Create video from multiple images (#10)

Author: correa-brian

.gitignore

@@ -1,2 +1,4 @@
 assets/*
 .DS_Store
+
+*.log

README.md

@@ -27,7 +27,7 @@ Sometimes you need a quick way to work with media files. For example:
 
 If you find yourself working with media files often, it may be helpful to have a library to automate your workflows.
 
-![GIF of Pluto demo](https://cosmos-media-content.s3.amazonaws.com/public-content/pluto_demo.gif)
+<img src="pluto_demo.gif?raw=true">
 
 To use the library, follow the prerequisites below and run from your terminal.
 
@@ -48,8 +48,8 @@ To get started, check out the table of contents below and follow these steps:
 
 1. Run the name of the command from your terminal like so:
 
-    ```bash
-        sh index.sh <command> <file1> <file2> <option1>
+    ```bash 
+    sh index.sh <command> <file1> <file2> <option1>
     ```
 
 1. Check the `assets` directory for the created file
@@ -58,6 +58,7 @@ To get started, check out the table of contents below and follow these steps:
 
 ## Table of Contents
 
+- [Convert multiple images to video](#convert-multiple-images-to-video)
 - [Convert image to video](#convert-image-to-video)
 - [Convert image to WebP](#convert-image-to-webp)
 - [Convert PDF to video](#convert-pdf-to-mp4)
@@ -70,6 +71,16 @@ To get started, check out the table of contents below and follow these steps:
 - [Extract frames from a video](#extract-frames-from-a-video)
 - [Modify video speed](#modify-video-speed)
 
+### Convert Multiple Images to Video
+
+This command can encode multiple image files into an MP4 video file. Pass in the desired transition (you can find all the available options in the [FFmpeg documentation](https://trac.ffmpeg.org/wiki/Xfade)), duration, and files you'd like to join.
+
+Usage:
+
+```bash
+sh index.sh multiple-images-to-video hblur 12 assets/image1.png assets/image2.png assets/image3.png assets/image4.png 
+```
+
 ### Convert Image to Video
 
 This command can encode an image file into an MP4 video file. Pass in the desired frame rate and duration. Frame rate will default to 24 frames per second and duration will default to 10 seconds.

library/multiple-images-to-video.sh

@@ -0,0 +1,61 @@
+#!/bin/bash
+
+# Check if the script is called with at least 4 arguments
+if [ "$#" -lt 4 ]; then
+    echo "Error: Insufficient number of arguments for filenames. Need at least 2 files."
+    echo "Usage: ./script.sh transition duration <filename1> <filename2>..."
+    exit 1
+fi
+
+# Store the filenames
+arguments=("$@")
+
+# Extract filenames
+transition="${arguments[0]}"
+duration="${arguments[1]}"
+file_args="${@:3}"
+
+IFS=' ' read -ra file_paths <<< "$file_args"
+
+command="ffmpeg -y -hide_banner"
+for f in "${file_paths[@]}"
+do
+    command="$command -loop 1 -i $f -t $duration"
+done
+
+count=$(awk -F' ' '{print NF}' <<< "$file_args")
+offset=$(echo "scale=0; $duration/$count" | bc)
+new_offset=$offset
+
+filter_complex="[0:v][1:v]xfade=transition=${transition}:duration=0.5:offset=${offset}"
+
+if [ "${count}" -gt 2 ]; then
+    initial_tag="t0"
+    filter_complex="$filter_complex[t0];"
+
+    index=2
+    new_offset=$((new_offset + offset))
+
+    rem_files="${@:5}"
+    IFS=' ' read -ra rem_file_paths <<< "$rem_files"
+    
+    for rf in "${rem_file_paths[@]}"
+    do
+        filter_complex="$filter_complex[${initial_tag}][${index}:v]xfade=transition=${transition}:duration=0.5:offset=${new_offset}"
+
+        if [ "${index}" -eq "$((count-1))" ]; then
+            filter_complex="$filter_complex[out]"
+        else
+            filter_complex="$filter_complex[t$index];"
+            initial_tag="t$index"
+        fi
+
+        new_offset=$((new_offset + offset))
+        index=$((index + 1))
+    done
+else
+    filter_complex="$filter_complex[out]"
+fi
+
+final_command="$command -filter_complex $filter_complex -r 30 -c:v libx264 -map [out] -pix_fmt yuv420p -t $duration -preset superfast assets/slide_show.mp4"
+$final_command