mga_vid and interlaced output via DVI (NOT tv-out)

[Michael Langguth]

hi all,

since many years i had my self made htpc running with a g400 and tvout via
rgb.

now i moved to a g550 and have a pioneer plasma connected with a dvi to hdmi
cable. i had to create some fb.mode entries but and it works fine in all
progressive modes (576p, 720p, 1080p). but from my point of view the pioneers
builtin deinterlacer is much better than any of mplayers deinterlacers.

so i tried to use 576i. after i realized that the horizontal resolution has
to be doubled from 720 to 1440, i got a framebuffer console working. mplayer
with -vo fbdev also works in the way one can expect from this mode.

with mga_vid my problem is that all lines are doubled. i see a stretched
picture consisting of the first 288 lines of the picture with correct width.
i tried this with test_mga_vid, same result: the test pattern are not square,
they have double height while the framebuffer console in the background is
ok.

for me this looks like some layer expects even and odd frames to be provided
one after the other, each with 288 lines instead of interleaved with 576
lines.

now the question: how can i fix this? is there any bes register witch has to
be set in a different way?

btw: when trying 1080i i have exectly the same problem.


thanks for any idea,

michael

[Attila Kinali]

Morgen!

On Sun, 9 Sep 2007 23:32:47 +0200

Post by Michael Langguth
so i tried to use 576i. after i realized that the horizontal resolution has
to be doubled from 720 to 1440, i got a framebuffer console working. mplayer
with -vo fbdev also works in the way one can expect from this mode.

I don't really understand what you are doing. Please
provide at least your xorg.conf, eventually used
mga_vid parameters and the parameters you pass to MPlayer.
See bugreports.html for a complete list of information needed.

Attila Kinali

[Michael Langguth]

On Tuesday, September 11, 2007 1:44 AM
Morgen!

Post by Attila Kinali
On Sun, 9 Sep 2007 23:32:47 +0200
so i tried to use 576i. after i realized that the horizontal
resolution has to be doubled from 720 to 1440...

I don't really understand what you are doing. Please
provide at least your xorg.conf, eventually used
mga_vid parameters and the parameters you pass to MPlayer.
See bugreports.html for a complete list of information needed.

hallo attila,

i try to play a video in standard pal resolution via dvi connected to hdmi.
as stated in my original posting, progressive modes work well in top quality.
only interlaced modes are missing for a perfect "tv-out 2.0".

the doubled horizontal resolution is part of the hdmi spcification (see
http://www.hdmi.org/pdf/HDMISpecInformationalVersion.pdf, capt. 6.4):

"Video formats with native pixel rates below 25 Mpixels/sec
require pixel-repetition in order to be carried across a TMDS
link. 720x480i and 720x576i video format timings shall always
be pixel-repeated."

this is the normal procedure used in any consumer device outputting 576i via
hdmi: the device doubles each pixel and sends the signal in 1440x576i to the
display. the display ignores every second pixel to get back the original
720x576i. if you look in the manual of flat tv's you often will read about
pal over hdmi as "720(1440)***@50hz". higher resolutions like 1080i have
high enough pixel rates and do not need this special treatment.


but thats not my problem. my problem is the doubling of vertical lines. i can
reproduce this in 576i and 1080i (which has no hor. doubling), independant of
mplayer just by using mga_vid_test. i do not use an x-server, i have a simple
text based "gui" running in a framebuffer console.

here my fb.modes entry for the interlaced modes:

mode "576i-50"
# hdmi cannot handle 13.5 mhz, so every pixel has to be doubled.
# D: 27.000 MHz, H: 31.250 kHz, V: 50.000 Hz
geometry 1440 576 1440 576 32
timings 37037 120 40 42 4 128 3
laced true
endmode

mode "1080i-50"
# D: 61.874 MHz, H: 28.124 kHz, V: 49.999 Hz
geometry 1920 1080 1920 1080 32
timings 16162 148 88 31 4 44 10
laced true
endmode

mplayer.conf is realative simple:

vo=mga
ao=alsa
fs=yes
framedrop=yes
cache=8192
monitoraspect=16:9
aspect=16:9
vop=hue
contrast=-15
brightness=10
saturation=-15
hue=0
rtc=1
mc=0.002
autosync=100
lirc=yes
lircconf=/usr/local/etc/lirc/mplayer.rc
joystick=no


insmod mga_vid is done without any parameters.


i am not sure if i was able to describe what i see on the screen: if i have a
1080i video, only the upper half of it will be displayed, zoomed to
fullscreen. egghead alert!

when i start mga_vid_test from the console, i see a rectangle instead of a
square. you remember, if you run mga_vid_test, the square is displayed over
the console. in my case this is also the case and the console remains visible
completely in correct aspect. only the test pattern is not square but a
rectangle with width:height = 1:2.

if it helps i can provide a photo.


by the way: is there any kind of description of the bes registers available?
may be i could try out something by my self...


viele grüße,

michael

[Attila Kinali]

On Tue, 11 Sep 2007 22:36:16 +0200

Post by Michael Langguth
i am not sure if i was able to describe what i see on the screen: if i have a
1080i video, only the upper half of it will be displayed, zoomed to
fullscreen. egghead alert!

Ok, i see what you are doing. Does mplayer -v say anything
special? (I doubt it, but...)

Post by Michael Langguth
by the way: is there any kind of description of the bes registers available?
may be i could try out something by my self...

I only have the specs of the G400, which are compatible
enough to get the G550 working, but i don't know whether
there are any subtle differences.

I think what happens is that the G550 expects the data
in field(Halbbild) form for the interlaced modes, though neither
mga_vid nor MPlayer are prepared for this.

If you have time at your hand and want to imporove mga_vid/MPlayer
to be able to use interlaced modi, please feel free to do so.


Attila Kinali