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• How to use the ffmpeg overlay_cuda filter to make a SBS video ?

  24 août 2020, par Maxtrix

  FFMPEG a few months ago launched the new version of FFMPEG with the new filter "overlay_cuda", this filter makes the same as the "overlay" but using an Nvidia card for applying it.

  


  I found on the FFMPEG website description of the filter, but no examples of how to use it. The only examples I found are from the developer commits but are to put a video or a photo over another video.

  


  I before the normal overlay filter to do this using a nullsrc image with the twice of width but now I don't know how to with this filter.

  


  Commit description : https://patchwork.ffmpeg.org/project/ffmpeg/patch/20200318071955.2329-1-yyyaroslav@gmail.com/
ffmpeg documentation webpage : https://ffmpeg.org/ffmpeg-filters.html#overlay_005fcuda-1

  


  I hope you can help me.

  


  Update :

  


  I made this FFmpeg order that :

  


  

  1. Input each video.

  


  2. The first video creates padding to the right and then is uploaded to the card's memory.

  


  3. With overlay Cuda, the other video puts on the right of the original video.

  


  


  ffmpeg -y -loglevel info \
-i $video_1  \
-hwaccel cuda -hwaccel_output_format cuda -i $video_2 \
-filter_complex \
" \
[0:v]pad=w=2*iw:h=ih:x=0:y=0,hwupload_cuda[base];
[base][1:v]overlay_cuda=x=800:y=0" \
-an -c:v h264_nvenc overlay_test.mp4


  


  But I get this error message :

  


  [overlay_cuda @ 0x55fdec4b2ec0] Can't overlay nv12 on yuv420p 
[Parsed_overlay_cuda_2 @ 0x55fdec4b2d80] Failed to configure output pad on Parsed_overlay_cuda_2
Error reinitializing filters!
Failed to inject frame into filter network: Invalid argument
Error while processing the decoded data for stream #1:0


  


  I have issues with the pixel formats, I hope you can help me.

  


  Update 2 :

  


  I finally solved the pixel format issue and now makes the overlay with the padding (adds space to the overlay video)

  


  This is the command that succeeds :

  


  ffmpeg -y -loglevel info \
-i $video_1  \
-hwaccel cuda -hwaccel_output_format cuda -i $video_2 \
-filter_complex \
" \
[0:v]pad=w=2*iw:h=ih:x=0:y=0,hwupload_cuda,scale_npp=format=nv12[base];
[base][1:v]overlay_cuda=x=800:y=0" \
-an -c:v h264_nvenc overlay_test.mp4



  


  Now I want to change x=800 to a variable like x=iw+1 but it seems this filter doesn't support that. Is there a way to set a global variable ?

  


• Compile the GPU version of FFMPEG on OpenCV

  22 juin 2018, par Dyex719

  When I try to use GPU
  FFMPEG on opencv by using a command like :

  VideoCapture cap("rtsp link");
  
  
  
  for(;;)
  
  {
  
  mat frame;
  
  cap>>frame;
  
  }

  I don’t see any output on nvidia-smi despite compiling the GPU version of FFMPEG.

  I am trying to get FFMPEG to use GPU to improve the speed of my program. I got FFMPEG from cloning https://git.ffmpeg.org/ffmpeg.git and followed the steps here https://developer.nvidia.com/ffmpeg to get it working.

  I have validated the results using nvidia-smi dmon -i 0 and have seen that dec% increases when I run the command ffmpeg -c:v h264_cuvid -i test_video.mp4 test_output.mkv.

  I then compiled Opencv to use the GPU enabled FFMPEG, I check this by running getBuildInformation from opencv :

  Video I/O:
DC1394 1.x: NO
DC1394 2.x: YES (ver 2.2.4)
FFMPEG: YES
codec: YES (ver 58.20.103)
format: YES (ver 58.17.100)
util: YES (ver 56.18.102)
swscale: YES (ver 5.2.100)
resample: NO
gentoo-style: YES
GStreamer: NO
OpenNI: NO
OpenNI PrimeSensor Modules: NO
OpenNI2: NO
PvAPI: NO
GigEVisionSDK: NO
UniCap: NO
UniCap ucil: NO
V4L/V4L2: NO/YES
XIMEA: NO
Xine: NO
gPhoto2: NO

  I cross-verify that I’m using the same ffmpeg (by checking the version numbers) :

  ffmpeg version N-91273-g67747c8 Copyright (c) 2000-2018 the FFmpeg developers
 built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.9) 20160609
 configuration: --enable-cuda --enable-cuvid --enable-nvenc --enable-nonfree --enable-libnpp --extra-cflags=-I/usr/local/cuda/include --extra-ldflags=-L/usr/local/cuda/lib64
 libavutil      56. 18.102 / 56. 18.102
 libavcodec     58. 20.101 / 58. 20.101
 libavformat    58. 17.100 / 58. 17.100
 libavdevice    58.  4.101 / 58.  4.101
 libavfilter     7. 25.100 /  7. 25.100
 libswscale      5.  2.100 /  5.  2.100
 libswresample   3.  2.100 /  3.  2.100

  Please advise me on how I should compile OpenCV to use the GPU version of FFMPEG. Thank you !

• How to generate video from images. Proper way

  2 mai 2021, par Ec7ipse

  Good day ! Im really curious how apps like (Unfold, or any instagram stories generation) work ? How they generate video ?

  


  I did some research on the internet, and found some info. But the question.

  


  

  1. Is it good to use some image processing libraries like(pguimage) to generate sequence of images and then use ffmpeg or another libraries to encode this sequence to video. Or maybe you know the proper method how to make it.

  


  2. How actually blender or after effect work ? Do they generate sequence of frames and then put them into ffmpeg or they use another technique ? I've stuck. Maybe you can give me some links ?

  


  


  I tried this on server using (c++) (CImage + ffmpeg) but it was slow. (2 min video was rendered within 8 min). CIMG library uses only cpu. So the main question, is it good to do like this : generate sequence of images and put them into ffmpeg or smt.

  


  Maybe you have some links.