VideoHelp Forum
+ Reply to Thread
Results 1 to 4 of 4
Thread
  1. Member
    Join Date
    Oct 2008
    Location
    United States
    Search Comp PM
    This may sound like a strange question but...

    I've taken the plunge and am recording and editing in AVCHD. I have my redundant backup library and love the fact that I can go grab a video off of an external hard drive to make a quick video. I only wish I had all my MiniDV tapes backed up this way but since an AVI from a MiniDV is 15GB/hour it would be a more costly use of hard drive space than AVCHD at 8GB/hour.

    Should I be concerned about a degradation in quality when converting a MiniDV's AVI to AVCHD?
    Quote Quote  
  2. aBigMeanie aedipuss's Avatar
    Join Date
    Oct 2005
    Location
    666th portal
    Search Comp PM
    probably not a drop in quality. most DVavi is used for dvd creation and compressed to mpeg-2 at under 8mbps and looks great. avchd at the same bitrate or higher will look fine.
    --
    "a lot of people are better dead" - prisoner KSC2-303
    Quote Quote  
  3. Member edDV's Avatar
    Join Date
    Mar 2004
    Location
    Northern California, USA
    Search Comp PM
    DV is more like 12.5 to 13.5 GB/hr.

    I'd only convert the material that you or your heirs don't intend to enhance or edit in the future. There will be some loss converting to h.264 and you will lose individual frames in the conversion to MPeg GOPs. Audio goes from uncompressed to compressed.

    Hard drives are getting so cheap I don't understand why conversion is worth the time needed to do it. Rumor is 1TB drives will be offered for $99 on Black Friday.

    I'd keep the tapes. Store in a cool dry place.
    Recommends: Kiva.org - Loans that change lives.
    http://www.kiva.org/about
    Quote Quote  
  4. Member vhelp's Avatar
    Join Date
    Mar 2001
    Location
    New York
    Search Comp PM
    I don't think you'll find any other codec format that compresses smaller than DV. Its a very tight codec. Never the less, there is also H264 (aka, x264 cli) that you might consider provided that you don't use any compression (ie, b-frames, etc) in it and only use the near lossess attributes:

    with -qp 0 I compressed a 1 minute demo DV sample down even further though not by much. The demo dv original (direct stream copy via virtualdub) was 225MB, and after running through the following:

    --> x264 -qp 0 --- plus a few other settings left over from experiments

    I managed a final filesize 211MB of near lossless mp4 video. That took roughly 2 minutes to process that one minute dv sample. Still, at this time it is not possible to examine the encoded mp4 for comparison purposes against the dv sample because nothing (no tools) seem to be able to open these lossless-ly.. least not that I have found out, so far. So, I can't really give you a difinitive number in terms of PSNR or how much of *real* lossless there actually is between the mp4 vs. dv sample

    Hmm.. a 1-TB drives will give you roughly 77 hours of dv storage. I don't know if thats considered enough for most people that deal with tons of video content every day, especially when video dealings churn like a convayor belt in everyday use. I mean, look at dvd recorders w/ HDD's. People have been going out and replacing their internal one for larger ones so they can get even more hours (in the hundreds) on them, and they are still not satisfied. I think that once you go past the 1-gig mark, we become too greedy and want more. I don't know.

    -vhelp 4911
    Quote Quote  



Similar Threads

Visit our sponsor! Try DVDFab and backup Blu-rays!