[FFmpeg-user] Transcoding foscam mkv to mp4 is resulting in larger files

Kai Hendry kai.hendry at gmail.com
Sun Sep 13 06:03:16 CEST 2015

Hi guys,

The Input #0, mpeg transcoding into mp4 (for iPhone playback via
Safari) is resulting in up 3x larger files. Why is that?

ffprobe of a typical MKV input file:

The ffmpeg log:

Sidenote: Found I had to put in a frame rate of 30 else things
wouldn't work. Really not sure why. Maybe someone can explain?

Example of the input:

Many thanks,

p.s. code for the project will eventually land up in

More information about the ffmpeg-user mailing list