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Discussion Starter · #1 ·
Can anyone describe the exact nature of the problem that the 30K exhibited when it "goes bad."


The reason I ask is that I'm recording MPEG-2 HD Transport Streams back to D-VHS from a PC.


The recording goes perfectly. My software shows very minor fluctuations in the outgoing bit stream.


When I play the tape, it plays fine for awhile. Then the blocking starts. Small blocks. Some times whole rows block. Then the the picture clears up for awhile. The it goes bad again.


Interestingly, if I capture to a PC while the playback occues, there are huge decrease in the bit rate while the pix degrades.


Or, put the other way, something in the deck seems to "slow down" which causes the bit rate to slow.


Sounds like a deck problem, BUT -- if I record other Transport Streams -- captured from the deck -- during the rcording the bit rate does NOT vary. And, there are no problems playing these streams back.


I don't know if we ever learned what JVC fixed. But I suspect that it is a control-loop problem. I think, when the transport encounters any variation in bit rates it can't compensate properly. In my case, the bit rate variations might be IN THE SOURCE. In other cases, it might be residue issues--hence the cleaning tape.


Any ideas? Can someone confirm what the 30K problem looked like?


By the way, the problem streams go back to an HDV camcorder and playback fine. Perhaps the transport control is better in the MiniDV camcorder.
 

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There was a bug that would exhibit this slow down that you describe in the earlier versions of the TSP2SP.ax filter. What version do you have? You should have the 1.1.7.8.2003 version. If you have an earlier one, you need to upgrade.
 

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Discussion Starter · #3 ·
I don't have this on my XP system. I do have:


MPTS2PKT.ax

PKT2MPTS.ax


In any case I'm using the Womble MPEG2VCR to convert PS to TS. It seems not to use this filter.
 

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Sorry, I assumed you were using DVHSTool or some other software that used TSP2SP.ax. So what do you use to send the TS to the JVC?
 

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d-v-c,


Forum member Robena has done a lot of work with Womble MPEG2VCR and has reported problems with the transport streams it generates. He has been working with the vendor to get the issues ironed out but the last word was that it wasn't quite ready for prime time.


--Jerome
 

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Discussion Starter · #6 ·
1) After converting PS to TS (under Virtual PC) I use the DVHScap software under OS X to send to the deck.


2) I have had zero help from Womble. Part of the problem is that so few folks know of D-VHS and even fewer know about HDV. So many folks use these tools for ripping DVDs, not for HD. :(


3) And I haven't found a Womble group.


4) But I'm still wondering what the 30K did when it played badly?
 

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Quote:
Originally posted by d-v-c


4) But I'm still wondering what the 30K did when it played badly?
I'm not convinced at all that this is a JVC issue. I would suspect a bug in either the womble or DVHSCap software. The thing that you describe usually happens when the timestamps are incorrect and so the data is sent to the deck slower than real time. The deck happily records the slower data and you get what you get when you play it back.
 

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Discussion Starter · #8 ·
Quote:
Originally posted by leszek1
The thing that you describe usually happens when the timestamps are incorrect and so the data is sent to the deck slower than real time. The deck happily records the slower data and you get what you get when you play it back.
Are you saying the timestamps control the sending of data out i.LINK?


If so, I wonder why I can watch the signal as it is being recorded--and it is perfect.


Or, are you saying the deck records the stream with the bad timestamps--and then when the tape is played, the timestamps are used. And, since they are wrong--the playback is screwed up?
 
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