[FFmpeg-user] File sizes after transcoding with ffmpeg.

ನಾಗೇಶ್ ಸುಬ್ರಹ್ಮಣ್ಯ (Nagesh S) nageshblore at gmail.com
Tue Dec 3 18:36:36 CET 2013

I am just curious to know, if the following file sizes sound ok after
transcoding with ffmpeg. Let me know what other information maybe needed.

I have an input video of around 10:11 of video in mp4. Conversion to mpg
with ffmpeg is done as follows.

ffmpeg -i in.mp4 -vf subtitles=sub.srt -codec:v mpeg2video -codec:a mp3

The mpg is then converted to VOB as follows. This is so that dvdauthor can
be used to add titles, chapters, etc.

ffmpeg -i in.mpg -target ntsc-dvd in.vob

After dvdauthor is run on in.vob, I am converting the DVD structure to .iso.

So, the file sizes are as follows:

in.mp4 - ~20MB
in.mpg - ~30MB
in.vob - ~109MB
dvd.iso - ~219MB

Thus, in other words, a 10 minute video is around 200MB in ISO format. I
understand, the behaviour of dvdauthor and mkisofs is not in the scope of
this forum. But, in your experience, is this 10 fold increase normal ?

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