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• AForge.Video.VideoException : Cannot allocate video picture

  23 octobre 2015, par user5389242

  I’m trying to convert images into a video file, but I’m getting the following error :

  An unhandled exception of type ’AForge.Video.VideoException’ occurred in AForge.Video.FFMPEG.dll

  Additional information : Cannot allocate video picture.

  The error occurs on writer.Open :

  writer = new VideoFileWriter();
  
  writer.Open("/output.avi", width, height, 30, VideoCodec.MPEG4, 1000000);

• SVT-AV1 : After encoding the video seeking is very bad in any video player (even HTML5)

  18 juin 2020, par Viktor Machnik

  i am using SVT-AV1 and FFMPEG to encode Videos into the AV1 video and opus audio codec (.webm), it works fine, except that the video seeking do not work really (extremly bad). When i seek, the CPU useage jumps up and it takes up to minutes until the seeking process finishes.

  



  Here is how i encode the videos :

  



  

  1. Convert any video into yuv : ffmpeg -i  -preset veryslow -level 6.2 .yuv

  


  2. First AV1 run svt-av1 -i '.yuv' -w  -h  --fps  --rc 0 -q 30 --preset 8 -b '.\output1.ivf' --output-stat-file '.\stat_file.stat' --keyint 1 --enable-restoration-filtering 1

  


  3. Second AV1 run svt-av1 -i '.yuv' -w  -h  --fps  --rc 0 -q 30 --preset 3 -b '.\output.ivf' --input-stat-file '.\stat_file.stat' --keyint 1 --enable-restoration-filtering 1

  


  4. Get source video audio in opus codec ffmpeg -i  -c:a libopus -vn -preset veryslow -level 6.2 output.ogg

  


  5. Get final .webm video ffmpeg -i output.ivf -i output.ogg -c copy output.webm

  


  



  I have allready tryed to play with the —keyin option, also just letting it away and use the encoder default, but the results are always the same. (--keyin 1 seems to work better than without this option, but also very very bad)

  



  What am i doing wrong ?

  



  Extras : I am using Windows 10 with downloaded version of SVT-AV1 and FFMPEG (I just renamed the SVT-AV1 Encoder .exe file to be svt-av1.exe). Used CPU is Ryzen 9 3900X

  


• Adding transparency to a video from black and white (and gray) alpha information video images

  3 juillet 2018, par Jan F.

  I’d like to create a video with transparency (and semi transparency) in android. The images of the source video are split into two images, the top one with color information (looks like the normal video image), the bottom one with alpha information (the same shapes but only in black and white and gray, black means transparent).

  This is the solution for iOS :
  https://medium.com/@quentinfasquel/ios-transparent-video-with-coreimage-52cfb2544d54

  What would be the best way to to this in android ?

  Can this be solved with javacv, FFmpegFrameGrabber, FFmpegFrameFilter etc.?

  Or better with OpenGL ES and shaders ?

  Are there any samples ?

  Thanks !