Compres Questions

[cigarsmoker]

Been reading all articles in DV for weeks now.

Still confused about one thing. Compresion.

I know we have all different standards when it comes to picture quality but.

I 'Capture' DV from my camcorder to DV AVI and due to the large file size I convert to MPG2 using main concept.

I cannot see any difference in quality myself but the main question is. Once re-encoded will there be further loss of quality when using video software IE Vegas. IE A minimum of 2 rencodes?

Does this also mean the quality of DVD camcorders is poorer to tape as this records in MPG2 on the fly?

Regards


Carl

[ZippyP.]

Any time that re-encoding (re-compressing) happens there will be some quality loss, it's best to avoid it if possible. If the bitrate is high enough then the losses can be minimized. I wouldn't say that the footage from DVD camcorders is poor, it's just not the right format if you wish to do anything but simple editting. You can do simple cut and splices without re-encoding, adding fades and transitions requires re-encoding of at least the transition portion.

[daamon]

Hi cigarsmoker,

Welcome to the forums...

If you're doing any editing (from basic trimming, to stuff like adding fades / effects etc.) then this is best done in DV AVI. This is because DV AVI is all I-frames. Only when you're finished editing should you go to MPEG2.

Although you can't see any difference (that's why MPEG2 is good), there is a difference in the way the video is represented. This post of mine will explain...

If you edit MPGs (which is tricky, coz the format isn't really designed for it) and then encode to MPEG2 again - yes, there'll be quality loss. Every time you're encoding you lose quality.

I can't comment on DVD camcorders as I don't own one, nor do I know exactly how they work.

Though, my guess would be that they're a gimmick (where the MPEG2 isn't as good as DV AVI) so the marketing can read "shoot the footage and play it straight on your DVD player - no fussing around in between".

The bit they don't tell you is that it's harder to edit etc. and so you get to see exactly what you shot - with all the mistakes in and no arrangement.

Hope that helps some...

[edDV]

I'll go a step further. DVD camcorders are a major step down from DV. They are for people who don't care about editing. Please don't come a crying after you make this decision.

http://www.masterdvd.com/sony-dvd-handycam.html

"However, as the video format for DVD is MPEG-2 rather than the DV Stream format used by most digital video editing applications. Legions of iMovie users are excluded from editing footage captured on these DVD camcorders because of the lack of a FireWire (iLink) interface, but Windows Movie Maker users are also excluded because Movie Maker can't import the MPEG-2 format. sony dvd camcorderHowever, Sony's thinking is not daft as it may seem. The vast majority of camcorder owners don't do anything with the footage they shoot other than watch it. They're not interested in importing it to a computer or editing it, or maybe they are but just never get around to doing it. For those people, who make up the mass market of camcorder owners, these Sony DVD camcorders could be ideal."

[cigarsmoker]

Yes thanks guys that all makes sense.

Read the other information you said and had to take some time off work due to headaches......LOL

I guess the last bit on DVD is right. How many people want to mess about with their video of the dog or family etc.

Ill keep the original tapes and struggle with the file size of the DV files. It was my intention to comp to MPG2 purley for backup.

Thanks for your help on this issue..