2 Replies Latest reply on Dec 11, 2014 5:24 PM by djbolivia1

    Possible to "Stitch" mp4's together easily?


      Hopefully this is a relatively simple question.  I'm a long time Premiere user but not a pro by any means.  Very simple edits, no After Effects, no real effects, just straightforward fades and edits of audio and video.


      I’ve been having problem exporting a particularly large project.  It’s over two hours long with five UHD sources throughout.  And unfortunately, although my laptop is pretty new and high-end, it’s just a laptop. Nowhere close to a proper desktop based system.  So the last time I tried to export the project, I got to 88% after five days, and then I had a non-Premiere problem that required a reboot.  I’m using the laptop constantly for other stuff, and realistically, trying to process something that intensive for close to a week while doing lots of other stuff isn’t often going to succeed.  I hope to do other similar projects in the future, so I'd rather not bite the bullet and wait, if I can figure out a better long-term approach.


      I decided to try to export the project as a series of half a dozen shorter exports of about twenty minutes each.  Those are each taking less than a day, so if I have to do a reboot for some reason, no big deal, I can either wait and do a few hours later, or do it immediately and just re-start the export of the smaller segment.


      Now I’m just looking for some advice to stitch them back together.  They’re all at the proper settings for the final full project (h.264 mp4 29.97 progressive 3840x1920) and no further editing will be needed, not even fades between the files.  I have them cut to the exact frames so they can just be attached back-to-back perfectly.


      Will an export of these sequential mp4’s at the exact same settings be processed far more quickly than if it was dealing with all the original rendering?  Failing that, is there any other software package that I could buy that would “stitch” everything together quickly without having to re-process everything?


      Win8.1, 16gig RAM, 500gb SSD, 2tb HDD for data, nVidia GeForce GTX 870M.


      Thanks for any suggestions!

        • 1. Re: Possible to "Stitch" mp4's together easily?
          djbolivia1 Level 1

          Ah, disregard this one, I think I've got it figured out.  I know there are lots of freeware programs out there that claim to do what I was looking for, but they all look sketchy and riddled with malware, so I was looking for a more professional product.


          But I just discovered that I should be able to do it in Windows 7 or 8 through the command prompt as administrator.  So basic, so easy.  If it doesn't work, I'll get back on here with a follow-up.


          Here's the command structure:



          Open the command prompt as administrator.
          Copy your files to your C:\ (its easier on the root, can be deleted afterwards)

          copy /b "C:\File.mp4" + "C:\File1.mp4" CombinedFile.mp4

          • 2. Re: Possible to "Stitch" mp4's together easily?
            djbolivia1 Level 1

            Yeah, that works for some sort of files (like text files) but I found out that it doesn't work for mp4's.  You'd have to somehow remove the container and then stitch the individual files and then re-container.


            I ended up trying a freeware program called Avidemux.  Worked great, very quick.  I tried to run the group of parts through a PP export to stitch, just out of curiousity.  It would have done it all in about six hours, which is a huge improvement over the multiple days that it took cumulatively to encode the various parts.  So PP wasn't smart enough to figure out that it could just merge them, but at least it recognized that no real hard lifting had to be done since the source files now all matched the output parameters.  So it was a semi-victory, but Avidemux was much faster.