[MPlayer-users] Erroneous Aspect Ratio detection on DVDs with Pan&Scan Feature

[Alexander Roalter]

Hello,
another issue which I came across and has never been addressed on this 
list will be presented in this posting:

It's about DVDs which have a Pan&Scan flag. Such a flag should in theory 
tell the player how to zoom into a video (given the case the DVD player 
is set to P&S instead of 4:3LB or 16:9), which should also include the 
possibility to PAN around (not simple zoom), but in all cases I've 
encountered so far does only zoom in (as with pressing the 'e'-Key in 
mplayer until the picture is full frame).

I've had this with older James Bond DVDs and recently on my Raging Bull 
Ultimate Gold Edition (German Version). This should be practically 
identical to the british Raging Bull Cinema Reserve or MGM Ultimate Edition.

Problem is: Although these DVDs are encoded anamorphic, mplayer thinks 
they're not and shows a stretched picture. Adding -aspect 16:9 helps, 
but this should be done automatically, as the correct aspect ratio is 
misdetected.

A comparison of the -identify-Output shows the mpeg DAR is set to 4:3 on 
raging bull, this is what mplayer then (wrongly) uses. Other than that 
there must be an indicator that this 4:3 is only in there for the 
pan&scan crap, but 16:9 is to be used instead... Any idea (or knowledge)?


Raging Bull: mplayer dvd://1 -identify

ID_VIDEO_ID=0
MPEG-PS file format detected.
ID_AUDIO_ID=128
VIDEO:  MPEG2  720x576  (aspect 2)  25.000 fps  6628.0 kbps (828.5 kbyte/s)
ID_FILENAME=dvd://1
ID_DEMUXER=mpegps
ID_VIDEO_FORMAT=0x10000002
ID_VIDEO_BITRATE=6628000
ID_VIDEO_WIDTH=720
ID_VIDEO_HEIGHT=576
ID_VIDEO_FPS=25.000
ID_VIDEO_ASPECT=0.0000
ID_AUDIO_FORMAT=8192
ID_AUDIO_BITRATE=0
ID_AUDIO_RATE=0
ID_AUDIO_NCH=0
ID_LENGTH=7423.96


The X-Files Season 7 Disc 4, anamorphic enhanced, with 4 Episodes @ 
45mins per disc: mplayer dvd://1 -identify

VIDEO:  MPEG2  720x576  (aspect 3)  25.000 fps  7500.0 kbps (937.5 kbyte/s)
ID_FILENAME=dvd://1
ID_DEMUXER=mpegps
ID_VIDEO_FORMAT=0x10000002
ID_VIDEO_BITRATE=7500000
ID_VIDEO_WIDTH=720
ID_VIDEO_HEIGHT=576
ID_VIDEO_FPS=25.000
ID_VIDEO_ASPECT=0.0000
ID_AUDIO_FORMAT=8192
ID_AUDIO_BITRATE=0
ID_AUDIO_RATE=0
ID_AUDIO_NCH=0
ID_LENGTH=2560.80

Oh, and BTW: since the length of a mpeg video cannot be estimated easily 
from the data itself (without seeking through the entire video), how 
about using the ID_LENGTH on DVDs, so at least there it would be known 
(or has there been a change I don't know of and this is done already?)