[MPlayer-users] Preserve interlacing; prevent tearing on TV-out?

Neologism Neologism at POBox.COM
Sun Oct 28 10:56:46 CET 2001


Thank you both for replying so quickly!

On 20 Oct 2001, Dan Hollis wrote:
> There is one possibility -- your vga convertor is trying to do "flicker
> fixing" to reduce flicker effects of single-pixel horizontal lines on
> output. This will *definitely* screw things up. Look to see if you have
> option to turn it off.

I'm using a cheap scan convertor (Antec TVator EXEC), and it doesn't
seem to have any such option.

> The final problem is that divx simply does't support interlaced video, so
> your chances of getting field order incorrect is high (roughly 50%).

I'm using Divx4, not DivX ;-), and it's claimed to be compliant with
MPEG4.  MPEG4 supports interlaced video.  I was unable, however, to find
any statement claiming that Divx4 supports interlaced video, and it's
closed source so who knows?

> Just forget this divx and use something built from the ground up with
> interlaced suppport: mpeg2. And use a dvd decoder card like realmagic
> hollywood plus.

More comments on MPEG4 below, but hey thanks for bringing the Hollywood
Plus to my attention.  I checked out NetStream 2000TV, a newer version,
which looks cool (composite outputs!), but is not quite right.

On 20 Oct 2001, Arpi wrote:
> btw deinterlace is not lossy at all, if you do it well.
> hint: double framerate and half vertical resolution - i mean
> split frames to fields.

Huh.  I sort of get this, but I don't see how playback would work
properly if the vertical resolution is halved?  It may be moot for me
anyhow, see below.

> msmpeg4 != iso mpeg4
Yes, but Divx4 != msmpeg4.  Divx4 is claimed to be ISO MPEG4 compliant
(http://forums.projectmayo.com/viewtopic.php?topic=2431&forum=3).

> what about old ati cards? they are still sold.. mach64 and rage128 cards.
> btw i never tried their tvout, but gatos supports them.

Thanks, I'll check 'em out.

I borrowed an nVidia card (Hercules GeForce3), and played my Divx4
videos through its TV-out.  The good news is that the interlacing
artifacts and tearing are gone!  The quality is just fine for me, so I
don't feel motivated to buy an MPEG2 hardware decoder (since I'm able to
decode MPEG4 adequately in software, I prefer the flexibility of mplayer
to a hardware solution).  The downsides are that I cannot tune the
overscan and the brightness is too high (and not changable).  I consider
this to be a proof of concept:  What I want is clearly a VGA card with a
TV-out.

Oh, BTW, using "-autoq 60" makes quite a difference!  Wow, what a
feature!  Thanks!

I now begin my search for the best VGA card.  For those interested, I
found the following from Home of TVTool
(http://www.tvtool.de/english/faq_e.htm#faq10):

> I recommend cards with the Conexant CX25871 TV chip. It seems to be
> the most powerful TV chip at the moment and gives a slightly better
> picture quality than other. Unfortunately one can´t say on which cards
> this is definetely found, because most manufacturers don´t use always
> the same one on their cards. As far as I know you can find it on
> Hercules GF3 cards and on the Asus 7100 Pro/TV (MX400) as well
> (without guarantee).

Cheers,
Neologism





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