Recorded TV programs still freezing occasionaly

JohnB47

I'm pretty sure I posted about this before but it will have been a few years ago. We have a Panasonic TV and Panasonic HDR. We record almost all programs and watch them later. We had a new amplified arial fitted at the same time.

We've had freezing problems since we bought these units - around 5 or 6 years ago. Everything goes fine then suddenly the picture freezes and then starts again a few seconds forward. The freeze can be momentary or up to two seconds. Very annoying. We had a period of a few months when almost no freezes occurred but recently they've started happening more often - perhaps one freeze every four programs. The freezes are recorded - I can go back and play again and the freeze occurs again. (Actually, my wife was watching live TV the other afternoon and had a couple of 'No Signal' breaks - it was snowing here so maybe it was that).

We had a guy come round and do various tests and he manually programmed the units to the best transmitter. Since then I've done exactly the same, manually tune to the one transmitter when new stations come along. Signal strength on all channels is excellent.

Has anyone any thoughts on what to try? Maybe a mains conditioner or different light bulbs (there's a CFL one right next to the units and it's a bit noisy).

Also, I'd be interested to hear if anyone else has these problems.

another_casualty

Have you reset tv channels ? Has your recorder got a socket for an Ethernet cable ? Is your recording space almost full up?

[Deleted User]

JohnB47 wrote: »

We had a guy come round and do various tests and he manually programmed the units to the best transmitter. Since then I've done exactly the same, manually tune to the one transmitter when new stations come along. Signal strength on all channels is excellent.

Presuming this is Freeview we're talking about I don't understand this manual tuning you're talking about.

Pull the aerial out of the back and do a full (automatic) re-scan for all channels, this will remove all channels saved. Then put the aerial back in and do another full re-scan.

JohnB47

Colin_Maybe wrote: »

Presuming this is Freeview we're talking about I don't understand this manual tuning you're talking about.

Pull the aerial out of the back and do a full (automatic) re-scan for all channels, this will remove all channels saved. Then put the aerial back in and do another full re-scan.

Yes, it's freeview. Manual is when you don't let the TV or HDR find what it thinks is the best transmitter channels. The guy knew which transmitter was best and he manually scanned-in each of the channels, meaning he selected the channels that he knew are used by this transmitter.

Doing an automatic scan would take me back to the start, where he said the units were confused and were selecting transmissions from more than one transmitter.

JohnB47

another_casualty wrote: »

Have you reset tv channels ? Has your recorder got a socket for an Ethernet cable ? Is your recording space almost full up?

Thanks. See my comment to Colin re tuning.

No, plenty of space (1Gb drive, only 20% used). No ethernet socket (so no, I can't copy the hard drive and reset/reformat the drive). Is that what you were thinking?

another_casualty

JohnB47 wrote: »

Thanks. See my comment to Colin re tuning.

No, plenty of space (1Gb drive, only 20% used). No ethernet socket (so no, I can't copy the hard drive and reset/reformat the drive). Is that what you were thinking?

I was thinking if there was an Ethernet cable , the signal would be stronger. I have a tv which is not smart. I have a humax recording device for freesat which has an Ethernet cable plugged in which so far,has been consistently able to pickup all channels .

Inner_Zone

another_casualty wrote: »

I was thinking if there was an Ethernet cable , the signal would be stronger. I have a tv which is not smart. I have a humax recording device for freesat which has an Ethernet cable plugged in which so far,has been consistently able to pickup all channels .

Ethernet socket will be for the Humax built in apps, has nothing to do with TV signal in this case.

another_casualty

Inner_Zone wrote: »

Ethernet socket will be for the Humax built in apps, has nothing to do with TV signal in this case.

Thanks for that .never knew that

psychic_teabag

JohnB47 wrote: »

I'm pretty sure I posted about this before but it will have been a few years ago. We have a Panasonic TV and Panasonic HDR. We record almost all programs and watch them later. We had a new amplified arial fitted at the same time.

We've had freezing problems since we bought these units - around 5 or 6 years ago. Everything goes fine then suddenly the picture freezes and then starts again a few seconds forward. The freeze can be momentary or up to two seconds. Very annoying. We had a period of a few months when almost no freezes occurred but recently they've started happening more often - perhaps one freeze every four programs. The freezes are recorded - I can go back and play again and the freeze occurs again. (Actually, my wife was watching live TV the other afternoon and had a couple of 'No Signal' breaks - it was snowing here so maybe it was that).

My guess would be that there was a glitch in the recorded (digital) video stream. The nature of video compression is that most frames are encoded as differences from the previous frame (and possibly in some cases from the next frame ?). It's only every Nth frame that contains the whole picture. So if there's an error in one of these key (?) frames (which the decoder can probably detect via checksum or something), it has to wait until the next valid full frame before it can start showing anything useful.

My system shows the occassional frame full of weird pixels, so maybe mine chooses just do draw whatever it got, whereas yours chooses to simply drop bad frames and wait for new data to come along. (Another misbevious my system has is premature ending a replay : it presumably misinterprets a frame header to be end of program, but if we just skip forwards, it can carry on from there.)

Because the glitch is in the recorded stream, it will do the same each time you play it.

Does your equipment have a way to show signal strength and error rate ?

Rodders53

Occasionally, too much signal can cause problems as much as too little... resulting in similar symptoms. Location/transmitter(s)? When did switchover occur for you?

Panasonic signal metering can be less than useful - depending on exact model of device... My older TVs showed 10 signal and 10 quality on signals before and after digital switchover when powers increased by 10x on my transmitter. My latest LCD TV from them in the bedroom is more useful, though. Precise models may help some with suitable knowledge advise?

Do these problems occur on ALL TV channels or only a select few? If so which channels? Check the metering on those channels (and also that the tuned frequency channel is for your preferred transmitter.)

(Recent changes to some transmitters for some services mean that they may now suffer from self-interference for some viewers. The need for a retune recently may be indicative of this. So a rough location and transmitter name(s) can be useful in diagnosing such.)

Lastly, electrical interference can cause similar symptoms... central heating thermostats and similar being a prime culprit.

It is always worth going over any hand-made aerial plug/sockets and re-making any loose or suspect ones. Many problems are caused by poor aerial connections. {Heating and cooling of connectors in use can cause poor connections over time.}