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• FFMpeg : Add background image during the process of video creation

  10 juillet 2018, par Killer

  In reference to my previous question FFMpeg : merge images with audio for specific duration I have successfully merged few images with audio for specific duration by using following command.

  ffmpeg \
  
  -y \
  
  -f concat \
  
  -safe 0 \
  
  -r 1/5 \
  
  -i concat.txt \
  
  -i audio.ogg \
  
  -c:v libx264 \
  
  -profile:v high \
  
  -crf 17 \
  
  -preset ultrafast \
  
  -strict experimental \
  
  -t 15 \
  
  output.mp4

  In order to add a background image, I tried to use https://superuser.com/a/876275/299733 and other solutions that exist on the web. But the given solution doesn’t overlay my images properly and I was getting black video throughout the duration. Therefore, I encode the resultant video from earlier command once again via :

  ffmpeg \
  
  -y \
  
  -loop 1 \
  
  -i bg.jpg \
  
  -i output.mp4 \
  
  -filter_complex "overlay=(W-w)/2:(H-h)/2:shortest=1,format=yuv420p" \
  
  -c:v libx264 \
  
  -profile:v high \
  
  -crf 17 \
  
  -preset ultrafast \
  
  -strict experimental \
  
  -t 15 \
  
  output2.mp4

  Now, I am able to get the desired result. Is there any way to merge both requests into a single pass ? Or a better way without loss of any performance ?

  Additional details :

  concat.txt

  file '/home/shubham/Desktop/FFMpeg/image_1.jpg'
  
  file '/home/shubham/Desktop/FFMpeg/image_2.jpg'
  
  file '/home/shubham/Desktop/FFMpeg/image_3.jpg'

  Based on @gyan response

  Updated concat.xml :

  file '/home/shubham/Desktop/FFMpeg/image_4.jpg'
  
  duration 5
  
  file '/home/shubham/Desktop/FFMpeg/image_5.jpg'
  
  duration 5
  
  file '/home/shubham/Desktop/FFMpeg/image_6.jpg'
  
  duration 5
  
  file '/home/shubham/Desktop/FFMpeg/image_6.jpg'

  Updated Command :

  ffmpeg \
  
  -y \
  
  -loop 1 \
  
  -i bg.jpg \
  
  -f concat \
  
  -safe 0 \
  
  -i concat.txt \
  
  -i audio.ogg \
  
  -filter_complex "[1]fps=25[v];[0][v]overlay=(W-w)/2:(H-h)/2:shortest=1,format=yuv420p" \
  
  -c:v libx264 \
  
  -profile:v high \
  
  -crf 17 \
  
  -preset ultrafast \
  
  -strict experimental \
  
  -t 15 \
  
  output.mp4

  The problem is that when images are of different resolution or even for the same resolution the images are skipped. And most of the times last image is shown. However, there are no criteria of which image is selected and which one is skipped.
  SAMPLE :
  https://drive.google.com/file/d/1JxCsV2eudKzdgWWuefXqdaWPaBf9Dzzd/view?usp=sharing

  However, if I repeatedly used the same image or copy the image and rename it. In both the cases, I get proper images on the background without any skipping.

  EDIT : 09 JULY 2018

  As @gyan stated in comments : Convert each image to same resolution and type.
  I check the info of images. via

   ffmpeg -i image_X.jpg

  And found out two images have different encoding :

  Image 1 : Stream #0:0 : Video : mjpeg, yuvj420p(pc, bt470bg/unknown/unknown), 640x480 [SAR 72:72 DAR 4:3], 25 tbr, 25 tbn, 25 tbc

  Image 2 : Stream #0:0 : Video : mjpeg, yuvj444p(pc, bt470bg/unknown/unknown), 640x480 [SAR 72:72 DAR 4:3], 25 tbr, 25 tbn, 25 tbc

  Which is the possible cause of the failure in merging.

• Create an RTP/RTSP or HTTP stream using OpenCV frames

  1er avril 2018, par Vector

  I have a custom board which takes input stream from a IP camera and the application perform facial detection using OpenCV on the input video stream.

  My use case is to provide an output stream through network which will be accessible through VLC on any device connected in the same network.

  I tried writing OpenCV frames through VideoWriter :

  VideoWriter outStream("/home/user/frames/frame.mjpg", CV_FOURCC('M','J','P','G'), CAP_PROP_FPS, img.size(), true);
  
   if (outStream.isOpened()){
  
       outStream.write(img);

  and creating a stream using mjpg_streamer like :

  mjpg_streamer -i "input_file.so -f /home/user/frames" -o "output_http.so -w /usr/local/www -p 5241"

  But the above process shows a lot of latency.
  I can’t use imshow as my hardware does not have any video output port.

  Here is my code : https://pastebin.com/s66xGjAC

• OpenCV WITH_FFMPEG : Unable to stop the stream : Inappropriate ioctl for device

  16 septembre 2017, par LaserJesus

  I’m receiving the error "Unable to stop the stream : Inappropriate ioctl for device" when trying to open a video file with OpenCV 3.2 in Python 3.5 on Ubuntu 16.04

  Before marking as a duplicate, please note that I’ve looked at a lot of posts and none of them solved the problem for me.

  I’ve setup a virtual environment under conda. I know there’s a way to install OpenCV with conda but I don’t believe it includes ffmpeg or other cuda abilities I need included. I’ve built the source for OpenCV 3.2 with WITH_FFMPEG on and WITH_LIBV4L on, which I’ve read could also be a solution to my problem. I’ve also set all of the python3 cmake variables to point to the python instance in the virtual environment in question :

  PYTHON3_LIBRARY               /home/brett/anaconda3/envs/opencvtest/lib/
  
  PYTHON3_LIBRARY_DEBUG         
  
  PYTHON3_NUMPY_INCLUDE_DIRS    /home/brett/anaconda3/envs/opencvtest/lib/python3.5/site-packages/numpy/core/include
  
  PYTHON3_PACKAGES_PATH  /home/brett/anaconda3/envs/opencvtest/lib/python3.5/site-packages/

  After generating the make configuration I compile inside the build directory with make -j8 then install with sudo make install. Everything runs successfully and in the install I see it declare that FFMPEG is ON. If I now start Python in the virtual environment I can import cv2, but I see the above error when I try to open a video file. I can capture video from the webcam without a problem. In python the command print(cv2.__file__) displays the directory :

  /home/brett/anaconda3/envs/opencvtest/lib/python3.5/site-packages/cv2.cpython-35m-x86_64-linux-gnu.so

  So it appears to be using the correct OpenCV library.

  I’ve also tried installing via conda with the command :

  conda install -c menpo opencv3 ffmpeg

  The output was :

  The following NEW packages will be INSTALLED:
  
  
  
      ffmpeg: 3.1.3-0 menpo 

  After the install completed I still get the same error message.

  What else do I need to do for Python to load a video file with the OpenCV version that I built under Conda ?