[FFmpeg-user] Any way to make this 2GB file any smaller?

Gilles codecomplete at free.fr
Tue Nov 19 01:11:44 CET 2013


On Sun, 17 Nov 2013 07:36:52 -0600, David Favor <david at davidfavor.com>
wrote:
>> ffmpeg.exe -i input.mpg -c:v libx264 -b:v 900k -s 640x360 -strict
>> experimental -c:a aac -ab 192k -ac 2 -ar 44100 -preset slower
>> output.mp4
>
>As an experiment, try -crf 20 -v:preset veryfast + check time to encode
>along with resulting files size.

Thanks for the idea. Apparently, it's "-preset veryfast":
https://trac.ffmpeg.org/wiki/x264EncodingGuide

The following command took almost 6 hours on my oldish AMD computer:

ffmpeg.exe -i input.mpg -c:v libx264 -b:v 900k -s 640x360 -crf 20
-preset veryfast -strict experimental -c:a aac -ab 192k -ac 2 -ar
44100 -preset slower output.crf.veryfast.mp4

The output is 11% of the original file (1.135.756.154  / 9.956.964.376
bytes).

================

>Also using libfaac instead of aac usually results in higher quality
>audio at lower bitrates. Or for same bitrate smaller audio.

I used "aac" because libfaac apparently requires compiling ffmpeg, and
I didn't want to spend time setting things up on my Windows host:
https://trac.ffmpeg.org/wiki/AACEncodingGuide



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