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• how to read partial fragmented mp4 from buffer or stdin

  1er mars 2023, par poush

  I am facing a weird challenge. I am still wondering if there's something wrong in my understanding of fragmented mp4 concepts.

  


  I have a buffer stream of a video file, that I am streaming from AWS. Subsequently I am passing it to stdin and using ffmpeg to encode it.

  


  What I want to achieve is if I skip 10000 initial bytes (say) from the source (which is S3 here), I still want to be able to encode the rest of the video in the buffer.

  


  I tried to create a fragmented mp4 (10s) and split the file into chunks of 20MB and now if I try to play any of the chunks except the first one, it doesn't work. I am trying to understand how HLS or Dash uses fragments to jump directly to a part of the video.

  


  I want to mimic basically the HLS player behaviour. Say, if I want to start streaming from S3 bucket from 200000 bytes, then I want to be able encode the video from there.

  


• Laravel Jobs (redis/database) + FFMpeg = application/octet-stream

  20 avril 2019, par Andreas

  I discovered something very strange. Whenever I try to use FFMpeg within a queue using redis or database, my converted videos always turn out with MIME "application/octet-stream".

  Here is the weird part. When I use the exact same code, and change the QUEUE_CONNECTION to sync instead, my videos gets converted to "video/webm" just as instructed.

  Does anyone have a clue as to why this is happening ? I have also tried multiple approaches converting, with laravel-ffmpeg and php-ffmpeg. Now I am using regular ol’ exec("ffmpeg").

  Thanks in advance !

• ffmpeg neighbor resize giving distortion when resizing video game footage. 2x2 pixels converted to 3x3 don't hold their color and are pixelated

  12 avril 2020, par PixelFrustated

  Here is my ffmpeg code :

  



  ffmpeg -i C :\FFMPEG\bin\input.mp4 -vf "scale=-2:1080" -sws_flags neighbor -c:v libx264 -crf 0 -preset Slow -c:a copy -b:a 320k C :\FFMPEG\bin\VIDEO2_1080p.mp4

  



  I'm converting a 720p video to 1080p. The game is 2x2 pixels and when I do the conversion they should be flat 3x3 pixels but instead they come out with slight miscolors on the insides between the pixels and their color is slightly off.

  



  Can anyone help me figure out why this warped ?

  



  Pixels on the left are 2x2 and are converted to the pixels on the right.

  



  Instead of 2x2 expanding out to a 3x3 it takes a weird blend going vertical but the horizontal pixels are just fine.