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• Playing large, 360 video files (4gb+), on Oculus Go, using Unity3D VideoPlayer

  15 avril 2020, par SteenPetersen

  I am using unity VideoPlayer to play 360 degree video files. Its all working wonderfully and I can build to Oculus Go and Quest without issue.

  



  The problem is that if the video file exceeds a file size of a little more than 4 GB then, once built, it wont play the file.

  



  Now this, to me, is odd behavior. The Oculus Go will play the video file if it is simply added to the gallery and played, telling me that the Oculus Go is capable of playing the file. I am a bit lost as to what to look at with this and how to go about fixing it. The 4GB file size limit reminded of the fat3d file size limit. But I'm unsure if this is related or not since it can play the video in the gallery.

  



  Thus far I have solved the problem by using FFMPEG to reduce the constant rate factor and thus quality of the video to get under the limit as this was hardly noticeable in the quality and reduced the file size significantly. The problem is that some videos are quite long and it seems that I actually need some of them to be approx 5 GB.

  



  Any insight is appreciated.

  


• A specific MP4 file is not playable with avfoundation in iOS

  3 juillet 2020, par Rabel Ahmed

  I have an mp4 video file that I want to play it in iOS using avfoundation. Unfortunately, the file is not being played and unable to save into the default gallery(photos) even it has h264 video codec and aac audio codec. And it is only playable when I reencode it using ffmpeg. I want to know why the file only becomes playable after reencoding the video ?

  


  Not Playable(originalFile.mp4) vs Playable File(outputFile.mp4) Information Comparison

  


  

  


  File is playable with avfoundation when these commands are being applied :

  


  


  1. ffmpeg -y -hide_banner -i originalFile.mp4 -f mp4 -vcodec h264 -vf scale=out_color_matrix=bt709 -color_primaries bt709 -color_trc bt709 -colorspace bt709 -b:v 5703k -acodec aac -b:a 249k outputFile.mp4

     


  


  2. ffmpeg -y -hide_banner -i originalFile.mp4 -f mp4 -vcodec h264 -acodec aac outputFile.mp4

     


  


  


  File is not playable with avfoundation when this command is being applied :

  


  

  1. ffmpeg -y -hide_banner -i originalFile.mp4 -f mp4 -vcodec copy -acodec aac outputFile.mp4

  


  


  originalFile.mp4 file link : https://drive.google.com/file/d/1-yZFL0EsLztMIfwU79Al6dv8gdwJyGAD/view?usp=sharing

  


  ffprobe streams of both files are here
https://www.diffchecker.com/VgZL66QB

  


• How can I simply do color interpolation on this image and then save the image ? With RGBA channels as example

  24 août 2020, par karl-police

  So I got this GIF here :

  


  

  


  As you can see, it has Red, Green and Blue in it. And it also has a full transparency in it. This was composed together with FFMPEG out of images that looked exactly like that.

  


   

  


  Then, with FFMPEG I "decomposed" the RGB and Alpha channels using the filter "extractplanes".

  


  The gallery of that, in correct order starting from up to down, can be found here :

  


  https://imgur.com/a/WN0aGuW

  


  I am not sure if this actually helps me or if I'm supposed to decompose them. Because apperantly now, after decomposing them, I'm supposed to modify them, but I'm not really sure how. It's like how do I modify the red channel that only has black and white, so all at the end, will match to the specified HEX color that I want it to be to.

  


   

  


  Now, my question is. How do I exactly make the color changing happen ? Can I do this simply with JavaScript ? Is it possible to do with FFMPEG, if possible without ImageMagicks ? Maybe a programming language where not much installation is needed to do that ?

  


  What I understood is that. These channels basically contain values from 0 to 255 with black and white. I think the "brightness" is that what 0 and 255. So something inbetween, would be like grey.

  


  So basically, like we do (255,0,0) for red. In these channels, if I want red somewhere I need to put one fully white pixel on the red channel and on all the other channels, there has to be a fully black pixel.

  


  That's the concept. Now is the question, how can I do this ?

  


   

  


  At the end I want to make it look like this one as example :

  


  

  


  This is from a game. So basically that's how it looks like in the game. And the game files only use these RGBA template sprites.

  


   

  


  I asked a similar question here : How to change colors of an image using RGBA and more channels independently of their color

  


  But somehow, I might didn't seem to explain it that well.

  


   

  


  I made a thing here to test around with things. I guess that's nearly close, but the lines are kinda weird. jsfiddle.net/qsgazubk