[FFmpeg-user] Webm Wrong Displaysize

[Mathieu Goutfreind]

720x576 (anamorphic DV-PAL 16:9) has been resized following your
instructions, the picture is stretched and the results seems worst :

mkvinfo : 
|+ Segment tracks
| + A track
|  + Track number: 1
|  + Track UID: 1
|  + Lacing flag: 0
|  + Language: und
|  + Codec ID: V_VP8
|  + Track type: video
|  + Default duration: 40.000ms (25.000 fps for a video track)
|  + Video track
|   + Pixel width: 768
|   + Pixel height: 432
|   + Display width: 1092
|   + Display height: 432
|   + Display unit: 3

But you're right it needs to be scaled to a 16:9 resolution without
"anamorphic", but the aspect has to be set to 1.22 not 16:9 (1.77) in
order to avoid distorsion.

Here is what I've done : 

ffmpeg -i MPG/M2U00019.MPG -vf scale=768:432 -aspect 1.22 -threads 4 -f
webm -vcodec libvpx -deinterlace -sameq -acodec libvorbis -alang fr -aq
90 -ac 2 -ab 160k -y M.webm

Thanks to you I've solved my problem.

Thank You

Le Mon, 13 Jun 2011 21:23:35 +0200,
Fabian Lesniak <fabian at lesniak-it.de> a écrit :

> I suggest to select a real 16:9 resolution, i.e. 768x432
> # ffmpeg -i file.mpg -vf scale=768:432 -aspect 16:9 ...
> 
> You may also want to crop some black borders, depending on your
> source, then I'd put the crop=x:y:a:b in front of the scale filter.
> 
> Am Montag, 13. Juni 2011, 22:50:17 schrieb Mathieu Goutfreind:
> > Le Mon, 13 Jun 2011 17:07:11 +0100,
> > 
> > startx <startx at plentyfact.org> a écrit :
> > > On Mon, 13 Jun 2011 18:47:14 +0200
> > > 
> > > Mathieu Goutfreind <mathieu_g1 at gmx.fr> wrote:
> > > > Hello,
> > > > 
> > > > I've got a small problem with webm.
> > > > Using ffmpeg the displaysize is incorrect.
> > > > 
> > > > libpostproc   51. 2. 0 / 51. 2. 0 Input #0, mpeg, from
> > > > 'M2U00008.MPG': Duration: 00:03:58.55, start: 0.072389, bitrate:
> > > > 9624 kb/s Stream #0.0[0x1e0]: Video: mpeg2video, yuv420p,
> > > > 720x576 [PAR 64:45 DAR 16:9],
> > > 
> > > this is probably because of "[PAR 4:3 DAR 16:9]" in the original,
> > > the pixel aspect ratio is 4:3 ( anamorphic widescreen ).
> > > 
> > > you need to set the aspect ratio or calculate the outcome
> > > manually.
> > > 
> > > startx
> > > _______________________________________________
> > > ffmpeg-user mailing list
> > > ffmpeg-user at ffmpeg.org
> > > http://ffmpeg.org/mailman/listinfo/ffmpeg-user
> > 
> > I've tried -aspect 16:9 but i've still the same result.
> > 
> > Maybe I'm using the wrong command ?
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