You can easily divide or cut an MP4 video based on timelines using FFmpeg. FFmpeg is a powerful command-line tool for handling multimedia files.
Here’s how to
do both of your cases:
Before You Start:
·
Install
FFmpeg: If you don’t have FFmpeg
installed, you’ll need to do that first. You can find instructions for your
operating system on the official FFmpeg website or by searching online (e.g.,
“install ffmpeg windows,” “install ffmpeg mac,” “install ffmpeg ubuntu”).
·
Understand
Timestamps: FFmpeg uses timestamps
in HH:MM:SS or SS (seconds) format. For example, 00:01:30 is 1 minute and 30 seconds, and 90 is
also 1 minute and 30 seconds.
Case 1: Divide into two parts at a point of time
Let’s say you
want to split a video input.mp4 at 00:05:00 (5 minutes) into two files: part1.mp4 and part2.mp4.
Command
for Part 1 (from beginning to the split point):
ffmpeg -i input.mp4 -ss 00:00:00 -to
00:05:00 -c copy part1.mp4
- · -i input.mp4: Specifies your input video file.
- · -ss 00:00:00: Starts the extraction from the beginning of the video. (You can omit this if you want to start from the very beginning, but it’s good for clarity).
- · -to 00:05:00: Specifies the end point of the extraction. The video will be cut up to this timestamp.
- · -c copy: This is crucial! It tells FFmpeg to copy the video and audio streams directly without re-encoding them. This makes the process extremely fast and avoids any quality loss.
Command
for Part 2 (from the split point to the end):
ffmpeg -i input.mp4 -ss 00:05:00 -c
copy part2.mp4
- · -i input.mp4: Specifies your input video file.
- · -ss 00:05:00: Specifies the start point of the extraction. The video will be cut from this timestamp.
- · -c copy: Again, use copy to avoid re-encoding.
Example
for a specific point in time (e.g., 1 minute 30 seconds):
ffmpeg -i your_video.mp4 -ss
00:00:00 -to 00:01:30 -c copy first_part.mp4
ffmpeg -i your_video.mp4 -ss
00:01:30 -c copy second_part.mp4
Case 2: Get a segment of video given two point of times
Let’s say you
want to extract a segment of input.mp4 from 00:01:00 (1 minute) to 00:03:30 (3 minutes 30 seconds) into a new file segment.mp4.
Command:
ffmpeg -i input.mp4 -ss 00:01:00 -to
00:03:30 -c copy segment.mp4
- · -i input.mp4: Specifies your input video file.
- · -ss 00:01:00: Specifies the start point of the segment.
- · -to 00:03:30: Specifies the end point of the segment.
- · -c copy: Uses stream copy for speed and quality preservation.
Alternative
using -t (duration) instead of -to (end time):
You can also
specify the duration of the segment using -t. The duration is calculated from the -ss (start)
point.
To get a 2
minute 30 second segment starting at 00:01:00:
ffmpeg -i input.mp4 -ss 00:01:00 -t
00:02:30 -c copy segment_duration.mp4
- · -t 00:02:30: Specifies the duration of the output segment. (3 minutes 30 seconds - 1 minute = 2 minutes 30 seconds).
Important Considerations:
·
Keyframes: When using -c
copy, FFmpeg cuts at the nearest
keyframe. This means your cuts might not be exactly at the
specified timestamp, but usually very close (within a fraction of a second). If
you need frame-accurate cuts, you’ll have to re-encode the video, which will be
slower and might result in some quality loss. For most practical
purposes, -c copy is sufficient and highly recommended.
·
Re-encoding
for Frame-Accurate Cuts (Slower & Quality Loss): If you absolutely need frame-accurate cuts and don’t
mind re-encoding (e.g., if you’re doing very precise editing), you would
omit -c copy and let FFmpeg re-encode. You might also want to
specify output quality settings (e.g., -crf for H.264).
·
ffmpeg -i input.mp4 -ss 00:01:00 -to
00:03:30 output_reencoded.mp4
·
Testing: Always test with a small segment or a copy of your
video first to ensure the commands work as expected before processing large or
important files.
By using
these FFmpeg commands, you can efficiently divide and extract segments from
your MP4 videos based on timelines.
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