6 Replies Latest reply on Sep 20, 2010 6:12 PM by Neofilm

    Horizontal lines after rendering?

    Andriante Level 1

      I have a video that is very 'fast' or theres a lot of movement in it.

       

      After I render it, it becomes very 'line-y' when ever there's quick movement. Basically I can see horizontal tearing lines.

       

      The source footage is not like this.

       

      Is there any special method or codec I can use to avoid this?

        • 1. Re: Horizontal lines after rendering?
          Neofilm Level 1

          Sounds like the video is interlaced. You computer is progressive scan and some cameras shoot interlaced. Older TV's are interlaced and some of the newer one's are both. If the end result is for computer only you'll want to de-interlace the video. If it's for TV only you can probably leave it alone and it should playback fine when you play it on a TV.

           

          I believe to de-interlace you only need to change it when you export to "Progressive Scan". However, you can also de-interlace the clips in your project before you export. I called Adobe tech support about this same thing several years ago and they suggested I do both, de-interlace the clips in the project and when you export it.

           

          You may have seen 1080i and 720p, etc... the P is for progressive scan and the I is for interlaced. I believe the reason for interlaced was because it's less bandwith to send half the image at a time (every other line) than the whole image. So, a broadcast need to use interlaced. But, everything I assume is moving to progressive scan. However, I imagine interlace will always be supported since so many things are interlaced.

           

          Simply play with a small clip by exporting it simply as it is and make a DVD of it, play it and see how it looks on your DVD player. My DVD player actually has a button on it for progressive scan. You may need to change a setting on it or your TV, or it may just play it as is. Then, if you're not happy with the results, try simply setting the export option to progressive scan.

           

          I don't have Premiere installed on this computer otherwise I'd look to see how to de-interlace the clips for you, but it's something easy like right clicking the clips on the timeline or something. I may look later and get back to you on that.

           

          Hope that helps!

          • 2. Re: Horizontal lines after rendering?
            Harm Millaard Level 7

            If you shot interlaced, keep it interlaced, unless you want to throw away half your vertical resolution. Do not use the program monitor for quality purposes, use a properly calibrated broadcast monitor to determine the quality.

            1 person found this helpful
            • 3. Re: Horizontal lines after rendering?
              Andriante Level 1

              It's actually a recording from a video game and the video will only be viewed on computer monitors

               

              Looks fine when I play it normally but after rendering it the horizontal lines become very noticeable.

               

              vlcsnap-2733558.png

              • 4. Re: Horizontal lines after rendering?
                Andriante Level 1

                Hey thanks for your excellent and elaborate reply!

                 

                You definitely put me on the right track, but I'm still no closer to fixing this.

                 

                I've tried like 10 different things and I've googled the heck out of this, but still haven't found a solution.

                 

                I posted a picture below of the problem, it might clarify

                 

                thanks!

                • 5. Re: Horizontal lines after rendering?
                  Neofilm Level 1

                  Just right click on the clip(s) and then select "field options" and then "always deinterlace" and/or (literally try one or the other and/or both on a small clip) upon export under the "video" tab on the right side half way down select "none (progressive)" in the "Feild Order:" drop down. One of those things or both of those things may work.

                   

                  Here's a help page on it: http://help.adobe.com/en_US/premierepro/cs/using/WSD69D6B9C-1F89-4c85-BCB3-2C946E26246D.ht ml#WS9393E273-9D4D-42f1-AEE5-6B2F9B8D4F46

                   

                  Hope it works for ya!

                  • 6. Re: Horizontal lines after rendering?
                    Neofilm Level 1

                    That's neat that you may loose half of your information but if it fixes the problem to deinterlace because the end result is not demanding of that much information then compression is inevitable anyways. I have always shot with interlaced and rendered out progressive and even compared the two and have never noticed a difference in quality. I would assume it depends on what you've got going on, try what I've suggested with a small clip and if that fixes it you're gold!