Trim Video with FFmpeg

2024-07-30 09:53 UTC gpt-4o Open in ChatGPT ↗

To trim a video between two specific timecodes using FFmpeg, you can use the -ss (start time) and -to (end time) options. Here is the command structure for trimming a video:

ffmpeg -i input.mp4 -ss 00:01:23 -to 00:02:34 -c copy output.mp4

In this example:

input.mp4 is the input video file.
00:01:23 is the start timecode (hh:mm:ss) where the trim will begin.
00:02:34 is the end timecode (hh:mm:ss) where the trim will end.
-c copy tells FFmpeg to copy the streams as is, without re-encoding, which is faster and retains the original quality.
output.mp4 is the output video file.

Make sure to replace input.mp4, 00:01:23, 00:02:34, and output.mp4 with your actual file names and timecodes. If you want to re-encode the video, you can remove the -c copy option and specify the desired codecs.

For example, if you want to re-encode the video, you can use:

ffmpeg -i input.mp4 -ss 00:01:23 -to 00:02:34 -c:v libx264 -c:a aac output.mp4

In this case:

-c:v libx264 specifies the video codec to use (H.264 in this case).
-c:a aac specifies the audio codec to use (AAC in this case).

To downscale a video by a factor of 2 using FFmpeg, you can use the -vf (video filter) option with the scale filter. Here’s how to do it along with trimming between two timecodes:

Determine the original resolution of your video.
Divide both the width and height by 2.
Use the scale filter to resize the video.

Here’s the command to trim the video between two timecodes and downscale it by a factor of 2:

ffmpeg -i input.mp4 -ss 00:01:23 -to 00:02:34 -vf "scale=iw/2:ih/2" -c:v libx264 -c:a aac output.mp4

In this example:

-i input.mp4 specifies the input video file.
-ss 00:01:23 specifies the start timecode.
-to 00:02:34 specifies the end timecode.
-vf "scale=iw/2:ih/2" applies the scaling filter to resize the video to half its original width and height.
-c:v libx264 specifies the video codec (H.264).
-c:a aac specifies the audio codec (AAC).
output.mp4 is the name of the output file.

This command will trim the video from 00:01:23 to 00:02:34 and downscale it by a factor of 2, re-encoding the video using the H.264 codec and the audio using the AAC codec.

To export a video as a series of JPEG images using FFmpeg, while also trimming it between two timecodes and downscaling the frames by a factor of 2, you can use the following command:

ffmpeg -i input.mp4 -ss 00:01:23 -to 00:02:34 -vf "scale=iw/2:ih/2" -q:v 2 output_%04d.jpg

In this command:

-i input.mp4 specifies the input video file.
-ss 00:01:23 specifies the start timecode.
-to 00:02:34 specifies the end timecode.
-vf "scale=iw/2:ih/2" applies the scaling filter to resize the video to half its original width and height.
-q:v 2 specifies the quality of the JPEG images (1 is the best quality, 31 is the worst).
output_%04d.jpg specifies the output format for the JPEG images. %04d is a placeholder for the frame numbers, padded with zeros to 4 digits.

This command will create a series of JPEG images (output_0001.jpg, output_0002.jpg, etc.) from the specified section of the video, with each frame downscaled by a factor of 2.