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Re: Mini DV transfers to DVDR:..what speed to preserve quality?

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videophile

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In Reply to: Mini DV transfers to DVDR:..what speed to preserve quality? posted by Waldteufel on March 28, 2005 at 13:09:46:

MiniDV is 25 Mb/sec motion JPEG encoded. This is a fairly high quality compression. To MPEG-2 transcode you will want to use the highest bit rate (quality mode) available to you. 2-hr bit rate will give you roughly the quality of a commercially mastered DVD, which I find to be pretty bad.

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Thanks, guess I'll just have to be more selective in editing... - Waldteufel 21:43:15 03/28/05 (2)
I was hoping to squeeze onto a single DVD, but will use 2 to be safe.
I was really surprised to see how much storage was required to store four 1-hr mini DV tapes on my HD...over 40GB! And here I thought 150GB was overkill! I trust VHS won't be as dense?
- Re: Thanks, guess I'll just have to be more selective in editing... - videophile 05:52:36 03/29/05 (1)
  It all depends on how much you compress the video. VHS is an analog format so there is also the question of how you want to sample it. The video bandwidth of a VHS recording usually limits the resolution to something less than D1 format (704x480). This, stored raw, would require a bit rate of around 240 Mb/sec, or over 100 GB per hour. The first thing compressors do is to convert to a luma/chroma color space and subsample the chroma 2:1 in both directions (humans are much less sensitive to loss in chroma resolution than luma). This cuts the bit rate in half. You might be able to get up to another 2:1 compression with a lossless entropy encoder. After this you will probably have to start throwing away information to get any more compression.
  - Wow, the plot thickens... - Waldteufel 07:03:23 03/29/05 (0)
    ...I would've thought VHS would be a snap. Looks like I'm going to need a whole helluva lot more storage than the 160GB I ordered with this G5. Every one of my VHS tapes has about 2 hours recorded. This is turning out to be a monumental project! Many of those tapes are 15 or 16 years old, which is why I want to preserve them for the kids. It would have also been nice to condense many hours worth of tapes to make a Christmas compilation that could be written to a couple DVDs. Sounds like that would involve an unmanagable file with my paltry storage. Wish I'd did more homework before ordering this MAC! I thought 1GB of RAM and 160GB storage was way more than I'd ever need.
    Thanks for enlightening me,
    W

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