crop=292:221:14:10" -c:a copy saddamdown_crop.wmv
  
  # remove logo 1
  
  ffmpeg -i saddamdown_crop.wmv -vf delogo=x=17:y=77:w=8:h=54 -c:a copy saddamdown_crop_delogo_1.wmv
  
  # remove logo 2
  
  ffmpeg -i saddamdown_crop_delogo_1.wmv -vf delogo=x=190:y=174:w=54:h=8 -c:a copy saddamdown_crop_delogo_1_delogo_2.wmv
  
  # stabilize
  
  ffmpeg -i saddamdown_crop_delogo_1_delogo_2.wmv -vf deshake saddamdown_crop_delogo_1_delogo_2_deshake.wmv

  Note : The video is of the Saddam Hussein execution.

• Use ffmpeg to modify single frame without remux ?

  6 février 2017, par 1337GameDev

  I am curious of a fast way to modify a video, slightly, as to force the video to hash differently than the source. I want to avoid changes to meta tags, as these are parsed from the container file and not the video data itself.

  I will be using a process to compare videos for analytical work, but the process requires the 2 inputs to have differing hashes for the video content (otherwise the analytical process yields odd results). I am testing an improvement on this process, and need to have very similar videos.

  I have currently just used a ffmpeg bash script and filtered a VERY light 2x2 pixel for the first second of the video (90% transparent) and this seems to do the trick as they hash differently, but it requires demux / remux of the video, which takes forever if I want to analyze a lot of videos.

  Is there a way, using ffmpeg, to simple modify a single frame (specified by a time value) and change a single pixel and just copy the rest of the video contents ?

• compiling FFmpeg on AIX

  3 mars 2017, par epitaxial

  I’m a hardware guy that likes to play around with different architectures and operating systems. Anyhow I’m trying to compile FFmpeg on AIX 7.1 using gcc but having some issues. I grabbed the latest code from git and while it does compile with a few warnings FFmpeg does not work. From my limited understanding it looks like the code is using 64 bit integers but was compiled as 32 bit ? Maybe someone can shed some light on this. Here is what happens when executing FFmpeg

  ./ffmpeg -i rtsp://192.168.1.9:554 -an -c copy -t 1:00:00 test.mp4
  
  ffmpeg version 3.2.git Copyright (c) 2000-2017 the FFmpeg developers
  
  built with gcc 4.8.5 (GCC)
  
  configuration: --enable-nonfree
  
  libavutil      55. 47.100 / 55. 47.100
  
  libavcodec     57. 81.100 / 57. 81.100
  
  libavformat    57. 66.102 / 57. 66.102
  
  libavdevice    57.  2.100 / 57.  2.100
  
  libavfilter     6. 74.100 /  6. 74.100
  
  libswscale      4.  3.101 /  4.  3.101
  
  libswresample   2.  4.100 /  2.  4.100
  
  [NULL @ 20932ac0] Value 0.000000 for parameter 'avioflags' is not a valid    set of 32bit integer flags
  
  [NULL @ 20932ac0] Value 2097664.000000 for parameter 'fflags' is not a valid set of 32bit integer flags
  
  [NULL @ 20932ac0] Value 0.000000 for parameter 'fdebug' is not a valid set of 32bit integer flags
  
  [NULL @ 20932ac0] Value 1.000000 for parameter 'f_err_detect' is not a valid set of 32bit integer flags
  
  [NULL @ 20932ac0] Value 1.000000 for parameter 'err_detect' is not a valid set of 32bit integer flags
  
  [RTSP demuxer @ 20933220] Value 0.000000 for parameter 'rtpflags' is not a valid set of 32bit integer flags
  
  [RTSP demuxer @ 20933220] Value 0.000000 for parameter 'rtsp_transport' is not a valid set of 32bit integer flags
  
  [RTSP demuxer @ 20933220] Value 0.000000 for parameter 'rtsp_flags' is not a valid set of 32bit integer flags
  
  [RTSP demuxer @ 20933220] Value 15.000000 for parameter 'allowed_media_types' is not a valid set of 32bit integer flags
  
  [rtsp @ 20932ac0] Unable to open RTSP for listening
  
  rtsp://192.168.1.9:554: Can't assign requested address

  Is my reasoning correct ? Thanks.