9 Replies Latest reply on Jul 31, 2010 1:29 PM by the_wine_snob

    How to correct pixel ratios?

    freethedata Level 1

      I quote the following from the Adobe Elements 8 Editor Help file on the topic, "Capturing or adding various aspect ratios":

       

      "If a specific type of image is consistently misinterpreted (distorted) when you add it, you can add to or change the entries in the Interpretation Rules.txt file by using a text editor, such as Notepad."

       

      I found the Interpretation Rules .txt file, and changed the ration for 720x480 frame files.  But this is a read only file, so I can't save the changes.  Besides, it does not appear as though Premier is accessing this file, since the default value for 720x480 files evaluates to "0.9" there, but Premier is actually using "0.9091".  So my question is:  How do I actually change the uniform rule for pixel aspect ration interpretation?

        • 1. Re: How to correct pixel ratios?
          Steve Grisetti Adobe Community Professional

          You should get my book! It's much more helpful than those Help files!

           

          You can only set up a project's settings when you first start the project. After that the settings are read-only.

           

          If, in the midst of a project, you need to change a clip's pixel aspect ratio, right-click on it on the timeline and select Interpret Footage.

           

          This only changes the PAR for the clip, of cours. Not for the entire project. But it can make fitting a clip into a project using another pixel aspect ratio.

          • 2. Re: How to correct pixel ratios?
            freethedata Level 1

            I did that.  When I created the project, I set the project setting to "NTSC-DV-widescreen", which is associated with a pixel ratio of 1.2121.  Yet when I got the media for the project, it displayed in the monitor window squeezed into a 4:3 frame with black sidebars.  When I rightclicked on the image thumbnail under the "project" menu for properties, it showed a ratio of "0.9091".  When I rightclicked on "interpret footage", it showed that the pixed aspect ratio defaulted to the ratio from the file, even though when I created the project, I selected Widescreen, with a project ratio of 1.2121.  This is very confusing.  Why is the project ratio being overridden by the file ratio?  Then I thought that "file" in this context might be the Interpretation Rules.txt file referred to in Help, which then has to be changed.  If not, then what do I have to do to get the widescreen image?  I can't change them one-by-one by clicking on each file and reinterpreting the footage, because there are over 120 small files, all widescreen, and that would be entirely too time consuming.

            • 3. Re: How to correct pixel ratios?
              the_wine_snob Level 9

              When you have Imported source footage into a Widescreen Project, that was, in fact, shot in Widescreen, but is not showing as such, there is a problem with PrE picking up the flag for Widescreen from the source file. That is what Interpret Footage is for - it forces PrE to do what it says in the name, "interpret footage."

               

              What happens when you choose Widescreen in Interpret Footage?

               

              Good luck,

               

              Hunt

              • 4. Re: How to correct pixel ratios?
                Steve Grisetti Adobe Community Professional

                And what kind of camcorder did your video come from and how did you get it into your computer? It could be that you captured it into a .9 PAR project even though the video itself was 1.2 PAR.

                • 5. Re: How to correct pixel ratios?
                  freethedata Level 1

                  When I chose widescreen (PRA=1.2121) in interpret footage, it displays in widescreen in the monitor pane, and it displays as widescreen on the TV after burning to disc.  But I have 120 clips I have to interpret, and don't want to click on them one-at-a-time.  I tried to click on a group of them using <Shift>+click, but the computer ran out of memory processing many clips.  I want to change the default PRA.  So I tried to change the Interpretation Rules.txt file, but found two problems:  The file is read only, so I can't save the changes; and two:  Premier Elements is not even accessing that file at all.  As proof that it does not access that file, one can see that the ratio for 720x480 pixel files in that Rules file evaluates to "0.9", yet Elements actually uses a PRA for that size file of "0.9091".  Therfore, logically, Elements cannot be reading that file or it would be using a PRA of "0.9" instead.

                  • 6. Re: How to correct pixel ratios?
                    the_wine_snob Level 9

                    For changing the Attributes of a file, see this:

                    Attributes_Properties.jpg

                    At about PrE 8 and PrPro CS4, Adobe changed the PAR values to reflect the figures used by the BBC. The rounding was altered from 1 - 2 points to 4. That will account for about 1 pixel change total.

                     

                    Good luck,

                     

                    Hunt

                    • 7. Re: How to correct pixel ratios?
                      freethedata Level 1

                      Steve asked what kind of camcorder I used.  This brings us back to the first discussion thread I started on this topic, "How to convert pixel aspect ratios en masse".  posted two days ago.  There I described that I am using a Samsung SD camcorder which records in MPEG4 format with h.264/AVC codec.  The camera is set to widescreen recording, which, as far as I can make out, uses 848(?)x480 pixes to capture an image, then squeezes it horizontially into a 720x480 frame.  The image displays as 4:3 squeezed in Quicktime, and in Adobe, and widescreen in Samsung's own software.  The previous discussion on this topic abended when Bill Hunt insisted I could not be using AVCHD codec in a SD camcorder.  That's true--but I said that the codec is AVC--not AVCHD, and that's what the manufacturer claims too in the product brochure and spec sheet.  As further support, see my last reply in the discussion thread referred to above.

                       

                      Anyway, I am trying to change the default aspect ratio or convert them en masse in the project, so I don't have to interpret the footage for each and every file I import from this camcorder one-by-one.  When I created the project, I set the presets to NTSC-widescreen, with a PAR of 1.2121, but the project setting was overridden the the ratio associated with this file size, which is wrong for these images.  Does Elements 8 have a fix for this, or must I work with the camcorder maker's own software?

                      • 8. Re: How to correct pixel ratios?
                        freethedata Level 1

                        OK, I tried that, but got the warning message when I saved the changed file:

                         

                        "Cannot create the C:...Interpretation Rules.txt file.

                         

                        Make sure the path and file name are correct."

                         

                        (BTW, how do you inser a screen print into this message?)

                         

                        So I still cannot save the changes, even though I unchecked read-only.

                        • 9. Re: How to correct pixel ratios?
                          the_wine_snob Level 9

                          There are basically three ways that a camera produces 16:9 Widescreen:

                           

                          1.) it shoots in Standard 4:3 (PAR = 0.9) and then crops off the top and bottom

                          2.) it shoots in Widescreen 16:9 (PAR = 1.2)

                          3.) it shoots true anamorphic squeezed into Standard 4:3, but then unsqueezes this to Widescreen

                           

                          There are probably several variations in there too.

                           

                          Whether an NLE can pick up the correct flags to handle the footage will depend on both the footage and on the NLE in use. Some NLE's do a better job, than others, but that is based on the footage, its header info and how it produces the flags. PrPro does a pretty good job at identifying true anamorphic, if one has properly set up their Project/Sequence. I do not know how well, or poorly, PrE might work with this footage. As I do not use any true anamorphic material, I have to plead ignorance as to what Project Presets might be available to specify true anamorphic material, nor how well such might be able to interpret that footage upon Import.

                           

                          The same thing can happen with a simple player. Some can pick up the flags, but some cannot. Some can be forced to display the footage properly, but some cannot.

                           

                          Many camera mfgrs. will furnish utilities to handle their particular application of Widescreen. Some will allow rudimentary editing, and many will also allow Export to other formats for additional editing.

                           

                          Good luck,

                           

                          Hunt