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NTSC mode
PostPosted: Sun Feb 08, 2004 10:37 am Reply with quote
Scott Larson
 
Joined: 15 Oct 2003
Posts: 713
Location: Portland, OR




I've been playng around with the PC2000 in NTSC mode this weekend and I've realized that i have no idea how it's supposed to work.

I used the tune program someone posted to put the card in NTSC mode and pick a channel. I hear analog audio so I know the frequency is correct and it's getting a NTSC signal. I've never used any other TV card before so I don't know where the video should be coming out. I guess I shouldn't have been expecting a MPEG transport stream coming out of /dev/dtv like when the card is in ATSC mode. I don't have a /dev/video32 device.

I've compiled xawtv and the best I've gotten is a black screen when it doen't seg fault.
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Re: NTSC mode
PostPosted: Mon Feb 09, 2004 4:41 am Reply with quote
Ulmo
 
Joined: 06 Nov 2003
Posts: 95
Location: Aptos,CA,USA




Scott Larson wrote:
I've been playng around with the PC2000 in NTSC mode this weekend and I've realized that i have no idea how it's supposed to work.


I went through this recently, too. It was funny how ignorant I was of this mode, since everything refers to it as "normal" V4L. Well, "normal" was not normal to me; I almost only have four MPEG devices (two in & three out (one device does both, in case your counting there got confused)), so non-MPEG isn't normal to me!

Quote:
I used the tune program someone posted to put the card in NTSC mode and pick a channel. I hear analog audio so I know the frequency is correct and it's getting a NTSC signal. I've never used any other TV card before so I don't know where the video should be coming out. I guess I shouldn't have been expecting a MPEG transport stream coming out of /dev/dtv like when the card is in ATSC mode. I don't have a /dev/video32 device.


/dev/dtv == /dev/video32 in terms of major & minor # & file type; the name doesn't matter. Anyway, I think it's character major 81 minor 0 for a system with its first V4L device being HD-2000 (check dmesg & syslog for registration:

Code:
Feb  8 23:36:17 bttv0: registered device video0
Feb  8 23:36:17 bttv0: registered device vbi0
Feb  8 23:36:17 bttv0: registered device dtv0
)

They mean character major 81 minor 0 for video0, and minor 32 for dtv0, and minor 224 for vbi (subject to my memory error here).

Quote:
I've compiled xawtv and the best I've gotten is a black screen when it doen't seg fault.



That's what I usually get, until I get it to tune to something correctly. Use "o" to get that control thing, then set the right modes, then up and down arrows, and when you find a channel, save it with the save channel function, then you can just hit a key to get to it.

If it starts to work, you'll get fuzz, or if you're lucky, it'll tune to something. Be sure to select the correct frequency table, depending on whether you have it plugged into cable or antenna. Once you figure out how to control channels (up & down arrows) and set the right norms, modes, inputs, etc., tune to something you know should work, then go back and forth between that and something else you know should work, experimenting.


The generic HD-2000 driver puts the normal bttv capture device at /dev/video0, instead of /dev/video32. This signals the driver to use a different set of ioctls, functions for just about all driver interaction, etc.. It is normal V4L/V4L2 support, in the case of BTTV.

Just so you know, in case you were curious, my aborted attempt (due to time constraints, not my ability, although more knowledge would certainly have made it faster for me) was to make it V4L2 compliant, which would have meant allowing any program to access any /dev node that refers to that card. This would have made xawtv a bit more trivial for you, since you would have already know a working device name.

I'm not sure whether or not you need special HD-2000 tools to put it into NTSC mode; xawtv has its own tuner access in it. You have to make sure to set all the values correctly (e.g., NTSC, and others I forget). Here's my example ~/.xawtv, but referring to some intermediary states of the driver I was working on, so you'll definitely need to make it correct for your (generic?) version of the driver (i.e., change "Television1" to "Television"):

Code:
[global]
ratio = 4:3
freqtab = us-cable
pixsize = 128 x 96
pixcols = 1
jpeg-quality = 75
keypad-ntsc = no
keypad-partial = yes
osd = yes
osd-position = 30 , 20
use-wm-fullscreen = yes

# [Station name]
# capture = overlay | grabdisplay | on | off
# input = Television | Composite1 | S-Video | ...
# norm = PAL | NTSC | SECAM | ...
# channel = #
# fine = # (-128..+127)
# key = keysym | modifier+keysym
# color = #
# bright = #
# hue = #
# contrast = #

[defaults]
group = main
norm = NTSC
input = Television1
capture = over
color = 47%
bright = 48%
hue = 48%
contrast = 40%

[KNTV]
channel = 11
input = Television
key = F11
capture = on
norm = NTSC

[KSBW]
channel = 8
input = Television
key = F8
capture = on
contrast = 37%
norm = NTSC

[KION]
channel = 46
input = Television
key = F4
capture = on
norm = NTSC

[KCBA]
channel = 35
input = Television
key = F3
capture = on
norm = NTSC

[Comedy]
channel = 63
key = F1
input = Television1
norm = NTSC

[SciFi]
channel = 68
key = F2
input = Television1
norm = NTSC


I wasn't able to get btaudio to work, although I made it load a few times.

xawtv is finicky.

The bttv drivers comply with V4L abilities that allow it to map the buffers directly to display memory as it comes in (called overlay mode, I think); I think it's some wacky thing not far from it going from the capture card directly to the display card, without stopping in the computer besides that. That's why xawtv can crash, perhaps your kernel even freeze, and well, you're still watching TV in its little window where X left it, and audio is fine.

There is another mode which is not overlay, but I never got that to work. That's what we need for recording.

mplayer also has a v4l mode. I never got it to work, but by then I was hacking the driver; I wrote an IOCTL walk-through diagnosis program that replaced what I was using mplayer for (just to see what the ioctls do and if they were working).


I haven't seen anything larger than a small xawtv window for this mode.

It doesn't get stereo.

All the antenna channels I get with NTSC I get better with ATSC, so for me it was mostly experimental for antenna, but I was also able to select the other input (with some of my driver patches) which I plugged the cable into. Of course, you don't have to select the second input for that; you can just put the cable in the first input, instead.


Ok, that was a rather verbose message for very little data. I hope I've helped.
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PostPosted: Tue Feb 10, 2004 2:13 pm Reply with quote
Scott Larson
 
Joined: 15 Oct 2003
Posts: 713
Location: Portland, OR




Well I haven't had any luck with this so far. When I run xawtv while the PC-2000 is in ATSC mode, all I get is the blue overlay. Apparently xawtv doesn't switch the card into NTSC mode.

When I force the card into NTSC mode and run xawtv, nothing happens. Then commands like ps and reboot stop working and I have to reset the machine. Same thing happens when I run xawtv -hwscan. Sad

Maybe I'm missing a driver patch.
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PostPosted: Tue Mar 16, 2004 2:08 am Reply with quote
Electrode
 
Joined: 06 Dec 2003
Posts: 18
Location: Michigan




Here's my problem. I set the card to NTSC mode with dtvsignal as mentioned in the docs that came with the card, then run xawtv. However, there is no "Television" input option, only "composite{0-2}" and "svideo". MPlayer says the same thing.

For anyone who has NTSC mode working, what drivers are you using? I'm using bttv-0.7.107 from bytesex.org with zzo's Gentoo patch on kernel 2.4.25.
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PostPosted: Tue Mar 30, 2004 1:33 am Reply with quote
Ulmo
 
Joined: 06 Nov 2003
Posts: 95
Location: Aptos,CA,USA




Electrode wrote:
For anyone who has NTSC mode working, what drivers are you using? I'm using bttv-0.7.107 from bytesex.org with zzo's Gentoo patch on kernel 2.4.25.


I certainly never got any of my Linux 2.6 patches to work with NTSC, so don't use those for that, unless someone fixed that. Someone will have to tell us whether others' patches for 2.6 do work with NTSC. They might have to revert to an earlier version of 2.6 to easily test that.

Anyway, I did get kernel 2.4 to work with NTSC. It took a while, and I stabbed at it a lot, so I have no idea any more what exact combination it was. I noticed xawtv doesn't exactly do what you tell it to do when you tell it something the first time; keep re-setting all its controls to something, perhaps something else then back, etc.. Look carefully at what it thinks it's set at.

I did make some patches to some version of xawtv which allowed one to select NTSC/ATSC and port #, I think, but I forget. That worked, sort of (unreliably). Plenty of people have gotten Myth to work with NTSC to some extent, all in kernel 2.4 as far as I know.
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NTSC
PostPosted: Thu Apr 01, 2004 2:38 am Reply with quote
inkling
 
Joined: 05 Feb 2004
Posts: 342




Hi All,

After watching ATSC for 2 months now, I can honestly say NTSC will make you go blind. Your parents weren't kidding. The stuff is blurry and makes your eyes work too hard to try to focus what can't be focused. I swear my eyesight has improved since I've been watching ATSC streams.

This is a joke, of course.

:>
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PostPosted: Sun May 02, 2004 10:49 am Reply with quote
Scott Larson
 
Joined: 15 Oct 2003
Posts: 713
Location: Portland, OR




I was finally able to get this to work with pdicamillo's patches to the bttv driver in the 2.4.25 kernel. I also manually applied the patches to automatically select the second tuner input in NTSC mode.

And, yeah, there are a lot of limitations. There's no capture or record although I can grab screen shots through xwd so applications can get to the buffers. The sound is mono (why?) and xawtv's mute doesn't work (I need to change it so it mutes the phin on my sound card). It also won't upscale the video so I'm stuck with 620x480. At least that keeps things from looking blurry. At this small size, the video looks fairly sharp and clear. There's lots of horizontal noise but that's from my cable company's weak analog signals (local OTA stations look much better).

The worst thing is the color. After watching ATSC for months, NTSC color looks awful. It looks like 8 bits of color splattered carelessly on B&W video as an afterthought.
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PostPosted: Sat Aug 14, 2004 12:14 am Reply with quote
Carnildo
Guest
 




Scott Larson wrote:
The worst thing is the color. After watching ATSC for months, NTSC color looks awful. It looks like 8 bits of color splattered carelessly on B&W video as an afterthought.


I have to agree. I just finished watching the last hour of the Olympic opening ceremony twice, and the color in the ATSC-HD version beats the NTSC version all hollow.
PostPosted: Wed Aug 18, 2004 2:07 pm Reply with quote
Scott Larson
 
Joined: 15 Oct 2003
Posts: 713
Location: Portland, OR




I've been forced to watch much of the Olympics in NTSC since two days of swimming, diving and gymnastics in HD were enough for me. After about an hour, my brain begins to get less picky about what it's seeing (or not seeing) and the poor quality becomes less distracting. I figure that's the effect that the eggheads who designed NTSC were counting on.

It helps to keep the saturation as low as you can tolerate.
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NTSC mode
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