Mailing List Archive

Wesley Belk wrote:

> What resolution are you running your desktop in?

The screen on which MythTV runs has 800x600

> What resolution are you capturing your video in?

Generally highest possible. I don't think my Athlon 1200 managed that,
though, so "only" 640x480.

> What is the resolution of the average TV?

Depends on the norm. PAL is 768(720?)x576, I think, so I use 800x600.
NTSC is something like 640x480.

> How are you outputing to your TV, with a Scan Converter or Video Card
> with TV Out?

Video card with TV out, nvidia with the binary nvidia driver, although I
have to warn you that it's unstable - I had lots of lockups (at least
with the previous version) until it worked, resulting in some data loss
on my disks (!) :-(. The scan converters I saw (a few years ago,
anyways, I haven't seen any recently) are too expensive, like $100-200.

If I had to buy a new card for MythTV, I guess I'd use a cheap ATI
Radeon 7000 with TV out for $35 or so, but first check that there are
drivers (preferably Open-Source) for the TV out.

> If I had to buy a new card for MythTV, I guess I'd use a cheap ATI
> Radeon 7000 with TV out for $35 or so, but first check that there are
> drivers (preferably Open-Source) for the TV out.

ATI has a statement on their website at the moment that TV out is not
supported on anything other than windows... I think that we will wait a
while yet before any ATI card is good for TV out.

On a similar note the new Matrox card (Parhelia) is touted as having
excellent quality tv and monitor output. However, a quick google turns up
only complaints about the quality of the driver and I couldn't find any
accounts as to whether tv out worked at all? (someone shout if it works for
you?)

I think NVidia is best for linux for the time being. I have my eye on the
new FX 5200 which is supposed to have all the FX technology, but will be air
cooled! Price is supposed to be about £100

Good for Quake and also silent!

On Thu, 2003-04-17 at 02:21, Wesley Belk wrote:
> What resolution are you running your desktop in?

800x600 for the screen I use when running myth...

>
> What resolution are you capturing your video in?

480x480, (MPEG4) looks as good as 640x480 as far as I can tell on my TV.
Uses a lot less CPU on my Athlon 1400 chip and saves me about 100 megs
on the half hour of recording as well..

>
> What is the resolution of the average TV?
>
> How are you outputing to your TV, with a Scan Converter or Video Card
> with TV Out?

Using TVout on my GeForce3 card using nvidia's drivers, which for me
works great....

Greg

>
>
>
> ______________________________________________________________________
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--
Greg <geflatt@hfx.eastlink.ca>

Technically NTSC is 320x240, PAL is 320x288. Of course, as far as capture goes, you do get some benefit by sampling at double the horizontal resolution. However, there isn't much reason to sample at double the vertical resolution. 320x480 for an NTSC signal should not look noticeably different than 640x480.

-----Original Message-----
From: Ben Bucksch [mailto:linux.news@bucksch.org]

Wesley Belk wrote:

> What is the resolution of the average TV?

Depends on the norm. PAL is 768(720?)x576, I think, so I use 800x600.
NTSC is something like 640x480.

This is the text from the backup:

WELCOME to our "Simply Parrots" Shoppe!

We are building our product catalog daily, so please be sure to stop in
often!

To celebrate our grand opening, our first 50 shoppers will be entered
into a "Grand Opening Drawing" to win a $1
00.00 shopping spree!! We are looking forward to welcoming old and new
friends!
<br><br>
We are pleased to offer discounts on all products to the following
groups:
Parrotlets Plus Members; Parrotlet Express Members and Avian Advantage
Buyers Group Members. If you belong to one of these groups,or
are an "international" customer, please see our "Policy" page for
ordering information!
<br><br>
Simply Parrots will strive to bring you and your birds the safest, most
innovative products available on the web
!
Questions: Please contact <A
HREF="mailto:administrator@simplyparrots.com">administrator@simplyparrot
s.com</A>
LIVE PERSON: (US) Toll Free help/order line 888.707.0400, (Int)
508.866.1152 or Fax 508.866.4676, Monday through
Friday, 8AM to 4PM EST. Orders may be placed on-line anytime!

<P>Can't find a product in our catalog? Write us, we'll find it for you!
SIMPLY PARROTS hopes to be your "one stop" shopping spot on
the web...




Thanks,
Brad Atkins
Manager, Technical Development

Sales & Support: 1-877-973-4968
Email: brad@youreshop.com

-----Original Message-----
From: mythtv-users-bounces@snowman.net
[mailto:mythtv-users-bounces@snowman.net] On Behalf Of jasonmiller
Sent: Thursday, April 17, 2003 10:23 AM
To: 'Discussion about mythtv'
Subject: RE: [mythtv-users] What Resolution Are You Using?

Technically NTSC is 320x240, PAL is 320x288. Of course, as far as
capture goes, you do get some benefit by sampling at double the
horizontal resolution. However, there isn't much reason to sample at
double the vertical resolution. 320x480 for an NTSC signal should not
look noticeably different than 640x480.

-----Original Message-----
From: Ben Bucksch [mailto:linux.news@bucksch.org]

Wesley Belk wrote:

> What is the resolution of the average TV?

Depends on the norm. PAL is 768(720?)x576, I think, so I use 800x600.
NTSC is something like 640x480.

_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

Stupid Outlook

Sorry for the extra noise.

Brad

-----Original Message-----
From: mythtv-users-bounces@snowman.net
[mailto:mythtv-users-bounces@snowman.net] On Behalf Of Brad Atkins
Sent: Thursday, April 17, 2003 11:26 AM
To: 'Discussion about mythtv'
Subject: RE: [mythtv-users] What Resolution Are You Using?

This is the text from the backup:

WELCOME to our "Simply Parrots" Shoppe!

We are building our product catalog daily, so please be sure to stop in
often!

To celebrate our grand opening, our first 50 shoppers will be entered
into a "Grand Opening Drawing" to win a $1
00.00 shopping spree!! We are looking forward to welcoming old and new
friends!
<br><br>
We are pleased to offer discounts on all products to the following
groups:
Parrotlets Plus Members; Parrotlet Express Members and Avian Advantage
Buyers Group Members. If you belong to one of these groups,or
are an "international" customer, please see our "Policy" page for
ordering information!
<br><br>
Simply Parrots will strive to bring you and your birds the safest, most
innovative products available on the web
!
Questions: Please contact <A
HREF="mailto:administrator@simplyparrots.com">administrator@simplyparrot
s.com</A>
LIVE PERSON: (US) Toll Free help/order line 888.707.0400, (Int)
508.866.1152 or Fax 508.866.4676, Monday through
Friday, 8AM to 4PM EST. Orders may be placed on-line anytime!

<P>Can't find a product in our catalog? Write us, we'll find it for you!
SIMPLY PARROTS hopes to be your "one stop" shopping spot on
the web...




Thanks,
Brad Atkins
Manager, Technical Development

Sales & Support: 1-877-973-4968
Email: brad@youreshop.com

-----Original Message-----
From: mythtv-users-bounces@snowman.net
[mailto:mythtv-users-bounces@snowman.net] On Behalf Of jasonmiller
Sent: Thursday, April 17, 2003 10:23 AM
To: 'Discussion about mythtv'
Subject: RE: [mythtv-users] What Resolution Are You Using?

Technically NTSC is 320x240, PAL is 320x288. Of course, as far as
capture goes, you do get some benefit by sampling at double the
horizontal resolution. However, there isn't much reason to sample at
double the vertical resolution. 320x480 for an NTSC signal should not
look noticeably different than 640x480.

-----Original Message-----
From: Ben Bucksch [mailto:linux.news@bucksch.org]

Wesley Belk wrote:

> What is the resolution of the average TV?

Depends on the norm. PAL is 768(720?)x576, I think, so I use 800x600.
NTSC is something like 640x480.

_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

No, THIS is the text from the backup:

WELCOME to our "Simply Parrots" Shoppe!
We are building our product catalog daily, so please be sure to stop in
often!

Would you like to watch tv or check the weather ? Maybe play a CD or some MP3s
...

SIMPLY PARROTS hopes to be your "one stop" shopping spot on
the web...

:-)
--- Brad Atkins <brad@youreshop.com> wrote:
> This is the text from the backup:
>
> WELCOME to our "Simply Parrots" Shoppe!
>
> We are building our product catalog daily, so please be sure to stop in
> often!
>
> To celebrate our grand opening, our first 50 shoppers will be entered
> into a "Grand Opening Drawing" to win a $1
> 00.00 shopping spree!! We are looking forward to welcoming old and new
> friends!
> <br><br>
> We are pleased to offer discounts on all products to the following
> groups:
> Parrotlets Plus Members; Parrotlet Express Members and Avian Advantage
> Buyers Group Members. If you belong to one of these groups,or
> are an "international" customer, please see our "Policy" page for
> ordering information!
> <br><br>
> Simply Parrots will strive to bring you and your birds the safest, most
> innovative products available on the web
> !
> Questions: Please contact <A
> HREF="mailto:administrator@simplyparrots.com">administrator@simplyparrot
> s.com</A>
> LIVE PERSON: (US) Toll Free help/order line 888.707.0400, (Int)
> 508.866.1152 or Fax 508.866.4676, Monday through
> Friday, 8AM to 4PM EST. Orders may be placed on-line anytime!
>
> <P>Can't find a product in our catalog? Write us, we'll find it for you!
> SIMPLY PARROTS hopes to be your "one stop" shopping spot on
> the web...
>
>
>
>
> Thanks,
> Brad Atkins
> Manager, Technical Development
>
> Sales & Support: 1-877-973-4968
> Email: brad@youreshop.com
>
> -----Original Message-----
> From: mythtv-users-bounces@snowman.net
> [mailto:mythtv-users-bounces@snowman.net] On Behalf Of jasonmiller
> Sent: Thursday, April 17, 2003 10:23 AM
> To: 'Discussion about mythtv'
> Subject: RE: [mythtv-users] What Resolution Are You Using?
>
> Technically NTSC is 320x240, PAL is 320x288. Of course, as far as
> capture goes, you do get some benefit by sampling at double the
> horizontal resolution. However, there isn't much reason to sample at
> double the vertical resolution. 320x480 for an NTSC signal should not
> look noticeably different than 640x480.
>
> -----Original Message-----
> From: Ben Bucksch [mailto:linux.news@bucksch.org]
>
> Wesley Belk wrote:
>
> > What is the resolution of the average TV?
>
> Depends on the norm. PAL is 768(720?)x576, I think, so I use 800x600.
> NTSC is something like 640x480.
>
> _______________________________________________
> mythtv-users mailing list
> mythtv-users@snowman.net
> http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users
>
> _______________________________________________
> mythtv-users mailing list
> mythtv-users@snowman.net
> http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users


__________________________________________________
Do you Yahoo!?
The New Yahoo! Search - Faster. Easier. Bingo
http://search.yahoo.com

jasonmiller wrote:
> Technically NTSC is 320x240, PAL is 320x288.

Well, technically NTSC is analog. There are two interlaced
fields of about 240 scan lines for a total of about 480
sacn lines that carry picture information. There are 525
total line including sync and such. Each scan line has analog
waves that have no digital resolution until there are sampled
and digitized. The horizontal sample timing is independent of
how many of the scan lines are being sampled so 720x160 and
160x480 are valid (but don't make much sense in practice ;-).

> Of course,
> as far as capture goes, you do get some benefit by sampling
> at double the horizontal resolution. However, there isn't
> much reason to sample at double the vertical resolution.
> 320x480 for an NTSC signal should not look noticeably
> different than 640x480.

It is noticeably different because there are 480 unique scan
lines of information and the higher horizontal timing will
preserve more detail. Because of the low quality of broadcast
television, lowering the width will usually do more good by
saving disk space and CPU time than harm by lowering the
perceived picture quality. See:

http://www.mythtv.org/docs/mythtv-HOWTO-19.html#ss19.4

-- bjm

There are still only roughly 240 scan lines on the screen per pass, correct? It is a matter of how you encode, whether you interlace two frames or overlay them that determines the digital vertical resolution. Now, all that said, and possibly incorrectly I'll admit :), since we need to deinterlace the Myth signal I should have known better! *crawls back into his hole*

-----Original Message-----
From: Bruce Markey [mailto:bjm@lvcm.com]
Sent: Thursday, April 17, 2003 3:01 PM
To: Discussion about mythtv
Subject: Re: [mythtv-users] What Resolution Are You Using?


jasonmiller wrote:
> Technically NTSC is 320x240, PAL is 320x288.

Well, technically NTSC is analog. There are two interlaced
fields of about 240 scan lines for a total of about 480
sacn lines that carry picture information. There are 525
total line including sync and such. Each scan line has analog
waves that have no digital resolution until there are sampled
and digitized. The horizontal sample timing is independent of
how many of the scan lines are being sampled so 720x160 and
160x480 are valid (but don't make much sense in practice ;-).

> Of course,
> as far as capture goes, you do get some benefit by sampling
> at double the horizontal resolution. However, there isn't
> much reason to sample at double the vertical resolution.
> 320x480 for an NTSC signal should not look noticeably
> different than 640x480.

It is noticeably different because there are 480 unique scan
lines of information and the higher horizontal timing will
preserve more detail. Because of the low quality of broadcast
television, lowering the width will usually do more good by
saving disk space and CPU time than harm by lowering the
perceived picture quality. See:

http://www.mythtv.org/docs/mythtv-HOWTO-19.html#ss19.4

-- bjm


_______________________________________________
mythtv-users mailing list
mythtv-users@snowman.net
http://lists.snowman.net/cgi-bin/mailman/listinfo/mythtv-users

jasonmiller wrote:
> There are still only roughly 240 scan lines on the screen
> per pass, correct?

Correct. You can think of it as 59.94 passes per second or
29.97 full frames per second. Way too much information can
be found at http://www.ntsc-tv.com/ .

-- bjm

Bruce Markey <bjm@lvcm.com> remarked:
> jasonmiller wrote:
> >Technically NTSC is 320x240, PAL is 320x288.
>
> Well, technically NTSC is analog. There are two interlaced
> fields of about 240 scan lines for a total of about 480
> sacn lines that carry picture information. There are 525
> total line including sync and such. Each scan line has analog

So, I note from the discussion that we're de-interlacing the video
on the way in, storing it progressive on disk, and then of course
interlacing it for going out to the TV. Would it not be better to
store it on disk as interlaced frames? I would think that without
the filters required it the video quality would be improved for more
than one reason.

Dan

Dan Hopper wrote:
> Bruce Markey <bjm@lvcm.com> remarked:
>
>>jasonmiller wrote:
>>
>>>Technically NTSC is 320x240, PAL is 320x288.
>>
>>Well, technically NTSC is analog. There are two interlaced
>>fields of about 240 scan lines for a total of about 480
>>sacn lines that carry picture information. There are 525
>>total line including sync and such. Each scan line has analog
>
>
> So, I note from the discussion that we're de-interlacing the video
> on the way in,

Kind of but it depends on what you mean by de-interlacing.
Both fields are written into a framebuffer with no
deinterlace algorithms applied. There is code to fix
interlace problems on playback (there was a patch for
record deinterlace recently but like some other recent
check-ins, this is a virtual easter egg. You can hit "x"
during LiveTV but I don't see the difference, it doesn't
seem to be stored anywhere and I don't see how it could
be applied to recordings. The author may have fun playing
with this but I don't see how users will find it useful).

> ...storing it progressive on disk, and then of course
> interlacing it for going out to the TV. Would it not be better to
> store it on disk as interlaced frames? I would think that without
> the filters required it the video quality would be improved for more
> than one reason.

I've thought the same thing that maybe 59.97 fps of 240
scan lines (compressing by comparing against two frames
earlier for the last frame of the same field) might be a
truer reproduction of the original TV signal.

Two problems. First, MythTV can be shown on a progressive
scan monitor with refresh rates other than 60 and even if
it is a TV, you might use 800x600 (or 1024x768) or have an
overscan offset or record with a height other than 480, etc.
All of these will cause the interlace fields to not line up.
Commercial DVRs have the advantage of knowing that they will
only be drawing a true NTSC raster.

Second, AFAIK, there is no access to the vertical refresh
timing of the graphics card so you can't know when to update
the framebuffer to be sure it will be drawn on the next pass.
If there is access to this information, I'd really like to
fix the playback jitter due to framebuffer updates not
accurately spaced with vertical refresh. This is what 'jitter
reduction' tries to mitigate but it can't truly be fixed
without knowing when the card is going to draw the next frame.


-- bjm

> Kind of but it depends on what you mean by de-interlacing.
> Both fields are written into a framebuffer with no
> deinterlace algorithms applied. There is code to fix

Oh, OK. Good to know.

> Two problems. First, MythTV can be shown on a progressive
> scan monitor with refresh rates other than 60 and even if
> it is a TV, you might use 800x600 (or 1024x768) or have an
> overscan offset or record with a height other than 480, etc.
> All of these will cause the interlace fields to not line up.
> Commercial DVRs have the advantage of knowing that they will
> only be drawing a true NTSC raster.

True, but I expect most folks without expensive progressive TV
monitors will be doing the NTSC in -> NTSC out case, so it'd be nice
if this could be optimized to do a one-to-one kind of deal with
respect to interlaced scan lines and such. Ideally, you'd just
overlay the menus on a signal that was otherwise unaltered with
respect to the input (well, ignoring compression artifacts).

> Second, AFAIK, there is no access to the vertical refresh
> timing of the graphics card so you can't know when to update
> the framebuffer to be sure it will be drawn on the next pass.
> If there is access to this information, I'd really like to
> fix the playback jitter due to framebuffer updates not
> accurately spaced with vertical refresh. This is what 'jitter
> reduction' tries to mitigate but it can't truly be fixed
> without knowing when the card is going to draw the next frame.

I don't know how to do it, but I do know that I've been able to get
my Timex Datalink watch working under Win2k on VMware under XF86 4.1
on Linux. The Datalink screen download function relies on
synchronizing with the vertical refresh I believe in order to obtain
the proper timing to talk to the watch. It throws the screen into a
60 Hz refresh mode and spaces lines to indicate bytes to download to
the watch. I believe if it doesn't update the framebuffer properly
with respect to the vertical refresh the data will be corrupted.

The point being, this is done under XFree86 so somehow VMware is
getting the synchronization information back to the Windoze app
while XF86 is driving the screen. It would seem _some_ sort of
mechanism exists to get the information. It'd be interesting to
know how.

Dan

On Monday 21 April 2003 11:01 pm, Bruce Markey wrote:
> Kind of but it depends on what you mean by de-interlacing.
> Both fields are written into a framebuffer with no
> deinterlace algorithms applied. There is code to fix
> interlace problems on playback (there was a patch for
> record deinterlace recently but like some other recent
> check-ins, this is a virtual easter egg. You can hit "x"
> during LiveTV but I don't see the difference, it doesn't
> seem to be stored anywhere and I don't see how it could
> be applied to recordings. The author may have fun playing
> with this but I don't see how users will find it useful).

It's pretty much half-implemented code =) It's not really meant for end-user
consumption. You have to exit/restart live-tv for it to take effect.

> Second, AFAIK, there is no access to the vertical refresh
> timing of the graphics card so you can't know when to update
> the framebuffer to be sure it will be drawn on the next pass.
> If there is access to this information, I'd really like to
> fix the playback jitter due to framebuffer updates not
> accurately spaced with vertical refresh. This is what 'jitter
> reduction' tries to mitigate but it can't truly be fixed
> without knowing when the card is going to draw the next frame.

I do know that (with the nvidia drivers at least), when the XSync() call
returns (after the XvShmPutImage()), that's just after it's displayed. Dunno
if that helps, but.. =) I'd recommend checking out tvtime's output loop..

Isaac