DV tape duplication?

[einsi]

Can i duplicate dv tapes by connecting two dv cameras directly via firewire-caple?

[jtor]

YES, as per a minidv camcorder's manual. Haven't tried it though, as I don't have a second minidv camcorder.

[yg1968]

I haven't tried it either but I believe that you should be able to do it provided that your digital camcorder has a "DV in" (which is usually but not always the case).

For a Sony camcorder, the first camcorder must have "DV out" "enabled" in the options in the camcorder's menu and the second camcorder must have "DV-out" "disabled" in the options of its menu. You also need a firewire cable (4 pin-4pin).

In any event, you can also make a DV tape duplicate through your computer:

1- import the DV to your hard drive through firewire
2- export the DV through firewire
3- record with a new blank tape

You can use a number of programs to do this. For example DVIO can do this.

[gmatov]

Can you tell me how big a file a DV tape makes?
My kids have them, but I've never copied to the 'puter.
They're only an hour long, aren't they?
Thanks.

[Jester700]

Yes, they're only an hour, but at 3.6MB/sec, it's a LOT of space. Somewhere around 14GB.

[gmatov]

Jester 700,
Now, that's ridiculous. If I'm not mistaken, DigiVideo cams only have about a 1/3 of a megapixel resolution CCD, about normal TV quality. At least that's what the ads for cameras that spec the CCD say, which makes you wonder what the super telephoto, 27 optical X 7000 digital looks like. That's not a quote, but I've seen a few that say something like that, about a 170000 total.
Something 35 miles away looks like it's on the end of your nose. At 7000 digital, they'd have to use the center 4 pixels, and then I guess it would BE like on the end of your nose, and you crossing your eyes to see it. Be about as clear as that would be on a TV screen.
I'm probably talking out my butt here, but I haven't seen any long tele shots from one of these things. I'd better reserve my judgement, and go try out my kid's camera. Maybe I'll be pleasantly surprised.
Thanks.
George

[MpegEncoder]

gmatov,

I'm not at all sure what that rant was all about, but Jester700 was correct. It's about 13 gig/hour for DV-AVI. Also, my TRV320 is about 1/2 megapixel resolution.

[yg1968]

You pretty much need an extra hard drive for video. But don't forget that this file is temporary as you will delete it once that you export it back to a DV tape or that you encode it to mpeg .

[Jester700]

Yes, they're about a third of a megapixel. A bitmap of that size is about a meg. Times 30 frames per second. That would be 30 megs uncompressed, not including timecode and other info. Good thing DV is compressed, eh?

[MpegEncoder]

You're right about that! I almost choke when I see some people here calling DV-AVI "raw" or "uncompressed". That would make an hour of video about 120 Gig, even without the audio!

[Jester700]

Actually, the 320 doesn't use all 460k for video. Much of that is for EIS. You REALLY get about 290k, IIRC. Which is on the low side for DV cams, but very good for the price. I like my TRV120.

[MpegEncoder]

I'm not sure what you're getting at here. The size of the CCD is not relevant to the DV-AVI "file" that your camcoder spits out over the firewire. Regardless of the number of CCD pixels the camcorder has the DV-AVI file that you get is 25 megabits per second.

[gmatov]

Thanks, all,
No, my comments on the size of the CCD are about the resolution of the finshed pic seen on the screen, not so much the size of the file. I haven't seen much of this stuff, particularly on Large Screen , projection type TVs. On a 25 or so, the pic is very good, I guess, at least what little I have seen.
Another grand coming in a few months, so I think I'll be seeing more, and, if I want a copy, I'll be working with it.
What size file will I wind up with at best resolution-best movie quality, should I render to SVCD, or, should things work out, to a Sony DVD burnt disk?
Storage-work space is no prob, as, if I need it, I just get another drive. With my ATA card, I have room for 3 more devices, 2 HDs and a burner. I should do that soon, as the 200gig on this mach is pret' near ate up. Since I own most of the DVDs copied onto it , I probably should delete them and just work from the disks.
Thanks, again.
George

[Jester700]

If you're going to watch on a big screen, I would definitely go for a DVD burner. I mean, if you're buying a big screen anyway, what's another $300?

[gmatov]

Jester,
Oh, heck no. I'm not interested in a big screen. My 25 is more than adequate for what I watch and to see the results of rips. I have asked a friend, who uses a Sony DRU500? ( he's updated the fw a couple times ) to test my VCDs, made with Flask, and with DVDx2.0, and who has a 52 inch HDTV, to judge the quality. He says they are quite watchable, even at that size.
No, I'll be satisfied if I can count fingers and toes, when I get around to playing with DV.
Now, am I mistaken in assuming that their camera is DV just because it uses the small tapes, and has a view screen to review the results of a video?
I don't know, as they aren't even sure of the make and model, as they told me a couple hours ago when I took 'em to dinner. I do know that it's the format that you can't buy the adapter to play in a VCR. Hell, I may still be in analog mode, in which case, at least, I do have a little experience. I have capped and edited tapes and TV, and with the info freely given in these forums, am learning how to turn into ( S ) VCDs, and someday, into htg DVDs.
I'll keep reading this stuff. Most of you guys are sharp as tacks at this. I learn something every time I come here.
Thanks.
George

[gmatov]

MpegEncoder,
I'm a little confused by the DV-AVI file size you mention. Surely, a larger number of CCD pixels has to make a larger file, which I can accept will be compressible to X, assuming that a DV-AVI file should be X. But doesn't that mean the result is more highly compressed, thus more is lost, thus the final result will be of lower quality?
My basis is that my 3 Megapixel Olympus Best quality JPG is about 1.8 to 2.1 meg file, whereas my son-in-law's 1 meg Olympus best quality is approximately 275 kilobytes.Doesn't DV compression work the same way? If it does, that would explain why they don't, since CCDs for cameras are way up to 6 or 7 MP. Compress that to fit a TV screen's res, and it would result in a purple (whatever) blotch.
Ah, well. At least I'm getting an education, here.
Thanks.
George
BTW, I took out my Pinnacle card to try my Hauppage Win TV, I forget which, I burned the box, and can't do diddly with it. Back to Pinnacle, this for the 1800XP. Ramble, ramble.

[Jester700]

Jester,
Now, am I mistaken in assuming that their camera is DV just because it uses the small tapes, and has a view screen to review the results of a video?
I don't know, as they aren't even sure of the make and model, as they told me a couple hours ago when I took 'em to dinner. I do know that it's the format that you can't buy the adapter to play in a VCR. Hell, I may still be in analog mode, in which case, at least, I do have a little experience. I have capped and edited tapes and TV, and with the info freely given in these forums, am learning how to turn into ( S ) VCDs, and someday, into htg DVDs.
George

If the tape is 2 inches or so on the long axis, it's a DV tape. If it's 4 inches or so, it's 8mm and could be digital (Digital8 format, same video specs as DV) or analog 8mm or Hi8. the presence of an LCD screen doesn't mean anything in this case.

Even if it's digital, you CAN cap it in analog with a range of resolutions & bitrates if you have an analog capture card and the cam has analog outs. It's just that digital transfer allows the least quality loss and so people usually use it if they have the capability.

[Jester700]

MpegEncoder,
I'm a little confused by the DV-AVI file size you mention. Surely, a larger number of CCD pixels has to make a larger file, which I can accept will be compressible to X, assuming that a DV-AVI file should be X. But doesn't that mean the result is more highly compressed, thus more is lost, thus the final result will be of lower quality?
My basis is that my 3 Megapixel Olympus Best quality JPG is about 1.8 to 2.1 meg file, whereas my son-in-law's 1 meg Olympus best quality is approximately 275 kilobytes.Doesn't DV compression work the same way? If it does, that would explain why they don't, since CCDs for cameras are way up to 6 or 7 MP. Compress that to fit a TV screen's res, and it would result in a purple (whatever) blotch.

It works different with vid than with stills. A digital video camera will output the resolution of the format. A DV or Digital8 transfer over firewire will be 720 x 480 no matter what the CCD res is. A high quality 3 chip DV camera can take full advantage of that resolution, whereas some of the cheapest single chippers can't. This results in less apparent video resolution (blurrier, "softer" image) on the cheaper cam, even though the DV file STILL has a res of 720 x 480.

It's like if you took a one megapixel still and resized the image in Photoshop to be twice the size. You'd have a higher resolution file (and greater file size) but no greater *apparent* resolution.

[MpegEncoder]

Very well put Jester700,

Bigger CCD = better quality not bigger file size

[gmatov]

MpegEncoder,
I think that's what I was trying to say, tho it may have been roundabout. A megapixel CCD would provide a better picture, uncompressed, than a 300k.
Strike that. I just backed up to Jester700's comment. A meg CCD, 1100 X 900 for simplicity, would compress to 720 X 480, approximately 350k, whereas his TRV120, 290k effective, has to interpolate to fill the screen, thus actually slightly degrading the result? Am I way off base here? Or is it just enlarging the picture itself to fill the screen, becoming "coarser" as an enlarged and cropped digi photo would do, no interpolating involved?
Mebbe I should stick to VHS, but this subject's so damn fun and interesting. I've got the gear, and it is keeping me from getting bored, tho sometimes frustrated.
Thanks,
George

[tomclary]

George,
You seem to be over complicating the subject. Digital Video is 720x480 regardless of the size of the CCD. The size of the CCD does have an effect on how good those 720x480 frames look but that does not bear any relation to how much disk space is taken up. DV is compressed a standard amount so the data transfer rate is constant and hence the disk usage.

If the video camera is digital, the tape format does not make much difference as long as the camera has a firewire interface. Is anyone aware of a consumer digital video camera that does not have a firewire aka ilink aka IEEE1394 interface? I can't think of one but then I have not looked. So if you don't have one already, get a firewire card for your PC and capture away. It will be more fun to play with on the PC than doing a camera to camera copy anyway.

Tom

[gmatov]

Tom,
I get your meaning on the size of the file. DV is DV, and requires processing of X meg of data to produce a picture to fill the screen with Y number of scan lines, 30 times per second. In addition, I presume, to a set aside of X for audio.
Now compressed a standard amount means to a standard size, no, meaning the bitrate can vary? Depending on CCD? Not to be ludicrous, and definitely not argumentive, if the CCD was coarse enough, no compression would be necessary, whereas a megapixel CCD requires compression to achieve the required bitrate. Just as DVDx sets 1150kbps for VCD, and 2376 average for SVCD to be compliant. Am I lost, or am I getting the drift?
On another note, I've finally made some SVCDs, because no-one could play my VCDs on their machines. Programs had told me a 2 disk VCD would require 4 disks in SVCD, and I balked at making my kids change 3 times to watch a 1 1/2 hour video. It doesn't seem to work that way. I am getting a third partial disk, max, and that is gratifying. As I have Dish and they don't, I can share movies that they can't get, and they can watch at their leisure. After I get them done, any how.
Hey, this IS fun.
Thanks. Nobody is even bitchin' that I write too long, either. Wow!!
George

[Jester700]

Tom,
I get your meaning on the size of the file. DV is DV, and requires processing of X meg of data to produce a picture to fill the screen with Y number of scan lines, 30 times per second. In addition, I presume, to a set aside of X for audio.
Now compressed a standard amount means to a standard size, no, meaning the bitrate can vary? Depending on CCD? Not to be ludicrous, and definitely not argumentive, if the CCD was coarse enough, no compression would be necessary, whereas a megapixel CCD requires compression to achieve the required bitrate. Just as DVDx sets 1150kbps for VCD, and 2376 average for SVCD to be compliant. Am I lost, or am I getting the drift?George

Think again of the still shot. If your final res after resizing was 720 x 480, it doesn't matter whether you started with 5 megapixels or 100 x 100. It would always end up as 720 x 480. Now with stills it IS different, since the jpg compression algorithm would make the size of the file that began life as 100 x 100 much smaller because of all the redundancy. DV doesn't work that way (though MPG does), so ALL DV files are 3.6MB/sec.

CCDs and their attendant electronics are a whole 'nother ball o' wax, since you're interested. A single megapixel CCD can't really give you 1000 x 1000 pixels in color. In B&W, yes. But to make color, there is a color grid across the CCD that reduces the resolution somewhat - not 1/3 as you might suspect, but reduced nonetheless. A 3 chip camera can give you the full resolution of the CCDs - this is why the pro cams are all 3 chippers. Naturally, given ENOUGH resolution a single works great - I imagine a single 10 megapixel CCD could handily beat a 3 chipper with 1 megapixel chips. And the CCD size plays a role - the more light it can gather, the less noise, especially in darker shots. But then there are issues besides the CCD itself - the electronics, the optics, etc.

[gmatov]

Jester700,
I'm afraid I've been talking about the wrong subject. You guys are talking DV, Digital Video, per se, and I have been thinking DVD, or the result of manipulating the DV file to make a compliant DVD. I think this is where I've been getting confused on compression. I've been talking about rendering to DVD compliant files, not the original 14 gig that the camera captures. These files would be deletable after rendering to DVD files, and I assume these become vobs(?) after rendering, or 1 giant vob? ( I have a file that was ripped with, I think VOB, that actually IS one giant vob. I hope I can convert it someday.)
Anyhow, if we take this to be my tack, you guys are all getting through to me.
Sorry to be so dense.
The chart says 25 mb for DV, and 3 to 8 (variable?) for DVD, which I assume means anywhere from 3 to 8-to 1 compression, no?
Thanks,
George

[Jester700]

Well it specifically means 3-8 megabits/sec - a megabit being 1/8 the data of a megabyte. But this also works out that the DVD compatible MPG2 file is 3 to 8 times compressed.

[tomclary]

George,
I will try to outline the process so you understand. There are more detailed guides for the various steps involved.
1) First you capture the footage from the Digital Video camera. It will be in DV format which is 720x480 pixels/frame, 29.97 frames per second, compressed a fixed amount for a data rate of 3.6mb/second.
2) Do any editing on the captured video.
3) Encode the video to MPEG-2 for DVD usage. The DV video is not needed after this point unless you decide to change the encoding parameters. Here is where there are a world of possibilities in how the data is encoded. How much it is compressed, what quality, etc. You seem more familar with still images, it is similar to specifying what quality you save a JPEG as which relates to the size of the file and picture quality.
4) You take the encoded video and use a DVD authoring package to create menus and chapters if you want and that package will then create the DVD Video related files such as the IFO and VOBs from the files you created. This can then be burned to a writable DVD and if all goes well, played on a stand alone DVD player.

You might want to try the 30 day trial of Ulead DVD MovieFactory. It supports the whole process from capturing the DV video, menus, chapters, MPEG encoding, and then mastering the DVD.

Hope this makes the picture a bit clearer for you.

[gmatov]

Jester700 and tomclary,
Clear as glass now. We were talking at crosspurposes, before. I was assuming we were on DVD, and we were talking "raw" DV data. And I get the bitrate from V and SVCDs.
I already own Ulead's DVD Workshop and Video Studio 6, plus a few more Ulead programs. They would never detect my Pinnacle card to allow me to use it, so I did my captures with the Pinnacle software. Now that I've changed to the Hauppage card, ( which I actually bought for my grandson's machine ), I'll try Ulead again. Mebbe it will allow me to use it for capture and edit, and hopefully, a better conversion than I've gotten from the Pinnacle program, although the "movie" was not terribly bad if you didn't expect DVD quality.
I hope I'm not out of line ( the warnings that we do not talk "this" in this forum ) if I ask you 2 and anyone else who can help, why, when DVDx says I am making a compliant V or SVCD, when I burn with Nero, it says not compliant and wants to make compliant. Something IS wrong, because they play in too few standalone DVD players. "No Disk". If this is verbotten here, which forum should I be in?
Thanks, again. Since they don't use it much, mebbe I'll ask to borrow my kids' Video Cam and play with it.
George

[tomclary]

George,
I have only used the Ulead software with a firewire card and digital video camera. So I don't know if it works or how well it works with a video capture card. I do know it works with AVI files so you could capture it with whatever software works with your capture card and then use the Ulead software to master the disk.

As to your other questions, I suggest you create a new thread in a more appropriate forum just because you will get quicker and more informed answers. This topic has drifted from the original topic. I have a DVD burner these days and never did more than dabble with VCD's and their variants.

Tom