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• Laravel php timelapse an UploadedFile video element, without saving it as a file

  24 août 2022, par The Blind Hawk

  I want to be able to change the frame rate of a video from 0.05fps to 3fps.
  
I receive the video as an Illuminate\Http\UploadedFile element, with mp4 format, how do I speed up its frame rate before sending it via email ?
  
The video is 25 minutes long, it should become 25 seconds long after changing the frame rate.
  
Is there a way to change the fps without saving the element as a File ?
  
I was planning to use the ffmpeg repository here but it requires me to save both the initial file, and the second file after changing the fps.

  
This is my code :

  


  <?php

namespace Server\Mail;

use Carbon\Carbon;
use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Mail\Mailable;
use Illuminate\Queue\SerializesModels;
use Illuminate\Http\UploadedFile;

class TimeLapse extends Mailable
{
    use Queueable, SerializesModels;

    public UploadedFile $video;

    public bool $is_timelapsed;

    public string $format;

    /**
     * Create a new message instance.
     */
    public function __construct(
        UploadedFile $video, 
        bool $is_timelapsed, 
        string $format
    ){
        $this->video = $video;
        $this->is_timelapsed = $is_timelapsed;
        $this->format = $format;
    }

    private function timelapse(){
        // here I want to change $video element's fps from 0.05 to 3
    }

    /**
     * Build the message.
     *
     * @return $this
     */
    public function build()
    {
        if ( !$is_timelapsed ) { timelapse(); }

        $this->subject('message')
                    ->text('emails.timelapse');

        $this->attach($this->video, [
            'as' => 'sample'.$format,
            'mime' => 'video/'.$format,
        ]);

        return $this;
    }
}


  


• create a movie in python [closed]

  23 mai 2017, par masoud

  I have some files with names (’Den_car_resample’ +’_ sdf_ ’+ str(n)+’.dat’) where n changes from 0 to 25. I wrote a code to read these files and plots the results.
  now I want to create a movie from these plots. at the end of the program, I used the avconv command to do that.
  but, unfortunately my code creates a movie but it is empty.
  I don’t know the reason exactly but I think, first, I have to define a frame to each plot and then create a movie.
  can anyone please tell me how can I define a frame and also the add bit_rate of the movie.

  import sys
  
  import subprocess   
  
  import sdf
  
  import numpy as np
  
  import matplotlib.pyplot as plt  
  
  import time
  
  import matplotlib.animation as Animation
  
  from matplotlib.font_manager import FontProperties
  
  fp = FontProperties('Symbola')
  
  
  
  ##################### information from EPOCH input.deck
  
  nx,ny= 1200, 1600
  
  xmin=-100e-6
  
  xmax = 110e-6
  
  ymin = -200e-6
  
  ymax = 200e-6
  
  X =np.linspace(xmin,xmax,nx)   
  
  Y =np.linspace(ymin,ymax,ny)
  
  
  
  #################
  
  for n in range(0,25):
  
    nstr = str(n)
  
  
  
  ######################..... reading Density of carbon
  
    filename ="Den_car_resample" +'_sdf_'+ str(n)+'.dat'
  
  
  
    with open(filename, 'rb') as f:                        
  
      data = np.fromfile(f, dtype='float64', count=nx*ny)  
  
  
  
    Den_car  = np.reshape(data, [ny, nx], order='F')
  
    Den_car= np.log10(Den_car)
  
  
  
    ######################  Display Carbon density
  
  
  
    fig = plt.imshow(Den_car,  extent=[X.min()*1e6, X.max()*1e6, Y.min()*1e6,Y.max()*1e6], vmin=24, vmax=29, cmap='brg', aspect='auto') 
  
    plt.suptitle('Den_car')
  
    plt.title('sdf '+ str(n)+'; Time= '+str(n*50)+'ps',color='green', fontsize=15)
  
    plt.xlabel('x($\mu$m)')
  
    plt.ylabel('y($\mu$m)')
  
    plt.text(-80,-40,'Den_Carbon',color='red', fontsize=15)
  
    plt.colorbar()
  
    plt.savefig( 'fig%06d.png' % n, bbox_inches='tight')          
  
  
  
    plt.pause(.1)
  
    plt.clf()  
  
    plt.close()
  
  
  
    ######################  Create movie
  
  
  
    subprocess.call("avconv -framerate 1 -i fig%06d.png -c:v libx264 -profile:v high -crf 20".split())
  
  
  
  sys.exit()

• Unable to run ffmpeg with qProcess to extract a single frame from Vide

  24 janvier 2018, par user3840315

  I am trying to extract a single frame from a video using the QProcess in qt framework and ffmpeg and store it in a tmp folder. When I run the program in terminal command line it is able to extract it but not when QProcess runs it. I’m developing on a mac. What am I doing wrong.

  QString extractSingleFrame(QString videoPath, QDir tmpDir)
  
  {
  
      QString program = ffmpegPath();
  
      QProcess *ffmpegProcess = new QProcess();
  
      QString arguments;
  
      QFileInfo videoInfo(videoPath);
  
      QString videoName = videoInfo.fileName();
  
  
  
      QString firstFrameName(tmpDir.absolutePath() + "/" + videoName + ".jpg");
  
      arguments = " -y -i " + QDir::toNativeSeparators(videoPath)
  
                  + " -frames:v 1 -q:v 1 -f image2 " + QDir::toNativeSeparators(firstFrameName);
  
  
  
      QFile::remove(firstFrameName);
  
      qDebug() << "Starting program" << program + arguments;
  
      ffmpegProcess->start(program + arguments);
  
      // ffmpegProcess->start(program , QStringList() <<  arguments); this also doesnt work
  
      if (ffmpegProcess->state() == QProcess::Starting){
  
         qDebug() << "program is starting" + ffmpegProcess->state();
  
      }
  
      ffmpegProcess->waitForFinished(-1);
  
  
  
      qDebug() << "done";
  
  
  
      delete ffmpegProcess;
  
  
  
      return firstFrameName;
  
  }

  This is the printed command
  to start the program "ffmpeg -y -i "/Users/userX/test.mov" -vframes 1 -q:v 1 -f image2 "/var/folders/s1/vtv2cx36p3h0000gn/T/test-ywDBgj/test.mov.jpg""