Author:David Bosch - Nov 3rd, 2022
What is video cropping?
Cropping a video means to trim the edges of the video frame to remove unwanted or unnecessary parts of the video. Cropping a video can be done using a video editing software or with a command-line tool like FFMPEG.
There are many potential use cases for cropping a video. Some common examples include:
- Removing black bars from a video that was recorded in a non-standard aspect ratio. This can improve the viewing experience by making the video fill the entire screen.
- Cropping a video to focus on a specific part of the frame. For example, if you recorded a video of a person speaking and you only want to show their face, you can crop the video to only show the area around their face.
- Cropping a video to create a specific aspect ratio. For example, if you recorded a video in a 4:3 aspect ratio but you want to share it on a platform that only supports 16:9 videos, you can crop the video to fit the 16:9 aspect ratio.
- Cropping a video to remove distractions or objects in the background. For example, if you recorded a video of yourself talking but there is a distracting object in the background, you can crop the video to remove the object and make the video more professional.
How to crop a video with FFMPEG?
Cropping a video with ffmpeg is a relatively simple process. Here is a step-by-step guide:
- First, you need to make sure you have ffmpeg installed on your computer. If you don't have it, you can download it from the official website.
- Once you have ffmpeg installed, open a command prompt or terminal window and navigate to the folder where the video you want to crop is located.
-
To crop a video with ffmpeg, you will need to use the following command:
ffmpeg -i input.mp4 -filter:v "crop=w:h:x:y" output.mp4In this command, input.mp4 is the name of the input video file, and output.mp4 is the name of the output video file that will be created after cropping.
The -filter:v "crop=w:h:x:y" part of the command specifies the cropping settings.
In this part of the command, w is the width of the cropped area, h is the
height of the cropped area, x is the horizontal offset of the top left corner of the cropped area,
and y is the vertical offset of the top left corner of the cropped area.
For example, -filter:v "crop=100:100:50:50" would crop a 100x100 pixel area starting at the coordinates (50, 50) of the input video.
Once you have entered the ffmpeg command with the correct cropping settings, press enter to execute it. ffmpeg will then begin to process the video and create the output file with the cropped area.
When the process is complete, you will have a new video file with the cropped area. You can then watch the video to make sure it was cropped correctly.
How to crop an image using FFMPEG?
FFMPEG can also be used to crop images like JPEG, PNG or other image formats.
To crop an image using ffmpeg, you can use the following command:
ffmpeg -i input.jpg -filter:v "crop=w:h:x:y" output.jpg
In this command, input.jpg is the name of the input image file, and output.jpg is the name of the output image file that will be created after cropping.
The -filter:v "crop=w:h:x:y" part of the command specifies the cropping settings.
In this part of the command, w is the width of the cropped area,
h is the height of the cropped area,
x is the horizontal offset of the top left corner of the cropped area,
and y is the vertical offset of the top left corner of the cropped area.
For example, -filter:v "crop=100:100:50:50" would crop a 100x100 pixel area starting at the coordinates (50, 50) of the input image.
Once you have entered the ffmpeg command with the correct cropping settings, press enter to execute it. FFMPEG will then process the image and create the output file with the cropped area.
When the process is complete, you will have a new image file with the cropped area. You can then view the image to make sure it was cropped correctly.
Other considerations
Here are a few additional things you should know about cropping videos:
- Cropping a video can affect the resolution and quality of the video. When you crop a video, you are effectively removing pixels from the edges of the frame. This can reduce the resolution and overall quality of the video, especially if you crop a large portion of the frame.
- The cropping settings you use will depend on the specific video and your goals for cropping it. There is no one-size-fits-all solution for cropping videos, so you will need to experiment with different settings to find the right balance between removing unnecessary content and maintaining the quality of the video.
- Some video editing software may offer more advanced cropping options than ffmpeg. For example, you may be able to specify the exact coordinates of the cropped area, or use a visual interface to select the area you want to keep. If you have access to a video editing software, you may want to use it instead of ffmpeg for more precise control over the cropping process.
- You can crop videos in any format that ffmpeg supports. ffmpeg is a versatile tool that can handle a wide range of video formats, so you can use it to crop videos regardless of their original format.
- If you are new to ffmpeg, it can take some time to learn the command-line syntax and all of the options available. However, once you get the hang of it, ffmpeg can be a powerful tool for quickly and easily cropping videos.
Self-evaluation
How do you crop a video using ffmpeg?
Can you use the crop filter to resize a video in ffmpeg?
What is the syntax for the crop filter in ffmpeg?
Published on November 3rd, 2022