4 Replies Latest reply on Feb 25, 2014 2:44 PM by DavidGaryEsp

    HD 25p to SD 50i: Best Process (Re-Interlace?)

    DavidGaryEsp Level 1

      Goal: Given footage (in a matching sequence) at HD 1920x1080 25fps, make a SD DVD at best quality.



      • The stated sequence is itself nested within a mastering sequence in order to convert to a format appriopriate to a SD-PAL DVD. 
      • The mastering sequence is 720x576 50i (meaning 50 interlaced fields per second), consistent with PAL.  The nested sequence is downscaled via its Motion properties.
      • Additionally, within the mastering sequence, a Fieldskit Reinterlacer effect is applied to the nested sequence.


      Have I done it right?  Is it a reasonable process?  Is there a better way to get the maximum resolution while avoiding flickering?


      Thanks for any pointers.

        • 1. Re: HD 25p to SD 50i: Best Process (Re-Interlace?)
          Ann Bens Adobe Community Professional & MVP

          I would leave the sequence at 1920x1080 25p and export to mpeg2-dvd 25p.

          1 person found this helpful
          • 2. Re: HD 25p to SD 50i: Best Process (Re-Interlace?)
            DavidGaryEsp Level 1

            Thanks Ann.


            I had noticed the progressive option (for DVD) but wondered (still do) whether that is only ok for modern flat screens (that most people have).  Presumably (?) it would not look so good (maybe shaky or ghosty on motion) on an old CRT TV, or indeed via some ancient DVD players?.  If so then I guess I could add some fine print to that effect, on the label.


            Incidentally my process did work, albeit taking 2 hours (at 98% of all 8 hyperthreads on my 4 core laptop) to render a 3 minute subset of the master sequence.  At that rate it would take around two full days to render the 1 hour overall sequence.  For greatest reinterlacing purity (at cost of processing) I had selected ReInterlacer's "motion estimation" mode.  I hope it was working subsequent to the frame size reduction.


            Your method of course worked far more quickly - about two-thirds of real time (2 mins for a 3 min sequence-selection).

            • 3. Re: HD 25p to SD 50i: Best Process (Re-Interlace?)
              Biggles Lamb Level 3

              Your finished mpeg2 or mp4 progressive vids will look OK on a HD flat screen.


              If you kept at HD it will look great.


              Premieres HD to SD down conversion is not the best especially if there is a lot of fast motion.


              I would stick to Bluray and forget DVD if you can.


              A HD TV will upscale a SD input and a growing number of players upscale.


              As a reminder in future use sequences that match the source and output as required.



              • 4. Re: HD 25p to SD 50i: Best Process (Re-Interlace?)
                DavidGaryEsp Level 1

                Trouble is, for one particular job the client specifically wants standard def.  That requirement is justified - I went to a meeting where people representative of their audience were present, and got the same response.  Hardly any of them have blu-ray viewing capability (whether or not they have flat screen TVs).  It is quite possible that they mostly have ancient but still functional DVD players on SCART connectors etc., or even analog modulators feeding RF to their favourite veteran CRT TVs.


                For that audience, my original aim was to use the HD sequence to generate an HD product eg straight H264 for computer-based viewing (since most have computers) and then nest that same sequence within an SD sequence, (re-interlaced) to produce a standard interlaced SD DVD, compatible with old CRT-based TVs.  I'm concerned how a progressive format DVD might appear in that scenario, so would be interested in anyone else's experience with that.


                In a few years time, when most of the audience's equipment has hopefully advanced, I might well drag the project back out of archive, to render the same video (or a derivative of it) in blu-ray or whatever most of them have by then (might even be streaming).  But for now it is not required.


                Multi-standard customers dictate a multi-standard workflow.