[FFmpeg-user] Splitting a video in chunks with the same size

Thu Jun 9 12:39:01 CEST 2016

If you are willing to do a little legwork, you can install
http://www.cygwin.com/

That will allow you to run the bash script. After that, you can just change
the way you split the files, instead of splitting by time you can split by
bytes or whatever metric you'd like. The script that I provide is pretty
generic sans bash but cygwin provides that for windows.

Best,
Owen

On Thu, Jun 9, 2016 at 4:03 PM, Celso Coutinho <20.celso at gmail.com> wrote:

> I don't think I can use this script... I should have mentioned that I am
> working on a windows environment... But I did mention that my goal was to
> split a video in equally sized chunks (in bytes, not in seconds).
>
> But thanks anyway :)  This will surely be helpful for someone else :)
>
> On 8 June 2016 at 16:40, blubee blubeeme <gurenchan at gmail.com> wrote:
>
> > Here is the script
> > In this script chunk_size and default_chunk_size = 600 seconds so my
> chunks
> > were 10 minutes, change the chunk size to whatever you like.
> >
> >
> -----------------------------------------------------------------------------------------------------------------------------------------------------------------------
> > #!/bin/bash
> > DIR="path/to/your/videos/*" #notice the trailing /*
> > OUT_DIR="path/where/output/files/go"
> > OUTPUT_FILE=""
> >
> > file_duration_float=0
> > file_duration_int=0
> > working_file_duration=0
> > default_chunk_size=600 #video length in seconds (10 minutes)
> > chunk_size=600 #video length in seconds (10 minutes)
> > chunk_start_time=0
> > chunk_end_time=0
> > iteration=0
> >
> > #extract simple metadata from files
> > for f in $DIR
> > do
> > echo $f
> > file_duration_float=$(ffprobe -i "$f" -show_format -v quiet | sed -n
> > 's/duration=//p')
> > file_duration_int=$( echo "($file_duration_float+0.5)/1" | bc )
> > working_file_duration_int=$file_duration_int
> > echo $file_duration_int
> >
> > #---------------------------------------------
> > # determine the start and end time of each clip
> > #---------------------------------------------
> > while [ $working_file_duration_int -gt -1 ]
> > do
> > filename=$(basename "$f")
> > input_file="$filename"
> > filename=${filename::-4}" "
> > file_extension=${f: -3}
> > input_file_dir=$(dirname "$f")"/"
> >
> >
> > if [ $iteration -eq 0 ]
> > then
> >             if [ $file_duration_int -le $chunk_size ]
> >             then
> >    working_file_duration_int=$((file_duration_int))
> >    chunk_start_time=0
> >    chunk_end_time=$(($working_file_duration_int))
> >                 echo "file is shorter than 10 minutes:
> > $working_file_duration_int  breaking early! iteration $iteration start:
> > $chunk_start_time end: $working_file_duration_int duration:
> > $working_file_duration_int video length left $working_file_duration_int"
> >
> > OUTPUT_FILE="$OUT_DIR$filename$iteration.mkv"
> > $(ffmpeg -hide_banner -loglevel panic -i "$f" -ss $chunk_start_time -t
> > $chunk_end_time [your options here ] "$OUTPUT_FILE")
> >                 break
> >             fi
> >
> > working_file_duration_int=$((file_duration_int - chunk_size))
> > chunk_start_time=0
> > chunk_end_time=$(($default_chunk_size))
> >
> > echo "iteration $iteration start: $chunk_start_time end: $chunk_end_time
> > duration: $default_chunk_size video length left
> $working_file_duration_int"
> >
> > OUTPUT_FILE="$OUT_DIR$filename$iteration.mkv"
> > $(ffmpeg -hide_banner -loglevel panic -i "$f" -ss $chunk_start_time -t
> > $chunk_end_time [your options here ] "$OUTPUT_FILE")
> > iteration=$((iteration+1))
> > fi
> > if [ $working_file_duration_int -le $chunk_size ]
> > then
> > chunk_size=$working_file_duration_int
> > working_file_duration_int=$((working_file_duration_int - chunk_size))
> > chunk_start_time=$(($chunk_start_time+$chunk_end_time))
> > chunk_end_time=$(($chunk_size))
> >
> > echo "early chunk size: $chunk_size iteration $iteration start:
> > $chunk_start_time end: $((chunk_start_time+chunk_end_time)) duration:
> > $chunk_end_time video length left $working_file_duration_int "
> >
> > OUTPUT_FILE="$OUT_DIR$filename$iteration.mkv"
> > $(ffmpeg -hide_banner -loglevel panic -i "$f" -ss $chunk_start_time -t
> > $chunk_end_time [your options here ] "$OUTPUT_FILE")
> > iteration=0
> > chunk_size=$default_chunk_size
> > break
> > else
> > chunk_start_time=$(($chunk_start_time+$chunk_end_time))
> > chunk_end_time=$(($chunk_size))
> > working_file_duration_int=$((working_file_duration_int - chunk_size))
> > echo "iteration $iteration start: $chunk_start_time end:
> > $((chunk_start_time+chunk_end_time)) duration: $chunk_end_time video
> length
> > left $working_file_duration_int "
> >
> > OUTPUT_FILE="$OUT_DIR$filename$iteration.mkv"
> > $(ffmpeg -hide_banner -loglevel panic -i "$f" -ss $chunk_start_time -t
> > $chunk_end_time [your options here ] "$OUTPUT_FILE")
> > iteration=$((iteration+1))
> > fi
> > done
> > echo "---------------- finished processing $f"
> > done
> >
> >
> -----------------------------------------------------------------------------------------------------------------------------------------------------------------------
> >
> > Let me know if you have any questions.
> >
> > On Wed, Jun 8, 2016 at 5:14 PM, Henk D. Schoneveld <belcampo at zonnet.nl>
> > wrote:
> >
> > >
> > > On 08 Jun 2016, at 11:01, blubee blubeeme <gurenchan at gmail.com> wrote:
> > >
> > > > I wrote a script to do this exact same thing. I will post it to this
> > list
> > > > when I get back to my machine.
> > > It can be done by splitting an all i-frame/key-frame mpeg transport
> > stream
> > > file with the split command. An all i-frame/key-frame conversion isn’t
> > very
> > > efficient in conversion, but that is a side-effect.
> > > >
> > > > On Wed, Jun 8, 2016, 16:56 Henk D. Schoneveld <belcampo at zonnet.nl>
> > > wrote:
> > > >
> > > >>
> > > >> On 08 Jun 2016, at 10:39, Celso Coutinho <20.celso at gmail.com>
> wrote:
> > > >>
> > > >>> Dear all,
> > > >>>
> > > >>> I want to be able to split a file in chunks with the same
> (previously
> > > >>> defined) size (except the last chunk, of course). I have been
> trying
> > > >>> several commands but without much success.
> > > >> Out of curiosity, what is the reason for wanting same-sized chunks ?
> > > >> Same-time chunks is what mostly is used.
> > > >>>
> > > >>> When I look into the documentation, I understand the *-fs* flag
> > allows
> > > me
> > > >>> to define the maximum size of the chunk I am obtaining in each
> time I
> > > run
> > > >>> *ffmpeg,* but I don't know how to define the starting point of the
> > > >> chunk. I
> > > >>> tried *-ss*, but it seems that I can only use it with time, rather
> > than
> > > >>> file size. Can someone enlighten me on this matter?
> > > >>>
> > > >>> Moreover, I have been trying to use the following command:
> > > >>>
> > > >>> *ffmpeg **-i raper.3gp -fs 102400 -vcodec copy -acodec copy
> -movflags
> > > >>> faststart output1.avi*
> > > >>>
> > > >>> But the output video has no sound, plus the duration is always
> > > incorrect
> > > >>> (video has 4 to 5 seconds, and the duration shown in the video is
> > like
> > > >> one
> > > >>> minute). Which codecs should I choose?
> > > >>>
> > > >>> Thanks in advance!
> > > >>>
> > > >>> Celso
> > > >>> _______________________________________________
> > > >>> ffmpeg-user mailing list
> > > >>> ffmpeg-user at ffmpeg.org
> > > >>> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
> > > >>>
> > > >>> To unsubscribe, visit link above, or email
> > > >>> ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
> > > >>
> > > >> _______________________________________________
> > > >> ffmpeg-user mailing list
> > > >> ffmpeg-user at ffmpeg.org
> > > >> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
> > > >>
> > > >> To unsubscribe, visit link above, or email
> > > >> ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
> > > > _______________________________________________
> > > > ffmpeg-user mailing list
> > > > ffmpeg-user at ffmpeg.org
> > > > http://ffmpeg.org/mailman/listinfo/ffmpeg-user
> > > >
> > > > To unsubscribe, visit link above, or email
> > > > ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
> > >
> > > _______________________________________________
> > > ffmpeg-user mailing list
> > > ffmpeg-user at ffmpeg.org
> > > http://ffmpeg.org/mailman/listinfo/ffmpeg-user
> > >
> > > To unsubscribe, visit link above, or email
> > > ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
> > >
> > _______________________________________________
> > ffmpeg-user mailing list
> > ffmpeg-user at ffmpeg.org
> > http://ffmpeg.org/mailman/listinfo/ffmpeg-user
> >
> > To unsubscribe, visit link above, or email
> > ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
> >
> _______________________________________________
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>
> To unsubscribe, visit link above, or email
> ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".
>