Bah! How do I change channels?

Bah! How do I change channels?

[George Adams]

Having gotten my Pinnacle HDTV Pro Stick working again under some old v4l drivers, I'm now facing a much more mundane problem - I can't figure out how to use the command line to change the channel.

The video feed (a closed-circuit feed) that's coming to the card is over a coax cable, and is on (analog) channel 3.  My goal is to take the input and use Helix Encoder to produce RealVideo output that can be played using Real Player (yeah, not the ideal situation, but it's what we're using for now)

Helix Producer (unlike "mencoder/mplayer") doesn't have the ability to change the channel - it can only take whatever is coming over the channel that the Pinnacle device is currently tuned to.  Devin pointed me to the "v4lctl" command, but I'm not having any luck with it yet.  

The following does NOT work (i.e. Helix Producer produces a feed of just static)

> v4lctl setchannel 3
> v4lctl setfreqtab us-bcast; v4lctl setnorm NTSC; v4lctl setchannel 3
(I tried all combinations with "us-cable" and "us-cable-hrc" for the frequency tables, and "NTSC-M" for the norm), but nothing worked.

But scantv seems to indicate that the channel is there:

> scantv -n NTSC -f us-bcast -a -c /dev/video0 -C /dev/null
scanning freqencies...
??  44.00 MHz (-   ): |   no
??  44.25 MHz (-   ): |   no
??  44.50 MHz (-   ): |   no
...
??  59.00 MHz (-   ): |   no
??  59.25 MHz (-   ): |   no
??  59.50 MHz (-   ): |   no
??  59.75 MHz (-   ):  \  raise
??  60.00 MHz (-   ):   | yes
??  60.25 MHz (-   ):   | yes
??  60.50 MHz (-   ):   | yes
??  60.75 MHz (-   ):   | yes
??  61.00 MHz (-   ):   | yes
??  61.25 MHz (3   ):   | yes
??  61.50 MHz (-   ):   | yes
??  61.75 MHz (-   ):   | yes
??  62.00 MHz (-   ):   | yes
??  62.25 MHz (-   ):  /  fall
=>  61.25 MHz (3   ): ???
[unknown (61.25)]
channel = 3

??  62.50 MHz (-   ): |   no
??  62.75 MHz (-   ): |   no
??  63.00 MHz (-   ): |   no
??  63.25 MHz (-   ): |   no

So, there it is.  Is there something wrong with my v4lctl command, then?  

Interestingly, after running tvtime-scanner, I note this in my ~/.tvtime/stationlist.xml file:
  
    
  

It has also spotted channel 3, but this time at 61.50Mhz, rather than 61.25Mhz (which is where I thought it ought to be).

So here is what WORKS:
- run tvtime, tune to channel 3, quit the program and start Helix Producer.  It will "see" the correct channel and show a nice clear picture.
- or, run an mplayer command like the following.  When it quits 5 seconds later, start Helix Producer.  Again, Helix will show the picture from channel 3:

>  mplayer -vo xv tv:// -tv driver=v4l2:alsa:immediatemode=0:adevice=hw.1,0:norm=ntsc:chanlist=us-cable:channel=3 -endpos 5


So, my horrible hack to get this working is to run the "mplayer" command before I start Helix Producer.  But surely there must be a better way!  Can I make v4lctl do the right thing?  Or is there another command-line tool that I can use?

Thanks again.



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Re: Bah! How do I change channels?

[Andy Walls]

On Thu, 2009-06-25 at 23:04 -0400, George Adams wrote:
> Having gotten my Pinnacle HDTV Pro Stick working again under some old
> v4l drivers, I'm now facing a much more mundane problem - I can't
> figure out how to use the command line to change the channel.
> 
> The video feed (a closed-circuit feed) that's coming to the card is
> over a coax cable, and is on (analog) channel 3.  My goal is to take
> the input and use Helix Encoder to produce RealVideo output that can
> be played using Real Player (yeah, not the ideal situation, but it's
> what we're using for now)
> 
> Helix Producer (unlike "mencoder/mplayer") doesn't have the ability to
> change the channel - it can only take whatever is coming over the
> channel that the Pinnacle device is currently tuned to.  Devin pointed
> me to the "v4lctl" command, but I'm not having any luck with it yet.  

I use either v4l2-ctl or ivtv-tune

$ ivtv-tune -d /dev/video0 -t us-bcast -c 3
/dev/video0: 61.250 MHz

$ v4l2-ctl -d /dev/video0 -f 61.250
Frequency set to 980 (61.250000 MHz)


Regards,
Andy

Re: Bah! How do I change channels?

[Devin Heitmueller]

On Fri, Jun 26, 2009 at 7:50 AM, Andy Walls<awalls@radix.net> wrote:
> I use either v4l2-ctl or ivtv-tune
>
> $ ivtv-tune -d /dev/video0 -t us-bcast -c 3
> /dev/video0: 61.250 MHz
>
> $ v4l2-ctl -d /dev/video0 -f 61.250
> Frequency set to 980 (61.250000 MHz)
>
>
> Regards,
> Andy

Hello Andy,

I had sent George some email off-list with basically the same
commands.  I think what might be happening here is the tuner gets
powered down when not in use, so I think it might be powered down
between the v4l-ctl command and the running of the other application.

I have sent him a series of commands to try where he modprobes the
xc3028 driver with "no_poweroff=1", and we will see if that starts
working.

Devin

-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com

Re: Bah! How do I change channels?

[Robert Krakora]

On Fri, Jun 26, 2009 at 9:42 AM, Devin
Heitmueller<dheitmueller@kernellabs.com> wrote:
> On Fri, Jun 26, 2009 at 7:50 AM, Andy Walls<awalls@radix.net> wrote:
>> I use either v4l2-ctl or ivtv-tune
>>
>> $ ivtv-tune -d /dev/video0 -t us-bcast -c 3
>> /dev/video0: 61.250 MHz
>>
>> $ v4l2-ctl -d /dev/video0 -f 61.250
>> Frequency set to 980 (61.250000 MHz)
>>
>>
>> Regards,
>> Andy
>
> Hello Andy,
>
> I had sent George some email off-list with basically the same
> commands.  I think what might be happening here is the tuner gets
> powered down when not in use, so I think it might be powered down
> between the v4l-ctl command and the running of the other application.
>
> I have sent him a series of commands to try where he modprobes the
> xc3028 driver with "no_poweroff=1", and we will see if that starts
> working.
>
> Devin
>
> --
> Devin J. Heitmueller - Kernel Labs
> http://www.kernellabs.com
>
> --
> video4linux-list mailing list
> Unsubscribe mailto:video4linux-list-request@redhat.com?subject=unsubscribe
> https://www.redhat.com/mailman/listinfo/video4linux-list
>
>

I had ran into this before with the KWorld a few months back.
However, whatever problem existed that forced me to add
"no_poweroff=1" to modprobe.conf for the em28xx module has went away.
I have been able to use v4l-ctl or ivtv-tune without any problems to
tune analog channels over cable.

-- 
Rob Krakora
Senior Software Engineer
MessageNet Systems
101 East Carmel Dr. Suite 105
Carmel, IN 46032
(317)566-1677 Ext. 206
(317)663-0808 Fax

Re: Bah! How do I change channels?

[Devin Heitmueller]

On Fri, Jun 26, 2009 at 1:19 PM, Robert
Krakora<rob.krakora@messagenetsystems.com> wrote:
> I had ran into this before with the KWorld a few months back.
> However, whatever problem existed that forced me to add
> "no_poweroff=1" to modprobe.conf for the em28xx module has went away.
> I have been able to use v4l-ctl or ivtv-tune without any problems to
> tune analog channels over cable.

Well, bear in mind that if you run v4l-ctl *after* the program is
streaming it should work.  However, if you run v4l-ctl and then try to
stream I suspect it will fail.

If it's working, then perhaps I should take a look at the power
management code in em28xx/xc2028 since I don't know why it would work
(and perhaps the tuner is *not* being powered down like it should be).

Devin

-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com

Re: Bah! How do I change channels?

[Robert Krakora]

On Fri, Jun 26, 2009 at 1:23 PM, Devin
Heitmueller<dheitmueller@kernellabs.com> wrote:
> On Fri, Jun 26, 2009 at 1:19 PM, Robert
> Krakora<rob.krakora@messagenetsystems.com> wrote:
>> I had ran into this before with the KWorld a few months back.
>> However, whatever problem existed that forced me to add
>> "no_poweroff=1" to modprobe.conf for the em28xx module has went away.
>> I have been able to use v4l-ctl or ivtv-tune without any problems to
>> tune analog channels over cable.
>
> Well, bear in mind that if you run v4l-ctl *after* the program is
> streaming it should work.  However, if you run v4l-ctl and then try to
> stream I suspect it will fail.
>
> If it's working, then perhaps I should take a look at the power
> management code in em28xx/xc2028 since I don't know why it would work
> (and perhaps the tuner is *not* being powered down like it should be).
>
> Devin
>
> --
> Devin J. Heitmueller - Kernel Labs
> http://www.kernellabs.com
>
>

Devin:

Yes, it is run after mplayer initially tunes it.  However, what is the
difference between mplayer tuning and v4l-ctl tuning?  They are both
submitting the same IOCTLs to the driver to accomplish the same end
result; or is mplayer probably submitting some additional IOCTLS to
"wake" the device?

Best Regards,

-- 
Rob Krakora
Senior Software Engineer
MessageNet Systems
101 East Carmel Dr. Suite 105
Carmel, IN 46032
(317)566-1677 Ext. 206
(317)663-0808 Fax

Re: Bah! How do I change channels?

[Devin Heitmueller]

On Fri, Jun 26, 2009 at 1:28 PM, Robert
Krakora<rob.krakora@messagenetsystems.com> wrote:
> Yes, it is run after mplayer initially tunes it.  However, what is the
> difference between mplayer tuning and v4l-ctl tuning?  They are both
> submitting the same IOCTLs to the driver to accomplish the same end
> result; or is mplayer probably submitting some additional IOCTLS to
> "wake" the device?

The issue is that the tuner gets powered down when the v4l device is
closed.  So, when running mplayer first, and then v4l-ctl is being
used to tune, the file handle is held active by mplayer.  But if you
run v4l-ctl first, the v4l-ctl opens the handle, tunes successfully,
and then closes the handle (which powers down the tuner).  Then when
running mplayer (or whatever app), the handle gets reopened but the
tuner is not tuned to the target frequency that v4l-ctl set.

Devin

-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com

Re: Bah! How do I change channels?

[Robert Vincent Krakora]

Devin Heitmueller wrote:
> On Fri, Jun 26, 2009 at 1:28 PM, Robert
> Krakora<rob.krakora@messagenetsystems.com> wrote:
>   
>> Yes, it is run after mplayer initially tunes it.  However, what is the
>> difference between mplayer tuning and v4l-ctl tuning?  They are both
>> submitting the same IOCTLs to the driver to accomplish the same end
>> result; or is mplayer probably submitting some additional IOCTLS to
>> "wake" the device?
>>     
>
> The issue is that the tuner gets powered down when the v4l device is
> closed.  So, when running mplayer first, and then v4l-ctl is being
> used to tune, the file handle is held active by mplayer.  But if you
> run v4l-ctl first, the v4l-ctl opens the handle, tunes successfully,
> and then closes the handle (which powers down the tuner).  Then when
> running mplayer (or whatever app), the handle gets reopened but the
> tuner is not tuned to the target frequency that v4l-ctl set.
>
> Devin
>
>   
Aaahh yes...I think that you have told me that once before...sorry for 
making you repeat yourself...

However, with ivtv-tune I can issue a tune to a channel and then open 
mplayer with no tuning parameters and that channel is playing...

-- 
Rob Krakora
Senior Software Engineer
MessageNet Systems
101 East Carmel Dr. Suite 105
Carmel, IN 46032
(317)566-1677 Ext. 206
(317)663-0808 Fax

Re: Bah! How do I change channels?

[Andy Walls]

On Fri, 2009-06-26 at 13:23 -0400, Devin Heitmueller wrote:
> On Fri, Jun 26, 2009 at 1:19 PM, Robert
> Krakora<rob.krakora@messagenetsystems.com> wrote:
> > I had ran into this before with the KWorld a few months back.
> > However, whatever problem existed that forced me to add
> > "no_poweroff=1" to modprobe.conf for the em28xx module has went away.
> > I have been able to use v4l-ctl or ivtv-tune without any problems to
> > tune analog channels over cable.
> 
> Well, bear in mind that if you run v4l-ctl *after* the program is
> streaming it should work.  However, if you run v4l-ctl and then try to
> stream I suspect it will fail.
> 
> If it's working, then perhaps I should take a look at the power
> management code in em28xx/xc2028 since I don't know why it would work


Hmm, that sure sounds like a V4L2 spec violation.  From the V4L2 close()
description:

"Closes the device. Any I/O in progress is terminated and resources
associated with the file descriptor are freed. However data format
parameters, current input or output, control values or other properties
remain unchanged."


Regards,
Andy

> (and perhaps the tuner is *not* being powered down like it should be).
> 
> Devin
> 

Re: Bah! How do I change channels?

[Devin Heitmueller]

On Fri, Jun 26, 2009 at 2:34 PM, Andy Walls<awalls@radix.net> wrote:
> Hmm, that sure sounds like a V4L2 spec violation.  From the V4L2 close()
> description:
>
> "Closes the device. Any I/O in progress is terminated and resources
> associated with the file descriptor are freed. However data format
> parameters, current input or output, control values or other properties
> remain unchanged."
>
>
> Regards,
> Andy

I have no idea how that would work with power management.  It would
mean that all the tuners and demod drivers which don't maintain state
across powerdown would have to maintain some sort of cache of all of
the programmed registers, and we would need to add some sort of
"wakeup" callback which reprograms the device accordingly (currently
we have a sleep callback but not a corresponding callback to wake the
device back up).

As a requirement, it might have been suitable for PCI cards where you
don't care about power management (and therefore never power anything
down), but I don't know how practical that is for USB or minicard
devices where power management is critical because you're on a
battery.

Devin

-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com

Re: Bah! How do I change channels?

[Andy Walls]

On Fri, 2009-06-26 at 14:47 -0400, Devin Heitmueller wrote:
> On Fri, Jun 26, 2009 at 2:34 PM, Andy Walls<awalls@radix.net> wrote:
> > Hmm, that sure sounds like a V4L2 spec violation.  From the V4L2 close()
> > description:
> >
> > "Closes the device. Any I/O in progress is terminated and resources
> > associated with the file descriptor are freed. However data format
> > parameters, current input or output, control values or other properties
> > remain unchanged."
> >
> >
> > Regards,
> > Andy
> 
> I have no idea how that would work with power management.  It would
> mean that all the tuners and demod drivers which don't maintain state
> across powerdown would have to maintain some sort of cache of all of
> the programmed registers, and we would need to add some sort of
> "wakeup" callback which reprograms the device accordingly (currently
> we have a sleep callback but not a corresponding callback to wake the
> device back up).

That sounds about right.


> As a requirement, it might have been suitable for PCI cards where you
> don't care about power management (and therefore never power anything
> down), but I don't know how practical that is for USB or minicard
> devices where power management is critical because you're on a
> battery.

All I'm saying is that it is obviously the expected behavior, it the
specified behavior, and all the userland apps and scripts are written
with that behavior in mind.

The applications' expectation of that behavior is, of course, why we are
having this discussion.

Assuming arguendo, maintaing state in the face of power management is a
hard requirement on the driver; I'll still contend it's harder to change
the existing base of applications and user scripts.  Until the spec and
all the existing apps change, not adhering to the spec leads to user
confusion.

My $0.02

Regards,
Andy

> Devin

Re: Bah! How do I change channels?

[Devin Heitmueller]

On Fri, Jun 26, 2009 at 3:02 PM, Andy Walls<awalls@radix.net> wrote:
> All I'm saying is that it is obviously the expected behavior, it the
> specified behavior, and all the userland apps and scripts are written
> with that behavior in mind.
>
> The applications' expectation of that behavior is, of course, why we are
> having this discussion.
>
> Assuming arguendo, maintaing state in the face of power management is a
> hard requirement on the driver; I'll still contend it's harder to change
> the existing base of applications and user scripts.  Until the spec and
> all the existing apps change, not adhering to the spec leads to user
> confusion.

I guess that means that every product that has a tuner which
implements the sleep callback is broken.  And yet this is the first
case I've heard a user complain, which makes me wonder how big a
population is out there that is using scripts to control the tuner.  I
suspect most people are just using applications like MythTV, xawtv or
tvtime, which won't have these issues.

I don't intend to come across as argumentative, but if we haven't
heard a massive outcry about this by now, maybe nobody actually cares
and thus we shouldn't spend the time to build a whole infrastructure
to preserve the driver state across the low power mode.  Those people
who really do care can just disable the power management with a
modprobe option.

Devin

-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com

Re: Bah! How do I change channels?

[Robert Vincent Krakora]

Devin Heitmueller wrote:
> On Fri, Jun 26, 2009 at 3:02 PM, Andy Walls<awalls@radix.net> wrote:
>   
>> All I'm saying is that it is obviously the expected behavior, it the
>> specified behavior, and all the userland apps and scripts are written
>> with that behavior in mind.
>>
>> The applications' expectation of that behavior is, of course, why we are
>> having this discussion.
>>
>> Assuming arguendo, maintaing state in the face of power management is a
>> hard requirement on the driver; I'll still contend it's harder to change
>> the existing base of applications and user scripts.  Until the spec and
>> all the existing apps change, not adhering to the spec leads to user
>> confusion.
>>     
>
> I guess that means that every product that has a tuner which
> implements the sleep callback is broken.  And yet this is the first
> case I've heard a user complain, which makes me wonder how big a
> population is out there that is using scripts to control the tuner.  I
> suspect most people are just using applications like MythTV, xawtv or
> tvtime, which won't have these issues.
>
> I don't intend to come across as argumentative, but if we haven't
> heard a massive outcry about this by now, maybe nobody actually cares
> and thus we shouldn't spend the time to build a whole infrastructure
> to preserve the driver state across the low power mode.  Those people
> who really do care can just disable the power management with a
> modprobe option.
>
> Devin
>
>   
Devin:

I care and I love the infrastructure that has been created.  However, it 
seems as though there are devices that do not conform to the paradigm or 
maybe they are not truly in "low power" mode.  My guess is the latter 
otherwise there would be a flurry of complaints.

Best Regards,

-- 
Rob Krakora
Senior Software Engineer
MessageNet Systems
101 East Carmel Dr. Suite 105
Carmel, IN 46032
(317)566-1677 Ext. 206
(317)663-0808 Fax

Re: Bah! How do I change channels?

[Devin Heitmueller]

On Fri, Jun 26, 2009 at 3:56 PM, Robert Vincent
> I care and I love the infrastructure that has been created.  However, it
> seems as though there are devices that do not conform to the paradigm or
> maybe they are not truly in "low power" mode.  My guess is the latter
> otherwise there would be a flurry of complaints.

Unfortunately, it's a little more complicated.  In the beginning, none
of the drivers did power management, and nobody cared because they
were all PCI cards and nobody would notice a 1 watt difference in
consumption on a 300 watt power supply.  These devices would maintain
persistent state across v4l closes because the chips were never
powered down.

Other devices, such as some USB devices, do have the power management
hooks implemented.  I don't know what the percentages are here (I
would have to look at the driver code to figure that out).  These
devices power down the chips when asked to by the bridge, and it is
typically triggered when no userland apps still have the v4l device
open.  In cases such as this, the power management works but it would
break cases where people used scripts to control the device.

There's probably a third class of devices worth mentioning: those that
really should be doing power management but aren't.  This includes all
the USB devices which burn your fingers and drain your laptop battery
from the time you plug it in until the time you unplug it, regardless
of whether you are using it.

It's not about "caring" or how much we do or do not love the
infrastructure.  It's about deciding what are the most important goals
given limited developer resources.  In this case, it's a question of
which is more important: incurring the cost of overhauling all the
drivers that do power management to have state persist after a power
down versus telling those users who use scripts to manually disable
power management.

Since we have no idea how many users use scripts to control their
tuners, and right now we don't know how many devices are effected, we
cannot really make any decisions one way or the other.

My hope is to see power management properly implemented in more
drivers since I'm concerned about the environment.  However, if I have
to do a huge overhaul of the state management in every driver just to
accommodate an unknown quantity of users, then I would have to think
twice about that.

Devin

-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com

Re: Bah! How do I change channels?

[Andy Walls]

On Fri, 2009-06-26 at 15:29 -0400, Devin Heitmueller wrote: 
> On Fri, Jun 26, 2009 at 3:02 PM, Andy Walls<awalls@radix.net> wrote:
> > All I'm saying is that it is obviously the expected behavior, it the
> > specified behavior, and all the userland apps and scripts are written
> > with that behavior in mind.
> >
> > The applications' expectation of that behavior is, of course, why we are
> > having this discussion.
> >
> > Assuming arguendo, maintaing state in the face of power management is a
> > hard requirement on the driver; I'll still contend it's harder to change
> > the existing base of applications and user scripts.  Until the spec and
> > all the existing apps change, not adhering to the spec leads to user
> > confusion.
> 
> I guess that means that every product that has a tuner which
> implements the sleep callback is broken.  And yet this is the first
> case I've heard a user complain, which makes me wonder how big a
> population is out there that is using scripts to control the tuner.  I
> suspect most people are just using applications like MythTV, xawtv or
> tvtime, which won't have these issues.


> I don't intend to come across as argumentative, but if we haven't
> heard a massive outcry about this by now, maybe nobody actually cares
> and thus we shouldn't spend the time to build a whole infrastructure
> to preserve the driver state across the low power mode.

Devin,

I'm not saying we need to fix every broken tuner driver.  I would
suggest, however, that if you fix the one at hand, you will provide a
template which others could follow as the problem crops up with other
devices.


>   Those people
> who really do care can just disable the power management with a
> modprobe option.

I doubt you'll here a massive outcry, as most users use a large
monlithic application (e.g. MyhtTV) that keep at least two device nodes
open, so even if they momentarily close one, it doesn't matter.

Where it hurts not to preserve state is for:

1. development and troubleshooting - small tools that do one thing and
can do them in whatever order you want simply are really nice to have
work.

In this thread I've seen a user trying to troubleshoot being affected by
not preserving state.



2. user work arounds or conveniences - a small tool used in a script to
twiddle a device setting.

Preserving state is often *not* used for saving the last tuned
frequency, but for other things like the last used input, volume level,
VBI settings, etc.




As I wave the V4L2 spec around like a blind follower of some sacred law,
I'm begin to feel like Piggy clinging to the conch shell in
_The_Lord_of_the_Flies_ , so....

If you think the V4L2 spec is bad, then propose a modification in
writing (an RFC) that you think makes sense.  Propose exceptions for
tuners and/or power management.

I'm not trying to be argumentative either.  I guess I'm just not a big
fan of "kicking the can down the road".  We all bear the burden of the
spec non-compliance in the power managment design and/or implementation,
in the form of additional user support and less flexible troubleshooting
steps, until it is resolved.  

I do, however, appreciate that there is only so much time to do useful
work and that one has to prioritize.  And I do also appreciate the large
amount of enegry you put into v4l-dvb.

Regards,
Andy

> Devin

RE: Bah! How do I change channels?

[George Adams]

Thanks again to both of you for your help.  I gave the no_poweroff flag a try, but didn't see any difference.  I also tried a "setchannel 3" during the middle of the encoding session, and also saw no change.
 
But I think I've found the problem:
 
> v4lctl setnorm NTSC; v4lctl setfreqtab us-bcast; v4lctl -v 1 setchannel 3
vid-open: trying: v4l2-old... 
vid-open: failed: v4l2-old
vid-open: trying: v4l2... 
v4l2: open
v4l2: device info:
  em28xx 0.1.1 / Pinnacle PCTV HD Pro Stick @ usb-0000:00:1a.7-1
vid-open: ok: v4l2
freq: reading /usr/share/xawtv/Index.map
v4l2:   tuner cap:
v4l2:   tuner rxs:
v4l2:   tuner cur: MONO
cmd: "setchannel" "3"
v4l2: freq: 0.000
v4l2: close
 
 
What?  freq: 0.000 ?  After finding the ivtv package and compiling its utils, I confirm it with this:
 
> v4l2-ctl -F
Frequency: 0 (0.000000 MHz)
 
> ivtv-tune -c 3
/dev/video0: 61.250 MHz
 
> v4l2-ctl -F              
Frequency: 980 (61.250000 MHz)
 
> v4lctl setchannel 3

> v4l2-ctl -F      
Frequency: 0 (0.000000 MHz)
 
 
So mysteriously, it seems like v4lctl is just plain not working.  And ivtv-tune, on the other hand, is working just fine.  After I do that and start Helix Producer, I see channel 3 just like I had hoped.
 
(strangely, v4lctl can do other things fine, like change the norm from NTSC to PAL.  It just can't change the channel.)
 
So, sorry that it went off in rabbit trails of the device powering down and so forth.  I wonder what happened to my v4lctl program, though?  xawtv itself (running in X) seems to work fine when I tell it to change the channel...
 

 
 
 

> Date: Fri, 26 Jun 2009 09:42:06 -0400
> Subject: Re: Bah! How do I change channels?
> From: dheitmueller@kernellabs.com
> To: awalls@radix.net
> CC: g_adams27@hotmail.com; video4linux-list@redhat.com; linux-media@vger.kernel.org
> 
> On Fri, Jun 26, 2009 at 7:50 AM, Andy Walls wrote:
>> I use either v4l2-ctl or ivtv-tune
>>
>> $ ivtv-tune -d /dev/video0 -t us-bcast -c 3
>> /dev/video0: 61.250 MHz
>>
>> $ v4l2-ctl -d /dev/video0 -f 61.250
>> Frequency set to 980 (61.250000 MHz)
>>
>>
>> Regards,
>> Andy
> 
> Hello Andy,
> 
> I had sent George some email off-list with basically the same
> commands. I think what might be happening here is the tuner gets
> powered down when not in use, so I think it might be powered down
> between the v4l-ctl command and the running of the other application.
> 
> I have sent him a series of commands to try where he modprobes the
> xc3028 driver with "no_poweroff=1", and we will see if that starts
> working.
> 
> Devin
> 
> -- 
> Devin J. Heitmueller - Kernel Labs
> http://www.kernellabs.com
_________________________________________________________________
Lauren found her dream laptop. Find the PC that’s right for you.
http://www.microsoft.com/windows/choosepc/?ocid=ftp_val_wl_290

Re: Bah! How do I change channels?

[Robert Krakora]

On Sat, Jun 27, 2009 at 12:25 AM, George Adams<g_adams27@hotmail.com> wrote:
>
> Thanks again to both of you for your help.  I gave the no_poweroff flag a try, but didn't see any difference.  I also tried a "setchannel 3" during the middle of the encoding session, and also saw no change.
>
> But I think I've found the problem:
>
>> v4lctl setnorm NTSC; v4lctl setfreqtab us-bcast; v4lctl -v 1 setchannel 3
> vid-open: trying: v4l2-old...
> vid-open: failed: v4l2-old
> vid-open: trying: v4l2...
> v4l2: open
> v4l2: device info:
>  em28xx 0.1.1 / Pinnacle PCTV HD Pro Stick @ usb-0000:00:1a.7-1
> vid-open: ok: v4l2
> freq: reading /usr/share/xawtv/Index.map
> v4l2:   tuner cap:
> v4l2:   tuner rxs:
> v4l2:   tuner cur: MONO
> cmd: "setchannel" "3"
> v4l2: freq: 0.000
> v4l2: close
>
>
> What?  freq: 0.000 ?  After finding the ivtv package and compiling its utils, I confirm it with this:
>
>> v4l2-ctl -F
> Frequency: 0 (0.000000 MHz)
>
>> ivtv-tune -c 3
> /dev/video0: 61.250 MHz
>
>> v4l2-ctl -F
> Frequency: 980 (61.250000 MHz)
>
>> v4lctl setchannel 3
>
>> v4l2-ctl -F
> Frequency: 0 (0.000000 MHz)
>
>
> So mysteriously, it seems like v4lctl is just plain not working.  And ivtv-tune, on the other hand, is working just fine.  After I do that and start Helix Producer, I see channel 3 just like I had hoped.
>
> (strangely, v4lctl can do other things fine, like change the norm from NTSC to PAL.  It just can't change the channel.)
>
> So, sorry that it went off in rabbit trails of the device powering down and so forth.  I wonder what happened to my v4lctl program, though?  xawtv itself (running in X) seems to work fine when I tell it to change the channel...
>
>
>
>
>
>
>> Date: Fri, 26 Jun 2009 09:42:06 -0400
>> Subject: Re: Bah! How do I change channels?
>> From: dheitmueller@kernellabs.com
>> To: awalls@radix.net
>> CC: g_adams27@hotmail.com; video4linux-list@redhat.com; linux-media@vger.kernel.org
>>
>> On Fri, Jun 26, 2009 at 7:50 AM, Andy Walls wrote:
>>> I use either v4l2-ctl or ivtv-tune
>>>
>>> $ ivtv-tune -d /dev/video0 -t us-bcast -c 3
>>> /dev/video0: 61.250 MHz
>>>
>>> $ v4l2-ctl -d /dev/video0 -f 61.250
>>> Frequency set to 980 (61.250000 MHz)
>>>
>>>
>>> Regards,
>>> Andy
>>
>> Hello Andy,
>>
>> I had sent George some email off-list with basically the same
>> commands. I think what might be happening here is the tuner gets
>> powered down when not in use, so I think it might be powered down
>> between the v4l-ctl command and the running of the other application.
>>
>> I have sent him a series of commands to try where he modprobes the
>> xc3028 driver with "no_poweroff=1", and we will see if that starts
>> working.
>>
>> Devin
>>
>> --
>> Devin J. Heitmueller - Kernel Labs
>> http://www.kernellabs.com
> _________________________________________________________________
> Lauren found her dream laptop. Find the PC that’s right for you.
> http://www.microsoft.com/windows/choosepc/?ocid=ftp_val_wl_290
>
> --
> video4linux-list mailing list
> Unsubscribe mailto:video4linux-list-request@redhat.com?subject=unsubscribe
> https://www.redhat.com/mailman/listinfo/video4linux-list
>
>

George:

Try 'v4l2-ctl -d /dev/video0 -f 61.250' to tune to broadcast channel 3
per one of Devin's e-mails to you.  I do not know why setchannel is
not working for you.  I use both ivtv-tune v4l2-ctl and both do work
and v4l2-ctl should work in this instance for you.  I always open my
USB TV device via mplayer not specifiying a channel and then use
ivtv-tune executed by a script that is run by an application to tune
channels.  I happened to notice that if I closed mplayer and used
ivtv-tune to tune to another channel and then open my USB TV device,
it would be tuned to that channel.

Andy:

I too care about the environment.  I am trying to find some extra time
to figure out if my KWorld 330U USB TV devices are actually going into
low power mode or not.  I would say not as they get really hot, so I
unplug them when I am not using them.  I told Devin I would work on
this and I have an accurate analog amp meter, but I got very busy at
work and at home with the kids.  However, I don't believe that the
answer is to disable power management as some of these parts get so
hot that leaving them in a powered state and tuned to a channel will
probably damage the device.  Remember, these are silicon tuners, not
the old discrete tuners that have way more surface area to dissipate
heat.

Devin:

Great job answering questions as usual.  ;-)

Best Regards,

-- 
Rob Krakora
Senior Software Engineer
MessageNet Systems
101 East Carmel Dr. Suite 105
Carmel, IN 46032
(317)566-1677 Ext. 206
(317)663-0808 Fax

Re: Bah! How do I change channels?

[Andy Walls]

On Sat, 2009-06-27 at 17:57 -0400, Robert Krakora wrote:

> Andy:
> 
> I too care about the environment.  I am trying to find some extra time
> to figure out if my KWorld 330U USB TV devices are actually going into
> low power mode or not.  I would say not as they get really hot, so I
> unplug them when I am not using them.  I told Devin I would work on
> this and I have an accurate analog amp meter, but I got very busy at
> work and at home with the kids.  However, I don't believe that the
> answer is to disable power management as some of these parts get so
> hot that leaving them in a powered state and tuned to a channel will
> probably damage the device.  Remember, these are silicon tuners, not
> the old discrete tuners that have way more surface area to dissipate
> heat.

Oh, I'm not against power management.  But state is lost - somethings
that's fixable with a lot of work apparently.  I was thinking maybe the
V4L2 spec could change.

I was also pondering maybe the final close() shouldn't be the trigger
for powering devices down.  How about the final close() + 30 seconds?
Or the final close() + some user set interval.  It seems like scheduling
delayed work to do something like that should be easy enough.  That
would require a spec change about state being only preserved until power
management powered the thing down and probably an additional ioctl()
added to set the powerdown delay.  The driver could probably default
delay to some interval that would be good for most users.

I don't know.  Just ideas...

Regards,
Andy

Re: Bah! How do I change channels?

[Devin Heitmueller]

On Sat, Jun 27, 2009 at 8:17 PM, Andy Walls<awalls@radix.net> wrote:
> Oh, I'm not against power management.  But state is lost - somethings
> that's fixable with a lot of work apparently.  I was thinking maybe the
> V4L2 spec could change.
>
> I was also pondering maybe the final close() shouldn't be the trigger
> for powering devices down.  How about the final close() + 30 seconds?
> Or the final close() + some user set interval.  It seems like scheduling
> delayed work to do something like that should be easy enough.  That
> would require a spec change about state being only preserved until power
> management powered the thing down and probably an additional ioctl()
> added to set the powerdown delay.  The driver could probably default
> delay to some interval that would be good for most users.
>
> I don't know.  Just ideas...

On the DVB side, there actually is a modprobe parameter for
dvb_frontend that allows you to defer putting the device to sleep
(defaults to zero seconds).  It would be a little trickier to do this
in v4l because of the differences in the in-kernel threading (dvb has
a dedicated thread for controlling the device).  Also, it's globally
defined, which is good from a consistency standpoint but annoying in
cases where some devices really should defer sleep for some period.

For example, the HVR-950q's i2c implementation is *really* slow (8
seconds to load the xc5000 firmware).  If I had been able to control
the delay on a per-device basis in the board definition I could have
set it to sleep after 10 seconds by default, which would have helped
in cases like the Kaffeine channel scanner which continuously
closes/opens the frontend as it scans.

Anyway, it's good to discuss this issue, since I hadn't really
considered the implications of the power management until George's
email.  I'm just not sure what the best approach is at this point and
will have to give it some more thought.

Devin

-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com

RE: Bah! How do I change channels?

[hermann pitton]

Hi,

Am Samstag, den 27.06.2009, 00:25 -0400 schrieb George Adams:
> Thanks again to both of you for your help.  I gave the no_poweroff flag a try, but didn't see any difference.  I also tried a "setchannel 3" during the middle of the encoding session, and also saw no change.

hm, I'm late on the party, but for Gerd's v4lctl try to RTFM.

The "setchannel" options reads from .xawtv.

For me it still works, but issues with tda827x silicon tuners are known
walking the ioctls.

Cheers,
Hermann

 
> But I think I've found the problem:
>  
> > v4lctl setnorm NTSC; v4lctl setfreqtab us-bcast; v4lctl -v 1 setchannel 3
> vid-open: trying: v4l2-old... 
> vid-open: failed: v4l2-old
> vid-open: trying: v4l2... 
> v4l2: open
> v4l2: device info:
>   em28xx 0.1.1 / Pinnacle PCTV HD Pro Stick @ usb-0000:00:1a.7-1
> vid-open: ok: v4l2
> freq: reading /usr/share/xawtv/Index.map
> v4l2:   tuner cap:
> v4l2:   tuner rxs:
> v4l2:   tuner cur: MONO
> cmd: "setchannel" "3"
> v4l2: freq: 0.000
> v4l2: close
>  
> 
> What?  freq: 0.000 ?  After finding the ivtv package and compiling its utils, I confirm it with this:
>  
> > v4l2-ctl -F
> Frequency: 0 (0.000000 MHz)
>  
> > ivtv-tune -c 3
> /dev/video0: 61.250 MHz
>  
> > v4l2-ctl -F              
> Frequency: 980 (61.250000 MHz)
>  
> > v4lctl setchannel 3
> 
> > v4l2-ctl -F      
> Frequency: 0 (0.000000 MHz)
>  
> 
> So mysteriously, it seems like v4lctl is just plain not working.  And ivtv-tune, on the other hand, is working just fine.  After I do that and start Helix Producer, I see channel 3 just like I had hoped.
>  
> (strangely, v4lctl can do other things fine, like change the norm from NTSC to PAL.  It just can't change the channel.)
>  
> So, sorry that it went off in rabbit trails of the device powering down and so forth.  I wonder what happened to my v4lctl program, though?  xawtv itself (running in X) seems to work fine when I tell it to change the channel...
>  
> 
> 
> 
> 
> 
> > Date: Fri, 26 Jun 2009 09:42:06 -0400
> > Subject: Re: Bah! How do I change channels?
> > From: dheitmueller@kernellabs.com
> > To: awalls@radix.net
> > CC: g_adams27@hotmail.com; video4linux-list@redhat.com; linux-media@vger.kernel.org
> > 
> > On Fri, Jun 26, 2009 at 7:50 AM, Andy Walls wrote:
> >> I use either v4l2-ctl or ivtv-tune
> >>
> >> $ ivtv-tune -d /dev/video0 -t us-bcast -c 3
> >> /dev/video0: 61.250 MHz
> >>
> >> $ v4l2-ctl -d /dev/video0 -f 61.250
> >> Frequency set to 980 (61.250000 MHz)
> >>
> >>
> >> Regards,
> >> Andy
> > 
> > Hello Andy,
> > 
> > I had sent George some email off-list with basically the same
> > commands. I think what might be happening here is the tuner gets
> > powered down when not in use, so I think it might be powered down
> > between the v4l-ctl command and the running of the other application.
> > 
> > I have sent him a series of commands to try where he modprobes the
> > xc3028 driver with "no_poweroff=1", and we will see if that starts
> > working.
> > 
> > Devin
> > 
> > -- 
> > Devin J. Heitmueller - Kernel Labs
> > http://www.kernellabs.com

RE: Bah! How do I change channels?

[George Adams]

A final wrapup (and again, thanks all of you - I'm indebted to you for your help):
 
after booting:
 
> v4l2-ctl -F
Frequency: 9076 (567.250000 MHz)
 
> ivtv-tune -c 3
/dev/video0: 61.250 MHz
> v4l2-ctl -F
Frequency: 980 (61.250000 MHz)
 
> v4l2-ctl -f 61.25
Frequency set to 980 (61.250000 MHz)
> v4l2-ctl -F           
Frequency: 980 (61.250000 MHz)
 
> v4lctl setchannel 3
> v4l2-ctl -F      
Frequency: 0 (0.000000 MHz)
 
Conclusion: I'll stick with ivtv-tune or v4l2-ctl and ignore the misbehaving v4lctl
 
Hermann: Thanks, but I think you're mistaking the v4lctl "setstation" command (which relies on .xawtv) and the "setchannel" command (which does not, at least according to the man page.)
 
 


----------------------------------------
> Subject: RE: Bah! How do I change channels?
> From: hermann-pitton@arcor.de
> To: g_adams27@hotmail.com
> CC: dheitmueller@kernellabs.com; awalls@radix.net; video4linux-list@redhat.com; linux-media@vger.kernel.org
> Date: Sun, 28 Jun 2009 03:39:05 +0200
>
> Hi,
>
> Am Samstag, den 27.06.2009, 00:25 -0400 schrieb George Adams:
>> Thanks again to both of you for your help. I gave the no_poweroff flag a try, but didn't see any difference. I also tried a "setchannel 3" during the middle of the encoding session, and also saw no change.
>
> hm, I'm late on the party, but for Gerd's v4lctl try to RTFM.
>
> The "setchannel" options reads from .xawtv.
>
> For me it still works, but issues with tda827x silicon tuners are known
> walking the ioctls.
>
> Cheers,
> Hermann
>
>
>> But I think I've found the problem:
>>
>>> v4lctl setnorm NTSC; v4lctl setfreqtab us-bcast; v4lctl -v 1 setchannel 3
>> vid-open: trying: v4l2-old...
>> vid-open: failed: v4l2-old
>> vid-open: trying: v4l2...
>> v4l2: open
>> v4l2: device info:
>> em28xx 0.1.1 / Pinnacle PCTV HD Pro Stick @ usb-0000:00:1a.7-1
>> vid-open: ok: v4l2
>> freq: reading /usr/share/xawtv/Index.map
>> v4l2: tuner cap:
>> v4l2: tuner rxs:
>> v4l2: tuner cur: MONO
>> cmd: "setchannel" "3"
>> v4l2: freq: 0.000
>> v4l2: close
>>
>>
>> What? freq: 0.000 ? After finding the ivtv package and compiling its utils, I confirm it with this:
>>
>>> v4l2-ctl -F
>> Frequency: 0 (0.000000 MHz)
>>
>>> ivtv-tune -c 3
>> /dev/video0: 61.250 MHz
>>
>>> v4l2-ctl -F
>> Frequency: 980 (61.250000 MHz)
>>
>>> v4lctl setchannel 3
>>
>>> v4l2-ctl -F
>> Frequency: 0 (0.000000 MHz)
>>
>>
>> So mysteriously, it seems like v4lctl is just plain not working. And ivtv-tune, on the other hand, is working just fine. After I do that and start Helix Producer, I see channel 3 just like I had hoped.
>>
>> (strangely, v4lctl can do other things fine, like change the norm from NTSC to PAL. It just can't change the channel.)
>>
>> So, sorry that it went off in rabbit trails of the device powering down and so forth. I wonder what happened to my v4lctl program, though? xawtv itself (running in X) seems to work fine when I tell it to change the channel...
>>
>>
>>
>>
>>
>>
>>> Date: Fri, 26 Jun 2009 09:42:06 -0400
>>> Subject: Re: Bah! How do I change channels?
>>> From: dheitmueller@kernellabs.com
>>> To: awalls@radix.net
>>> CC: g_adams27@hotmail.com; video4linux-list@redhat.com; linux-media@vger.kernel.org
>>>
>>> On Fri, Jun 26, 2009 at 7:50 AM, Andy Walls wrote:
>>>> I use either v4l2-ctl or ivtv-tune
>>>>
>>>> $ ivtv-tune -d /dev/video0 -t us-bcast -c 3
>>>> /dev/video0: 61.250 MHz
>>>>
>>>> $ v4l2-ctl -d /dev/video0 -f 61.250
>>>> Frequency set to 980 (61.250000 MHz)
>>>>
>>>>
>>>> Regards,
>>>> Andy
>>>
>>> Hello Andy,
>>>
>>> I had sent George some email off-list with basically the same
>>> commands. I think what might be happening here is the tuner gets
>>> powered down when not in use, so I think it might be powered down
>>> between the v4l-ctl command and the running of the other application.
>>>
>>> I have sent him a series of commands to try where he modprobes the
>>> xc3028 driver with "no_poweroff=1", and we will see if that starts
>>> working.
>>>
>>> Devin
>>>
>>> --
>>> Devin J. Heitmueller - Kernel Labs
>>> http://www.kernellabs.com
>
>
_________________________________________________________________
Windows Live™ SkyDrive™: Get 25 GB of free online storage.
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RE: Bah! How do I change channels?

[hermann pitton]

Hi,

Am Samstag, den 27.06.2009, 22:36 -0400 schrieb George Adams:
> A final wrapup (and again, thanks all of you - I'm indebted to you for your help):
>  
> after booting:
>  
> > v4l2-ctl -F
> Frequency: 9076 (567.250000 MHz)
>  
> > ivtv-tune -c 3
> /dev/video0: 61.250 MHz
> > v4l2-ctl -F
> Frequency: 980 (61.250000 MHz)
>  
> > v4l2-ctl -f 61.25
> Frequency set to 980 (61.250000 MHz)
> > v4l2-ctl -F           
> Frequency: 980 (61.250000 MHz)
>  
> > v4lctl setchannel 3
> > v4l2-ctl -F      
> Frequency: 0 (0.000000 MHz)
>  
> Conclusion: I'll stick with ivtv-tune or v4l2-ctl and ignore the misbehaving v4lctl
>  
> Hermann: Thanks, but I think you're mistaking the v4lctl "setstation" command (which relies on .xawtv) and the "setchannel" command (which does not, at least according to the man page.)

I can for sure tell, that, if I rename/remove my .xawtv, "setchannel"
does not work anymore and I see exactly what you reported initially.

That can be looked up in the code and it also should not matter that I
have a dual install of xawtv-3.95 and 4x since both start to exist.

Cheers,
Hermann
 
> 
> 
> ----------------------------------------
> > Subject: RE: Bah! How do I change channels?
> > From: hermann-pitton@arcor.de
> > To: g_adams27@hotmail.com
> > CC: dheitmueller@kernellabs.com; awalls@radix.net; video4linux-list@redhat.com; linux-media@vger.kernel.org
> > Date: Sun, 28 Jun 2009 03:39:05 +0200
> >
> > Hi,
> >
> > Am Samstag, den 27.06.2009, 00:25 -0400 schrieb George Adams:
> >> Thanks again to both of you for your help. I gave the no_poweroff flag a try, but didn't see any difference. I also tried a "setchannel 3" during the middle of the encoding session, and also saw no change.
> >
> > hm, I'm late on the party, but for Gerd's v4lctl try to RTFM.
> >
> > The "setchannel" options reads from .xawtv.
> >
> > For me it still works, but issues with tda827x silicon tuners are known
> > walking the ioctls.
> >
> > Cheers,
> > Hermann
> >
> >
> >> But I think I've found the problem:
> >>
> >>> v4lctl setnorm NTSC; v4lctl setfreqtab us-bcast; v4lctl -v 1 setchannel 3
> >> vid-open: trying: v4l2-old...
> >> vid-open: failed: v4l2-old
> >> vid-open: trying: v4l2...
> >> v4l2: open
> >> v4l2: device info:
> >> em28xx 0.1.1 / Pinnacle PCTV HD Pro Stick @ usb-0000:00:1a.7-1
> >> vid-open: ok: v4l2
> >> freq: reading /usr/share/xawtv/Index.map
> >> v4l2: tuner cap:
> >> v4l2: tuner rxs:
> >> v4l2: tuner cur: MONO
> >> cmd: "setchannel" "3"
> >> v4l2: freq: 0.000
> >> v4l2: close
> >>
> >>
> >> What? freq: 0.000 ? After finding the ivtv package and compiling its utils, I confirm it with this:
> >>
> >>> v4l2-ctl -F
> >> Frequency: 0 (0.000000 MHz)
> >>
> >>> ivtv-tune -c 3
> >> /dev/video0: 61.250 MHz
> >>
> >>> v4l2-ctl -F
> >> Frequency: 980 (61.250000 MHz)
> >>
> >>> v4lctl setchannel 3
> >>
> >>> v4l2-ctl -F
> >> Frequency: 0 (0.000000 MHz)
> >>
> >>
> >> So mysteriously, it seems like v4lctl is just plain not working. And ivtv-tune, on the other hand, is working just fine. After I do that and start Helix Producer, I see channel 3 just like I had hoped.
> >>
> >> (strangely, v4lctl can do other things fine, like change the norm from NTSC to PAL. It just can't change the channel.)
> >>
> >> So, sorry that it went off in rabbit trails of the device powering down and so forth. I wonder what happened to my v4lctl program, though? xawtv itself (running in X) seems to work fine when I tell it to change the channel...
> >>
> >>
> >>
> >>
> >>
> >>
> >>> Date: Fri, 26 Jun 2009 09:42:06 -0400
> >>> Subject: Re: Bah! How do I change channels?
> >>> From: dheitmueller@kernellabs.com
> >>> To: awalls@radix.net
> >>> CC: g_adams27@hotmail.com; video4linux-list@redhat.com; linux-media@vger.kernel.org
> >>>
> >>> On Fri, Jun 26, 2009 at 7:50 AM, Andy Walls wrote:
> >>>> I use either v4l2-ctl or ivtv-tune
> >>>>
> >>>> $ ivtv-tune -d /dev/video0 -t us-bcast -c 3
> >>>> /dev/video0: 61.250 MHz
> >>>>
> >>>> $ v4l2-ctl -d /dev/video0 -f 61.250
> >>>> Frequency set to 980 (61.250000 MHz)
> >>>>
> >>>>
> >>>> Regards,
> >>>> Andy
> >>>
> >>> Hello Andy,
> >>>
> >>> I had sent George some email off-list with basically the same
> >>> commands. I think what might be happening here is the tuner gets
> >>> powered down when not in use, so I think it might be powered down
> >>> between the v4l-ctl command and the running of the other application.
> >>>
> >>> I have sent him a series of commands to try where he modprobes the
> >>> xc3028 driver with "no_poweroff=1", and we will see if that starts
> >>> working.
> >>>
> >>> Devin
> >>>
> >>> --
> >>> Devin J. Heitmueller - Kernel Labs
> >>> http://www.kernellabs.com

RE: Bah! How do I change channels?

[hermann pitton]

Hi,

Am Sonntag, den 28.06.2009, 05:53 +0200 schrieb hermann pitton:
> Hi,
> 
> Am Samstag, den 27.06.2009, 22:36 -0400 schrieb George Adams:
> > A final wrapup (and again, thanks all of you - I'm indebted to you for your help):
> >  
> > after booting:
> >  
> > > v4l2-ctl -F
> > Frequency: 9076 (567.250000 MHz)
> >  
> > > ivtv-tune -c 3
> > /dev/video0: 61.250 MHz
> > > v4l2-ctl -F
> > Frequency: 980 (61.250000 MHz)
> >  
> > > v4l2-ctl -f 61.25
> > Frequency set to 980 (61.250000 MHz)
> > > v4l2-ctl -F           
> > Frequency: 980 (61.250000 MHz)
> >  
> > > v4lctl setchannel 3
> > > v4l2-ctl -F      
> > Frequency: 0 (0.000000 MHz)
> >  
> > Conclusion: I'll stick with ivtv-tune or v4l2-ctl and ignore the misbehaving v4lctl
> >  
> > Hermann: Thanks, but I think you're mistaking the v4lctl "setstation" command (which relies on .xawtv) and the "setchannel" command (which does not, at least according to the man page.)
> 
> I can for sure tell, that, if I rename/remove my .xawtv, "setchannel"
> does not work anymore and I see exactly what you reported initially.
> 
> That can be looked up in the code and it also should not matter that I
> have a dual install of xawtv-3.95 and 4x since both start to exist.

for the record: The above is true for a FlyVideo3000 (card=2) on the
saa7134 driver. It has a hardwired analog IF demod chip and no extras
for PM on the PLL chip.

It gets more interesting with tuners with some tda988x and further.

The rest is the well known history ;)

Cheers,
Hermann


> > 
> > 
> > ----------------------------------------
> > > Subject: RE: Bah! How do I change channels?
> > > From: hermann-pitton@arcor.de
> > > To: g_adams27@hotmail.com
> > > CC: dheitmueller@kernellabs.com; awalls@radix.net; video4linux-list@redhat.com; linux-media@vger.kernel.org
> > > Date: Sun, 28 Jun 2009 03:39:05 +0200
> > >
> > > Hi,
> > >
> > > Am Samstag, den 27.06.2009, 00:25 -0400 schrieb George Adams:
> > >> Thanks again to both of you for your help. I gave the no_poweroff flag a try, but didn't see any difference. I also tried a "setchannel 3" during the middle of the encoding session, and also saw no change.
> > >
> > > hm, I'm late on the party, but for Gerd's v4lctl try to RTFM.
> > >
> > > The "setchannel" options reads from .xawtv.
> > >
> > > For me it still works, but issues with tda827x silicon tuners are known
> > > walking the ioctls.
> > >
> > > Cheers,
> > > Hermann
> > >
> > >
> > >> But I think I've found the problem:
> > >>
> > >>> v4lctl setnorm NTSC; v4lctl setfreqtab us-bcast; v4lctl -v 1 setchannel 3
> > >> vid-open: trying: v4l2-old...
> > >> vid-open: failed: v4l2-old
> > >> vid-open: trying: v4l2...
> > >> v4l2: open
> > >> v4l2: device info:
> > >> em28xx 0.1.1 / Pinnacle PCTV HD Pro Stick @ usb-0000:00:1a.7-1
> > >> vid-open: ok: v4l2
> > >> freq: reading /usr/share/xawtv/Index.map
> > >> v4l2: tuner cap:
> > >> v4l2: tuner rxs:
> > >> v4l2: tuner cur: MONO
> > >> cmd: "setchannel" "3"
> > >> v4l2: freq: 0.000
> > >> v4l2: close
> > >>
> > >>
> > >> What? freq: 0.000 ? After finding the ivtv package and compiling its utils, I confirm it with this:
> > >>
> > >>> v4l2-ctl -F
> > >> Frequency: 0 (0.000000 MHz)
> > >>
> > >>> ivtv-tune -c 3
> > >> /dev/video0: 61.250 MHz
> > >>
> > >>> v4l2-ctl -F
> > >> Frequency: 980 (61.250000 MHz)
> > >>
> > >>> v4lctl setchannel 3
> > >>
> > >>> v4l2-ctl -F
> > >> Frequency: 0 (0.000000 MHz)
> > >>
> > >>
> > >> So mysteriously, it seems like v4lctl is just plain not working. And ivtv-tune, on the other hand, is working just fine. After I do that and start Helix Producer, I see channel 3 just like I had hoped.
> > >>
> > >> (strangely, v4lctl can do other things fine, like change the norm from NTSC to PAL. It just can't change the channel.)
> > >>
> > >> So, sorry that it went off in rabbit trails of the device powering down and so forth. I wonder what happened to my v4lctl program, though? xawtv itself (running in X) seems to work fine when I tell it to change the channel...
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>> Date: Fri, 26 Jun 2009 09:42:06 -0400
> > >>> Subject: Re: Bah! How do I change channels?
> > >>> From: dheitmueller@kernellabs.com
> > >>> To: awalls@radix.net
> > >>> CC: g_adams27@hotmail.com; video4linux-list@redhat.com; linux-media@vger.kernel.org
> > >>>
> > >>> On Fri, Jun 26, 2009 at 7:50 AM, Andy Walls wrote:
> > >>>> I use either v4l2-ctl or ivtv-tune
> > >>>>
> > >>>> $ ivtv-tune -d /dev/video0 -t us-bcast -c 3
> > >>>> /dev/video0: 61.250 MHz
> > >>>>
> > >>>> $ v4l2-ctl -d /dev/video0 -f 61.250
> > >>>> Frequency set to 980 (61.250000 MHz)
> > >>>>
> > >>>>
> > >>>> Regards,
> > >>>> Andy
> > >>>
> > >>> Hello Andy,
> > >>>
> > >>> I had sent George some email off-list with basically the same
> > >>> commands. I think what might be happening here is the tuner gets
> > >>> powered down when not in use, so I think it might be powered down
> > >>> between the v4l-ctl command and the running of the other application.
> > >>>
> > >>> I have sent him a series of commands to try where he modprobes the
> > >>> xc3028 driver with "no_poweroff=1", and we will see if that starts
> > >>> working.
> > >>>
> > >>> Devin
> > >>>
> > >>> --
> > >>> Devin J. Heitmueller - Kernel Labs
> > >>> http://www.kernellabs.com
> 
>