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• Frame works/Packages for video editing in IOS ?

  16 juillet 2014, par 2vision2

  I’ve just started working on video editing application for IOS.

  What i am trying to do :

  Trying to create a typical Video Editing application with the following features.

  1. Frames split-up(thumbnails)
  2. Adding/merging videos
  3. Adding audio to the video.
  4. Audio/Video Fadeouts.
  5. Zoom in and Zoom out functionalities
  6. Adding subtitles/Titles
  7. Audio Filtering.

  What have i done so far :

  Put a detail pre development study and found that FFMPEG can do the job. I have taken
  the latest version of FFMPEG and built for IOS as .a files.

  However, i feel extremely hard to create a sample programs as i am beginner in ios.

  Also i’ve found that the IOS SDK frameworks like CoreVideo, CoreAnimation, CALayers may help.

  Now reading about OpenGLES.

  What’s my problem :

  1. Any help regarding finding the framework/package (from apple or third party) for the video editing application ?

  2. Is FFMPEG the only option ? If yes, can you guys give me a link or sample programs to start with FFMPEG ?

• Fast detect QR algorithm on video file

  2 avril 2020, par Сергей toff

  Can any one share how to fast detect QR code on bitmap with out recognize

  



  I Use Zxing and Acord FFMPEG for get QR code seconds on video.
But it's very hard to processor time.

  



     BarcodeReader reader = new BarcodeReader();&#xA;   reader.AutoRotate = true;&#xA;   reader.Options.TryHarder = false;&#xA;   reader.Options.PureBarcode = false;&#xA;   reader.Options.PossibleFormats = new List<barcodeformat>();&#xA;   reader.Options.PossibleFormats.Add(BarcodeFormat.QR_CODE);&#xA;   return reader;&#xA;</barcodeformat>

  



  it's skeleton class
use instance of this

  



      static Result Recognize(Bitmap image)
    {
        var n = new BarcodeSingleton().GetInstance();
        return n.Decode(image);
    }


  



  so in the frame capture

  



   for(int i = 0; i < reader.FrameCount; i+= 1)
 {
     var videoFrame = reader.ReadVideoFrame();
     drawTextProgressBar(i, (int)reader.FrameCount);
     var r = Recognize(videoFrame);
 }


  



  ma by i can multi thread read VideoFile.. But not in this library

  


• How do I increase the quality of a gif using ffmpeg from a web address [closed]

  1er août 2023, par Alteria

  I'm using command line/powershell on windows 11 along with ffmpeg to download gifs from web addresses. When I do this, though, the quality of the output is greatly decreased, even if the original file was itself a gif. Is there w way to fix this ?

  


  I'm doing this with .gif files, as well as .mp4 and .webm files using web links and addresses.

  


  The command I use is ffmpeg -i https://somewebsite.com/12345.gif "custom name.gif" when downloading gifs. The quality is always slightly decreased, and in some cases very decreased. I would like to keep this from happening. I also use the exact same command when downloading .gif's and .mp4's, with ffmpeg -i https//:somewebsite/123456.webm "custom name.gif" and ffmpeg -i https://somewebstie/123456.mp4 "custom name.gif" respectivly.

  


  What should I use instead of this in order to maintain the quality of the original .gif files and get better quality .gifs from the .webm and .mp4's ?

  


  =============

  


  Some of the other answers I have looked for have not answered what to do with links, and the other example haven't worked either.

  


  The one-liner command ffmpeg -ss 23.0 -t 1.8 -i input.mp4 -filter_complex "[0:v] split [a][b];[a] palettegen [p];[b][p] paletteuse" output_trimmed_enhanced.gif supplied at banner-bear.com did not work, instead throwing an error 
*This specific example used a .gif file for the ffmpeg -i <file></file>, but the same error occurs when using .mp4's and .webm ;s

  


  I am also aware of the tool "gifski", posed by another user when they were asked a similar question on stack overflow (the question available here FFmpeg : high quality animated GIF ?). I would prefer to not download additional software in order to do what I wanted, so is there a way to circumvent this ?

  


  Edit

  


  I have found this forum post as one of the answers of this question : How do I convert a video to GIF using ffmpeg, with reasonable quality ?. This was the fourth (4th) answer down. This solution worked ! The command itself looks like this ffmpeg -i input.mp4 -filter_complex 'fps=10,scale=320:-1:flags=lanczos,split [o1] [o2];[o1] palettegen [p]; [o2] fifo [o3];[o3] [p] paletteuse' out.gif.

  


  I, however, have absolutely no idea how this command works. While this does work, I think it's going to be hard to remember this (and other) long commands. I want to be able to remember the commands as much as possible, and also to know what each part of it does. Is there an easier or shorter way of doing this command ? Or if not, what exactly does that command above do ?

  


  *I had seen palettegen and paletteuse when searching for the answer to this question, but I had a hard time understanding and following the documentation give on FFmpeg's Filter Documentation FFmpeg Filters Documentation, as well as other stack-overflow questions on these commands. Can someone show me coherent or simplified documentation for the problem I am trying to solve.