20 Replies Latest reply on Jan 3, 2008 4:17 PM by (ElvisLives)

    CBR more compatible?

      Been learning on Adobe forums that there's a lot more to transferring VHS to DVD than meets the eye! One thing I haven't read here (that I've read elsewhere) is that CBR encoding produces a more universally readable disk than VBR. Am I nuts? Maybe I've misunderstood the whole thing.

      Thanks in advance.
        • 1. Re: CBR more compatible?
          Jim_Simon Level 8
          I haven't found any difference, and would not believe someone who said they did.
          • 2. Re: CBR more compatible?
            John T Smith Adobe Community Professional & MVP
            To Burn Error Proof DVDs (Well, close to error proof!)

            • Use the SLOWEST possible burn option your burner will allow in Encore, since it is much better to take a bit more time burning the disc than it is to burn "fast" and have a disc that won't play
            • Set the VIDEO portion of the transcoding options to a Maximum of 7,000 so your burned disc will have a better chance at playing in desktop players (which support burned discs, if at all, only as an "after thought" of the DVD specification)
            • Use AC3 or PCM audio transcode settings for best player compatibility (some discussion of MPEG audio not being supported by all players, especially for NTSC discs)
            • Buy and use Taiyo Yuden (or Verbatim?) brand blank discs
            • Read this ENTIRE message Concerning Replication
            • And this one About Authoring and Playing a DVD
            • Discussion of Peak Bitrate
            • Here is one Bit Budget Calculator
            • 3. Re: CBR more compatible?
              akribie Level 2
              If you have a LiteOn burner, Kprobe 2 is very useful to judge burn quality and error rates.

              My Kprobe analysis with Ritek media suggests that it is better to burn DVDs at their rated speed than more slowly, contrary to advice frequently given in forums.

              I'd be interested to know if others have test results to support the 'burn slowly' suggestion.
              • 4. Re: CBR more compatible?
                Ruud Blauw Level 1
                David,

                The results from tests done by the German computer magazine c't (tests only available in print) consistently show better readability when DVDs are burned with a lower than rated speed.

                These tests were performed by AudioDev , a professional optical media testing outfit, using specialized and very expensive testing equipment. While utilities like KProbe and Plextools can give some indication of the quality of a burned disc they can't give an accurate picture - simply because a real test requires calibrated, precision hardware.
                • 5. Re: CBR more compatible?
                  Level 1
                  Maybe I'm revealing my ignorance here (won't be the first time), but Jim's first response: < I haven't found any difference(between CBR/VBR disc compatibility), and would not believe someone who said they did > seems to be the consensus and the conversation seems to have morphed into a discussion of the stability of discs burned at faster/slower speeds. Which is a good conversation. So, VBR encoded discs play as reliably as CBR encoded discs, all things being equal I presume.

                  Thanks.
                  • 6. Re: CBR more compatible?
                    Curt Wrigley Level 4
                    > So, VBR encoded discs play as reliably as CBR encoded discs, all things being equal I presume.

                    Assuming VBR rates are set appropriately as described earlier. I find people manually tweeking vbr settings tend to screw them up more easly than cbr.

                    Assuming they are equal; consider this; There is no advantage to vbr if the program will fit on the dvd useing a good cbr rate. cbr will encode much faster.
                    • 7. Re: CBR more compatible?
                      Harm Millaard Level 7
                      > There is no advantage to vbr if the program will fit on the dvd useing a good cbr rate. cbr will encode much faster.

                      Even though the latter statement is 100% correct, the first part is not correct. There is a definite advantage in multi-pass VBR for instance with dissolves, which are notoriously hard on the encoder. 2-pass may not show significant advantages, but they are there, albeit with much longer encoding times. When you use 9-pass encoding with Cinemacraft encoder, you will surely see a large improvement in quality, as well as a large increase in encoding times. In general it depends on your footage and the time available what you choose.
                      • 8. Re: CBR more compatible?
                        akribie Level 2
                        VBR also seems to give reduced motion artifacts for rapid movement in shot.

                        Key to success is to keep the maximum video rate down to a value that gives headroom for audio and doesn't stress the player too much, and to keep the minimum high enough to give clean results. Some players don't like higher data rates, so depending on playback requirements you may need to sacrifice best quality for wider compatibility.
                        • 9. Re: CBR more compatible?
                          Jim_Simon Level 8
                          >Some players don't like higher data rates,

                          Another myth. ALL DVD players can handle the maximum bitrate as defined by the DVD standard. This myth came about apparently because some players have trouble reading some disks, and their error compensation can't recover fast enough. A lowered bitrate gives the apparency of a solution. But it is a false solution in my opinion.

                          Using three simple guidelines, I maintain that you can make a disk readable at any allowed bitrate on any DVD player.

                          1. Always use good media.

                          2. Use a good burner.

                          3. Use the proper format. (Some players prefer -R, some prefer +R)
                          • 10. Re: CBR more compatible?
                            Curt Wrigley Level 4
                            > There is a definite advantage in multi-pass VBR for instance with dissolves, which are notoriously hard on the encoder.

                            Perhaps so. But the large majority of the audiance here uses encore or other consumer based encoders which dont offer 9 pass encoding. Ergo the nature of my statement.
                            • 11. Re: CBR more compatible?
                              akribie Level 2
                              Most problems I've come across with skipping due to data rates close to the DVD rated maximum has been with computer replays on older equipment rather than standalone players, and sometimes due to the audio decoding overhead rather than the video stream.

                              And I find that burning as DVD-ROM seems to be more compatible across the range of players than straight +R or -R.
                              • 12. Re: CBR more compatible?
                                Level 1
                                There are some divided opinions on these issues, but I'm going to summarize the answers I'm going to run with for now (Looking for widest disc compatibility/best quality in a big VHS->DVD job at the moment). Anybody can lemmeknow if any are invalid conclusions:

                                1) Use CBR of 7000Kb/s if your project will fit on the DVD. (Quality of dissolves will be the same as a VBR with a max rate of 7000Kb/s, plus you'll save encoding time)
                                2) Notch down burn speed one step from the maximum allowed for a more reliable burn
                                3)DVD -R provides better compatibility with older players
                                4) Use quality disks, ie. Verbatim. Pick a disc using Phthalocyanine or Metal-Azo dyes for longevity
                                5) Use a quality drive.
                                6) When I have to use VBR for projects longer than an hour, set minrate as high as 4Mbs, maxrate at 7Mb/s, and jiggle the target rate 'til it fits. Maybe lower the minrate as low as 2.5Mb/s(?) to avoid having to go below a 5.5Mb/s(?) target rate.

                                Did I get it all? Thanks.
                                • 13. Re: CBR more compatible?
                                  Phil Griffith Level 2
                                  I would go down more than a notch from highest burn speed.
                                  • 14. Re: CBR more compatible?
                                    Jim_Simon Level 8
                                    I think you can safely go over 7 max for VBR if you need to. I keep mine at 8.6 for video all the time without issue. But overall the guidelines look very usable.
                                    • 15. Re: CBR more compatible?
                                      Ruud Blauw Level 1
                                      >This myth came about apparently because some players have trouble reading some disks...

                                      Which doesn't make it a myth but truth. :) Yes, ALL set top DVD players should be able to support the spec maximum of 9.8Mb/s (audio + video) when reading from a replicated/pressed DVD, but no DVD player is required to work with burned discs.

                                      I have had to author DVDs (and re-author maxed out discs made by others) for clients who were using these players that have problems reading from burned discs. Good burner, good media, not-too-fast burn speed and a moderate bit rate usually does the trick. XD
                                      • 16. Re: CBR more compatible?
                                        Jim_Simon Level 8
                                        The myth part is that the disk can't be read at that bitrate. When in fact a better burn on better media using a format the player likes will work perfectly fine at the same exact bitrate.
                                        • 17. Re: CBR more compatible?
                                          Bill Heslip Level 1
                                          I would never bank on a $39 DVD player to be able to maintain maximum bitrate, although you may get away with it most of the time (the spec is not always a priority in China as we've learned from lead-laden toys).

                                          Laptop playback is even touchier, so I use a max of 6.5 for those devices. As for burn speed, I'm very conservative using only 2x. This insures a disc with fewer errors and extends the longevity of your burner. As for burned discs not being part of the spec, well, I disagree.

                                          Oh, and only Verbatim used here.
                                          • 18. Re: CBR more compatible?
                                            Jim_Simon Level 8
                                            I would bank on the $39 player to handle the maximum, at least if it displays the DVD logo I would.

                                            The issue has been having trouble reading some disks, and not being able to keep up. Lowering the bitrate takes off some of the pressure to keep up when errors occur, so it was falsely assumed that the DVD player could not handle the higher bitrate.

                                            The actual problem was that the player had trouble reading that disk. When you create a disk that the player can read by using my three guidelines, then that same player has no trouble keeping up with any legal bitrate.
                                            • 19. Re: CBR more compatible?
                                              Bill Heslip Level 1
                                              >The issue has been having trouble reading some disks, and not being able to keep up. Lowering the bitrate takes off some of the pressure to keep up when errors occur, so it was falsely assumed that the DVD player could not handle the higher bitrate.

                                              Unusual logic, as the end result is the same.
                                              • 20. Re: CBR more compatible?
                                                Level 1
                                                So there you have it... 15 responses and 15 different answers. :)

                                                I truly believe you're all wrong. For every burn you're at the mercy of the employee who happened to bo on duty during the making of the DVD media and player. :)