3 Replies Latest reply on Jul 30, 2013 6:37 AM by joshweiland

    Simple Question - Which format should I be rendering videos in for my task.


      Hey guys , I have a JVC Everio 1080p Camcorder that produces AVCHD type videos in .MTS  format.  I'm using Adobe Premiere and after effects CS5.5


      All I'm doing with these 10 minute clips is removing greenscreen to replace it with a whitebackground.. So the end result is simply me standing against a plain white background. (originally shot in front of my greenscreen of course).


      Heres the reason I'm having trouble..

      After effects crashes when trying to key out the background when I have the option for "render multiple frames simultaneously" selected.. I've tweaked my settings to get the best performance I know of but keylight causes a crash consistently..


      If I dont have multiple frames rendering at the same time this 10 minute movie takes like 10 hours to render to a .h264 format which is the final format my clients need..


      So I did a lot of research and came to the conclusion that I should render my MTS movie in  Quicktime - format with the Animation codec selected (if that makes sense?)   Something about the MTS video not having enough keyframe information and that causes the speed bottleneck and crashing.. I hope I'm right there..


      Anyway , since I render the movies as .MOV now and THEN perform the greenscreen keying that way onces its an .MOV movie ...keylight does it in only 2 hours instead of 10 (which I think can still be improved) ..


      I can deal with that for now.. BUT


      My main problem/question..


      DISK SPACE =(     The original MTS file may be like 3-4 gigs but when rendering it to an MOV file it turns into anywhere from 90-140 gigs...


      I'm quickly running out of space..


      Can anyone help me tweak my operation and tell me how to either cut the rendering times down or tell me a better format to render this video in so that its not HUGE and wont take 10 hours AND possibly wont make keylight crash?

      As I mentioned I think it was crashing with my earlier method because I was trying to key out the greenscreen and  replace with a white background on the original .MTS file in after effects while converting it  straight to .H264 in one go.


      I've just bought a brand new laptop  

      System Specs:  I7 processor , 12GB ram , GeForce GTX 765 video card (if that matters)

      1 hard drive with 2 partitions  1 is 450GB and the other half of it is 250GB.



      I have , but am not using , an external hard drive capable of storing 500GB..


      When rendering my videos I at least drag them off the SD Card that the camera has them on and put them onto the main hard drive.. The rendered file is also burning to the same hard drive (which I think is a problem?) i'm not sure if I should have the original video and the one being rendered on the same hard drive or if I should put one or the other on the external hard drive. (disk cache question here maybe?) 


      I'm very much a video editing newbie but I understand a good bit of computer lingo.


      If anyone can help I'll be very grateful! 


      Did I miss giving any valuable information here? (please forgive me I've been up for 24 hours and I'm delerious) 

        • 1. Re: Simple Question - Which format should I be rendering videos in for my task.
          joshweiland Level 2

          What is the speed of your processor?  When rendering a project like yours, GPU doesn't have an effect.


          You should be able to key the .MTS file without first transcoding to a .MOV.


          When you have "render multiple frames" enabled and AE crashes, is there any specific error message that appears?


          Your disk setup is not ideal, reading and writing to the same disk.  Any reason why you partitioned the drive?  Are you reading/writing to a single partition?  Unless your external HDD is USB3.0 or eSATA, it's probably not fast enough to use.

          • 2. Re: Simple Question - Which format should I be rendering videos in for my task.
            Supernabby Level 1

            The drive came partitioned when I got it.


            When I do keying with the .MTS file it renders like 800 frames quickly then adobe pops up an error that keylight crashed and at this point begins to render them as if "render multiple frames" has been unchecked.. it just goes really slow after the crash.

            Ill have to reduplucate the problem and paste the exact error. Ill try to get to that soon.


            My processor is the latest I7 processor  (intel I7 4700MQ)


            I am reading and writing to the same disk yes.  I think my harddrive is 3.0. Should I have the MTS file on the main drive or should it be reading the MTS file from the hard drive and rendering to the main drive? How should I go about that?




            When I read something about


            ((I'm attempting to reduplicate the problem but would you know it has rendered 2000+ frames of the .MTS file and still going strong O_0))  Jeez...


            I can deal with this thing taking 7 hours to render the greenscreen straight off the MTS file and formatting it straight to h.264 as an .mp4..   I just cant deal with it crashing mid-way and taking 14 hours or so.

            Can you tell me if .MTS file contains enough keyframes for after effects to work with, without crashing?  I was thinking that was the whole problem so I was starting to format them as .MOV files as another article suggested. The rendering certainly goes much faster but the space is my only issue now...  but hell if it wants to do what its doing RIGHT NOW , I dont care if I have to wait 6 hours.. this is easier than converting to different formats and stuff. 


            If it comes back up with the erorr I'll repost it .. most likely it will after I give up on it again and assume its going to work right !  Bah..  

            • 3. Re: Simple Question - Which format should I be rendering videos in for my task.
              joshweiland Level 2

              It's possible that "render multiple frames" won't work in Keylight with AVCHD.  AVCHD footage is dependent on I-frames (what you're calling keyframes), and it's likely that Keylight works frame-by-frame and frames must be handled linearly in order.  Also, AVCHD requires significant horsepower to decode.


              So it makes sense that your QuickTime files key/export much more quickly.  Considering the huge file sizes, your QT files are either uncompressed or losslessly compressed.  So the overhead from the AVCHD format itself has been moved from happening before Keylight to conversion to the QT files.


              At this point, I think things are working correctly.  However, there are still some optimizations you can use to (hopefully!) speed things up.


              How fast is your internal hard drive?  Most laptop hard drives are very slow.  If your external drive is USB3.0, it may be even faster than your internal one.  Use ATTO Disk Benchmark to gauge this.  I would store your source files on the faster drive, and export to the slower one.


              Keylight (and any pro keying solution, really) requires horsepower.  It has to analyze each frame, which takes time.  If you can reduce the amount of frame Keylight has to analyze, it will speed things up considerably.  Here's two methods of doing this:


              1. If the subject is fairly stationary, and let's say he's in the middle of the frame, mask out the left and right sides of the frame using the Pen tool.  This will cut down the size of the frame Keylight has to process.
              2. Another option is to FIRST use a simple color key to key out everything but the outer edge around your subject.  Then add Keylight, which will only have to key out this outer edge.  For an example of this, see http://vimeo.com/34365256 at the 9-minute mark.  BRILLIANT!


              The first option is quicker to implement, but if your subject fills the frame there might not be enough area to mask out to improve render speed.  The second option takes more time to set up, but should help significantly.


              Let me know what you try and how it works for ya!