Panasonic DMR EX75EBS - recording problem - jerky video

A

avk

Guest
Hi, it is my first time starting a thread, so hopefully I have got it right.

I also have a problem with my EX75 which has occurred twice now. I recorded a film from C4 recently, one night in SP to HD. About an hour into the movie, it changed such that whilst the audio was OK, the video was only showing at a guess one frame in every two or three, with a resulting picture which was very jerky.

When the image went to black at the end of the film about an hour later, just before the credits started rolling the image came good again.

It happened again yesterday afternoon, recording I think More4. I think it might have recorded the affected content whilst I was watching back other content from the HD, but I am not sure.

I guess it could have been a problem with the London DTT mux on each occasion, but I am more inclined to believe there is an STB receiver issue.

The other issues I have are a single failed timer recording and picture drop outs occasionally on playback of HD recorded content.

Has anyone else had these problems I wonder? Also, is there a way to defragment the HD without a re-format of the disk?

Thanks
AVK
 

alan sh

Active Member
I get this with anything other than BBC1 on freeview - the signal quality from my "local" transmitter is awful and the picture goes jerky.

Alan
 

Gavtech

Administrator
Hi, it is my first time starting a thread, so hopefully I have got it right.

I also have a problem with my EX75 which has occurred twice now. I recorded a film from C4 recently, one night in SP to HD. About an hour into the movie, it changed such that whilst the audio was OK, the video was only showing at a guess one frame in every two or three, with a resulting picture which was very jerky.

When the image went to black at the end of the film about an hour later, just before the credits started rolling the image came good again.

It happened again yesterday afternoon, recording I think More4. I think it might have recorded the affected content whilst I was watching back other content from the HD, but I am not sure.

I guess it could have been a problem with the London DTT mux on each occasion, but I am more inclined to believe there is an STB receiver issue.
Welcome to the forum.

Faults of this nature are difficult to trace and diagnose... but seem almost invariably to be down to reception issues .. and can be caused by interference, which can be due to almost anything ... and may be just transient.

It is also known that unwanted data can sometimes get left in the buffers and cause problems. A power reset will usually clear such problems. [ albeit that loses the EPG until it is refreshed] .
The other issues I have are a single failed timer recording
Not a known problem. Can you describe the circumstances?
and picture drop outs occasionally on playback of HD recorded content.
Again probably due to a reception issue... I am assuming that the dropout was recorded that way - Could you reproduce the dropout by rewinding?

Also, is there a way to defragment the HD without a re-format of the disk?

No - Unfortunately not.
 
A

avk

Guest
Hello Gavtech, thank you for your constructive comments. Sorry for taking so long to respond. I can't quoite get the hang of how to apply quotes so apologies for not following the standard format.

Anyway in response:

Jerky Video:

Faults of this nature are difficult to trace and diagnose... but seem almost invariably to be down to reception issues .. and can be caused by interference, which can be due to almost anything ... and may be just transient.

I have a very strong signal being served by Crystal Palace about 7 miles away and have never had any issues with the DTT signal on an ancient ITV Digital PACE box.

It is also known that unwanted data can sometimes get left in the buffers and cause problems. A power reset will usually clear such problems. [ albeit that loses the EPG until it is refreshed].

If that is the cause, how can I reliably guarantee that I will be able to make a successful recording?

Failed timer recording:

Unfortunately I cannot describe the circumstances as I was not expecting the failure originally and I have been unable to repeat it.

Picture dropouts:

Again probably due to a reception issue... I am assuming that the dropout was recorded that way - Could you reproduce the dropout by rewinding?

The dropout is present in the recording, i.e. it repeats if I replay again. By dropout I mean a loss of a few frames. Due to the strong signal received, I am much more inclined to believe that this is due to the hard disk being unable to keep up, probably when moving from one part of the disk to another as it becomes fragmented.

Regards
 
A

avk

Guest
It has happened again - this time with Five (on freeview).

Has anyone elseout there experienced every second video frame being dropped leading to a staccato image but still have perfect audio?

Note: the image does not go black in between frames; it is just that each frame has a persistence roughly double the nomal display time.
 

Hal_loe

Active Member
I have a very strong signal being served by Crystal Palace about 7 miles away and have never had any issues with the DTT signal on an ancient ITV Digital PACE box.

If that is the cause, how can I reliably guarantee that I will be able to make a successful recording?

You are very close to the transmitter, depending how your TV aerial system is setup, you could quite easily be suffering from too much signal.

About 4 years ago, we decided to fit a new loft aerial and distribution amplifier.

We fitted the new aerial and new cables to each required outlet, aligned the aerial using the analogue signal...

The Freeview signal was useless (pixalation all the time) and the analogue signal had interference.

We only live 6 miles from our local transmitter. Luckily my dad spent a year helping setup OnDigital and said straight away we have got too much signal.

We fitted an attenuator and both Freeview and Analogue were then perfect.

When Digital switch over is complete and they turn the digital signal power up, we will have to change the attenuator to a larger one.

There is going to be a huge bunch of problems for people.

Hope that helps.
 

maldonian

Active Member
When Digital switch over is complete and they turn the digital signal power up, we will have to change the attenuator to a larger one.
I doubt it, and you may not even need an attenuator after switch off.

If an attenuator is needed now it's because the analogue signals are too strong, not the digital signals. Digital reception is affected because the very strong analogue signals overload the digital tuner's input. The digital signals are currently much weaker than the analogue ones (the digital transmitter powers are typically around 2% of the analogue transmitter powers at the same site). If the analogue signals weren't present the digital reception would probably be fine with or without the attenuator.

After switch off the digital transmitter powers will be increased, though possibly not up to the current analogue powers. Even if they are, the level of overloading that caused the analogue patterning you saw may not be sufficient to stop digital reception working.
 

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