Re: [mythtv-users] Summery of my problems
Robert Johnston wrote: On 1/26/06, Dylan R. Semler [EMAIL PROTECTED] wrote: I've only really been working with LiveTV so far. HD is able to stream pretty well to the frontend, but there are some problems. In the first minute or so after I change a channel, there are a few pauses but eventually it smooths out (something I can live with). However, whenever there is fast motion in the video, every other line gets slightly offset--I guess this is described as combing. How do I fix this? Enable DeInterlacing. The Combing is your (Progressive) laptop display trying to show an interlaced signal. DeInterlacing corrects this. This did the trick For analog, the picture quality is pretty bad (noisy) and there are about three or four horizontal lines at the top of the screen that have some random patterns of black and white streaks. The picture quality is much better using tvtime and those lines do not appear. Those lines are called the VBI (Vertical Blank Interrupt). They're what gets sent as the TV's scanning electron beam travels from bottom-right to top-left to start the next screenful. The Random Patterns you see are (Most likely) the Timecode, and the Closed Captioning data. You can adjust the Overscan parameters in Myth to remove these. Adjusting the overscan in myth turned out to be less than ideal. First of all, the adjustments apply to both the HD and the analog feeds so if I make adjustments that remove the black vbi lines on the top in analog I have to live with a few unchanging colored lines at the bottom of HD--very annoying. Furthermore, my vertical over/underscan percentage would ideally be less than 1 (to cleanly remove all of the vbi lines and nothing more), but myth only seems to allow integers for this field. When this is set to 1 there are a few colored lines at the bottom of the picture similar to what is seen in HD. Also, I found changing the 'Scan displacement (Y)' didn't seem to do anything. As for the noise, make sure that Myth is tuning into the same frequency (EXACTLY the same frequency) as TVTime is. It sounds like Myth's off by a few Khz. Also, the color balance is not quite right, but when I press F to 'rotate between Picture Adjustments (Colour, Hue, etc.)', nothing happens. If I press 'G', I am able to make the adjustments for the recording. Also, the backend logs indicate that its using v4l v1 rather than v4l v2: IIRC, ATI cards don't support the XV picture controls. This is a problem with their drivers. Not surprising, however, if I run the frontend on the master backend with the GeForce2 as well as another frontend with a GeForce4 and still, I have the same result; pressing 'f' in livetv does nothing. Channel(/dev/video0)::SwitchToInput(in 0): Error -1 while setting video mode (v2), Invalid argument, trying v4l v1 2006-01-26 22:52:21.234 Channel(/dev/video0)::SwitchToInput(in 0): Setting video mode with v4l version 1 worked Check the drivers you are using. Non-mythtv issue but maybe someone has a clue. The master backend does not draw the desktop onto the entire monitor or tv (when using s-video out). There is a black bar on the left side where the monitor and tv are scanning, but nothing is drawn (does that make any sense?). I am currently running without any nvidia drivers, but the problem exists with a driver installed as well. Any ideas? Make sure you are using the NVidia driver (Just having it installed does no good, it needs to be defined in your Xorg.conf/XFree86Settings-4 file). Also check your ModeLines to make sure you're using a proper modeline for your display (And make sure you have the correct type of TV-Out defined. Outputting a PAL picture to an NTSC TV will give black borders, as the picture sizes are different). I installed the nvidia driver and made the adjustments to xorg.conf, which seems to have helped for the monitor. However, tv out still is not perfect. I set tv-out standard to NTSC in xorg.conf (which is the default anyways), however it does not fill the entire screen. I'm pretty sure this TV was bought in the US but maybe I'll play with the other format options and see if I get lucky. Other things I forgot to bring up. My laptop has a widescreen display (16:10) and analog displays in full screen (i.e. stretched.) Is it possible to have it displayed at the correct aspect ratio with black bars on the sides? ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Summery of my problems
Michael T. Dean wrote: On 01/27/2006 01:07 AM, Robert Johnston wrote: On 1/26/06, Dylan R. Semler [EMAIL PROTECTED] wrote: For analog, the picture quality is pretty bad (noisy) and there are about three or four horizontal lines at the top of the screen that have some random patterns of black and white streaks. The picture quality is much better using tvtime and those lines do not appear. As for the noise, make sure that Myth is tuning into the same frequency (EXACTLY the same frequency) as TVTime is. It sounds like Myth's off by a few Khz. Being off by a few KHz shouldn't matter. Many of the NTSC cable channel frequencies are off by 12.5 KHz (and the same goes for IRC, and HRC varies by 5-15KHz), but the tuner hardware's fine-tuning mechanism should still be able to find the appropriate center frequency. See http://www.gossamer-threads.com/lists/mythtv/dev/164614#164614 (which was totally ignored by the guy complaining in Trac that the frequencies are off) for an in-depth listing of what frequencies are off and why it shouldn't matter. If you (Dylan) want to try an academically-correct list of frequency definitions, I'd be happy to create one for you (against SVN--just let me know which frequency list you're using: ntsc_bcast, ntsc_cable, ntsc_hrc, ntsc_irc (I'm assuming NTSC based on your e-mail address)), but you'll have to do all the testing because I don't have any RF-modulated sources. Well it's worth a shot. I'd love to get better picture quality. I'm using ntsc_cable. Or, to find out if it's worth testing a more precise frequency list, play with the fine tuning values in Myth for the affected channels. And, most importantly, make sure you're using the right tuner definition--just because you get a bad picture doesn't mean you've chosen the right tuner; often it means you've chosen the wrong one. ;) By choosing the right tuner, are you referring to the setting in mythtv-setup - capture cards? I have the standard V4l capture card selected for analog. ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Summery of my problems
On 01/28/2006 12:46 PM, Dylan R. Semler wrote: Michael T. Dean wrote: Or, to find out if it's worth testing a more precise frequency list, play with the fine tuning values in Myth for the affected channels. And, most importantly, make sure you're using the right tuner definition--just because you get a bad picture doesn't mean you've chosen the right tuner; often it means you've chosen the wrong one. ;) By choosing the right tuner, are you referring to the setting in mythtv-setup - capture cards? I have the standard V4l capture card selected for analog. No, I mean the tuner definition used by your tuner module. Some cards autodetect the tuner, while others force the user to specify a tuner using either the deprecated tuner module option: options tuner type=XX or the card option: options ivtv tuner=XX or options bttv tuner=XX or ... I've seen many people who thought they choose the right one--typically because the one on the HOWTO they were reading didn't work, so after Googling, they found that they could just change the number, and after experimenting with 2 or 3, they found one that gave video/audio on some channels, so they thought they had it. What they don't typically realize is that there are about 70 tuner definitions, so choosing 2 or 3 at random (or, more likely, from the low-end, or right next to the one in the HOWTO) you're unlikely to pick the right one. Also, what most people don't realize is that given any particular tuner, the likelihood of several definitions providing perfect audio/video on some channels is extremely high, but only one definition should provide perfect audio/video on all channels. Mike ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Summery of my problems
Michael T. Dean wrote: On 01/28/2006 12:46 PM, Dylan R. Semler wrote: Michael T. Dean wrote: Or, to find out if it's worth testing a more precise frequency list, play with the fine tuning values in Myth for the affected channels. And, most importantly, make sure you're using the right tuner definition--just because you get a bad picture doesn't mean you've chosen the right tuner; often it means you've chosen the wrong one. ;) By choosing the right tuner, are you referring to the setting in mythtv-setup - capture cards? I have the standard V4l capture card selected for analog. No, I mean the tuner definition used by your tuner module. Some cards autodetect the tuner, while others force the user to specify a tuner using either the deprecated tuner module option: options tuner type=XX or the card option: options ivtv tuner=XX or options bttv tuner=XX I'm not sure about any of this. My tuner worked for analog right when I plugged it in. I just booted and ran tvtime, no problems. For HD i did have to load the firmware and make some udev adjustments. ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Summery of my problems
On 01/28/2006 12:46 PM, Dylan R. Semler wrote:
Michael T. Dean wrote:
On 01/27/2006 01:07 AM, Robert Johnston wrote:
On 1/26/06, Dylan R. Semler [EMAIL PROTECTED] wrote:
For analog, the picture quality is pretty bad (noisy)... The picture quality
is much better using tvtime and those lines do not appear.
As for the noise, make sure that Myth is tuning into the same
frequency (EXACTLY the same frequency) as TVTime is. It sounds like
Myth's off by a few Khz.
Being off by a few KHz shouldn't matter. Many of the NTSC cable channel
frequencies are off by 12.5 KHz (and the same goes for IRC, and HRC
varies by 5-15KHz), but the tuner hardware's fine-tuning mechanism
should still be able to find the appropriate center frequency. See
http://www.gossamer-threads.com/lists/mythtv/dev/164614#164614 (which
was totally ignored by the guy complaining in Trac that the frequencies
are off) for an in-depth listing of what frequencies are off and why it
shouldn't matter.
If you (Dylan) want to try an academically-correct list of frequency
definitions, I'd be happy to create one for you (against SVN--just let
me know which frequency list you're using: ntsc_bcast, ntsc_cable,
ntsc_hrc, ntsc_irc (I'm assuming NTSC based on your e-mail address)),
but you'll have to do all the testing because I don't have any
RF-modulated sources.
Well it's worth a shot. I'd love to get better picture quality. I'm
using ntsc_cable.
OK. Attached is a patch that will correct the frequencies used for
ntsc_cable, ntsc_hrc, and ntsc_irc. Those used for ntsc_bcast are
already correct. Apply the patch to current SVN and recompile and
install to test.
Note, however, that it may be better to leave ntsc_cable (standard
cable) unmodified. The modified channels in the standard cable
definition are definitely using frequencies that are not used by the
cable company, but that's because the FCC requires that they be offset.
(Cable channels operating on frequencies used in the aeronautical
radiocommunications bands 118-137MHz, 225-328.6MHz, and 335.4-400MHz are
required to be offset by 12.5kHz from 25kHz-spaced channels, and those
on frequencies used in the aeronautical radiocommunications bands
108-118MHz and 328.6-335.4MHz are required to be offset by 25kHz from
50kHz-spaced channels.) The FCC doesn't specify whether the offset
should be positive or negative, but it's more common within the cable
industry to use a positive offset. The current standard cable
definition uses the frequency before the offset (which is right in the
middle of a positive or negative offset), but the patched version
assumes a positive offset (meaning that if a cable company uses a
negative offset, we'll be off by 25kHz on many channels and 50kHz on 98
and 99).
So, since you're a standard cable user, please let me know if you really
do see a difference with the modified frequency values--and try not to
be swayed by the placebo effect. ;) If there really is a difference
(and I still don't think there will be), we may want to call the
modified ntsc_cable NTSC Cable (1) and create another that uses a
negative offset and label it NTSC Cable (2).
Those most likely to see any difference with the patch are HRC users (as
some of their frequencies--mainly the higher frequencies--were off by as
much as 60kHz). However, it's likely the only difference they will see
will be a slightly faster tuning cycle (unlikely to be noticeable in
Myth, though, because of the other delays in channel changing--and,
quite possibly, not noticeable at all by human perception even if you
tried the before/after frequencies in tvtime or something).
Also, technically, standard cable doesn't have a channel 1, and HRC and
IRC don't have T-7 through T-14 (but, I fixed the IRC definitions,
since IRC was a modified copy of standard and standard had defined T-7
through T-14 incorrectly). While we could remove them, it's probably
not worth the effort...
BTW, this patch definitely needs testing before being applied to SVN
(and should probably do something smarter with the standard cable
definition, as described above). Therefore, I'm not putting it in a
ticket, but it's here for anyone who wants to test/use it.
Mike
Index: libs/libmythtv/frequencies.c
===
--- libs/libmythtv/frequencies.c(revision 8744)
+++ libs/libmythtv/frequencies.c(working copy)
@@ -109,9 +109,9 @@
{ 12,205250 },
{ 13,211250 },
-{ 14,121250 },
-{ 15,127250 },
-{ 16,133250 },
+{ 14,121262 },
+{ 15,127262 },
+{ 16,133262 },
{ 17,139250 },
{ 18,145250 },
{ 19,151250 },
@@ -121,35 +121,35 @@
{ 22,169250 },
{ 23,217250 },
{ 24,223250 },
-{ 25,229250 },
-{ 26,235250 },
-{ 27,241250 },
-{ 28,247250 },
-{ 29,253250 },
-{ 30,259250
Re: [mythtv-users] Summery of my problems
Michael T. Dean wrote: On 01/28/2006 12:46 PM, Dylan R. Semler wrote: Michael T. Dean wrote: On 01/27/2006 01:07 AM, Robert Johnston wrote: On 1/26/06, Dylan R. Semler [EMAIL PROTECTED] wrote: For analog, the picture quality is pretty bad (noisy)... The picture quality is much better using tvtime and those lines do not appear. As for the noise, make sure that Myth is tuning into the same frequency (EXACTLY the same frequency) as TVTime is. It sounds like Myth's off by a few Khz. Being off by a few KHz shouldn't matter. Many of the NTSC cable channel frequencies are off by 12.5 KHz (and the same goes for IRC, and HRC varies by 5-15KHz), but the tuner hardware's fine-tuning mechanism should still be able to find the appropriate center frequency. See http://www.gossamer-threads.com/lists/mythtv/dev/164614#164614 (which was totally ignored by the guy complaining in Trac that the frequencies are off) for an in-depth listing of what frequencies are off and why it shouldn't matter. If you (Dylan) want to try an academically-correct list of frequency definitions, I'd be happy to create one for you (against SVN--just let me know which frequency list you're using: ntsc_bcast, ntsc_cable, ntsc_hrc, ntsc_irc (I'm assuming NTSC based on your e-mail address)), but you'll have to do all the testing because I don't have any RF-modulated sources. Well it's worth a shot. I'd love to get better picture quality. I'm using ntsc_cable. OK. Attached is a patch that will correct the frequencies used for ntsc_cable, ntsc_hrc, and ntsc_irc. Those used for ntsc_bcast are already correct. Apply the patch to current SVN and recompile and install to test. Note, however, that it may be better to leave ntsc_cable (standard cable) unmodified. The modified channels in the standard cable definition are definitely using frequencies that are not used by the cable company, but that's because the FCC requires that they be offset. (Cable channels operating on frequencies used in the aeronautical radiocommunications bands 118-137MHz, 225-328.6MHz, and 335.4-400MHz are required to be offset by 12.5kHz from 25kHz-spaced channels, and those on frequencies used in the aeronautical radiocommunications bands 108-118MHz and 328.6-335.4MHz are required to be offset by 25kHz from 50kHz-spaced channels.) The FCC doesn't specify whether the offset should be positive or negative, but it's more common within the cable industry to use a positive offset. The current standard cable definition uses the frequency before the offset (which is right in the middle of a positive or negative offset), but the patched version assumes a positive offset (meaning that if a cable company uses a negative offset, we'll be off by 25kHz on many channels and 50kHz on 98 and 99). So, since you're a standard cable user, please let me know if you really do see a difference with the modified frequency values--and try not to be swayed by the placebo effect. ;) If there really is a difference (and I still don't think there will be), we may want to call the modified ntsc_cable NTSC Cable (1) and create another that uses a negative offset and label it NTSC Cable (2). Those most likely to see any difference with the patch are HRC users (as some of their frequencies--mainly the higher frequencies--were off by as much as 60kHz). However, it's likely the only difference they will see will be a slightly faster tuning cycle (unlikely to be noticeable in Myth, though, because of the other delays in channel changing--and, quite possibly, not noticeable at all by human perception even if you tried the before/after frequencies in tvtime or something). Mhhh, probably good to improve, but for the silicon tuners i know about, (which are both the ones we use on our products as well as some others), this makes no difference at all. Most modern (silicon) tuners are able to finetune to the correct frequency if the initial frequency is within 125KHz of the correct frequency. We make use of this is the scanning algo, as this makes it possible in Europe to scan with 250KHz steps in case we have to do a frequency sweep Please keep in mind, Europe cable does not have any standard to adhere to. Cheers, Rudy ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Summery of my problems
On 01/28/2006 08:29 PM, Rudy Zijlstra wrote: Michael T. Dean wrote: On 01/28/2006 12:46 PM, Dylan R. Semler wrote: Michael T. Dean wrote: On 01/27/2006 01:07 AM, Robert Johnston wrote: On 1/26/06, Dylan R. Semler [EMAIL PROTECTED] wrote: For analog, the picture quality is pretty bad (noisy)... The picture quality is much better using tvtime and those lines do not appear. As for the noise, make sure that Myth is tuning into the same frequency (EXACTLY the same frequency) as TVTime is. It sounds like Myth's off by a few Khz. Being off by a few KHz shouldn't matter. Many of the NTSC cable channel frequencies are off by 12.5 KHz (and the same goes for IRC, and HRC varies by 5-15KHz), but the tuner hardware's fine-tuning mechanism should still be able to find the appropriate center frequency. See http://www.gossamer-threads.com/lists/mythtv/dev/164614#164614 (which was totally ignored by the guy complaining in Trac that the frequencies are off) for an in-depth listing of what frequencies are off and why it shouldn't matter. If you (Dylan) want to try an academically-correct list of frequency definitions, I'd be happy to create one for you (against SVN--just let me know which frequency list you're using: ntsc_bcast, ntsc_cable, ntsc_hrc, ntsc_irc (I'm assuming NTSC based on your e-mail address)), but you'll have to do all the testing because I don't have any RF-modulated sources. Well it's worth a shot. I'd love to get better picture quality. I'm using ntsc_cable. OK. Attached is a patch... If there really is a difference (and I still don't think there will be) Read this probably good to improve, but for the silicon tuners i know about, (which are both the ones we use on our products as well as some others), this makes no difference at all. Most modern (silicon) tuners are able to finetune to the correct frequency if the initial frequency is within 125KHz of the correct frequency. We make use of this is the scanning algo, as this makes it possible in Europe to scan with 250KHz steps in case we have to do a frequency sweep Please keep in mind, Europe cable does not have any standard to adhere to. That's what I've been saying all along--since someone mentioned that the frequency might be off by a few kHz... However, it's hard to convince people it's not a problem if they can't test it for themselves... ;) Personally, I don't think it's worth changing the definitions in the source, but between the This is so trivial to fix that it's silly not to. comment in Trac ( http://svn.mythtv.org/trac/ticket/610 and my response http://www.gossamer-threads.com/lists/mythtv/dev/164614#164614 ), and common wisdom about using the finetune values to adjust frequencies by a few kHz (which is often suggested), I figured a patch on the list that lets people see for themselves that it doesn't matter would be the best way to get other people to see it my way. Mike ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Summery of my problems
On 01/27/2006 01:07 AM, Robert Johnston wrote: On 1/26/06, Dylan R. Semler [EMAIL PROTECTED] wrote: For analog, the picture quality is pretty bad (noisy) and there are about three or four horizontal lines at the top of the screen that have some random patterns of black and white streaks. The picture quality is much better using tvtime and those lines do not appear. As for the noise, make sure that Myth is tuning into the same frequency (EXACTLY the same frequency) as TVTime is. It sounds like Myth's off by a few Khz. Being off by a few KHz shouldn't matter. Many of the NTSC cable channel frequencies are off by 12.5 KHz (and the same goes for IRC, and HRC varies by 5-15KHz), but the tuner hardware's fine-tuning mechanism should still be able to find the appropriate center frequency. See http://www.gossamer-threads.com/lists/mythtv/dev/164614#164614 (which was totally ignored by the guy complaining in Trac that the frequencies are off) for an in-depth listing of what frequencies are off and why it shouldn't matter. If you (Dylan) want to try an academically-correct list of frequency definitions, I'd be happy to create one for you (against SVN--just let me know which frequency list you're using: ntsc_bcast, ntsc_cable, ntsc_hrc, ntsc_irc (I'm assuming NTSC based on your e-mail address)), but you'll have to do all the testing because I don't have any RF-modulated sources. Or, to find out if it's worth testing a more precise frequency list, play with the fine tuning values in Myth for the affected channels. And, most importantly, make sure you're using the right tuner definition--just because you get a bad picture doesn't mean you've chosen the right tuner; often it means you've chosen the wrong one. ;) (And, it's completely possible to get a perfect picture/audio on some channels and a bad picture/audio on other channels when choosing the wrong tuner definition.) Mike ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
Re: [mythtv-users] Summery of my problems
On 1/26/06, Dylan R. Semler [EMAIL PROTECTED] wrote: Hello list, I've gotten everything with my myth system set-up marginally well, but I'm still having some annoying problems. So here's what I'm running: Master backend (Dell 8200 circa 2002): Intel Pentium 4 (probably about 2 GHz) Nvidia GeForce2 MX Fedora Core 4 with kernel 2.6.14-1.1656_FC4 mythtv rpms from atrpms pcHDTV-3000 Frontend (laptop): Intel Centrino 1.6 GHz ATI mobility radeon 9700 Fedora Core 4 with kernel 2.6.14-1.1656_FC4 mythtv rpms from atrpms I've only really been working with LiveTV so far. HD is able to stream pretty well to the frontend, but there are some problems. In the first minute or so after I change a channel, there are a few pauses but eventually it smooths out (something I can live with). However, whenever there is fast motion in the video, every other line gets slightly offset--I guess this is described as combing. How do I fix this? Enable DeInterlacing. The Combing is your (Progressive) laptop display trying to show an interlaced signal. DeInterlacing corrects this. For analog, the picture quality is pretty bad (noisy) and there are about three or four horizontal lines at the top of the screen that have some random patterns of black and white streaks. The picture quality is much better using tvtime and those lines do not appear. Those lines are called the VBI (Vertical Blank Interrupt). They're what gets sent as the TV's scanning electron beam travels from bottom-right to top-left to start the next screenful. The Random Patterns you see are (Most likely) the Timecode, and the Closed Captioning data. You can adjust the Overscan parameters in Myth to remove these. As for the noise, make sure that Myth is tuning into the same frequency (EXACTLY the same frequency) as TVTime is. It sounds like Myth's off by a few Khz. Also, the color balance is not quite right, but when I press F to 'rotate between Picture Adjustments (Colour, Hue, etc.)', nothing happens. If I press 'G', I am able to make the adjustments for the recording. Also, the backend logs indicate that its using v4l v1 rather than v4l v2: IIRC, ATI cards don't support the XV picture controls. This is a problem with their drivers. Channel(/dev/video0)::SwitchToInput(in 0): Error -1 while setting video mode (v2), Invalid argument, trying v4l v1 2006-01-26 22:52:21.234 Channel(/dev/video0)::SwitchToInput(in 0): Setting video mode with v4l version 1 worked Check the drivers you are using. Non-mythtv issue but maybe someone has a clue. The master backend does not draw the desktop onto the entire monitor or tv (when using s-video out). There is a black bar on the left side where the monitor and tv are scanning, but nothing is drawn (does that make any sense?). I am currently running without any nvidia drivers, but the problem exists with a driver installed as well. Any ideas? Make sure you are using the NVidia driver (Just having it installed does no good, it needs to be defined in your Xorg.conf/XFree86Settings-4 file). Also check your ModeLines to make sure you're using a proper modeline for your display (And make sure you have the correct type of TV-Out defined. Outputting a PAL picture to an NTSC TV will give black borders, as the picture sizes are different). Hope this helps. -- Robert Anaerin Johnston ___ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
