[FFmpeg-user] Worse quality than mencoder [SOLVED]

Jan Sever n32 at email.cz
Wed Nov 26 14:36:52 CET 2014

On 2014-11-26 12:30, Moritz Barsnick wrote:
> Are you absolutely sure?
I'm sorry, they're the same only for the second pass: that was the problem.

> You're doing two-pass, right? If that is why these logs each contain
> two outputs from the encoders, then you're doing something
> significantly wrong:
> mencoder.txt:x264 [info]: profile Main, level 3.0
> mencoder.txt:x264 [info]: profile High, level 4.0
> ffmpeg.txt:[libx264 @ 0x63c9c0] profile Main, level 4.0
> ffmpeg.txt:[libx264 @ 0x63c9c0] profile High, level 4.0
Level was not the problem.
> The libx264 settings from the first pass and second pass differ
> significantly from each other - and in a different manner in ffmpeg and
> mencoder. Only the second pass settings seem identical, which may be
> why you see the same embedded in the file. 
Yes, you're right, that was the problem. The encoders set some parameters
for quicker first pass (I knew that), but what I didn't know that ffmpeg doesn't
set fast_pskip=1 and ref=1 while mencoder does.

> AFAIU you need to use identical codec options in both passes, and it
> seems you're not doing that. That _may_ be the cause for your
> observations.
In fact, it is. I compared the achieved quality after changing the two mentioned
parameters and it looks almost the same now. So marking as SOLVED. Thanks
everybody for your precious help.

Jan Sever

More information about the ffmpeg-user mailing list