12-25-2003,11:59 AM
As long as it is a compliant DVD stream, it will play them. This could be an issue with the software used to generate the DVD. The usual cause for problems is actually the burn speed vs. the media compatability against the drive's firmware. Check the stickies about athe test utility for Pioneer drives. These utilities work on all DVD recorders, it's just that the issues were mostly with Pioneers at the time. For testing, it is usually best to go at 2X on generic media to start with. This is the first place to look since it is the most common, and easiest to remedy.
Some encoding issues/fixes to consider when creating movie DVD's:
1.) If backing up originals, you'll need to DeMacro/DeCSS the source while ripping it to the Hard Drive. There are some utilities that claim to be able to do this and copy directly to DVD-R on the fly, but it is always best to rip it to the HD first and then re-encode/burn it to DVD-R in a seperate process. This ensures a clean, consistent burn--as well as more accurate decryption. An excellent tool for this process is DVDDecrypter. It now has an ISO mode that you can use for copying DVD5 and PS2's as an image and retaining as much of the source as possible. Decrypter can also burn ISO's directly to a blanc disc.
2.) If generating your movie streams from homebrew movies, you need to make sure it meets the DVD MPEG2 specs. The source can be any format that your encoder supports, but the audio/video needs can be a bit limited. Typically, the audio should typically be mpeg/PCM audio (mpa/wav) 224+ kbps, 44.1/48 Khz. The video stream needs to have a decent minimum speed--especially if using a variable bitrate. 750 KBps should be the minimum used to ensure the buffers stay full and keep your transitions (black screens especially) from pixellating or going green in the black parts. Maximum bit rate can be whatever you want, but it is a good idea to cap it around 7-8 MBps to keep the files from getting too big. Only go higher if your colors are not accurately transferred or if you are getting heavy pixellation. You should use a high quality motion search also to prevent this. Yes, it slows the process down, but can make a big difference in quality.
3.) GOPS's and filters should be set to industry standards unless you have a need to increase quality to match the source. Remember you are resampling your source. Chances are (for the most part) you will have a slight decrease in quality. The GOP's can be adjusted to compensate a bit (fewer B frames), but it will send your average bit rates upward, so you will have to balance this against your file size to make sure it fits on the DVD. I find running just I and P frames is the simplest way to do this if you have the head room. You'll know if this is an issue because you will see the quality of the picture cycle up and down in a pattern. The quality of the frames basically flows downward from I->P->B. The standard format is a cycling IPBBPBBPBB... structure. So if your B frames are really crappy, you'll notice it. Dropping the B frames entirely will wipe it out, but will shoot the size up. If this gets too big, try increasing the P, and dropping the B to 1 (IPBPBPBPBPB...).
If you notice the motion segments are stuttering/skipping it is likely due to interlacing settings. In many cases, interlacing is not needed and is on by default in encoders because they were primarily designed for duping interlaced DVD's. It is usually corrected by running DeInterlace. You will notice duplicated frames when you run it in slow motion if interlace settings are an issue. Sometimes deinterlacing can cause dropped frames and images will appear to jump around on the screen. In this case, you need to run interlacing to catch the dropped frame. This can be tricky because sometimes there is actually a "half-frame" with staggered lines and a full frame without. Both these images can reference the same frame, or one can be the transition between two solid frames and you have to capture the right frame(s)--A or B search order, and sometimes it vary and you need a smart filter that can detect which one (auto setting). The original PeterPan DVD was famous for interlacing snafus. Sometimes you'll have to also choose from Field or Search order, depending on how it is done. Field search can be more accurate, but Frame is usually fine.
4.) Don't encode and directly burn to DVD-R--invest in an RW for testing. Alternately, you could burn all files to your hard drive first and preview them (it is much faster). If your application doesn't have that ability, try running them through another app that does to test the different settings. There is a great VCD encoding tool you can get for free that you can use to test this. It can import different streams, but is geared towards AVI, MPEG1, and MPEG2 streams. TMPGEnc can be found all over the place, and will run SVCD for 30 days, but runs VCD encodes indefinitely for free. You can process a 5 minute clip of the movie and play it back in just about any media player to see how the video looks. When you have the interlacing/GOP locked down, set these options in your DVD creation program and let her rip.
This is a very condensed (believe it or not) version of the processes involved, more info can be gathered at several other sites. A few good ones to bookmark:
http://www.riphelp.com/articles/dvdripping.html
http://www.digital-digest.com/dvd/articles/index.html
http://www.dvdr-digest.com/software/...download&cid=3
http://www.dvdsoft.net/modules.php?n...orderby=titleA
http://www.elby.ch
http://www.dvd-recordable.net/module...ads&file=index
Good Luck
Raist
If it ain't broke don't try to fix it! But, hell if you can tweak that bastard just a little bit more....hehehe.