6 Replies Latest reply on May 14, 2012 9:16 AM by Jim_Simon

    1080/60p -> Blu-ray help!

    ChasHertz

      I realize this issue has been previously discussed in multiple threads, but I’m still having trouble understanding, and would greatly appreciate any help

      The high definition Panasonic consumer camcorders (e.g. TM700, TM900, X900M) have five recording modes (not counting the recent addition of 3D and iFrame modes), specified as 1080/60p, and HA, HG, HX, and HE.  The manual is not very informative, but specifically states that the last four are all 1080/60i, with varying bitrates, HA the highest and HE the lowest.

       

      The consensus in this forum and elsewhere seems to be that if one wishes to output video to a Blu-ray disc, this is best done as 720/60p, as Blu-ray standards don’t support 1080/60p. I understand that part.  But then it is said that therefore one shouldn’t bother recording in 1080/60p (except for archival or possible future purposes), but rather in, say, HA.

       

      That’s the part I don’t understand.  What is the advantage of converting 1080/60i to 720/60p, vs 1080/60p to 720/60p? Naively (and I am really naïve, I’ll admit), it would seem that progressive -> progressive would be more straightforward than interlaced -> progressive, and that therefore one should go ahead and record in 1080/60p.  Am I wrong?  Can someone explain it to me?  Or point me to a thread where this issue is specifically discussed?

       

      Thanks.

        • 1. Re: 1080/60p -> Blu-ray help!
          Harm Millaard Level 7

          I simply shoot in the best format available on the camera, TM700 in 1920/50P, XF300 in 1920/50i 422 and let AME take care of the conversions needed for final delivery. BTW, I don't downrez to 720, but keep it at 1080 and adjust the framerate and interlaced/progressive as needed. (I'm in PAL land, hence the 50 FPS)

          • 2. Re: 1080/60p -> Blu-ray help!
            Jim_Simon Level 8

            output video to a Blu-ray disc, this is best done as 720/60p

             

            If you want 60p, then 720 is your only option.  However, Blu-ray fully supports 1080i/30 (which most, if not all, cameras incorrectly label as 60i).  So for Blu-ray delivery of HD content in ATSC-land, you can shoot...

             

            720p/24

            720p/60

            1080p/24

            1080i/30

             

            All four will happily go onto a Blu-ray without conversion.  (And "without conversion" is almost always the best option.)

             

            What many cameras offer that will NOT go onto Blu-ray is 720p/30 and 1080p/60.  So if you intend Blu-ray delivery, it may be best to avoid those formats, as they'll invoke the unwanted "conversion" to make them work.

            • 3. Re: 1080/60p -> Blu-ray help!
              ChasHertz Level 1

              I appreciate your comments.  I think you're saying that the X900M's HA through HE modes are not really 1080/60i, as the manual states, but 1080/30i.  Assuming that's correct, then the HA fomrat would be the way to go, IF I was certain that the intended output was for Blu-ray, in its present incarnation.  On the other hand, it would be nice to have the superior 1080/60p in archive, for possible future use in an updated Blu-ray standard that supported it, or some post-Blu-ray form.  (This is all personal stuff, it's not like I give something to the client and then just move on.) So I guess the question is, what do I lose by letting Premiere Pro do the conversion? Does it just take more time for Premiere Pro to do its thing, is some sort of artifact introduced, or what?  I know it's hard to quantify stuff like that, but can you give me some sense of the downside? The previous poster, Harm Millaard, doesn't seem to think it's a problem, though I'll have to admit that I'm naive enough not to know what "AME" means...

              • 4. Re: 1080/60p -> Blu-ray help!
                Jim_Simon Level 8

                the X900M's HA through HE modes are not really 1080/60i, as the manual states, but 1080/30i.

                 

                Exactly.  Technically speaking 60i means 60 interlaced frames per second, and there just is no such animal.  What they mean when they say that is 60 interlaced fields per second, which is the equivalent to 30 interlaced frames.  The issue is that saying "interlaced fields" is redundant, kind of like saying a female woman.  Nobody says that.  You say woman, or female, but not both.  Same applies here.  If you list it as interlaced, you don't also list the fields, always and only the frames.

                 

                 

                what do I lose by letting Premiere Pro do the conversion?

                 

                The best way to know is to run some tests.  If you can live with the converted video on Blu-ray, go for it.  If you find any artifacts that are objectionable, it might not be a good idea to shoot 1080p/60.  (The i or p should go before the slash, by the way, not after the frame rate.  That's another thing a lot of camera makers get wrong.)

                 

                AME means the Adobe Media Encoder.  It's the program that get's called up when you hit Queue from the export settings dialog.

                • 5. Re: 1080/60p -> Blu-ray help!
                  ChasHertz Level 1

                  Thanks very much.  I thought the i's and p's looked out of place, but I dutifully copied them that way from the Panasonic manual.

                   

                  Again, I'm pretty naive about all this, and my eyes aren't well trained to look for problems, plus of course it's hard to video two temporally separated sequences, one in 1080p/60 and one in 1080i/30, in precisely the same way.  Can you guess what kind of artifacts might be introduced, i.e. what I should be watching for in making the comparison of the Blu-ray outputs?

                  • 6. Re: 1080/60p -> Blu-ray help!
                    Jim_Simon Level 8

                    I don't have access to a camera that records 1080p/60, so I have no way to test.