FFmpeg How to split video efficiently

Question

I wish to split a large avi video into two smaller consecutive videos  I am using ffmpeg   One way is to run ffmpeg two times   ffmpeg -i input avi -vcodec copy -acodec copy -ss 00 00 00 -t 00 30 00 output1 avi ffmpeg -i input avi -vcodec copy -acodec copy -ss 00 30 00 -t 00 30 00 output2 avi   But according to manpage of ffmpeg  I can make more than one ouput file from one input file using just one line   ffmpeg -i input avi -vcodec copy -acodec copy -ss 00 00 00 -t 00 30 00 output1 avi      -vcodec copy -acodec copy -ss 00 30 00 -t 00 30 00 output2 avi   My question is  does the later approach save computation time and memory

User · Answer

Here is a perfect way to split the video. I have done it previously, and it's working well for me.

ffmpeg -i C:\xampp\htdocs\videoCutting\movie.mp4 -ss 00:00:00 -t 00:00:05 -async 1 C:\xampp\htdocs\videoCutting\SampleVideoNew.mp4 (For cmd). shell_exec('ffmpeg -i C:\xampp\htdocs\videoCutting\movie.mp4 -ss 00:00:00 -t 00:00:05 -async 1 C:\xampp\htdocs\videoCutting\SampleVideoNew.mp4') (for php).

Please follow this and I am sure it will work perfectly.

User · Answer

Here s a useful script  it helps you split automatically  A script for splitting videos using ffmpeg     bin bash      Written by Alexis Bezverkhyy  lt alexis grapsus net gt  in 2011   This is free and unencumbered software released into the public domain    For more information  please refer to  lt http   unlicense org  gt     function usage               echo  Usage   ffsplit sh input file chunk-duration  output-filename-format               echo -e   t - input file may be any kind of file reconginzed by ffmpeg              echo -e   t - chunk duration must be in seconds              echo -e   t - output filename format must be printf-like  for example myvideo-part- 04d avi              echo -e   t - if no output filename format is given  it will be computed    automatically from input filename       IN FILE   1  OUT FILE FORMAT   3  typeset -i CHUNK LEN CHUNK LEN   2     DURATION HMS   ffmpeg -i   IN FILE  2 gt  amp 1   grep Duration   cut -f 4 -d      DURATION H   echo   DURATION HMS    cut -d     -f 1  DURATION M   echo   DURATION HMS    cut -d     -f 2  DURATION S   echo   DURATION HMS    cut -d     -f 3   cut -d     -f 1  let  DURATION     DURATION H   60   DURATION M     60   DURATION S     if     DURATION     0      then             echo  Invalid input video              usage             exit 1 fi    if     CHUNK LEN     0      then             echo  Invalid chunk size              usage             exit 2 fi    if   -z   OUT FILE FORMAT      then             FILE EXT   echo   IN FILE    sed  s         a-zA-Z0-9        1                FILE NAME   echo   IN FILE    sed  s           a-zA-Z0-9      1                OUT FILE FORMAT    FILE NAME - 03d   FILE EXT               echo  Using default output file format    OUT FILE FORMAT  fi    N  1  OFFSET  0  let  N FILES   DURATION   CHUNK LEN   1     while     OFFSET  -lt   DURATION      do             OUT FILE   printf   OUT FILE FORMAT    N               echo  writing  OUT FILE   N  N FILES                  ffmpeg -i   IN FILE  -vcodec copy -acodec copy -ss   OFFSET  -t   CHUNK LEN    OUT FILE              let  N   N   1              let  OFFSET   OFFSET   CHUNK LEN  done

User · Answer

Didn t test ist  but this looks promising   Basic stream segmenter  It is obviously splitting AVI into segments of same size  which implies these chunks don t loose quality or increase memory or must be recalculated   It also uses the codec copy - does that mean it can handle very large streams   Because this is my problem  i want to break down my avi so i could use a filter to get rid of the distorsion  But a whole avi runs for hours

User · Answer

one simple way is to use trim option with publitio url-based api    once  you get your video uploaded  just set start offset and end offset in url  so 2 eo 2  like so       https   media publit io file so 2 eo 2 tummy mp4   this will create instantly new videos starting from 2nd second and 2 seconds in length  you can split videos this way anyway you like

User · Answer

Here is a simple Windows bat file to split incoming file into 50 parts  Each part has length 1 minute  Sorry for such dumb script  I hope it is better to have a dumb windows script instead of do not have it at all  Perhaps it help someone   Based on  bat file for loop  from this site    set var 0  echo off  start set lz  if  var  EQU 50 goto end if  var  LEQ 9 set lz 0 echo part  lz  var  ffmpeg -ss 00  lz  var  00 -t 00 01 00 -i  1 -acodec copy -vcodec copy  2  lz  var  mp4 set  a var  1 goto start   end echo var has reached  var   exit

User · Answer

does the later approach save computation time and memory    There is no big difference between those two examples that you provided  The first example cuts the video sequentially  in 2 steps  while the second example does it at the same time  using threads   No particular speed-up will be noticeable  You can read more about creating multiple outputs with FFmpeg  Further more  what you can use  in recent FFmpeg  is the stream segmenter muxer which can      output streams to a number of separate files of nearly fixed duration  Output filename pattern can be set in a fashion similar to image2

User · Answer

In my experience  don t use ffmpeg for splitting join   MP4Box  is faster and light than ffmpeg  Please tryit  Eg if you want to split a 1400mb MP4 file into two parts a 700mb you can use the following cmdl  MP4Box -splits 716800 input mp4 eg for concatenating two files you can use   MP4Box -cat file1 mp4 -cat file2 mp4 output mp4   Or if you need split by time  use -splitx StartTime EndTime   MP4Box -add input mp4 -splitx 0 15 -new split mp4

User · Answer

The ffmpeg wiki links back to this page in reference to  quot How to split video efficiently quot   I m not convinced this page answers that question  so I did as  AlcubierreDrive suggested    echo  quot Two commands quot   time ffmpeg -v quiet -y -i input ts -vcodec copy -acodec copy -ss 00 00 00 -t 00 30 00 -sn test1 mkv time ffmpeg -v quiet -y -i input ts -vcodec copy -acodec copy -ss 00 30 00 -t 01 00 00 -sn test2 mkv echo  quot One command quot   time ffmpeg -v quiet -y -i input ts -vcodec copy -acodec copy -ss 00 00 00 -t 00 30 00     -sn test3 mkv -vcodec copy -acodec copy -ss 00 30 00 -t 01 00 00 -sn test4 mkv  Which outputs    Two commands real    0m16 201s user    0m1 830s sys 0m1 301s  real    0m43 621s user    0m4 943s sys 0m2 908s  One command real    0m59 410s user    0m5 577s sys 0m3 939s  I tested a SD  amp  HD file  after a few runs  amp  a little maths  Two commands SD 0m53 94  2 wins   One command  SD 0m49 63    Two commands SD 0m55 00   One command  SD 0m52 26  1 wins   Two commands SD 0m58 60  2 wins   One command  SD 0m58 61   Two commands SD 0m54 60   One command  SD 0m50 51  1 wins   Two commands SD 0m53 94   One command  SD 0m49 63  1 wins    Two commands SD 0m55 00   One command  SD 0m52 26  1 wins   Two commands SD 0m58 71   One command  SD 0m58 61  1 wins  Two commands SD 0m54 63   One command  SD 0m50 51  1 wins    Two commands SD 1m6 67s  2 wins   One command  SD 1m20 18    Two commands SD 1m7 67   One command  SD 1m6 72  1 wins  Two commands SD 1m4 92   One command  SD 1m2 24  1 wins  Two commands SD 1m1 73   One command  SD 0m59 72  1 wins  Two commands HD 4m23 20   One command  HD 3m40 02  1 wins  Two commands SD 1m1 30   One command  SD 0m59 59  1 wins    Two commands HD 3m47 89   One command  HD 3m29 59  1 wins    Two commands SD 0m59 82   One command  SD 0m59 41  1 wins    Two commands HD 3m51 18   One command  HD 3m30 79  1 wins    SD file   1 35GB DVB transport stream HD file   3 14GB DVB transport stream Conclusion The single command is better if you are handling HD  it agrees with the manuals comments on using -ss after the input file to do a  slow seek   SD files have a negligible difference  The two command version should be quicker by adding another -ss before the input file for the  a  fast seek  followed by the more accurate slow seek

User · Answer

http   ffmpeg org trac ffmpeg wiki Seeking 20with 20FFmpeg may also be useful to you  Also ffmpeg has a segment muxer that might work   Anyway my guess is that combining them into one command would save time

[ffmpeg] FFmpeg: How to split video efficiently?

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