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• FFmpeg/OpenCV force ignore input frame duration with rtsp ?

  6 août 2019, par ZisIsNotZis

  I was experiencing a ~5 sec delay when playing a rtsp stream from an IP camera. After a bunch of googling (especially this question), I reduced the delay to ~1 sec using the following command :

  ffplay -fflags nobuffer -flags low_delay -framedrop -strict experimental \
  
         -probesize 32 -sync ext rtsp://xxx.xxx.xxx.xxx

  But when I tried mplayer -benchmark command from the same question, I found the delay immediately goes away (i.e. almost 0 delay).

  In the man page of mplayer, it sais :

  -benchmark

  Prints some statistics on CPU usage and dropped frames at the end of playback. Use in combination with -nosound and -vo null for benchmarking only the video codec.

  NOTE : With this option MPlayer will also ignore frame duration when playing only video (you can think of that as infinite fps).

  I feel this "ignore frame duration" is the key to the question, but after a bunch of googling, I didn’t find any flag related to this in ffmpeg. I’m wondering how to force ignore input frame duration in ffmpeg ?

  On the other hand, the reason I’m using ffmpeg is because I need to do image processing using opencv, while I found it seems to be using some part of ffmpeg under-the-hood when doing

  cv.VideoCapture('rtsp://xxx.xxx.xxx.xxx')

  A solution that directly solves the problem in opencv would be even more appreciated. I did try reading the VideoCapture repeatedly in a separate thread, that didn’t help.

  ---

  Some info about the RTSP stream : h264, 1920x1080, 15fps, 1 key frame per 4s

  Some other solutions I tried :

  ffmpeg -r 99999 -i ...
  
  # didn't work
  
  
  
  mplayer ... -dumpstream
  
  # it core dumped

• Android - Adding Effects to Videos like Instagram

  7 novembre 2017, par San

  I am in need of a idea to apply filters to video like Instagram, video trimming and fetching images from the video. I have researched a lot and all I can come up with is the following ways to achieve what I want :

  1. FFMPEG
  2. Open CV
  3. Camera2 API

  FFMPEG :

  As far as FFMPEG is considered, majority of the average level droid devs feel that its a pain cause it involves NDK and compiling the FFMPEG commands.The above mentioned link is self-explanatory and it saves me the pain of setting up the NDK but the biggest drawback in this is that its not stable and its REALLY slow.
  My query on this topic is that how do I compile FFMPEG into my project. I have gone through several links to integrate FFMPEG as follows :

  One

  Two

  Three

  The third link seemed to make sense but ultimately I couldn’t understand completely and go where,do what after following those steps.

  Question 1 :

  Is there is a solid Android - FFMPEG Integration Document that can help a beginner like me ?

  Open CV

  Question 2 :

  I haven’t tried Open CV yet but will it be worth it ?

  Camera2 API

  Question 3 :

  As far as I researched, I can see that the Camera2 API can help us shoot videos and images with effects added to it but will it be useful for me to process the already existing videos and images ? I don’t have the requirement to add effects to the camera while its captured, its aftermath is where I want to add my effects.

  If someone is kind enough to accept my stupidity and help me out, I am thankful to them.

  Will going ahead with FFMPEG be good or OpenCV or Camera2 API will be better ?

• Android - Adding Effects to Videos like Instagram

  10 mai 2016, par San

  I am in need of a idea to apply filters to video like Instagram, video trimming and fetching images from the video. I have researched a lot and all I can come up with is the following ways to achieve what I want :

  1. FFMPEG
  2. Open CV
  3. Camera2 API

  FFMPEG :

  As far as FFMPEG is considered, majority of the average level droid devs feel that its a pain cause it involves NDK and compiling the FFMPEG commands.The above mentioned link is self-explanatory and it saves me the pain of setting up the NDK but the biggest drawback in this is that its not stable and its REALLY slow.
  My query on this topic is that how do I compile FFMPEG into my project. I have gone through several links to integrate FFMPEG as follows :

  One

  Two

  Three

  The third link seemed to make sense but ultimately I couldn’t understand completely and go where,do what after following those steps.

  Question 1 :

  Is there is a solid Android - FFMPEG Integration Document that can help a beginner like me ?

  Open CV

  Question 2 :

  I haven’t tried Open CV yet but will it be worth it ?

  Camera2 API

  Question 3 :

  As far as I researched, I can see that the Camera2 API can help us shoot videos and images with effects added to it but will it be useful for me to process the already existing videos and images ? I don’t have the requirement to add effects to the camera while its captured, its aftermath is where I want to add my effects.

  If someone is kind enough to accept my stupidity and help me out, I am thankful to them.

  Will going ahead with FFMPEG be good or OpenCV or Camera2 API will be better ?