9 Replies Latest reply on Feb 18, 2009 3:13 PM by davegots

    Compression question

    davegots
      I have an interesting thing happening and I wanted to see what y'all think.

      I'm using CS3 8.0.2.27 on a 1.8 Ghz G5 Tower with 2.5 GB DDR SDRAM, OSX 10.4.11, quicktime version 7.5.5.

      I have an 8 seconds mov, 1920x1080, that I'm bringing into AE to apply some effects to. Basically, I'm trying to match grain on something that was shot HD to something that was shot on 16mm film. The original clip is 10.3 MB. If I run some MisFire Dust and Scratches along with MisFire Grain and desaturation, when I run it out with MPEG 4 compression (the best compression I've found), the resulting movie is 7.7 MB. Sounds pretty normal. MisFire wasn't giving me the results I was looking for, so I turned it off and ran with just AE Add Grain. I did get the look that I was after, but the resulting file is 185 MB and I'm having problems getting quicktime to play it back at speed. The clip is mostly dark with a few brighter spots in it and the grain is only on 20% of the low end. Does it really sound right that an Add Grain would make the file so huge?

      Any thoughts or suggestions would be appreciated.

      Thanks.

      Dave
        • 1. Re: Compression question
          Level 1
          It sounds to me like you rendered to an uncompressed codec.

          MPEG4 isn't a production codec, it's a delivery codec and you'll get much better results if you use something other than AE for this kind of GOP compression.
          • 2. Re: Compression question
            Andrew Yoole MVP & Adobe Community Professional
            As Rick says, MPEG4 is a really bad codec to use for anything except delivery (typically online use).

            Adding grain will certainly expand file size, as the grain reduces the number of consecutive identical pixels, which are the basis for many codec's ability to reduce file size. But the vast difference you're seeing does not make sense, so it's likely something about the compression type has changed.
            • 3. Re: Compression question
              davegots Level 1
              Thanks for the responses. I've tried just about all the codecs that AE has to offer and MPEG4 gives me the smallest file size and retains relatively the same color as the original file. I'm not sure what else to try. It doesn't seem like an uncommon thing to simply add grain over a movie and then render out a new movie. I understand that we're breaking the consecutive identical pixels, but going from 7 to 185 MB seems quite excessive for what I'm doing.

              Andrew, if you think the compression type has changed, how do you think I can fix that?

              Thanks again.
              • 4. Re: Compression question
                Navarro Parker Level 3
                No offense, but if you think 185MB is large for 8 seconds of 1080p video, you need to get a bigger hard drive.

                MPEG4 is terribly lossy. (And Quicktime's MPEG-4 is the worst encoder ever)
                Additionally, its long GOPs make it murder to edit with. Would you save a photo to JPEG, edit it, and then resave it to JPEG? Hopefully, the answer is no. Because lossy compression has cumulative image degradation each time it's compressed.

                But back to your question... Noise makes compression less efficient. So with a lossy codec... more noise = larger file.
                • 5. Re: Compression question
                  Level 1
                  I would render uncompressed or lossless like Animation, then open up QT Pro and render H264 for web delivery. I'd never send an MPEG4 file to another app for finishing.

                  It's not surprising that AE render engine would make an MPEG 4 file grow when you add some grain. Are you sure that you rendered to MPEG4? It's easy to select a different setting and not notice it. Check the QT info on your movie to make sure.
                  • 6. Re: Compression question
                    davegots Level 1
                    Thanks for the responses everyone.

                    I definitely rendered it MPEG4. 185 MB is fine for my hard drive, but I'm FTPing it to someone who is going to be using it in FCP for final tweaking and I'm going to be doing a few more clips for him so I'm just trying to find find the best combination to get the file size smaller (and still good quality) for easier usability on his end.

                    I guess I should be less concerned with the file size and use a better codec for optimum quality. I didn't realize that MPEG4 was so terribly bad but now I know. The final output will be HD-DVD or maybe projected in a small theater, so from the sounds of it, I should be using animation compression or there's DVCPRO HD 1080i50 or DVCPRO HD 1080i60 which may work for my use?

                    Thanks a lot. I haven't done much HD stuff in AE, so I'm learning as I go along. I owe y'all a beer.

                    Dave
                    • 7. Re: Compression question
                      Andrew Yoole MVP & Adobe Community Professional
                      As you say, QT Animation or DVCPRO HD codecs are MUCH better options.

                      Others: QT ProRes (High Quality), or QT PhotoJPEG (above 75% quality ideally), both which will give good quality results without being as large as lossless formats like Uncompressed or QT Animation.

                      It wouldn't hurt to give the editor a call and confirm what format the production is using natively - could be you'll save everybody headaches by using the same format.
                      • 8. Re: Compression question
                        Mylenium Most Valuable Participant
                        >but I'm FTPing it to someone who is going to be using it in FCP for
                        >final tweaking and I'm going to be doing a few more clips for him so >I'm just trying to find find the best combination to get the file size >smaller (and still good quality) for easier usability on his end.

                        Well, since you still seem in the process of actualyl producing the stuff, there are two questions:

                        a) Could the editor live with a low-quality version as a temporary placeholder during offline editing?

                        b) Once the product is done, could you not just send him an external harddrive with the files via UPS EXpress or such?

                        If both questions can be answered wit a yes, then the course of action to me seems clear....

                        Mylenium
                        • 9. Re: Compression question
                          davegots Level 1
                          Yup, sounds good fellas. The editor is working in FCP on a Macbook Pro so it's not like he's got the greatest capabilities in the world. I'll check and see what format he'll be using and in the meantime send him lower quality stuff as a placeholder. I'm sure my higher quality stuff will be just fine for final.

                          Thanks much.