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

[Celso Coutinho]

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
> > >>> _______________________________________________
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> > >>> ffmpeg-user at ffmpeg.org
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> > >>>
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> > >>
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> > >>
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> >
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