[MEncoder-users] filesize become very big after convertion
bugfood-ml at fatooh.org
Mon Aug 21 20:06:36 CEST 2006
Achilles Xu wrote:
> Hello mencoder-users,
> I use the following command to convert some video to flv file format.
> mencoder aaa.mov -o aaa.flv -of lavf -oac mp3lame -lameopts abr:br=56 -ovc lavc -lavcopts vcodec=flv:vbitrate=16000:mbd=2:mv0:trell:v4mv:cbp:last_pred=3 -srate 22050 -lavfopts i_certify_that_my_video_stream_does_not_use_b_frames
> The 16000 vbitrate is for get best quality, but the filesize become twice or three times.
> What can I do to decrease the filesize without losing quality?
Unless you absolutely have to convert, the best solution is to leave the
original file alone. Except when encoding with a lossless codec (which
results in a very large output file), there is no way to re-encode
without losing quality. Specifiying a high bitrate only minimizes the
There are a few other ways to reduce the loss in quality.
1. Use two pass encoding. Read the manual for the vpass option.
2. Use a better format. FLV isn't that great. H.264 (with the x264
codec) and MPEG-4 (with XviD or lavc codecs) can each do much better.
3. Scale the video down somewhat (-vf scale=xxx:yyy). This will make the
video smaller, of course, and lose some detail, but to a certain point
this usually looks better than blocky artifacts.
4. Use different lavcopts. The ones you have look pretty good, though,
so I wouldn't expect too much improvement there. These are the ones I
used for some flv stuff a while ago. Add your own vbitrate and vpass.
You may get a slight improvement there. Maybe not. I didn't test them
More information about the MEncoder-users