10 Replies Latest reply on Aug 23, 2009 8:57 AM by Mylenium

    AVIs from AE need rendering in PPro

    OsakaWebbie Level 1

      I'm an AE novice, so this is probably something simple.  When I use AVI files from AE compositions in Premiere Pro, they require rendering (have the red line above them even where there are not effects or transitions) while AVIs captured from my camera or generated by Premiere Pro's "Export Movie" do not.  A second render is a waste of resources and probably a loss of quality, so I'd like to get things configured so that PPro is happy with my AE-rendered AVIs the way they are.

       

      My PPro project settings are DV NTSC, 29.97 fps, 720x480, pixel aspect ratio 0.9, display format 30fps drop-frame.  My AE project settings are Timecode Base: Auto, NTSC: Drop Frame.  I'm sure there is simply some setting that isn't matching, but I'm not sure what it would be.  A lot of the terms in the Render settings are unfamiliar to me, so I don't know which ones would affect this issue.  If it's relevent, the AE project I'm using was originally made in AE 6.0 and recently opened in CS4 and re-edited.  Both AVIs that were made in 6.0 and the new one I just made in CS4 do the same thing in PPro (whose version is CS3, if that makes any difference).

        • 1. Re: AVIs from AE need rendering in PPro
          Todd_Kopriva Level 8

          What codec are you using in these AVI containers that you render and export from After Effects?

          • 2. Re: AVIs from AE need rendering in PPro
            Mylenium Most Valuable Participant

            AVI is just a container format. Whatever you capture in Premiere therefore can be any kind of compression under the hood that necessarily must not be compatible with other programs. DV is one such specific case. Since it is a heavily compressed format to ensure realtime capabilities even on weak computers, its primary use is in editing programs that can capture such data streams directly from cameras or can generate them internally. That being so, AE is a whole differnt story. As a compositing program, AE favors quality over realtimeness and compression and thus is severely limited in outputting such formats. Its default is Uncompressed, which is probably what you see and why it requires to be converted in Premiere. You should however be perfectly able to set other compressions in the Output Module Settings. Here's the stinker, though: AE does not support multi-frame temporal compression as required by many compressed formats, so the quaality will often be terrible, and secondly you will not get access to the DV CoDec such as used by Premiere. You may choose Microsoft DV and others, but in essence you'll be back to square one as those will laso require to be rendered/ transcoded in Premiere's timeline. So to cut a long story short: What you see is normal. You should not be concerned about losing quality - as long as you use uncompressed or losslessly compressed intermediate formats such as Quicktime PNG and Animation and obey the correct render settings, you do not degrade the quality.

             

            Mylenium

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            • 3. Re: AVIs from AE need rendering in PPro
              OsakaWebbie Level 1

              Yes, your guess is correct that I'm outputting as lossless (perhaps that is the default?)  I don't know if that answers Todd's question or not - "lossless" is not technically a codec, but there is likely to be one obvious lossless codec that AE uses by default.  (I can't check right now because my computer is busy encoding a PPro sequence into a file for DVD, and I have been having lots of errors and memory problems lately, so I don't want to try doing two things at once.)

               

              From what you are saying, it sounds like there is no codec I can select (whether lossless or lossy) that will not need rendering again in PPro.  That surprises me, as what I'm doing would be a very common workflow, perhaps the most common way to use the two programs.  In fact, I discovered that the amount of work required by PPro to render my AE footage even just enough for real-time preview was so great that in one instance it refused to show me anything at all (I had a title on top of the footage and was referencing the sequence in another sequence but with no further editing; other sections of the sequence that had DV-AVI clips with effects and titles were previewed okay, but the section from AE showed nothing).  That can get pretty frustrating...

              • 4. Re: AVIs from AE need rendering in PPro
                yenaphe Level 4

                well in order for your workflow to work you just have to configure 2 things:

                 

                1) Your AE comp shall match your Ppro sequence type (aspect ration, width, height...)

                2) Your AE render settings must match your Ppro footage type.

                 

                So if you are working with dv footage in Ppro, you have to configure AE to render DV AVI (or DV QT on a mac). You do this in the output module.

                 

                Your workflow is one of the most used between the two apps, but it is not automatic, you still have to match the 2 aformentionned points.

                 

                And if you tryed to read from Ppro your uncompressed footage, it's normal that it struggled because uncompressed footage needs very fast HDDs to be streamed correctly.

                 

                Last but not least, don't be confused with lossy & lossless codecs. Lossy means that the codec will reduce the quality (exemple; mpeg2, dv, hdv, h264, ...) and lossless will mean that it compress the file without reducing the quality (exemple: animation, png seq, tiff seq with lzw...)

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                • 5. Re: AVIs from AE need rendering in PPro
                  Mylenium Most Valuable Participant

                  That surprises me, as what I'm doing would be a very common workflow, perhaps the most common way to use the two programs.

                   

                  Actually it's not that surprising. It's really mostly a limitation in how AE works under the hood and not that unusual for compositing programs. Other programs like Fusion or Nuke are also limited in their realtime playback capabilities and exporting compressed media. It's of course logical in a way - since the processed frames do not yet exist, there is no way to analyze their visual structure and figure them into the compression algorithm. One way to avoid that, is why many "professionals" use different formats and workflows and with dedicated capture equipment to get access to a set of CoDecs that can be used more consistently in all programs. During capture then the source gets converted into losslessly compressed data that can be treated over and over without degenerating. Of course even pros use compressed acquisition formats such as P2, DVCPro, AVCHD etc. and then they suffer the same limitations. Then, as anyone else, they will have to render the clips to an intermediate format with matching settings and import them into their edit suites. One way to minimize that extra rendering would be to use DynamicLink, but unfortunately that would require you to have installed the programs from a suite (Master Collection, Production Premium) all at the same version level, so at this point it's not really an option for you. And depending on what hardware you have, it may be slow to work with, because it's quite memory hungry....

                   

                  Mylenium

                  • 6. Re: AVIs from AE need rendering in PPro
                    OsakaWebbie Level 1

                    Mylenium said:

                    AE does not support multi-frame temporal compression as required by many compressed formats, so the quaality will often be terrible, and secondly you will not get access to the DV CoDec such as used by Premiere. You may choose Microsoft DV and others, but in essence you'll be back to square one as those will laso require to be rendered/ transcoded in Premiere's timeline.

                    Sébastien Périer said:

                    Your workflow is one of the most used between the two apps, but it is not automatic, you still have to match the 2 aformentionned points.

                    The impression I got from Mylenium's post was that even if I chose Microsoft DV as the codec, it will still require rendering, and also be lousy quality.  I know that there are many "lossless-only" purists out there, but I am satisfied with the normal type of DV compression even for two or three generations, even though it is technically lossy - my final format is MPEG2-DVD, which is much more compressed.  But if it didn't do any multi-frame comparison for its compression...  Anyway, Mylenium scared me away from even trying to change the output settings, as it sounded like it would not solve my problem at all.  But after reading Sébastien's post I decided to try it, and at least at first glance it appears to work fine - the footage goes on the PPro timeline without the red "I need to be rendered" bar, and at least on my screen the quality looks okay to me - I see no visible artifacts.  I don't know how to tell if it is doing any frame-to-frame comparison, or how much harm I might be doing to the quality of my final DVD data by doing it this way, but it sure works faster!

                    ...don't be confused with lossy & lossless codecs.

                    Don't worry, I understand that - a simple example is JPG vs. TIFF, as both compress but TIFF is lossless.  But I don't know the subtle differences between different video codecs, and until yesterday I didn't know about the output settings in the render queue pane of AE.  (Since everything else I have worked with on this Windows machine has always used Microsoft DV as the codec for AVI's, I was lulled into the assumption that that would be the default in AE as well.)  If Mylenium is right that AE's output functionality for that codec is not as clever as that in PPro, perhaps this method will come back to bite me, but meanwhile, it looks like it will improve my workflow tremendously.  Perhaps if I re-render my current clips it might even reduce some of my memory problems in PPro - right now, about once an hour or so I get a complaint from PPro about limited memory (or runtime error messages) and have to reboot.  [In case you are tempted to ask, I have 2GB of RAM and have my paging file set to a fixed 8GB, but I'm still running out.  I don't have that much AE footage yet, but I will be adding more.]

                     

                    If my current settings (Render Settings: "DV Settings", Output Settings: "Microsoft DV") are not really the same as the normal Microsoft DV that I use for everything else(even though they are accepted as native footage by PPro), please speak up again.  I won't delete the lossless versions of the clips (which are about 8 times the size of the DV ones) until I'm sure I won't regret changing my workflow.

                    • 7. Re: AVIs from AE need rendering in PPro
                      OsakaWebbie Level 1

                      Oh, our posts "crossed in the mail" - I only saw Mylenium's most recent one after I sent mine.

                      It's of course logical in a way - since the processed frames do not yet exist, there is no way to analyze their visual structure and figure them into the compression algorithm.

                      Why is that any different in AE from PPro if you have effects, transitions, etc.?  PPro uses two passes in some of the export modes, for that very reason.
                        Sure, it is typical to have more layers and other fancy stuff in AE, but I would have thought the basic concepts would be the same - real-time preview does only a rudamentary render just to give you something rough to look at, and the real render process looks as as many frames as necessary to create the clip in the format you requested, using as much time, memory, and hard disk space as it needs.

                      One way to minimize that extra rendering would be to use DynamicLink, but unfortunately that would require you to have installed the programs from a suite (Master Collection, Production Premium) all at the same version level, so at this point it's not really an option for you. And depending on what hardware you have, it may be slow to work with, because it's quite memory hungry....

                      Yeah, I heard all about Dynamic Link when CS4 was making its big splash and I decided to learn more about what newer versions were up to (at that time I only had the "Video Collection", which was non-bundled bundle of PPro 1.0, Encore 1.0, AE 6.0, and Audition 1.0).  But at that point I had hardly used AE at all, mostly because I didn't understand it (all my versions are Japanese, and some of this video terminology is hard enough to understand in English!), and I imagined (apparently correctly) that using something like Dynamic Link to force continual subprocessing of AE compositions in a PPro environment would send smoke rising from any normal computer.

                      • 8. Re: AVIs from AE need rendering in PPro
                        yenaphe Level 4

                        Well the difference is in the design of the two apps. As an NLE, the rendering/previewing code of premiere pro is targeted at realtime playback. It can for exemple read gop structures, and for effects it extrapolate the values and that's it.

                         

                        As a compositing app, AE is aimed at fidelity even in the previewing process, thus not real time. When AE displays a frame, it reads that only frame (that means that it has to reconstruct it if it's one in the middle of a gop structure), uncompressed it into ram to get the accurate value for each pixel, and then displays it. Thats why the playback performances are so different between the two, and even if all compositors I know would like to have faster previewing inside AE, none would actually exchange this behavior for a NLE like behavior.

                         

                        For that reason 2 pass encoding is not available directly from AE render queue, but you can get it from Adobe Media Encoder that can open AE sequences directly.

                        • 9. Re: AVIs from AE need rendering in PPro
                          OsakaWebbie Level 1

                          Okay, so that creates a couple more questions in my mind about what I'm really getting when I output a comp from AE as DV-AVI for use in PPro:

                           

                          1. If better fidelity is achieved in a frame-by-frame approach (which makes sense), then why did Mylenium say that a DV-encoded file from AE would look so bad?  If it's a DV-AVI file with all frames being I-frames (that's what it sounds like both of you are saying), I would think the filesize would be big but the quality would be even better than if some data from frame to frame is extrapolated.  When making a DV-AVI, I have never been given a choice of bitrate, so I assume the size can grow to fit the need.  Am I understanding this correctly?  If so, then what am I missing about how this adversely affects the image quality?

                           

                          2. Video interlacing seems a bit related to the frame comparison discussion.  I have been changing the Render Settings from "Best settings" to "DV settings", particularly because I wonder if otherwise it wouldn't be interlaced.  I generally prefer the interlaced smooth "video" look to the "film-like" look of progressive, so I want to make sure that at least the final result (out of PPro, for DVD) is interlaced.  Am I right in thinking that for that reason I should choose "DV settings"?  Or would it end up that way as part of the MPEG2 encoding in PPro regardless of the source footage?

                          • 10. Re: AVIs from AE need rendering in PPro
                            Mylenium Most Valuable Participant
                            When making a DV-AVI, I have never been given a choice of bitrate, so I assume the size can grow to fit the need.

                             

                            DV works with a fixed data rate of 3.7 MBit/s, so there is nothing to adjust. File sizes increase linearly the longer a clip gets. As for quality and other considerations - as long as it works for you, there is nothing wrong with it. While we pros may sometimes get a bit nosy about such matters and have enough reasons to not use it, there is per se no right or wrong. It all depends. However, the fact remains - it is already compressed and quite agressively at that. At the risk of causing further confusion, I recommend you check the Wikipedia article on it. Especialyl the the part on chroma subsampling is what would be important for most compositing tasks as well as the DCT compression, which is similar to what's used in JPEGs, causing more or less visible block artifacts.

                             

                            Am I right in thinking that for that reason I should choose "DV settings"?

                             

                            DV settings are merely a Render Settings preset such as you can create yourself. It just has the field rendering turned on by default, whereas the Best Settings hasn't. Otehr than that, their otehr settings are identical. read that help article and you'll understand.

                             

                            Mylenium