[MEncoder-users] mencoder: mp2->mp4 autoaspect question

[Toerless Eckert]

On Wed, Sep 22, 2010 at 03:27:20PM +0000, Carl Eugen Hoyos wrote:
> > ffmpeg -i 001.mpg -vcodec mpeg4  -b 1500k 001.avi
> 
> Works fine with a not-too-ancient version (only latest svn is supported, the
> same is true for MPlayer/MEncoder).

Unfortunately i couldn't get it to work, not even with the latest SVN.
I'd really appreciate if you could tell me anything more about the
parameters you used to test. I am also of course not 100% sure that
the players i use support to switch the aspect ratio on an mpeg4 stream
(vlc, mplayer with ffmpeg).


Cheers
    Toerless

P.S.:As far as de-interlacing is concerned: I just have not found the time
to figure out the best possible de-interlacer/parameters , so i am
delaying that decision to the decoder where i can change it over time.

Also: I understand how i would loose some quality/bitrate by using
interlaced encoding, but i also have not seen sufficient evidence that that
de-interlcidng would result in ultimately a better viewing experience
than interlaced displaying of the non-de-interlaced encoding.

P.S.2: my ffmpeg version:
> ffmpeg --version
> FFmpeg version SVN-r25190, Copyright (c) 2000-2010 the FFmpeg developers
>   built on Sep 25 2010 01:50:11 with gcc 4.3.4
>   configuration: --prefix=/usr --libdir=/usr/lib --shlibdir=/usr/lib --mandir=/usr/share/man --enable-static --enable-shared --cc=i686-pc-linux-gnu-gcc --enable-gpl --enable-version3 --enable-postproc --enable-avfilter --disable-stripping --disable-debug --disable-doc --disable-network --disable-vaapi --disable-static --disable-vdpau --enable-libmp3lame --enable-libvorbis --enable-libx264 --enable-libxvid --disable-indev=v4l --disable-indev=v4l2 --disable-indev=oss --disable-indev=jack --enable-x11grab --disable-outdev=oss --disable-altivec --cpu=i686 --enable-hardcoded-tables
>   libavutil     50.28. 0 / 50.28. 0
>   libavcore      0. 9. 0 /  0. 9. 0
>   libavcodec    52.90. 0 / 52.90. 0
>   libavformat   52.78. 5 / 52.78. 5
>   libavdevice   52. 2. 2 / 52. 2. 2
>   libavfilter    1.44. 0 /  1.44. 0
>   libswscale     0.11. 0 /  0.11. 0
>   libpostproc   51. 2. 0 / 51. 2. 0

---- end
> 
> > ffmpeg -i 001.mpg -vcodec mpeg4  -b 1500k 001.mp4
> 
> Does not work...
> 
> [...]
> 
> > > > If not, how difficult would it to add this to mencoder ?
> > > 
> > > Please note that mencoder is not actively maintained and that you should use
> > > ffmpeg for most transcoding.
> > 
> > If ffmpeg is supported it should have a better man page.
> 
> The project maintainer does not disagree;-)
> http://thread.gmane.org/gmane.comp.video.ffmpeg.devel/117633/focus=117728
> 
> > Took me eternities to figure out there's something like '-flags +ildct+ilme'.
> 
> But you qualified by finding them;-)
> Note that I would advise you to de-interlace instead - the patch for yadif in
> FFmpeg is ready, but not yet committed ;-(
> 
> Carl Eugen
> 
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