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I've been capturing VHS and TV at full D1 for the last year or so. Today I decided to try 1/2 D1 for VHS to see how much more I could fit on a disk. I created a 2 hour disk with half D-1 and I could only fit about 20% more video on the 1/2 D1 disk than full D-1. Is that about right?
Is there any other advantage to capturing at 1/2 D-1.
And if I capture direct from TV rather than VHS, is there any quality loss using 1/2 D1?
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Assuming you are capturing MPEG2, use VBR with average bitrate of 4000 and max of 5500. VHS has a maximum resolution of something less than 300, SVHS is a maximum if 360. Capturing at 352X480 (half D1) will give excellent results, anything more is not noticable. Using a bitrate more than 4500 average in half D1 will be wasted.
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File size has nothing to do with resolution. Its all down to bitrate and playing time. Use a bitrate calculator.
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> File size has nothing to do with resolution. Its all down to bitrate and playing time.
In that case, why would anyone ever use 1/2 D1? If it doesn't make smaller files then what difference does it make?
And, while I don't want to dispute you on something you probably know more about than me- I captured the same 30 minutes of video at full D-1 and 1/2 D-1 using the exact same settings for capture. As I wrote above, the 1/2 D-1 file was about 20% smaller. Since the only thing different was the resolution it's hard for me to believe that resolution has nothing at all to do with file size. -
Well, depending on what software u use to encode, if in VBR mode it doenst sound too far fetched that it would reduce the file size...
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At 1/2 D1 you can use roughly half the bitrate to get the same approximate quality as at full D1. Thus roughly half the file size. Some people report a noticeable difference in appearance between 1/2 D1 and full D1 from VHS sources. Others not. In my experience, I notice it being slightly softer in appearance, but an acceptable compromise considering the difference in file size.
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1/2 D1 uses a smaller resolution (352x480) than full D1 (720x480). With this smaller resolution you can use less bitrate without getting blockiness, artifacts, etc. I use 3000k average and 4000k max. for 1/2 D1. For full D1 I use 6000k average and 8000k max. Theoretically this will produce app. 1/2 the file size using 1/2 D1. However you have to take into account high and low action scenes. Do a test with the stated above settings on 4-5 minutes of the same video and note the difference of the finished file size. 1/2 D1 on standard tv or vhs with the above settings will give good results. For digital cable or satellite the source is higher quality so full D1 will give better results. You won't get better quality by raising the resolution of the source video but you will get a larger output file because of having to use a higher bitrate to accomodate the higher resolution. You have to match the bitrate with the resolution to get end results.
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Thanks for the replies. Guess I'll just experiment with bitrate on a few videos and see what I like.
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A big part of it is how you cut down from your capture to half-D1. If you just resize a 720x480 file to 352x480 using a resizing algorithm, it will take a long time and not look so good. The clip should be cropped to 704x480 (8 bits per side), then resized.
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If I had to resize or re-encode I wouldn't waste the time. I capture with MovieMill and it allows me to capture directly to 1/2 D-1.
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Does this capture directly to mpeg-2 and do you have any controll over the bitrate it uses to encode your videoOriginally Posted by BobK
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20%? Then you didn't do it correctly. For 1/2 D1 use an average of 2500 and a peak of 5000. You should be right at 4 hours per DVDR. That's about all I capture to anymore. Since all my TV's are under 27" there isn't much point of going full D1.
I capture a lot of animated stuff, as well as action. Currently I'm capturing Tripping the Rigt, Stripperella, Soprano's and Sex and the City (2 are done for the season, but I'm missing eps). Never a macroblack to be seen. I also never capture to MPEG2, since it's a waste of effort(unless you go allI, then what's the point?). Analog TV captures nearly always benefit form noise filtering, capturing to MPEG2 defeats that purpose.To Be, Or, Not To Be, That, Is The Gazorgan Plan -
> 20%? Then you didn't do it correctly.
Probably not. But that was just a test to see what difference there was. I captured both at the same settings (4700) to see there was a difference. I'm sure if I capture the half D1 at 2500 or even 3000 there'll be a bigger difference from full D1 at 4700.
I capture to mpeg 2 for several reasons. The biggest one is the capture card I currently use will only capture to mpg 1 or mpg 2. The 2nd biggest one is that I'm not interested in spending hours to convert to mpg 2 after capturing.
> Since all my TV's are under 27" there isn't much point of going full D1.
Not unless you plan to get a bigger TV someday. -
>>I capture with MovieMill and it allows me to capture directly to 1/2 D-1
> Does this capture directly to mpeg-2 and do you have any controll over the bitrate it uses to encode your video
Sorry- I missed that question the last time.
I use Movie Mill with a Snazzi III PCI card. It does capture directly to mpeg-2 and you can set the bitrate to whatever you want before you start the capture (you can also set the peak bit rate, resolution, and frames per GOP).
It also has 3 options for input video filtering but I don't really know much about them. I just check the 'Input is VCR' box since I'm capturing from video tape mostly.
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