[mythtv-users] Viktor! You were right!!!
st3v3.sm1th at gmail.com
Wed Jun 20 22:52:35 UTC 2007
---------- Forwarded message ----------
From: Steve Smith <st3v3.sm1th at gmail.com>
Date: 20-Jun-2007 23:51
Subject: Viktor! You were right!!!
To: Discussion about mythtv <mythtv-users at mythtv.org>
I've hooked up my PAL TV via a VGA->SCART RGB cable.
I use an X modeline with the "interface" flag that results in a mode with
25hz FRAME rate which is 50 hz FIELD rate.
Playing some interlaced files without deinterlace (but with OpenGL video
sync, and video as a time base) results in the fields being shown out of
order. (other files work OK) or to a 25FPS playback rather than pseudo 50hz
(see my "What don't I get here" posts)
The recommended work around is to use bob-deinterlace...
So as recommended I enable bob-deinterlace.....
2007-06-20 23:04:08.802 The realtime priority setting is not enabled.
2007-06-20 23:04:08.815 Using deinterlace method bobdeint
2007-06-20 23:04:08.920 nVidiaVideoSync: VBlank ioctl did not work,
unimplemented in this driver?
2007-06-20 23:04:08.921 DRMVideoSync: Could not open device /dev/dri/card0,
No such file or directory
2007-06-20 23:04:08.926 OpenGLVideoSync: GLX extensions: GLX_EXT_visual_info
GLX_EXT_visual_rating GLX_SGIX_fbconfig GLX_SGIX_pbuffer GLX_SGI_video_sync
GLX_SGI_swap_control GLX_EXT_texture_from_pixmap GLX_ARB_multisample
2007-06-20 23:04:08.928 OpenGLVideoSync: x,y -> 360, 288
2007-06-20 23:04:09.023 Using OpenGLVideoSync
2007-06-20 23:04:09.023 Set video sync frame interval to 40000
2007-06-20 23:04:09.024 Video sync method can't support double framerate
(refresh rate too low for bob deint)
2007-06-20 23:04:09.024 Set video sync frame interval to 40000
2007-06-20 23:04:09.035 Using deinterlace method onefield
2007-06-20 23:04:09.045 Using video as timebase
2007-06-20 23:04:09.045 Video timing method: SGI OpenGL
2007-06-20 23:04:09.045 Refresh rate: 40013, frame interval: 40000
'video_output' mean = '40538.84', std. dev. = '16889.77', fps = '24.67'
Notice the line......
2007-06-20 23:04: 09.024 Video sync method can't support double framerate
(refresh rate too low for bob deint)
To me this looks like Myth has seen that the mpeg is at 25FPS,
has looked at the video mode and seen 25FPS also,
but bob-deinterlace effectively doubles the rate to 50, oh dear we don't
support that....use onefield instead....
WRONG in this case!!
We are using an ****INTERLACED**** mode so we can support the full 50hz just
at half the vertical resolution!
So yes it looks like Viktor's patch is correct after all....although he
shouldn't need to be. Really myth should have a proper interlaced output
mode i.e. you tell it you are using an interlaced display, it syncs to the
refresh and displays the fields in order at the right time. No deinterlace
required we leave that to the TV. IS THIS POSSIBLE IN MYTH???
In the mean time I need to do my first compile of Mythtv....
On 15/06/07, Viktor Avramov < drvik at bigpond.net.au> wrote:
> I recommend using a VGA -> SCART cable... then you will have very precise
> control of what goes to the TV.... I had a problem like you using PAL
> on a 50Hz interlaced TV... I wrote a patch which doubles the framerate for
> interlaced modes... I now use it wil BOB deinterlacing and the result is
> silky smooth!
> Here's the patch.... do with it what you will... I submitted it for
> in trunk but it was rejected because it's flawed in it's logic... all I
> say is on my setup it's the only way of getting smooth, fluid motion....
> devs told me to use the myth-vid branch instead!!
> Index: libs/libmythtv/videoout_xv.cpp
> --- libs/libmythtv/videoout_xv.cpp (revision 12477)
> +++ libs/libmythtv/videoout_xv.cpp (working copy)
> @@ -308,6 +308,9 @@
> if (rate == 0)
> rate = 60;
> + if (mode_line.flags && 0x010) // #define V_INTERLACE 0x010
> + rate = rate * 2; // if modeline is interlaced then
> the effective refresh rate
> if (rate < 20 || rate > 200)
> VERBOSE(VB_PLAYBACK, LOC + QString("Unreasonable refresh rate
> %1Hz "
> mythtv-users mailing list
> mythtv-users at mythtv.org
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