Results 1 to 7 of 7

Thread: Lossless Capture??

  1. #1
    Join Date
    Apr 2004
    Location
    South Africa
    Posts
    13

    Default Lossless Capture??

    Quote from another topic

    "Capturing via DV (aka I1994, ilink or Firewire) is a lossless process - the video transferred from your camcorder is an identical copy of the original. "

    I certainly do not experience this. I use Premier Pro to capture using IEEE and the copy (AVI) is definately not the same as the original? I do not drop any frames during capture and receive Zero errors after the capture has completed.

    However, the copy has a loss in resolution, very jerky and when the camera moves a bit fast, the edges of images (people etc) are blocky or edgy and looks distorted.

    I have made ad DVD thinking that the quality will be good on playback using set top but it is exactly the same as the capture copy.

    Any ideas?

  2. #2
    Join Date
    Nov 2003
    Location
    Kent
    Posts
    11,514
    Blog Entries
    24

    Default

    This is the trusty "interlaced video" problem. And now for the brief explanation: when TV's were desigened, the technology wasn't able to build up a picture in one go. Instead, alternate lines of the display were scanned and shown as seperate frames. Thus, for 25 frames of video per second under the PAL standard, there are actually 50 interlaced frames shown.

    Now technology has progressed and video monitors are able to show progressive (or de-interlaced) video. As such, when monitors display interlaced footage, the alternate lines are displayed at the same time and you get a "keying" type effect. This is because two seperate parts of the video are played at once.

    So, to render video playable on a monitor, you need to de-interlace the footage. I believe DVDs play okay on a PC as software DVD players have built in de-interalce filters. I may be wrong. You shouldn't have to worry about de-interlacing if you're making a DVD.

    Phew, that was the quick and dirty explanation (not necesarily 100% accurate!)

  3. #3
    Join Date
    Nov 2003
    Location
    Kent
    Posts
    11,514
    Blog Entries
    24

    Default

    Oh, and the DV AVI is an identical copy as the AVI is just a wrapper for the data recieved from the camcorder. Any loss in quality in conversion from AVI to MPEG is due to the transcoding process. I suggest you read the sticky about DVDs in the DVD authoring forum. In addition, some people complain about the Microsoft DV decoder not being quite up to scratch. This results in DV AVI playback not being as good as it could be - but the actual data is there, so on conversion to MPEG2, everything looks perfect!

  4. #4
    Join Date
    Apr 2004
    Location
    South Africa
    Posts
    13

    Default

    Thanks for the reply.

    If I want to make DVD's that can be played on both TV and Monitor, should I always de-interlace?

    After editing the video in Adobe Premier should I first export to DV AVI and then export to MPEG2?

    I also don't think I am doing the export to MPEG2 correctly. The quality of the MPEG2 file is less than the DV AVI. What should the settings of export to MPEG2 be for the DVD to be the best possible quality?

  5. #5
    Join Date
    Apr 2004
    Location
    Houston, Texas
    Posts
    142

    Default

    I may be missing something but I think your problem is that mpeg-2's have a much lower quality because they're compressed.

  6. #6
    Join Date
    Nov 2003
    Location
    Kent
    Posts
    11,514
    Blog Entries
    24

    Default

    You can get high quality providing you use a good encoder and the correct settings. As with MP3 vs WAV, the alogrithms used in MPEG2 are such that to the naked eye ther (or ear!) there is no noticable deteriation in quality from the original. In practice, and depending on how many "key" frames (not the correct terminology, but gives the casual user a better insight) and the video bitrate, quality varies dramatically.

    A good start would be the quick guide to DVD encoding I wrote a made a sticky in the DVD authoring forum. To be honest, all this is covered much more comprehensively in previous posts

  7. #7
    Join Date
    Feb 2004
    Location
    Bracknell, Berkshire, UK
    Posts
    5,191

    Default

    Fungus,

    I would suggest that whiloe you're playign with settigns and finding what works for you that you use a re-writable DVD and only about a minute's worth fo video to save on render, encoding and writing times.

    If your aim i to produce a movie that's viewable on both monitor and TV then it's ahrd work as the two mediums are different.

    One comment of yours worries me is that you say the quality of watching the movie on the TV is still the same poor picture. Makes me wonder if it is a settign sissue rather than an interlacing issue. Unless your TV is progressive scan in which case it is acting much as a monitor would I suppose.

    When you've done your video capture and have a very large AVI file what is the quality like when you view that file - in media player? Presumably it is ok. If so then it is your rendering/edporting options that might need tuning. If that large avi file is poor then you have different problems - with the actual import process. using firewqire though, the avi should be an exact copy of what's on the camera.

    If you can extract a still from your movie showing the quality it might helps us here. IT will likely be obvious if it is just an interlacing problem or not from a decent screen capture.

Similar Threads

  1. Premier Pro Capture with ATI Rage Theater Video Capture card
    By Nolubez in forum Adobe Premiere, Premiere Elements, and After Effects
    Replies: 6
    Last Post: 01-15-2006, 07:37 PM
  2. Blank capture window, but capture ok
    By Incitatus in forum Adobe Premiere, Premiere Elements, and After Effects
    Replies: 6
    Last Post: 12-29-2005, 09:19 AM
  3. My video capture process is locked - can't capture
    By Lance2004 in forum Hardware Problems
    Replies: 0
    Last Post: 03-27-2004, 11:20 PM
  4. How do i capture my pc-screen using a video-capture-card?
    By hagbard in forum General video editing software help and advice
    Replies: 5
    Last Post: 12-04-2003, 11:12 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •