HDV capture quality, am I expecting too much?

tzl99 wrote on 9/15/2006, 2:07 PM

Hi everyone,
I've been looking in this forum's messages going back to Nov 2005 to see if I can find a solution to my problem but I haven't so I've posted this to ask for help. I recently bought a Sony HDR-HC3 along with Sony Vegas Movie Studio + DVD 7 that I've upgraded to 7a, build 52. When I capture the HDV clips that I recorded in the last few days the image doesn't look as good as I had hoped. And it isn't as good as when I connect the camera directly to an HDTV and play it back. On the HDTV, the clips are great and everything I expected with HD.

On my computer it doesn't look as nice or sharp. It is similar to this post from "loganross":
http://www.sonymediasoftware.com/forums/ShowMessage.asp?MessageID=463011&Replies=2

I would like to capture and edit HDV and keep it in HD on a backup harddrive until someday in the future if I get a recordable HD-DVD drive. Occasionally, I'll make SD DVD for family. I've read the camcorder manual, the VMS 7 manual and as I said have looked at months of messages in this forum. I know this is a long post so I will break it in sections and wonder if anyone can point out what I'm doing wrong. My system specs are at the bottom:

1. I make sure I've recorded HDV on the camera and when I play back on the camera the display shows "HDV1080i" as opposed to "DV SP" when I tried some SD clips.
2. Under camera settings, I make sure the "i.Link conv" is set to "off" so it doesn't automatically convert to DV.
3. I connect the firewire cable to the motherboard's firewire port. It is listed as "Texas Instruments OHCI Compliant IEEE 1394 Host Controller". The camera shows up in Win XP SP2 in device manager under "Sound, video and game controllers" as "AV/C Tape Device".

(Interestingly, when I have the conversion of HDV->DV, it shows up under "Imaging Devices --> Sony DV Camcorder")

4. I start up VMS7, go "File->Capture video" and select HDV.
5. Under Project properties, I select the template as "HDV 1080-60i (1440x1080) 29.970 fps. Field order is "upper field first". I set the resolution rendering to "best". For deinterlace, I've tried none, interpolate and blend.

6. In the capture window, initially there is no device. Using the "Prefs" tab I pick device type as "IEEE 1394/MPEG2-TS Device" and then I see "Sony HDR-HC3" and select it.

7. Now I have control of the camera via the software buttons. I find my clip and capture it as a ".m2t" file.

Now here is my problem, when I view this file it doesn't look that great. I'm wondering if I need to select the capture bitrate? Is it too low? I have one clip of my cat that looks great on HDTV. It is just 22 s long and the "m2t" file is around 62-64 MB. Is that about right? If I capture the video with the "HDV->DV" conversion as an SD video it also is nearly the same size and looks quite similar.

In VMS under properties, it says the HDV clip is 1440x1080. The SD clip properties show it as 720x480.

I can play the "m2t" file using Nero Showtime (I have Nero 6.6.0.5). I can also play it back with VLC media player. Don't get me wrong, the videos look ok but not as sharp and detailed as the TV or I would like. Have I made any mistakes so far with the capturing?

On "Loganross"s post, he mentioned using Ulead VideoStudio 10 so I downloaded the trial version and used it to capture the same clip. It captured it as an MPG file with the properties of "1440x080, 29.97 fps, 25000 kbps" and it is about 68 MB so about the same. When I play both the Ulead capture and the VMS capture back, they look about the same to me. So if I have made a mistake in the way I've captured the video I hope someone here can point it out so I can correct it.

If I have been doing it properly, I guess this is as good as it gets with this software and the HC3 camera? BTW, I've downloaded the WMV HD clips from Microsoft's site and they seem to look better. Thanks for any help and sorry for such a long post.

tzl99 (Louie)

System:
Abit AN8-Ultra board w/ X2-4400 processor, 2 GB ram, nvidea 7800 GTX 256 MB card, using onboard Firewire port.
I have 2 internal drives, one IDE 160 GB w/ 60 GB free and 1 SATA 250 GB drive with 190 GB free. Both are defragmented and I capture generally to the SATA. I have a 320 GB external drive which I'll use for storage of the final files when done iwith them.
OS is XP SP2, fully updated as of Sept 12, 2006.

Comments

Tim L wrote on 9/15/2006, 8:29 PM

I don't have any experience with HDV, but perhaps I can offer some insight.

First of all, you don't have any kind of selection of download quality or bitrate when capturing your video from the camcorder. When you "capture" from a digital camcorder (via Firewire/1394), you are really doing a file transfer from the tape in your camcorder to your computer's hard drive. Your camcorder tape records digital 1's and 0's -- like a data file. When you capture this to the computer, your hard drive ends up with an exact, bit-by-bit copy of the data from the camcorder tape. Unless you are dropping frames during capture, the file on your computer should be 100% identical to the video on the camcorder tape.

Secondly, camcorder video almost always looks worse on the computer screen than it does on a TV. The reason is that almost all video is interlaced video, while computer displays are progressive displays. Normal HDV video is typically 30 1440x1080 "frames" per second, but it is interlaced, meaning for 1/60th of a second you see only the odd scan lines, and for the next 160th of a second you see only the even scan lines. "Interlaced" mode is how all old style tv's work, and how the 1080i HDV format works. You basically have 60 exposures per second, but each exposure has only odd lines, or only even lines (because the TV signals or videotapes do not have enough bandwidth to include *all* scan lines every 60th of a second).

However, interlaced video shown on a progressive display never looks quite right. Basically, the computer display shows both odd and even lines at the same time -- or show only odd lines with some interpolation of them to fill in the even lines, then show all the even lines from the next 1/60th of a second with an interpolation of those lines to fill in the odd lines. I'm not well educated in how the conversion occurs (bob and weave and blend...), but even standard definition video doesn't look as good on the computer screen as it does on a TV screen.

Now with Standard Definition, we would usually tell someone "don't worry -- edit the project, burn a DVD, and it will look great on the TV screen". With HDV, however, you don't (yet) have an option to burn a high-def DVD to see how it looks. Go ahead and edit a bit, and try either burning a standard definition DVD, or try to "print to tape" back to your camcorder, and when you view on a TV you might be more encouraged.

Perhaps someone with HDV experience will post with better information.

Tim L

tzl99 wrote on 9/16/2006, 1:47 PM

Tim L,
Thanks for the reply. I've been capturing analog video from cable for a few years now but this is my first camcorder. When I read a review on the HC3 here:
http://www.camcorderinfo.com/content/Sony-HDR-HC3-Camcorder-Review.htm

It discussed the fact that the camera compresses to MPEG2. Before buying the camera I had figured the mpeg file would just be copied from the tape to the computer. What threw me off was the process called "capture" which reminded me of capturing analog video. I wondered if the camera were playing the video and then the computer had to recompress it. I'm glad to know it is a bit perfect copy across firewire. Though if it is essentially a file transfer, I'm not sure why there would be dropped frames (though I haven't had any reported so far)? In the end, I suppose that means that the "m2t" files are MPEG files?

You're likely right about the image not looking as good on a computer monitor as it does on the TV. I'm going to take your advice and "not worry" too much this weekend. I'm going to string a few clips together and I'm going to see if I can "print to tape" back to the camcorder and then play the final file on the TV. If it still looks good (despite what it looks like on the computer) then I'll be happy.

Thanks for taking the time to reply and offering some reassurance, I appreciate it.

Louie (TZL99)