On Sat, 18 Mar 2006, Trent Piepho wrote:
> mplayer is right about the DAR. If you do the math, (720*10)/(480*11) =
Actually mplayer either off or the input stream is incorrect.
Take a 720x480 MPEG-2 file and play it and note that 1.33 is printed:
Playing foo.m2v.
VIDEO: MPEG2 720x480 (aspect 2) 29.970 fps 7500.0 kbps (937.5 kbyte/s)
File not found: '/Users/sms/.mplayer/default.sub'
Failed to open /Users/sms/.mplayer/default.sub
==========================================================================
Opening video decoder: [mpegpes] MPEG 1/2 Video passthrough
VDec: vo config request - 720 x 480 (preferred colorspace: Mpeg PES)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
The selected video_out device is incompatible with this codec.
Try adding the scale filter, e.g. -vf spp,scale instead of -vf spp.
VDecoder init failed :(
Opening video decoder: [libmpeg2] MPEG 1/2 Video decoder libmpeg2-v0.4.0b
Selected video codec: [mpeg12] vfm: libmpeg2 (MPEG-1 or 2 (libmpeg2))
==========================================================================
Audio: no sound
Starting playback...
VDec: vo config request - 720 x 480 (preferred colorspace: Planar YV12)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.
SwScaler: using unscaled Planar YV12 -> Packed YUY2 special converter
VO: [macosx] 720x480 => 720x540 Packed YUY2
Plain as day "Movie-Aspect is 1.33:1".
Nary a 1.36 in sight.
If MPlayer is printing out 1.36 then the input stream doesn't have the
720x480 frame size or something else is awry with the input stream
(aspect in the header is incorrect or something).
Rec.601 pixels mean that 720x480 goes to 720x540 and voila you have
a 4/3 image. The 704x480 is, as you know from experience, is scaled
to 704x528 by MPlayer. But I prefer to run actual experiments to
demonstrate a point rather soooo
VIDEO: MPEG2 704x480 (aspect 2) 29.970 fps 7500.0 kbps (937.5 kbyte/s)
File not found: '/Users/sms/.mplayer/default.sub'
Failed to open /Users/sms/.mplayer/default.sub
==========================================================================
Opening video decoder: [mpegpes] MPEG 1/2 Video passthrough
VDec: vo config request - 704 x 480 (preferred colorspace: Mpeg PES)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
The selected video_out device is incompatible with this codec.
Try adding the scale filter, e.g. -vf spp,scale instead of -vf spp.
VDecoder init failed :(
Opening video decoder: [libmpeg2] MPEG 1/2 Video decoder libmpeg2-v0.4.0b
Selected video codec: [mpeg12] vfm: libmpeg2 (MPEG-1 or 2 (libmpeg2))
==========================================================================
Audio: no sound
Starting playback...
VDec: vo config request - 704 x 480 (preferred colorspace: Planar YV12)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.
SwScaler: using unscaled Planar YV12 -> Packed YUY2 special converter
VO: [macosx] 704x480 => 704x528 Packed YUY2
Gosh, 1.33 again. Can't seem to get a 1.36 today. Maybe the files
are too well formed :)
I don't like MPlayer's behaviour because it's upscaling vertically which
is bad when dealing with interlaced material. What would be nicer
would be to take into account the rectangular pixels but scale
horizontally. Thus 704x480 10:11 would go to 640x480 - it's still
4/3 but without vertical upscaling. The 720 case is weird - probably
need to crop to 704 and then scale.
For MPlayer to print 1.36, and it would be nice to see the complete
output of MPlayer from the stream that is being played when 1.36 is
printed, the dimensions or other attribute of the file are banged up
somehow.
Steven Schultz
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