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Understanding DVD Compression?

Posted by ryuzaki0 on from the something-doesn't-quite-add-up-here dept.

canyon289 asks: "My friends and I created a full length movie using a regular Sony Camcorder. After importing and editing all of the video and audio in Adobe Premiere, the exported AVI comes out to 19 gigs. The length of the movie is 90 minutes. We tried compressing it with Nero Burning Rom to a 4.7 single layer DVD but when played in a standard DVD player theres pixelation and frame skips aplenty. Does anyone know how to fit the movie into a DVD (preferably 4.7) and still maintain adequate quality?"

11 of 114 comments (clear)

  1. No problem! by Wavicle · · Score: 5, Funny


    Just download your movie off the net. Someone will have shrunk it to fit on a CD-ROM.
    </sarcasm>

    --
    Education is a better safeguard of liberty than a standing army.
    Edward Everett (1794 - 1865)
  2. Cinema Craft Encoder by Anonymous Coward · · Score: 4, Informative

    CCE is the standard used in the rampant legal archiving of DVDs. Best DVD encodes I've seen of any of the major products. Nero has a quick and dirty encoder that is fitting 1hr-1:30 on a DVD5 with decent quality, but CCE sets the standard.

    1. Re:Cinema Craft Encoder by Sancho · · Score: 4, Informative

      You're incorrect, sir.

      First of all, DVDShrink doesn't drop frames. It modifies the coefficient data in the stream to reduce the overall file size. It leaves the motion vector information (which is really the hardest part of encoding) untouched. It is extremely fast compared to re-encoding because the bulk of the work is done. Nero has a very similar product, but it doesn't work on CSS-encrypted discs. In neither case are frames dropped--in fact, because they maintain the motion vector information, every frame is necessarily maintained in the output. These are considered transcoders.

      Nero also has an AVI to MPEG encoder you can use. This one might "drop" frames (or more accurately, there may not be a 1:1 correlation in frames between the two products) but it will still produce roughly 30fps NTSC output. This is a true encoder and will go through roughly the same steps as any other MPEG encoder (including CCE). The difference is that it's not really made for high-quality encodings. It's made for your average Joe to put his videos on DVDs.

  3. Multiple passes by tomstdenis · · Score: 4, Informative

    MPEG only specifies the decoder not the encoder. So

    1. Choose a quality encoder
    2. Use a high quality mode (if it has one) usually this enables more MV searches
    3. Use multiple passes if supported. This helps distribute the bandwidth where it is needed more.

    Mencoder [part of mplayer] can encode DVDs using lavc that look [for the most part] just as good as the original on a CD. It'd be trivial to get near losslessness in the size of a DVD.

    Tom

    --
    Someday, I'll have a real sig.
  4. Use another compression engine? Audio too big? by Sancho · · Score: 5, Informative

    You want a multi-pass, high quality encoder to create your output files. For video and on Windows, I suggest Tsunami Mpeg Encoder (TMPGEnc). It's been a few years since I've messed with any of this, but it was quite good and inexpensive 3-4 years ago. It does 2-pass encoding and can output any number of DVD-compatible formats.

    If you're still having problems, you might try reducing the resolution. DVD supports 704(720) or 352 vertical lines. Obviously quality suffers as you reduce resolution, but if you're having problems squeezing your content onto a DVD at 720 lines, you may just get an overall increase in quality this way.

    Also, you don't talk much about your audio. Is it raw audio (which is really big and uses up lots of room on the disc that could be devoted to video)? You may have good results compressing this, as well.

    I like http://www.doom9.net/ for all things video/dvd/vcd. They have a number of guides which detail the various methods of compression and burning. It's pretty likely that you'll find the tips you need there.

    1. Re:Use another compression engine? Audio too big? by towzzer · · Score: 5, Informative

      Like the other comments i recommend a high quality encoder, my preference is Cinema Craft Encoder. I've tried the nero encoder and anything i put it comes out looking quite horrible. If there is alot of noise you might need a bit of a smoother filter to help the mmpeg-2 compression. Try getting a program called avi2dvd, it does everything for you and you only need to input which encoder you'd like to use (free ones are provided).

  5. Feel free to adapt by Anonymous Coward · · Score: 5, Informative

    ffmpeg -i INPUT.avi -target ntsc-dvd 01.mpg
    mkdir dvd
    dvdauthor -o dvd -t -v 4:3 01.mpg
    dvdauthor -o dvd -T
    growisofs -Z /dev/dvd -dvd-video dvd
    rm -r dvd 01.mpg

    1. Re:Feel free to adapt by julesh · · Score: 4, Informative

      ffmpeg -i INPUT.avi -target ntsc-dvd 01.mpg

      I'd recommend, as a minimum:

      ffmpeg -i INPUT.avi -async 1 -hq -b 5000 -ab 224 -target ntsc-dvd -y output.vob

      Play with the numbers 5000 and 224 until you have an output file that'll fit on your 4.7gb disc. The formula is (number_of_seconds * total_of_bitrates) / 8 / 1024 / 1024 = megabytes of output. You'll need it to be less than about 4400. Aim for 4200 if you don't want to have to reencode if it runs too high, because ffmpeg is a variable-rate encoder that just aims for the target you specify and often seems to overestimate how much data it can put in.

      DVDAuthor's a great way of mastering the DVDs and learning to produce menus with it can be fun. Both of these programs work fine on Windows.

  6. You need to author first by seinman · · Score: 4, Informative

    Basically, you need to author your DVD. Authoring takes the AVI file output of Premiere, compresses the video to MPEG2, the audio to AC3, creates menus (if you want them) and prepares and burns the entire thing. Good authoring software does a MUCH better job at compression than the crappy encoder in Nero, since these programs are designed to create only video DVDs, whereas Nero is designed to do everything (and none of it particularly well). As you're already using Adobe products, you may want to try Encore. It's their DVD authoring application. However, if you're open to other options, I highly recommend Sony DVD Architect. Both of those programs will create splendid quality results; the difference is that Adobe's Encore will give you more options (but is harder/more confusing for beginners) while Sony's DVD Architect will be much easier to learn and use (however lacks some of the fancy features that Encore provides).

  7. File info by canyon289 · · Score: 4, Informative

    Oh yes. Im very sorry that I forgot to mention the details. Here they are. Pixels: 720 x 480 Duration: 1:30:32 Audio Bitrate: 1536 Kbps Audio Sample Size: 16 bit Audio Format: PCM Framerate: 29 frames a second (can't lower this anymore, The movie gets too choppy) Video Sample Size: 24 bit

  8. DivxtoDVD by 1u3hr · · Score: 4, Informative
    There are a bunch of forums to get you going. Slashdot isn't one of them. VideoHelp is one of the larger, and friendlier, ones, with links to tools and such. Afterdawn has a very good archive of software.

    Simple, free, one-click solution: DivxtoDVD. Fast and easy, quite good results.

    If you want to get into it more, you need Avisynth (to load the AVI, scale it, apply filters); a video encoder (I like HCenc), an audio encoder (like BeSweet), an authoring app (like GUifor DVDAuthor, finally a burning app (use Nero or whatever came with your burner).

    These are all free Windows software, you can do it all in Linux, but it's not so user-friendly. Most Mac users tend to use commercial software.