[FFmpeg-user] filter_complex concat large number of files.

[Gyan Doshi]

On 01-06-2018 05:58 AM, William C Bonner wrote:
> I'm using ffmpeg to concatenate a large number of files from my dash cam
> and then speed things up by a factor of 60.
> 
> It works properly when the number of files is small, but fails as the
> filter_complex option string expands. I'm generating the command line from

The workaround is to use the concat demuxer.

Generate a text file, say, videos.txt, listing all files in order

     file "G:\\ROAV\\MOVIE\\2018_0529_112356_056.MP4"
     file "G:\\ROAV\\MOVIE\\2018_0529_112447_057A.MP4"
     file "G:\\ROAV\\MOVIE\\2018_0529_112450_058A.MP4"
     [continued ...]


Then run

     ffmpeg -f concat -safe 0 -i videos.txt -vf 
"setpts=(1/60)*PTS,drawtext=fontfile=C\\\\:/WINDOWS/Fonts/consola.ttf:fontcolor=white:fontsize=80:y=main_h-text_h-50:x=50:text=WimsWorld" 
-c:v libx265 -crf 23 -preset veryfast -movflags +faststart -bf 2 -g 15 
-pix_fmt yuv420p -y "C:\\Users\\Wim\\Video\\RoavConcatTest.mp4"


Regards,
Gyan