7 Replies Latest reply on Jul 14, 2011 3:37 AM by dsdsdsdsd

    how big should a 4-min HD video be?

    dsdsdsdsd Level 1



      I made a video in AE, which uses primarily .mov's as assets ( renders from  cinema4d ). both c4d and ae are set to 1280x720.


      when I render out of AE, I am getting an 11GB file, .avi.


      I am wondering what would be a reasonable target filesize for my 4min hd .avi.





        • 1. Re: how big should a 4-min HD video be?
          Mylenium Most Valuable Participant



          For the rest we'd need more info about the intended use - there is no general formula.



          • 2. Re: how big should a 4-min HD video be?
            dsdsdsdsd Level 1

            good articles ... what we have now is the uncompressed avi ... I'll play with various compression settings.


            my project will be for a 42" tv screen ( HD ), and will be run off of a flash drive ( so the flash drive will need to be fast itself ).


            I suppose that my concern is that I don't have access ( nor experience ) working with large screens such as tv screens, so I don't really no what I should be shooting for. I know that I have common low-res avi's for tv shows that are usually 150MB for 30 minutes of medium-res audio/video.


            so if I do some cheap math: ( 4/30 )minutes * 150MB * ((1280*720)/(624*352))pixels = 84MB.


            based on this I should shoot for a 84MB .avi for a 42" HD tv screen ... does this sound reasonable??

            • 3. Re: how big should a 4-min HD video be?
              Mylenium Most Valuable Participant

              The size doesn't matter as long as the data rate is something the screen can swallow. AVI is just a container, what matetrs is the CoDec used inside. Anyway, I'd consider it a moot point. Based on your description you will probably use H.264 or DivX since that's what those decoder chips are made for and you very much have no problem once you realize that. All that matters is balancing out the quality vs. a suitable data rate and then in turn the file size and for all intents and purposes, that could be about 20MB only even at full HD res. Basicalyl you'd just take your existing AVI and mangle it through Adobe Media Encoder using a suitable preset. most of them default to 6-8MB/s, which is just fine for most tasks, but feel free to go higher. Just keep in mind that there may be a data rate limit in teh decoder chip in the TV itself, so don't overdo and perhaps look up the specs on that....



              • 4. Re: how big should a 4-min HD video be?
                Navarro Parker Level 3

                I would add that running your 11GB file through Handbrake would probably produce a smaller, better looking file than Adobe Media Encoder. Nothing against AME, but Handbrake's default presets produce some really good h264 results at much lower bitrate. It's Constant Quality slider is a little more manageable and automated than manually setting bitrates.

                • 5. Re: how big should a 4-min HD video be?
                  dsdsdsdsd Level 1

                  I've been using AE to render the final output, trying various settings, but when I select h.264 the render fails:


                  "After Effects: AEGP Plugin Media IO Plugin:
                  There is a mismatch between Output Module setting and Transcode Settings.
                  Please verify your settings and try again."



                  QUESTION: I have built everything at 1280x720, but it seems that several of the 'high def' codec default to much lower resolutions ... does a 42" tv require 1280x720 ( 72dpi ) ?


                  I think ae's h.264 defaults to 720x480 or something along that line.

                  • 6. Re: how big should a 4-min HD video be?
                    Mylenium Most Valuable Participant

                    It tells you exactly what you need to know - MPEG encoding is tied to specific matrices and profiles and there is only limited room for creatively combining resolutions and framerates. You can perfectly use your 1280x720 video, but at the right frame rates and interlace settings - 24p, 50i, 50p. Additionally, you must make sure that you set the same framerates inside the encoder panel, not just in the AE comp plus you must also set the profile level accordingly. I recommend you do a little searching on teh web and read the help files. If all fails, you can always set profile level to 5.1, which is the most liberal and allows almost any arbitrary combination, but this may again cause problems with your decoder chip, as most of them are designed to work on profile level 4.0/4.1, which is what BluRay and digital TV use, hence the relationship.



                    • 7. Re: how big should a 4-min HD video be?
                      dsdsdsdsd Level 1

                      we're believing that .m2v is our way to go, using sorenson squeeze's 720p29.97 MPEG-2 w DolbyDigital - TS  format.



                      will a .m2v be suitable to run from a flash drive to output onto a 42" screen ( I know that, in general, it will run from a flash drive )?