DV and VHS cap file sizes

[newbie]

Don't know if it's me or my mind playing tricks on me. I'd captured 1.5 hrs of (PAL) DV at full DVD resolution, the file size is ~30GB. I'd captured
2 hrs of (NTSC) VHS at 640x480 and the file size is 55GB+ ... both are
with Huffy codec. Am I missing something here?

[twodogs]

DV is a codec. Huffy is a codec. You can't use both at the same time.
Suggest that the 30gb is DV and the 55gb is Huffy. Sounds about right to me.

[newbie]

You're right. I couldn't use Huffy with DV capture. The difference here is PAL DV and NTSC VHS. Could it be the VHS has more frames to capture (because NTSC) and as the result produce bigger file size?

[twodogs]

No. Changes to frame rate (like this) do not have a significant impact on file size.
Your difference is in the codec. Huffy compression ratio is about 2.6:1. DV is about 5:1 (but dont take these figures as gospel)

[Dragonsf]

90 min DV (PAL) capture should result in max 18GB and not 30GB.

[Gristle McThornbody]

DV should end up at about 13GB an hour (NTSC). You must not be using a DV codec to capture your footage. Check your settings. It would also help to know what program you are using to capture with.

[Dragonsf]

DV should end up at about 13GB an hour (NTSC). You must not be using a DV codec to capture your footage. Check your settings. It would also help to know what program you are using to capture with.

that's what I said:90min=1.5hours=5400*3.5MByte/s=18.9 GByte.

[dilligaf]

DV should end up at about 13GB an hour (NTSC). You must not be using a DV codec to capture your footage. Check your settings. It would also help to know what program you are using to capture with.

that's what I said:90min=1.5hours=5400*3.5MByte/s=18.9 GByte.

That's a practical size too, I capped my first video yesterday to DV, 19~20Gb for 94 mins.

[newbie]

Thanks all for you replies. Actually, I cap my PAL DV clip with VirtualVCR through analog card. I couldn't not get a good quality with firewire capture (?).

With VirtualVCR and analog card, I'm able to use Huffy as codec. Apart from NTSC has more frames than PAL (for a given length), I don't have an explanation for the difference in file sizes!

[TODD]

I have noticed that when my DV files are converted to VCD or SVCD, they look much worse than my VHS conversions. I think that since the DV file has much more sharpness than than the VHS file, the limited bitrate is used up much more quickly, and the quality dimishes. A blur filter would therefore help. For your situation, the added sharpness of the DV capture (even through analog RCA) results in a larger compressed file size. Same thing occurs with jpg compression of still images: more complicated scenes take more room.

[newbie]

Thanks Todd,
I'm having exact same problem as you mentioned. That is, could not get a decent quality with VCD from my DV capture. In fact, it's worse than VCD captured from VHS.

Mind tell me what exactly did you do to improve the VCD quality from DV capture? I'm thinking of going for low res DVD (video bit rate of 8000) from DV.

[kitty]

Anyone who gets used to the full resolution of DV will look at the resulting squished low bitrate VCD and say it's not great quality. Many go to SVCD but DVD is the ultimate.

Your encoder may have alot to do with it. I found Pinnacle to produce horrid VCD from DV. TMPGenc was much better.

[newbie]

kitty,
I'd tried with all sort of different mpeg encoders but still could not get a decent VCD quality. I also tried with different capture cards to be sure that it's not the card. Since I don't have a DVD burner so I can't go for DVD. Now I realise that it has to be the bitrate of VCD. I will have to go for CVD or low res DVD. The reason I refused to go for CVD/SVCD is their file size.