[FFmpeg-user] Size of cropped video segments

[Carl Eugen Hoyos]

2017-02-08 17:29 GMT+01:00 Chao Zhou <czhou5 at binghamton.edu>:

> I am cropping a video to 9 small segments with the command below:
>
> ffmpeg -i source.mp4 -filter_complex \
> "[0:v]crop=1/3*in_w:1/3*in_h:0:0[out1];[0:v]crop=1/3*in_w:1/3*in_h:1/3*in_w:0[out2];\
> [0:v]crop=1/3*in_w:1/3*in_h:2/3*in_w:0[out3];[0:v]crop=1/3*in_w:1/3*in_h:0:1/3*in_h[out4];\
> [0:v]crop=1/3*in_w:1/3*in_h:1/3*in_w:1/3*in_h[out5];[0:v]crop=1/3*in_w:1/3*in_h:2/3*in_w:1/3*in_h[out6];\
> [0:v]crop=1/3*in_w:1/3*in_h:0:2/3*in_h[out7];[0:v]crop=1/3*in_w:1/3*in_h:1/3*in_w:2/3*in_h[out8];[0:v]crop=1/3*in_w:1/3*in_h:2/3*in_w:2/3*in_h[out9]"
> \
> -map "[out1]" out1.mp4 -map "[out2]" out2.mp4 -map "[out3]" out3.mp4 \
> -map "[out4]" out4.mp4 -map "[out5]" out5.mp4 -map "[out6]" out6.mp4 \
> -map "[out7]" out7.mp4 -map "[out8]" out8.mp4 -map "[out9]" out9.mp4

Complete, uncut console output missing.

> I expect the size of total 9 segments will be larger than the source video

Why?

> since the search space of the segment became smaller and encoding
> efficiency reduced.

Even if this were a valid argument (I apparently misunderstand it due to
the language barrier) it is certainly not a sufficient argument for a bigger
(or smaller) filesize: You can either specify a bitrate or output quality (which
is the default for x264), in case of quality several other factors are
responsible for the output filesize.

Carl Eugen