How I could cut the last 7 seconds of my video with ffmpeg?

Question

I captured a video from my camera, but I don't know exactly how long it is. I want to use FFmpeg to keep and cut only the last 7 seconds of the video. Is this possible?

I tried the command:

ffmpeg -t 00:00:07 -i input.avi -vcodec copy newfile.avi

But it only skips the first 7 seconds of the video, and displays the video flipped.

Answer 1

Use the -sseof (seek relative to End of File) option.

Say you want to keep the last 7 seconds, you can use:

ffmpeg -sseof -7 -i input.mp4 -c copy output.mp4

See the documentation here.

Note: This answer was posted in 2014 when this option did not exist. It was only added in 2015 — answer updated since.

Answer 2

Three different scenarios. I added the first two for clarification.

1. Want to keep only the last N seconds of a video instead of [-ss #] use [-sseof -#]

   Example: -sseof -7

   $ ffmpeg -sseof -7 -i input.mp4 -c copy output.mp4
   

   Keeps the last 7 seconds of the video and discards the rest

2. Want to delete the last N seconds of a video and keep the rest. (Manually enter duration).

   This option requires manual entry of end time (for automatic, see #3)

   Use -ss and -t (duration from start point) or -to (specific timestamp)

   You'll need to calculate the end time manually for this option.
   Examples:

   $ ffmpeg -ss 00:00:00 -to 01:32:00 -i input.mp4 -c copy output.mp4;
   

   Keeps the video from timestamp 00:00:00 to timestamp 01:32:00

   $ ffmpeg -ss 00:00:04 -t 01:00:00 -i input.mp4 -c copy output.mp4;
   

   Keeps the video from timestamp 00:00:04 to timestamp 01:00:04
   1 hour long video.

3. Want to delete the last N seconds of a video and keep the rest. (Auto-detect duration of file)

   You'll need to use both ffmpeg and ffprobe, but it can all be done in terminal, with very little code.

   The only way to cut off seconds based on the end time is to get the end time. I do batch processing of videos with varied lengths, so manually looking up and inputting each duration was out of the question. I needed to automatically access the duration value and pass it to ffmpeg.

   The Magic Formula:

   duration=`ffprobe -v error -show_entries format=duration -of csv=p=0 input.mp4`
   duration=`bc $duration - seconds`
   

   Example:

   $ duration=`ffprobe -v error -show_entries format=duration -of csv=p=0 input.mp4`
   $ duration=`bc $duration - 7`
   $ ffmpeg -ss 00:00:00 -to $duration -i input.mp4 -c copy output.mp4
   

   Removes the last 7 seconds of the video.

Answer 3

Here is a bash script for convenience:

#!/bin/bash
Arguments
FILE_RAW=$1
TRIM_EOF_DURATION=${2:-1.0} # Default is 1.0 second trimmed from EOF
Prepare variables
BASE_PATH=$(dirname $(readlink -f $FILE_RAW))
FILENAME_EXT="$(basename "${FILE_RAW}")"
FILENAME_ONLY="${FILENAME_EXT%.}"
EXT_ONLY="${FILENAME_EXT#.}" # Or hardcode it like "mp4"
FILENAME_ONLY_PATH="${BASE_PATH}/${FILENAME_ONLY}"
Trim EOF duration
INPUT_DURATION=$(ffprobe -v error -select_streams v:0 -show_entries stream=duration -of default=noprint_wrappers=1:nokey=1 "${FILENAME_ONLY_PATH}.${EXT_ONLY}")
OUTPUT_DURATION=$(bc <<< "$INPUT_DURATION"-"$TRIM_EOF_DURATION")
ffmpeg -i "${FILENAME_ONLY_PATH}.${EXT_ONLY}" -map 0 -c copy -t "$OUTPUT_DURATION" "${FILENAME_ONLY_PATH}Trim${TRIM_EOF_DURATION}.${EXT_ONLY}"

Note: Make script executable: chmod +x trim_video.sh

Usage (Output File: <PATH_TO_INPUT_VIDEO>_Trim_<TRIM_EOF_DURATION>.mp4)

. <PATH_TO_THIS_SCRIPT>/trim_video.sh <PATH_TO_INPUT_VIDEO> <OPTIONAL_TRIM_EOF_DURATION>

Example: Trim 7.0 seconds from EOF (Output: ~/Videos/input_video_Trim_7.0.mp4)

. ~/trim_video.sh ~/Videos/input_video.mp4 7.0

Answer 4

Here's a script for Windows' cmd.exe that doesn't use ffprobe (only uses ffmpeg):

@echo off  
setlocal
if "%~1"=="" (

    echo Usage: %~n0 input_video_file seconds_to_remove

    goto :eof

)
set "input=%~1"

set "x=%~2"

set "output=%~n1_trimmed%~x1"
REM Get duration from ffmpeg output

for /f "tokens=1,2 delims=, " %%a in ('ffmpeg -i "%input%" 2^>^&1 ^| findstr /i "Duration"') do (

    set duration=%%b

)
echo Duration string: %duration%
REM Use PowerShell to get total duration in seconds

for /f "usebackq delims=" %%d in (powershell.exe -NoProfile -Command "[TimeSpan]::Parse('%duration%').TotalSeconds") do set "DURATION=%%d"
echo Total duration: %DURATION% seconds
REM Calculate new duration

for /f "usebackq delims=" %%e in (powershell.exe -NoProfile -Command "%DURATION% - %x%") do set "NEW_DURATION=%%e"
echo New duration: %NEW_DURATION% seconds
REM Run ffmpeg to trim the video

ffmpeg -i "%input%" -t %NEW_DURATION% -c copy "%output%"
echo The output file "%output%" has been created without the last %x% seconds.

Example of use:

script.bat input.mp4 7

will remove the last 7 seconds in input.mp4: it'll create a new file input_trimmed.mp4

If one uses this script on videos that have telemetry information (e.g., GoPro GPMF), replace ffmpeg -i "%input%" -t %NEW_DURATION% -c copy "%output%" with:

REM Run ffmpeg to trim the video  
ffmpeg -i "%input%" -t %NEW_DURATION% -map 0:v -map 0:a -map 0:3 -copy_unknown -tag:2 gpmd -c copy "%output%"  

(the extra attributes -map 0:v -map 0:a -map 0:3 -copy_unknown -tag:2 gpmd keeps the telemetry information)