DVD-RAM files and PC dvd players vary footage lengths !

[Merlin]

I have noticed that the footage length of a VOB file sitting on my PC HDD became shorter after it was Quickstream fixed (QSF) by Videoredo. In fact it was now back to the length of footage still on the Panny EH50 DVD/HDD combos hard drive. This original footage surprisingly became longer in terms of mins and secs when dubbed to DVD-RAM, remaining at that longer length once onto PC, until quickstream fixed !

Why is this and how are the inconsistent footage length results below explained, are we all seeing footage at non design lengths when writing vhs to dvd ?

I decided to carry out some experiments comparing files before and after Quickstreamfix (QSF) which give rather interesting results :-

Test_1 Camcorder footage , VHS-C placed in caddy and played from VCR onto Panny EH50.


PC Player digital VOB file PC digital mpg file PC after QSF
Videoredo 25m43sec 24m51sec 52secs faster (loss of 3.37% on length)
PowerDVD 24m51sec 24m51sec no loss but both are the shorter length !!!
WinDVD 25m46sec 25m04sec 42secs faster (loss of 2.7% on length)
Win_MediaPlayer cant Play 24m50sec
CreativeLabs cant Play 24m50sec

So two progs see the original VOB file as 25m43s and one sees it the same length before/after QSF !...also two different shortage rates.

Test2 Again amcorder VHS-C footage saw no change in footage length this time. It matched the original on the HDD of the Panny. WinDVD though saw it 10secs quicker before and after QSF.


VHS cassette pre-recorded cassette..
file played on the Panasonic DMR EH50 DVD/HDD combo ..... 30m57sec
file played on the Panasonic DMR EH50 DVD/HDD combo after dubbing to DVD-RAM..before RAM disc removed ..... 31m41sec...thats 44secs longer (after dubbed to RAM

PC Player digital VOB file PC digital mpg file PC after QSF
Videoredo 31m41sec 30m59sec 42 secs faster (loss of 2.2% on length)
PowerDVD 30m59sec 30m59sec no loss but both are shorter length !!!
WinDVD 31m24sec 31m02sec 22secs faster (loss of 1.16% on length)
Win_MediaPlayer cant Play 30m59sec

Three of the QSF results match the original HDD file on the Panny, and interestingly PowerDVD for the VOB file sees its length prior to the DVD-RAM dubbing !
Videoredo sees the DVD-RAM length and after QSF creates the HDD file length which three players recognise.
WinDVD this time sees the VOB file as longer than the original on the HDD, in test_2 it saw it as shorter !!!


In Summary, comparing footage times within one programs clock system.
Videoredo sees shortening of footage in Tests 1 and 3
WinDVD sees shortening of footage in Tests 1 and 3
PowerDVD sees NO shortening in Tests 1,2,3 but times are shorter, longer, shorter respectively of those evident
WindowsMediaPlayer sees the QSF file length like Videoredo does, which for tests 2 and 3 is the length of the original on the Panny HDD (perhaps also for Test_1 if only I had not erased it off the HDD)


Importantly what is noticeable in BOTH lots of camcorder footage is that the QSF footage is visually too quick !
One cannot say that QSF has recreated the true length and speed of the footage. In tests 2 and 3 the resulting footage matches that on the HDD though !!!
Thus can one in fact say that without QSF, footage will be the wrong speed, being too slow when first written to DVD-RAM as VOB and copied onto the PC.
That means anyone not using Videoredo for QuickstreamFix and just chaptering up VOB files and burning to disc will end up with slower than original footage.


I have spoken to Panasonic who mentioned that differences from camcorder could be due to the footage being made of scenes, but that doesnt explain why the pre-recorded continual footage tape shows time differences.

Timebase correction between the VCR and the Panny was then mentioned, yet I understood there was no need for such when doing my research and buying the unit.

Try the footage from camcorder straight to the panny they suggested.

Merlin