In this article, we will discuss how to concatenate JPG images and MP4 clips while scaling the first frame and adjusting the clip resolution and frame rate using Windows 10. This process can be useful for creating custom video intros, thumbnails, or image sequences.
Prerequisites
To follow this guide, you will need the following tools:
- A text editor, such as Notepad++ or Visual Studio Code
- FFmpeg, a powerful multimedia framework
Installing FFmpeg
Before we begin, let's install FFmpeg on your Windows 10 system:
- Download the latest FFmpeg release from https://ffmpeg.org/download.html
- Extract the downloaded archive to a desired location, e.g., C:\Program Files\FFmpeg
- Add the FFmpeg bin directory to your system PATH environment variable
Concatenating JPG Images
First, let's learn how to concatenate multiple JPG images into a single image:
Step 1: Create a text file with image file paths
Create a new text file called "concat.txt" and add the paths of your JPG images, one per line:
input1.jpg
input2.jpg
input3.jpg
Step 2: Use FFmpeg to concatenate the images
Open a command prompt and navigate to the directory containing the "concat.txt" file and FFmpeg. Run the following command:
ffmpeg -i concat:v=0:f=concat@inputs=concat.txt output.jpg
Concatenating MP4 Clips
Now let's learn how to concatenate multiple MP4 clips:
Step 1: Create a text file with clip file paths
Create a new text file called "input.txt" and add the paths of your MP4 clips, one per line:
input1.mp4
input2.mp4
input3.mp4
Step 2: Use FFmpeg to concatenate the clips
Open a command prompt and navigate to the directory containing the "input.txt" file and FFmpeg. Run the following command:
ffmpeg -i input.txt -c:v copy -c:a aac -strict experimental output.mp4
Scaling the First Frame
To scale the first frame of an MP4 clip, we need to extract the first frame as a JPG image, scale it, and then add it back to the clip:
Step 1: Extract the first frame as a JPG image
Use the following command to extract the first frame of an MP4 clip as a JPG image:
ffmpeg -i input.mp4 -vframes 1 first_frame.jpg
Step 2: Scale the first frame
Use a graphic editor, such as Adobe Photoshop or GIMP, to scale the first frame to your desired resolution:
Step 3: Re-encode the scaled first frame as a JPG image
Save the scaled first frame as a JPG image with the highest possible quality:
jpegoptim first_frame_scaled.jpg
Step 4: Concatenate the scaled first frame and the original clip
Use FFmpeg to concatenate the scaled first frame and the original clip:
ffmpeg -i input.mp4 -i first_frame_scaled.jpg -filter_complex "[0:v]setpts=0.01[v0];[1:v]setpts=N/STS[v1];[v0][v1]concat=n=2:v=1:a=1[outv];[0:a][1:a]concat=n=2:a=1[outa]" -c:v libx264 -crf 18 -pix_fmt yuv420p output_scaled.mp4
Adjusting Clip Resolution and Frame Rate
To adjust the clip resolution and frame rate, use the following FFmpeg options:
- -vf scale=w:h:force_original_aspect_ratio=1: Set the output resolution (w:h).
- -r: Set the output frame rate (fps).
For example:
ffmpeg -i input.mp4 -vf "scale=1280:720:force_original_aspect_ratio=1" -r 30 output_resized_30fps.mp4