Conquering Time Limits: Speeding Up Dashcam Footage for Social Media with FFmpeg and PHP

Introduction:

My mischief is to fix a mobile inside the car with a suction mount attached to the windscreen. This mobile would capture video from start to finish of each trip. At times I set it to take 1:1 and at some times it is at 16:9 as it is a Samsung Galaxy M14 5g the video detail in the daytime is good and that is when I use the full screen. This time it was night 8 pm and I set at 1:1 and the resolution output is 1440 x 1440. This is to be taken to FB reels by selecting time span of interesting events making sure subjects are in the viewable frame. Alas, Facebook will take only 9:16 and a max of 30 seconds in the reels. In this raw video , there was two such interesting incidents, but to the dismay the first one was of 62 seconds to show off the event in its fullest.

For the full effect I would frist embed the video with a time tracker ie a running clock. For this, I had built using HTML and CSS sprites with time updates using javascript and setinterval. http://bz2.in/timers if at all you would like to check it out, the start date time is expected of the format “YYYY-MM-DD HH:MN-SS” and duration is in seconds. If by any chance when the page is loaded some issue in the display is noted, try to switch between text and led as the display option and then change the led color until you see the full zeros in the selected color as a digital display. Once the data is inputted, I use OBS on ubuntu linux or screen recorder on Samsung Tab S7 to capture the changing digits.

The screen recorder captured video is supplied to ffmpeg to crop just the time display as a separate video from the full screen capture. The frame does not change for each session. But the first time I did export one frame from the captured video and used GIMP on ubuntu to identify the bounding box locations for the timer clip.
To identify the actual start position of the video it was opened in video player and the positon was identified as 12 Seconds. Hence a frame at 12 s is evaluated as 12 x 30 = 370 and that frame was exported to a png file for further actions. I used the following command to export one frame.

ffmpeg -i '2025-02-04 19-21-30.mov' -vf "select=eq(n\,370)" -vframes 1 out.png

By opening this out.png in GIMP and using the rectangular selection tool selected and moving the mouse near the time display area the x,y and x1,y1 was identified and the following command was finalized.

ffmpeg -i '2025-02-04 19-21-30.mov' -ss 12 -t 30 -vf "crop=810:36:554:356" -q:v 0 -an timer.mp4

The skip (-ss 12) is identified manually by previewing the source file in the media player.

The relevant portion from the full raw video is also captured using ffmpeg as follows.

ffmpeg -i 20250203_201432.mp4 -ss 08:08 -t 62 -vf crop=810:1440:30:0 -an reels/20250203_201432_1.mp4

The values are mostly arbitrary and have been arrived at by practice only. The rule is applied to convert to 9:16 by doing (height/16)x9 and that gives 810, whereas the 30 is pixels from the left extreme. That is because I wanted the left side of the clip to be fully visible.

Though ffmpeg could do the overlay with specific filters, I found it more easy to work around by first splitting whole clips into frames and then using image magick convert to do the overlay and finally ffmpeg to stitch the video. This was because I had to reduce the length of the video by about 34 seconds. And this should happen only after the time tracker overlay is done. So the commands which I used are.

created few temporary folders

mkdir ff tt gg hh

ffmpeg -i clip.mp4 ff/%04d.png
ffmpeg -i timer.mp4 tt/%04d.png

cd ff

for i in *.png ; do echo $i; done > ../list.txt
cd ../

cat list.txt | while read fn; do convert ff/$fn tt/$fn -gravity North -composite gg/$fn; done

Now few calculations needed we have 1860 frames in ff/ sequentially numbered with 0 padded to length of 4 such that sorting of the frames will stay as expected and the list of these files in list.txt. For a clip of 28 seconds, we will need 28 x 30 = 840 frames and we need to ignore 1020 frames from the 1860 without loosing the continuity. For achieving this my favorite scripting language PHP was used.

<?php

/* 
this is to reduce length of reel to 
remove logically few frames and to 
rename the rest of the frames */

$list = @file('./list.txt');  // the list is sourced
$frames = count($list); // count of frames

$max = 28 * 30; // frames needed

$sc = floor($frames / $max);
$final = [];  // capture selected frames here
$i = 0;

$tr = floor($max * 0.2);  // this drift was arrived by trial estimation

foreach($list as $one){
  if($i < $sc){
     $i++;
  }else{
    $final[] = trim($one);
    $i = 0;
  }
  if(count($final) > $tr){
  	$sc = 1;
  }
}


foreach($final as $fn => $tocp){
   $nn = str_pad($fn, 4, '0', STR_PAD_LEFT) . '.png';
   echo $tocp,' ',$nn,"\n";
}

?>

The above code was run and the output was redirected to a file for further cli use.

php -q renf.php > trn.txt

cat trn.txt | while read src tgt ; do cp gg/$src hh/$tgt ; done

cd hh
ffmpeg -i %04d.png -r 30 ../20250203_201432_1_final.mp4

Now the reel is created. View it on facebook

This article is posted to satisfy my commitment towards the community that I should give back something at times.

Thankyou for checking this out.

Creating a Dynamic Image Animation with PHP, GIMP, and FFmpeg: A Step-by-Step Guide

Introduction

In this blog post, I’ll walk you through a personal project that combines creative image editing with scripting to produce an animated video. The goal was to take one image from each year of my life, crop and resize them, then animate them in a 3×3 grid. The result is a visually engaging reel targeted for Facebook, where the images gradually transition and resize into place, accompanied by a custom audio track.

This project uses a variety of tools, including GIMP, PHP, LibreOffice Calc, ImageMagick, Hydrogen Drum Machine, and FFmpeg. Let’s dive into the steps and see how all these tools come together.

Preparing the Images with GIMP

The first step was to select one image from each year that clearly showed my face. Using GIMP, I cropped each image to focus solely on the face and resized them all to a uniform size of 1126×1126 pixels.

I also added the year in the bottom-left corner and the Google Plus Code (location identifier) in the bottom-right corner of each image. To give the images a scrapbook-like feel, I applied a torn paper effect around the edges. Which was generated using Google Google Gemini using prompt “create an image of 3 irregular vertical white thin strips on a light blue background to be used as torn paper edges in colash” #promptengineering

Key actions in GIMP:

  • Crop and resize each image to the same dimensions.
  • Add text for the year and location.
  • Apply a torn paper frame effect for a creative touch.

Organizing the Data in LibreOffice Calc

Before proceeding with the animation, I needed to plan out the timing and positioning of each image. I used LibreOffice Calc to calculate:

  • Frame duration for each image (in relation to the total video duration).
  • The positions of each image in the final 3×3 grid.
  • Resizing and movement details for each image to transition smoothly from the bottom to its final position.

Once the calculations were done, I exported the data as a JSON file, which included:

  • The image filename.
  • Start and end positions.
  • Resizing parameters for each frame.

Automating the Frame Creation with PHP

Now came the fun part: using PHP to automate the image manipulation and generate the necessary shell commands for ImageMagick. The idea was to create each frame of the animation programmatically.

I wrote a PHP script that:

  1. Reads the JSON file and converts it to PHP arrays, which were manually hard-coded into the generator script. This is to define the positioning and resizing data.
  2. Generates ImageMagick shell commands to:
  • Place each image on a 1080×1920 blank canvas.
  • Resize each image gradually from 1126×1126 to 359×375 over several frames.
  • Move each image from the bottom of the canvas to its final position in the 3×3 grid.

Here’s a snippet of the PHP code that generates the shell command for each frame:

This script dynamically generates ImageMagick commands for each image in each frame. The resizing and movement of each image happens frame-by-frame, giving the animation its smooth, fluid transitions.


Step 4: Creating the Final Video with FFmpeg

Once the frames were ready, I used FFmpeg to compile them into a video. Here’s the command I referred, for the exact project the filnenames and paths were different.

ffmpeg -framerate 30 -i frames/img_%04d.png -i audio.mp3 -c:v libx264 -pix_fmt yuv420p -c:a aac final_video.mp4

This command:

  • Takes the image sequence (frames/img_0001.png, frames/img_0002.png, etc.) and combines them into a video.
  • Syncs the video with a custom audio track created in Hydrogen Drum Machine.
  • Exports the final result as final_video.mp4, ready for Facebook or any other platform.

Step 5: The Final Touch — The 3×3 Matrix Layout

The final frame of the video is particularly special. All nine images are arranged into a 3×3 grid, where each image gradually transitions from the bottom of the screen to its position in the matrix. Over the course of a few seconds, each image is resized from its initial large size to 359×375 pixels and placed in its final position in the grid.

This final effect gives the video a sense of closure and unity, pulling all the images together in one cohesive shot.

Conclusion

This project was a fun and fulfilling exercise in blending creative design with technical scripting. Using PHP, GIMP, ImageMagick, and FFmpeg, I was able to automate the creation of an animated video that showcases a timeline of my life through images. The transition from individual pictures to a 3×3 grid adds a dynamic visual effect, and the custom audio track gives the video a personalized touch.

If you’re looking to create something similar, or just want to learn how to automate image processing and video creation, this project is a great starting point. I hope this blog post inspires you to explore the creative possibilities of PHP and multimedia tools!

The PHP Script for Image Creation

Here’s the PHP script I used to automate the creation of the frames for the animation. Feel free to adapt and use it for your own projects:

<?php

// list of image files one for each year
$lst = ['2016.png','2017.png','2018.png','2019.png','2020.png','2021.png','2022.png','2023.png','2024.png'];

$wx = 1126; //initial width
$hx = 1176; //initial height

$wf = 359;  // final width
$hf = 375;  // final height

// final position for each year image
// mapped with the array index
$posx = [0,360,720,0,360,720,0,360,720];
$posy = [0,0,0,376,376,376,752,752,752];

// initial implant location x and y
$putx = 0;
$puty = 744;

// smooth transition frames for each file
// mapped with array index
$fc = [90,90,90,86,86,86,40,40,40];

// x and y movement for each image per frame
// mapped with array index
$fxm = [0,4,8,0,5,9,0,9,18];
$fym = [9,9,9,9,9,9,19,19,19];

// x and y scaling step per frame 
// for each image mapped with index
$fxsc = [9,9,9,9,9,9,20,20,20];
$fysc = [9,9,9,10,10,10,21,21,21];

// initialize the file naming with a sequential numbering

$serial = 0;

// start by copying the original blank frame to ramdisk
echo "cp frame.png /dev/shm/mystage.png","\n";

// loop through the year image list

foreach($lst as $i => $fn){
    // to echo the filename such that we know the progress
    echo "echo '$fn':\n"; 

    // filename padded with 0 to fixed width
    $newfile = 'frames/img_' . str_pad($serial, 4,'0',STR_PAD_LEFT) . '.png';

// create the first frame of an year
    echo "composite -geometry +".$putx."+".$puty."  $fn /dev/shm/mystage.png  $newfile", "\n";

    $tmx = $posx[$i] - $putx;

    $tmy = $puty - $posy[$i];

    // frame animation
    $maxframe = ($fc[$i] + 1);
    for($z = 1; $z < $maxframe ; $z++){

        // estimate new size 
        $nw = $wx - ($fxsc[$i] * $z );
        $nh = $hx - ($fysc[$i] * $z );

        $nw = ($wf > $nw) ? $wf : $nw;
        $nh = ($hf > $nh) ? $hf : $nh;

        $tmpfile = '/dev/shm/resized.png';
        echo "convert $fn  -resize ".$nw.'x'.$nh.'\!  ' . $tmpfile . "\n";

        $nx = $putx + ( $fxm[$i] * $z );
        $nx = ($nx > $posx[$i]) ? $posx[$i] : $nx; 

        if($posy[$i] > $puty){
            $ny = $puty + ($fym[$i] * $z) ;
            $ny = ($ny > $posy[$i]) ? $posy[$i] : $ny ;
        }else{
            $ny = $puty - ($fym[$i] * $z);
            $ny = ($posy[$i] > $ny) ? $posy[$i] : $ny ;
        }

        $serial += 1;
        $newfile = 'frames/img_' . str_pad($serial, 4,'0',STR_PAD_LEFT) . '.png';
        echo 'composite -geometry +'.$nx.'+'.$ny."  $tmpfile /dev/shm/mystage.png  $newfile", "\n";
    }

    // for next frame use last one
     // thus build the final matrix of 3 x 3
    echo "cp $newfile /dev/shm/mystage.png", "\n";
}

Creating a Time-lapse effect Video from a Single Photo Using Command Line Tools on Ubuntu

In this tutorial, I’ll walk you through creating a timelapse effect video that transitions from dark to bright, all from a single high-resolution photo. Using a Samsung Galaxy M14 5G, I captured the original image, then manipulated it using Linux command-line tools like ImageMagick, PHP, and ffmpeg. This approach is perfect for academic purposes or for anyone interested in experimenting with video creation from static images. Here’s how you can achieve this effect. And note that this is just an academic exploration and to be used as a professional tool the values and frames should be defined with utmost care.

Basics was to find the perfect image, and crop it to 9:16 since I was targetting facebook reels and the 50 MP images taken on Samsung Galaxy M14 5G are at 4:3 with 8160×6120 and Facebook reels or YouTube shorts follow the format of 9:16 and 1080×1920 or proportionate dimensions. My final source image was 1700×3022 added here for reference. Had to scale it down to keep inside the blog aesthetics.

Step 1: Preparing the Frame Rate and Length
To begin, I decided on a 20-second video with a frame rate of 25 frames per second, resulting in a total of 500 frames. Manually creating the 500 frames was tedious and any professionals would use some kind of automation. Being a devops enthusiast and a linux fanatic since 1998 my choice was shell scripting. But addiction to php as an aftermath of usage since 2002 kicked up inside me and the following code nippet was the outcome.

Step 2: Generating Brightness and Contrast Values Using PHP
The next step was to create an array of brightness and contrast values to give the impression of a gradually brightening scene. Using PHP, I mapped each frame to an optimal brightness-contrast value. Here’s the PHP snippet I used:

<?php


$dur = 20;
$fps = 25;
$frames = $dur * $fps;
$plen = strlen(''.$frames) + 1;
$val = -50;
$incr = (60 / $frames);

for($i = 0; $i < $frames; $i++){
   $pfx =  str_pad($i, $plen, '0', STR_PAD_LEFT);

    echo $pfx, " ",round($val,2),"\n";

    $val += $incr;
}

?>

Being in ubuntu the above code saved as gen.php and after updating the values for duration and framerate this was executed from the cli and output redirected to a text file values.txt with the following command.

php -q gen.php > values.txt 

Now to make things easy, the source file was copied as src.jpg into a temporary folder and a sub-folder ‘anim’ was created to hold the frames. Here I already had a script which will resume from where left off depending on the situation. the script is as follows.

#!/bin/bash


gdone=$(find ./anim/ -type f | grep -c '.jpg')
tcount=$(grep -c "^0" values.txt)
todo=$(( $tcount - $gdone))

echo "done $gdone of ${tcount}, to do $todo more "

tail -$todo values.txt | while read fnp val 
do 
    echo $fnp
    convert src.jpg -brightness-contrast ${val} anim/img_${fnp}.jpg
done

The process is quite simple, first code line defines a var gdone by counting ‘.jpg’ files in the ‘anim’ sub-directory and then taking total count from values.txt the difference is to be done the status is echoed to output and a loop is initiated with reading the last todo lines from values.txt and executing the conversion using the convert utility of imagemagick. In case this needs to be interrupted, I just close the terminal window from xwindows, as a subsequent execution will continue from where leftoff. Once this is completed, the frames are stitched together using ffmpeg using the following commad.

ffmpeg -i anim/img_%04d.jpg -an -y ../output.mp4

The filename pattern %04d is decided from the width of number of frames plus 1 as in the php code the var $plen on code line 4 is taken for the str_pad function input padd length.

The properties of final output generated by ffmpeg is as follows. Note the dimensions, duration and frame rate do comply as decided on startup.

From Laggy Listings to Lightning Speed: A Database Optimization Case Study

Problem: Filtered listings on the web frontend were taking a long time (22-25 seconds) to load.

Analysis: Identified inefficient database queries as the culprit. Specifically, tables lacked proper indexing, causing the database to scan through a large amount of data unnecessarily when filtering was applied. Joins with filtering conditions were especially slow because the primary key alone wasn’t enough to optimize the search.

Solution:

  • Added required indexes: Created indexes on the columns used for filtering. Indexes act like an organized filing system for the database, allowing it to quickly locate relevant data based on the filter criteria. This significantly reduces the amount of data the database needs to scan.
  • Combined partitioning with the filter field and primary key: Partitioning is a technique that divides large tables into smaller, more manageable chunks. By combining partitioning with the filter field and the primary key, you further optimized the search process. When a filter is applied, the database can quickly identify the relevant partition(s) containing the filtered data, reducing the search scope even further.
  • Few code changes: When analyzed in detail found that in this particular scenario the concerned situation demanded only to fetch those records related to the currently logged in user. The original developers had used a join statement with the user_master and condition was user name. But the userid (int ) was already in the session, so just tweaked to remove the join statement and use the userid from the session to filter on the single table with userid = ‘xx’ condition.

Result: These optimizations led to a significant improvement in performance. The filtered pages now load and render in just 4-5 seconds, which is a massive improvement from the original 22-25 seconds.

Percentage decrease in loading time:

  • The average of the original loading time range: (22 seconds + 25 seconds) / 2 = 23.5 seconds
  • The difference between the original and optimized times: 23.5 seconds – 4.5 seconds = 19 seconds
  • Divide this difference by the original average time and multiply by 100% to arrive at a percentage: (19 seconds / 23.5 seconds) * 100% = 80.85% (approximately 81%) decrease in loading time.

Percentage increase in loading speed:

  • Calculate the improvement by dividing the original average time by the optimized time and multiply by 100%: (23.5 seconds / 4.5 seconds) * 100% = 522.22% (approximately 522%) increase in loading speed. This is absolutely insane and mind-blowing.

The anonymized captures of Firefox developer tools network performance analysis is added.

screenshots of analysis

Compressing php source files for embedded applications

Compressing php code is not been a tough task, and this is not for the purpose of obfuscating or encoding to make closed source distribution. But to create compact files which can be used in embedded web applications

Compressing php code is not been a tough task, and this is not for the purpose of obfuscating or encoding to make closed source distribution. But to create compact files which can be distributed by pasting into inline text, or into email without the need for attaching. The size will be drastically reduced. Actually at Saturn we did this to help us achieve to load a whole application on to a very space constrained flash disk. We were the least bothered about the process cycles taken to evaluate the php files since they will happen only once in a blue moon when the embedded system restarts. I am pretty sure that for closing source, there are other solutions.
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WordPress – preview and modify a theme till we are satisfied

Since we at Saturn provide wordpress as a CMS, and have more than a handful of experienced WordPress customizers, and themeres we have handled several challeges related to WordPress. The latest one being that the client was offered a facelift, and they wanted to preview the progress of integration. I searched the plugin repositories and blogs, found a lot of solutions, which include theme switchers, theme preview, and even suggestions to have a local copy. Well with our client, we could not think of a local copy, since the database dump itself was about 320GB and the images and videows was a whopping 1200 GB. Well after reading through the source of get_option, a wave struck me.



function new_theme_preview(){
    if(isset(
$_COOKIE['ShowNewTheme'])){
        return 
'myNewTheme';
    }
    return 
false;
}
 
add_filter('pre_option_current_theme''new_theme_preview'10);
 


I added the above to the end of an active plugin, then created two files newtheme.php and oldtheme.php, containing code to set and remove the cookie. The files were put into the top level folder. Once I am done with the theming, I could remove all these manually.

// newtheme.php
setcookie 'ShowNewTheme''1');
header("Location: ./");
 
//oldtheme.php
setcookie 'ShowNewTheme'false);
header("Location: ./");
 

php-cron – schedule jobs to run by the second and more

Yet another challenge, mostly like all other developers, ours at Saturn too believed that scheduled jobs could be run to the lowest frequency at every minute. This stands true if the job is handled only by *nix cron or by windows scheduler. For even further control one should write a Sleep-And-Run. I used to do this in shell script for most of my requirements. Just the other day some one challenged me to get done with one similar in php.

The outcome is a crude one, ServiceManager, which runs based on a configuration file and its run frequency. Best not to change the frequency or your configuration would never support anything less than the frequency as well as will only support multiples of the frequency. The configuration file is the famous ini file format with item names in square brackets, with configuration on two lines. The sample attached ServiceManager.ini should give an idea.
Continue reading “php-cron – schedule jobs to run by the second and more”

php smtp email direct to mail box delivery

For sending status mails, with varying from addresses, for several of our projects at Saturn, we were using the phpmailer which uses our smtp server with authentication. Well our smtp host had a limitation of 250 emails per day. When our requirements grew out of this limit, mails started to pile up. Sure I could install exim4 or sendmail on my boxes, and that is what I did for immediate resolution. But here comes a new requirement, that the mails sent should be marked as such, and those which failed should be marked with the exact response of the receiving end mailserver.

At this point I thought about an SMTP direct to mail box Delivery system. My favorite language being PHP, and primary library being Google, I tried all possible ways, according to me, and they were not the right ones as I came to know later. All these did not get me in the right direction. And finally thought about writing one. Here too, being lazy, wanted to have the code from some ones work to ignite me. Okay I found the phpbb’s smtp.php referred on the net, and the function smtpmail from the same was the right choice.
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A Mathematical Captcha – Reinventing the Wheel

I had seen numeric computational captcha or Mathematical captcha where one has to calculate the answer of an equation with simple arithmetic and supply the result for verification.

For a long time I have been using the image captcha with random characters, and got fed up. I had seen numeric computational captcha or Mathematical captcha where one has to calculate the answer of an equation with simple arithmetic and supply the result for verification. Last night I was pondering over this while watching a movie on the TV. Well the out come is obvious.
Continue reading “A Mathematical Captcha – Reinventing the Wheel”