NextPVR Usability Issue

[PVRDon]

This is a long post, but the length is necessary to describe the following usability issue:

NextPVR Version 3.5.7 appears to not properly manage a tuner lock on an HDHomerun Model: HDHR4-2US.

Discussion:

I have two computer systems that access the HDHomerun tuner:

System 1 – used exclusively for recording TV and always using tuner 0
System 2 – used exclusively for watching TV, always using tuner 1, and locked with system IP address

Update: System 2 uses VLC to view the TV stream, and is invoked via a CMD batch file.

If System 2 is using tuner1 on the HDHomerun device and NextPVR on System 1 needs that tuner for recording, NextPVR does not appear to know that it is locked by another IP address.

The end result is that no data is recorded and – more importantly – no errors are displayed by NextPVR - at least, none that I can find.

I understand that I create the problem by asking NextPVR to record using a tuner in use by another system, but trying to determine why there is no data being recorded is often very difficult after the fact. The reason being that: I do not always remember exactly when I start and stop watching TV on System 2.

Even if I have created the problem, I still believe that NextPVR should display some sort of error message on the GUI screen for that recording, such as is displayed when the recording is cancelled early. I have attached a screen print of that screen as an example.

That error message should indicate something to the effect that a needed tuner was locked and not available for recording.

Thanks in advance for any comments on this issue.

[BrettB]

System 1 – used exclusively for recording TV and always using tuner 0
System 2 – used exclusively for watching TV, always using tuner 1, and locked with system IP address

Let me see if I'm understanding your situation, because I've had to read through it a few times now...

System 2 is supposed to always only use tuner 1 (or no tuners)
System 1 is supposed to use tuner 0 first, but if tuner 0 is not available, then you want it to try to use tuner 1. If tuner 1 is not available (because System 2 is using it to watch something), then you want NextPVR to immediately mark the recording as failed due to the fact that no tuner was available for the recording.

Is that understanding correct?

First off, you should post a .zip of your logs directory that corresponds to your example along with the specific steps you took to create the situation. So, in your example, did you actually cancel (from the NextPVR application) the highlighted recording from WHAM-HD? And what parameters did you use (specifically for pre-padding, post-padding, start-time, end-time, and channel) for any scheduled recordings? All of these factors affect NextPVR's recording scheduling and implementation logic.

[Graham]

I still believe that NextPVR should display some sort of error message on the GUI screen for that recording ...

I have a paralleprocessing.bat that contains

Code:

timeout 10
if %~z1 lss 1000000 goto small

:small

if %4 equ 24 msg graham Small ... %5 ...on... Blackgold

where "msg" is a command that does not exist in Home versions of Windows ... There is probably some other way to send a message from the system account (where the bat file runs) to the logged on account where the message needs to be displayed. ALternatively, some SQL whizz can tell us a SQL statement that will update the database when the file is small (indicating that it is not receiving data). Someone might know a command to send an email ... or a SMS message ... or do something else.

[PVRDon]

Brett, thank you for taking the time to read my post.

Yes, you have correctly understood my issue:
1. NextPVR should determine if a tuner is locked before attempting to use that tuner.
2. If the tuner is not available due to being locked, display informative text on the GUI in the “Recordings” section for all affected recordings.

The attachment in my first post is merely an example of where the informative message could appear and is not a indication of any problem.

Graham, there are many workarounds when a recording shows up with a zero length, but the above is the most direct way to illuminate the issue – IMHO.

I attempted to re-create the scenario for Brett as follows:

NextPVR padding:
Pre-padding – 1 minute
Post-Padding – 2 minutes

Step 1 : System 2 - Start watching TV at 12:00 – Channel QVCHD – on tuner 1
HDHomerun tuner parameters: us-cable:4 program=2
Note: I believe the actual channel is immaterial.

Step 2. Reboot System 1

Step 3. System 1 - Schedule WHAM channel at 12:30 for 30 minutes – channel 1200
HDHomerun tuner parameters: us-cable:71 program=1

Step 4. System 1 - Schedule WHEC channel at 12:30 for 30 minutes – channel 1203
HDHomerun tuner parameters: us-cable:114 program=1

Step 5. NextPVR starts recording at 12:29 for both channels.

The TV channel continues to stream normally

Step 6. NextPVR ends recording for both channels at 13:02.

Results:

The WHAM channel has a length of 2,321.296 KB.

The WHEC channel has a length of 0 KB.

The TV system continues to stream normally.

The logs associated with this test are attached.

BTW, I use a CMD batch file and the Silicon Dust “hdhomerun_config” command to set and clear the tuner "lockkey" parameter.

Thanks again to Brett and Graham for your consideration of my post.

Update: I went back to delete the above test recordings and discovered the attached error message from NextPVR. I believe this serves to show it was trying to use the tuner, and it should not have, because it was locked by another system.

[sub]

Update: I went back to delete the above test recordings and discovered the attached error message from NextPVR. I believe this serves to show it was trying to use the tuner, and it should not have, because it was locked by another system.

When using the BDA drivers (like NextPVR does for this type of HDHR), the HDHomeRun doesn't have any mechanism to tell me the device is locked, and doesn't return any errors, but should give you a message like the one you've indicated above. ie, "No errors, but no data delivered. This is usually because the device failed to lock a signal".

[PVRDon]

sub,

Thank you for the information.

I was hoping that, since NextPVR can set the "lockkey" parameter (with IP address), it could also query it. I guess not.

As we understand, there are many reasons that data is not delivered, and information on device locking would help narrow down the search path.

Thanks again.

[sub]

I was hoping that, since NextPVR can set the "lockkey" parameter (with IP address), it could also query it. I guess not.

It does if you're using an HDHomeRun Prime. For every other type of HDHomeRun it uses the BDA drivers, and these just looks like every other QAM/ATSC device, and doesn't know about extra stuff like lock keys etc which aren't part of the BDA interface.

On an HDHomeRun prime you do get information about the device being locked etc.

As we understand, there are many reasons that data is not delivered, and information on device locking would help narrow down the search path.

The reason it go not data from the device isn't known to NextPVR in this type of setup.

[PVRDon]

sub,

I guess I should pop for a prime, then.

Not to belabor the point, but, the HDHomerun Tuner Status shows a resource lock when NextPVR is using the tuner to either view or record a channel.

It seems you are saying that NextPVR is not responsible for this "Resource Lock"?

Any thoughts on this?

Many thanks - I know you are very busy...

[sub]

Not to belabor the point, but, the HDHomerun Tuner Status shows a resource lock when NextPVR is using the tuner to either view or record a channel.

It seems you are saying that NextPVR is not responsible for this "Resource Lock"?

When you're using a QAM/ATSC BDA device, this is all happening automatically behind the scenes in the BDA driver that SiliconDust provide.