Recherche avancée

Sur d’autres sites (12825)

• How do you generate a looping animated gif for Facebook with ffmpeg

  7 février 2020, par Alan W. Smith

  When I paste a giphy url (like this one) into a facebook post or comment, the gif plays immediately and loops indefinitely. When I upload ones I make from ffmpeg, neither of those things happen. You have to click a play button to start the animation and then it ends after one time through.

  I have a couple of ffmpeg commands I use to create the gifs. They are :

  ffmpeg -ss 10 -t 5  -i input.m4v -vf "fps=15,scale=800:-2:flags=lanczos,palettegen" -y palette.png

  and

  ffmpeg -ss 10.6 -t 5 -i input.m4v -i palette.png -filter_complex "fps=15,scale=800:-1:lanczos[video];[video][1:v]paletteuse" output.gif

  The first one generates a custom color pallet that’s used by the second one to create a high quality animated gif. I’ve also tried adding -loop 0 (i.e. ffmpeg -ss 10.6 -t 5 -i input.m4v -i palette.png -filter_complex "fps=15,scale=800:-1:lanczos[video];[video][1:v]paletteuse" -loop 0 output.gif) but that didn’t work either.

  I also tried uploading the ffmpeg generated images to a personal website and calling them from there but those didn’t load at all.

  In case it helps, here’s a copy of one of the gifs (which autostarts and loops on StackOverflow for me but not on FB)

  

  How does one go about creating a gif that will autostart and loop indefinitely for facebook ?

  (Note : I’ve got no problem if I need to do something with a personal website, but I don’t want to use Giphly or the other animated gif sites directly if at all possible. Also worth pointing out that I discovered if I download the image from giphly and upload it, it doesn’t autostart either. So, this may be something internal to FB, but I’d still like to figure that out.)

• Using ffmpeg.exe making the computer slow in task manager it takes over 1GB of memory how can i fix it ?

  29 mai 2013, par Revuen Ben Dror

  In mt Form1 i have this code :

  private void StartRecording_Click(object sender, EventArgs e)
  
          {
  
  
  
              ffmp.Start("test.avi", 25);
  
              timer1.Enabled = true;
  
          }

  ffmp is a variable of my class : Ffmpeg
  In this class i add frames to a pipe and create an avi file.

  using System;
  
  using System.Collections.Generic;
  
  using System.Linq;
  
  using System.Text;
  
  using System.Threading.Tasks;
  
  using System.Drawing;
  
  using System.IO.Pipes;
  
  using System.Runtime.InteropServices;
  
  using System.Diagnostics;
  
  
  
  namespace ScreenVideoRecorder
  
  {
  
      class Ffmpeg
  
      {
  
          NamedPipeServerStream p;
  
          String pipename = "mytestpipe";
  
          byte[] b;
  
          System.Diagnostics.Process process;
  
  
  
          public Ffmpeg()
  
          {
  
  
  
          }
  
  
  
          public void Start(string FileName, int BitmapRate)
  
          {
  
              p = new NamedPipeServerStream(pipename, PipeDirection.Out, 1, PipeTransmissionMode.Byte);
  
              b = new byte[1920 * 1080 * 3]; // some buffer for the r g and b of pixels of an image of size 720p 
  
              process = new System.Diagnostics.Process();
  
              process.StartInfo.FileName = @"D:\pipetest\pipetest\ffmpegx86\ffmpeg.exe";
  
              process.EnableRaisingEvents = false;
  
              process.StartInfo.WorkingDirectory = @"D:\pipetest\pipetest\ffmpegx86";
  
              process.StartInfo.Arguments = @"-f rawvideo -pix_fmt bgr0 -video_size 1920x1080 -i \\.\pipe\mytestpipe -map 0 -c:v libx264 -r " + BitmapRate + " " + FileName;
  
              process.Start();
  
  
  
              process.StartInfo.UseShellExecute = false;
  
              process.StartInfo.CreateNoWindow = false;
  
  
  
              p.WaitForConnection();
  
          }
  
  
  
          public void PushFrame(Bitmap bmp)
  
          {
  
  
  
              int length;
  
              // Lock the bitmap's bits.
  
              Rectangle rect = new Rectangle(0, 0, bmp.Width, bmp.Height);
  
              //Rectangle rect = new Rectangle(0, 0, 1280, 720);
  
              System.Drawing.Imaging.BitmapData bmpData =
  
                  bmp.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadOnly,
  
                  bmp.PixelFormat);
  
  
  
              int absStride = Math.Abs(bmpData.Stride);
  
              // Get the address of the first line.
  
              IntPtr ptr = bmpData.Scan0;
  
  
  
              // Declare an array to hold the bytes of the bitmap.
  
              //length = 3 * bmp.Width * bmp.Height;
  
              length = absStride * bmpData.Height;
  
              byte[] rgbValues = new byte[length];
  
  
  
              int j = bmp.Height - 1;
  
              for (int i = 0; i < bmp.Height; i++)
  
              {
  
                  IntPtr pointer = new IntPtr(bmpData.Scan0.ToInt32() + (bmpData.Stride * j));
  
                  System.Runtime.InteropServices.Marshal.Copy(pointer, rgbValues, absStride * (bmp.Height - i - 1), absStride);
  
                  j--;
  
              }
  
  
  
              p.Write(rgbValues, 0, length);
  
  
  
              bmp.UnlockBits(bmpData);
  
  
  
          public void Close()
  
          {
  
              p.Close();
  
          }
  
      }
  
  }

  The problem is when i'm running my application in this from my visual studio 2012 pro and click the button it's openning a console window and start the processing .

  I tracked over it through the task manager on ffmpeg.exe and saw that it started from 996mb and very quick jumped ot 1040mb memory usage. The cpu usage was only 16%

  Once i close ended this task the ffmpeg.exe everything was back to move smooth.
  When it's working and i tried to drag my Form around the screen for example it was moving slow and also with some stuttering .

  Closed the ffmpeg.exe and i could drag the Form around smooth and quick like in regular way as it should be.

  I tried to google for it and found some others with the same problem i think but i'm not sure where is the problem and how to fix it.

  I'm not sure what version of ffmpeg.exe i have i'm using now but i read in some places that it's not working better with new versions but maybe i mistake here .

  My windows is 8 with 6gb of ram .

• aacdec : move from scalefactor ranged arrays to flat arrays

  14 mai 2024, par Lynne

  aacdec : move from scalefactor ranged arrays to flat arrays
  AAC uses an unconventional system to send scalefactors
  
  (the volume+quantization value for each band).
  
  Each window is split into either 1 or 8 blocks (long vs short),
  
  and transformed separately from one another, with the coefficients
  
  for each being also completely independent. The scalefactors
  
  slightly increase from 64 (long) to 128 (short) to accomodate
  
  better per-block-per-band volume for each window.
  To reduce overhead, the codec signals scalefactor sizes in an obtuse way,
  
  where each group's scalefactor types are sent via a variable length decoding,
  
  with a range.
  
  But our decoder was written in a way where those ranges were carried through
  
  the entire decoder, and to actually read them you had to use the range.
  Instead of having a dedicated array with a range for each scalefactor,
  
  just let the decoder directly index each scalefactor.
  This also switches the form of quantized scalefactors to the format
  
  the spec uses, where for intensity stereo and regular, scalefactors
  
  are stored in a scalefactor - 100 form, rather than as-is.
  USAC gets rid of the complex scalefactor handling. This commit permits
  
  for code sharing between both.
  

  • [DH] libavcodec/aac/aacdec.c
  • [DH] libavcodec/aac/aacdec.h
  • [DH] libavcodec/aac/aacdec_dsp_template.c