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Several Questions I am sure E-80 owners would like to know:

1. What does this mean and does it exist on this unit? When would you get lossless dub and under what circumstances?

2. On inputting our VHS tapes to HDD- Is hi speed dub better than xp for burning the DVD? Assuming the input is one hour xp or different configurations.

3. Should High speed dub ever be used for a resolution advantage with a DVD-R disc. On a Ram disc we know it is advantageous in speed and is quicker by about a half in burning. Does Ram give better resolution than DVD-R disc?

What kind of disc did Panny intend High speed dub to be for - Ram only? I have noticed that it knocks off only about 5 or 6 minutes on a one hour XP inputted DVD-R disc.
 

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"1. What does this mean and does it exist on this unit? When would you get lossless dub and under what circumstances?"


It means that when you record a program to the HDD in DVD-R compatible mode it can be losslessly dubbed (i.e., no re-encoding/no loss in PQ) to DVD-R as a straight digital transfer at a 1x data transfer rate ~1385 KB/s which requires about 56 minutes to transfer one full DVD disc's worth of data (since this is a constant bitrate data transfer, its 56 min regardless of the original recording mode, i.e, a 1-hour XP recording and a 6-hour EP recording will take 56 min to transfer). High speed mode also allows you to retain your user selected marker points as chapter stops.


If you don't use high speed mode, then there appears to be a re-encoding step when dubbing to DVD-R which could cause a small but barely perceptible degradation in PQ, the dub is done in real time (1 hour recording takes 1 hour, 6 hour recording takes 6 hours), and chapter stops are automatically placed at 5-minute intervals (user selected marker points on the source program are not transferred).


During both high speed dubbing and normal dubbing from HDD to DVD-R, the source program which resides on the HDD in DVD-VR format file structure (single vro file and ifo/bup files in a DVD_RTAV folder) is converted to playback deck compatible DVD-Video file structure (sequential 1 GB vob files, ifo/bup files in a Video_ts folder). During high speed dubbing this file structure transfer is done losslessly. DVD-RAM uses the DVD-VR format file structure. There is no difference in video resolution or quality between the two file structures. DVD-Video format is the standard video playback file structure used by standalone playback decks. Panasonic has incorporated DVD-VR support in all its players now to allow Panasonic DVD Record deck DVD-RAMS to be played back directly without the need to convert to DVD-R's.


"2. On inputting our VHS tapes to HDD- Is hi speed dub better than xp for burning the DVD? Assuming the input is one hour xp or different configurations."


You are mixing terminology. Hi speed dub is a means to transfer from HDD to DVD-R and is independent of record mode. XP is a record mode. The real question is whether high speed dub gives better PQ vs. real-time dub and the answer appears to be yes because a re-encoding step is not involved in a high speed dub. Plus you get custom chapter stops. Another option is to record in XP directly from the inputs to DVD-R (sometimes referred to as "on-the-fly" recording to DVD-R). This should theoretically result in the same PQ as a high speed dub but has the disadvantage that the resultant recording cannot be edited, you cannot set your own chapter stops, and if the recording somehow messes up during the "on-the-fly" recording process you may get a coaster or glitched recording forcing you to start from the beginning, in real time.


"3. Should High speed dub ever be used for a resolution advantage with a DVD-R disc. On a Ram disc we know it is advantageous in speed and is quicker by about a half in burning. Does Ram give better resolution than DVD-R disc?"


There is no resolution advantage with high speed dub on a DVD-R vs. a RAM disc. It has nothing to do with resolution or bitrate differences between the two recording mediums. See explanation to 1, above.


"What kind of disc did Panny intend High speed dub to be for - Ram only? I have noticed that it knocks off only about 5 or 6 minutes on a one hour XP inputted DVD-R disc."


Apparently, Panny intended high speed dubs for both DVD-R and DVD-RAM recording. See explanation to 1 above for the difference in recording file structures between a DVD-R recorded in DVD-Video format vs. a DVD-RAM recorded in DVD-VR format. The resolution and bitrate are the same in each case for a given recording (i.e., the video and audio streams are equivalent, assuming a lossless, high speed dub is used to record each from the same HDD source file). The difference in high speed dub data transfer rate (1x for DVD-R vs. 2x for DVD-RAM) is merely a function of the burning capability of the DVD drive installed in the Panny recorder. Note that the E100 will support 4x high speed dubs to DVD-R because the burner has been upgraded.
 

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Just to be clear, if we take HoustonGuy's parenthetical reference to "high speed" off his question, don't we also get lossless dubbing if you dub in the same mode as the original recording (eg., XP > XP, SP > SP ...)? This assumes the recording(s) fit disc capacity, but HoustonGuy's Q didn't specify otherwise.


I've picked up on the same mode lossless dubbing from other threads. I hope this is true because I've recorded programs to my HDD (E100) in XP with intentions of dubbing them to DVD-R in XP, being careful to stay within the DVD's capacity.
 

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We are not sure that non-high speed mode "same mode" dubs (e.g., SP-to-SP) are lossless. It appears that ALL real time dubs involve some re-encoding. I wouldn't worry about it, though, regardless of whether re-encoding does or does not take place for same-mode dubs, the PQ hit is arguably unoticeable. We can make the definitive statement that high speed dubs are direct digital transfers and are indeed lossless.


Vic
 
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