7 Replies Latest reply on Jun 1, 2011 11:20 AM by redbourn

    square pixels and fields?

    redbourn Level 1


      Hi,

      at the moment I'm downloading videos from various news sources and re-editing them to gain experience.

      The edited vids would eventually be put on a webpages.

      Should I choose "square pixels"?

      And how about the "field" ?

      BTW I had a couple of files that GSpot couldn't read and I downloaded MediaInfo and really like it.

      Any help would be much appreciated,

      Michael

        • 1. Re: square pixels and fields?
          Jon-M-Spear Level 4

          Legality and copyright issues aside...

           

          What is probably more important that specific field order and PAR issues is the fact that a PP sequence should contain assets of a similar nature.

           

          I tend to base a compilation-style master edit on the format of the majority of the material.  That will, to an extend determine whether the sequence is edited anamorphic/square, progressive/interleaved.  The assets that do not conform to the sequence format should be reformatted so that they do.

           

          Once a master edit is complete, it is in the transcoding that the various codecs can be applied.

           

          Web formats vary, even withinn a codec group.  PAR on h.264, for example, is governed by the source material.  720p is 16:9 anamorphic, whilst 1080p is square pixel.   All are progressive (I think) , ie, non-interleaved.

           

          If you do not know what format the source material is, in PP CS5 and 5.5, drag it onto the New Item icon in the Project Folder.  Do this with all the material you want to use and then make a value judgement as to the format you'll use to edit.

          1 person found this helpful
          • 2. Re: square pixels and fields?
            Jim_Simon Level 8
            720p is 16:9 anamorphic

             

            1280 x 720 is a square pixel 16:9 format.

             

            1440 x 1080 is an anamorphic 16:9 format.

             

            1920 x 1080 is a square pixel 16:9 format.

             

            There are no defined 720 anamorphic formats.

            1 person found this helpful
            • 3. Re: square pixels and fields?
              redbourn Level 1

              Thank you Jim and JMS.

               

              What about the fields issue, upper, lower or progressive?

               

              Michael

              • 4. Re: square pixels and fields?
                Jon-M-Spear Level 4

                Your choice.

                 

                Like I said, whether your timeline is progressive or upper/lower depends either upon the source material or what you want to edit in!   Interlacing was a means of displaying motion on CRT TVs. With things moving increasingly, if not totally, over to the LCD panel, the move is over to progressive (non-interlaced) outputs.

                 

                In the end it doesn't matter, provided it plays correctly without combing etc.  Because ofnits final use, almost all of my work is now output as progressive, no matter the format of the source material - however, I may have edited in an interlaced timeline.  It depends

                 

                You can usually detect whether the source material is interlaced by playing it. Premiere Pro does allow you to interpret the footage so that material of one persuasion can play in a timeline of another.

                 

                DV is always lower field (PAL and NTSC)., for example.

                 

                There are MANY internet posts discussing the pros and cons of interlacing.

                • 5. Re: square pixels and fields?
                  Jim_Simon Level 8

                  There's a whole lot of misinformation in the above post.

                   

                  For starters, whether you use a progressive or interlaced sequence will depend on your source footage, but should not be subject to the whims of "what you want to edit in".  The guideline is to use a sequence that matches your footage.

                   

                  Interlacing was not invented to deal with motion on CRTs.  It was invented as a way to save broadcast bandwidth - by sending only half the image at a time.

                   

                  As for the move to progressive because of flat panel TVs, that is also not true.  Both HDTV and Blu-ray specs were defined when CRTs were still the norm.  Flat panels became popular later.  So the majority of broadcasts are still interlaced (1080i), and while most Hollywood movies are progressively encoded onto Blu-ray, most consumer/prosumer cameras are recording 1080i/30, which is what ends up on your burned Blu-ray.  So interlacing is still very much with us.  Granted, either the Blu-ray player or the TV will be deinterlacing the interlaced signal for display on a flat panel, all of which are progressive displays by nature.  But the source material is still interlaced, and will come out of PP as such in many cases.  Web delivery is the one exception, where you will always want your output to be progressive, regardless of how it started out.

                   

                  Yes, DV is primarily LFF (PAL captured on a Matrox system being the lone exception), but all HD interlacing will be UFF.

                  • 6. Re: square pixels and fields?
                    Jon-M-Spear Level 4

                    I stand by what I said.  I fear that JS has read my post without interpretation.  Perhaps my fault for over simplifying.

                     

                    I merely implied that one must not get too hung up on the interlace/non-interlace issue - as modern editing allows the editor to deal with it easily.  Whilst it is the norm to edit in a way that best suits the source material, there are many, many occasions where a timeline must include material from different sources.  In these cases it is impossible to edit natively.  My point is that it simply does not matter.  There are easy workarounds.

                     

                    Likewise, I used shorthand in explaining CRT interlacing.  I didn't actually say it was to allow motion, I said that it was a way of displaying it.  I chose not to get bogged down in the technical reasons for it.

                     

                    As for flat panels  my comment still stands.  More codecs/formats are moving away from interlaced to progressive for many reasons.  One of these is the increasing predominance the flat screen  - whatever the reason, technology or transmission bandwidth issues.

                    • 7. Re: square pixels and fields?
                      redbourn Level 1

                      "Legality and copyright issues aside...".

                       

                      The vids that I'm downloading have embed codes but I stopped using links several months ago because the links often when dead.

                       

                      I do often tweak them though ;-)

                       

                      The overall sound is more often than not about 4-6 db on the low side and the timing on some of the cuts is terrible.

                       

                      When non-linear first came in a lot of younger guys took over from the older guys because they got a hold on the technology faster.

                       

                      The problem was that they'd never learned how to edit.

                       

                      Michael