8 Replies Latest reply on May 16, 2010 9:20 PM by EskimoSteve

    Bitrate won't change - Elements 8

    EskimoSteve

      Hi,

       

      I'm attempting to output a file with the following settings in the Share/Playback on my PC area:

       

      H.264 Blu-ray

      1280x720

      VBR, 2pass

      Target Bitrate 1.5

      Maximum Bitrate 10

       

      The estimated file size is 43 megabytes. (Which is about correct for the type of video I'm encoding according to a premiere pro user).

       

      The file size the results is about 3 times that - 135 megabytes.

       

      On inspecting the file, it appears that the target bitrate is set to 2.5. Even when moving the bitrate down (eg to 0.75 in elements), it still produces a similarly large file.

       

      Any ideas? I have made sure that elements is updated. Although I could run a converter to compress the file properly, I don't want to have to do this each time.

       

      thanks,

       

      Steve.

        • 1. Re: Bitrate won't change - Elements 8
          Steve Grisetti Adobe Community Professional

          A 43 meg BluRay disc? Are you sure about that?

           

          BluRay discs have 25 or 50 gigs of space on them.

           

          In any event, 99% of the time you can just leave Premiere Elements at its default Share settings for BluRay and you'll get excellent results. There's no real value in trying to force the program to increase the quality of the output.

          • 2. Re: Bitrate won't change - Elements 8
            A.T. Romano Level 7

            Steve

             

            I would like to give answering your question a try, but I do need some clarification and details on what you are doing.

             

            What Premiere Elements 8.0.1 project preset (new project dialog) did you set for this project?

            What is the Timeline content in estimated MB/GB and run time (minutes/hours)? What is the video compression of the source media?

            When you get to the Share section, it appears that you are selecting:

            Share

            Personal Computer

            MPEG

            Then what preset are you selecting? Is it H264 1920 x 1080i30 or H.264 1440 x 1080i30 and not HD720p since you say you are after a 1280 x 720 file?

            And, under the Advance Button, are you changing the frame size from 1920 x 1080 or 1440 x 1080 to 1280 x 720?

            Also, there are you setting the Target Bitrate = 1.5 Mbps (megabits per second) and the Maximum Bitrate = 1.0 Mbps (megabits per second)?

            It would appear that the allowable range of the Bitrate Sliders (Target or Maximum) is 0.19 Mbps (megabits per second) to 21 Mbps (megabits per second).

            Just before you hit the Save button in the MPEG dialog box for the preset that you have selected, what does it say there for File Size and Duration?

             

            If I am understanding you correctly, you are saying that you are expecting a 43 MB file and getting a 135 MB file size.

             

            With the above requested information, I will do some exploration, experimentation (some calculations beforehand).

             

            I am not sure where Steve Grisetti's question about the 43 MG Bluray Disc factors into all this so I will leave that for another time.

             

            ATR

            • 3. Re: Bitrate won't change - Elements 8
              EskimoSteve Level 1

              Hi ATR.,

               

              Here are the details:

               

              Project Preset:

               

              Share

              Personal Computer

              MPEG

              H.264 Blu-ray 1440x1080i30

               

              Under Advanced, changing from 1440x1080 to 1280x720

              PAL

              VBR, 2 Pass

              Target Bitrate set for 1.5

              Maximum bitrate set for 10

               

              Audio is dolby digital 128kbps, 48khz

               

              Estimate file size is 43 MB and duration of 1 minute 51 seconds.

               

              Source files are avi files produced by Nikon D90.

               

              As mentioned, as friend has Adobe Premiere and has used similar settings for similar files, resulting in the 43mb file for this duration.

               

              Also (this may be an incorrect assumption) but because the bitrate on examining the file is 2.5 rather than 1.5 - I'm assuming that this is the cause in the larger file size. Even if I put the slide on 0.75 target bitrate the resultant bitrate is 2.5. It doesn't appear to have any effect - yet elements does report that the expected file size is different.

               

              Many thanks,

               

              Steve.

              • 4. Re: Bitrate won't change - Elements 8
                Steve Grisetti Adobe Community Professional

                I'm not sure why you're not selecting the option to Share/To Disc/BluRay if you want to create a BluRay. That will give you the highest possible quality -- assuming your project settings match your source video.

                • 5. Re: Bitrate won't change - Elements 8
                  EskimoSteve Level 1

                  Hi Steve,

                   

                  We're trying to minimise filesizes in order to share the videos online - but not using flash, rather H264 - which can also be put onto blu-ray if required.

                  Trying to get a "Best of both worlds" scenario.

                   

                  I'm essentially trying to emulate what my professional friend does commercially with great success, but using elements rather than adobe premiere.

                  It should be possible - and appears to be possible - but doesn't seem to work as I thought it would.

                   

                  If file sizes weren't an issue, blu-ray default would be fine, but I just want to adjust the bit rate down a bit to have the files a bit smaller.

                   

                  regards,

                   

                  Steve.

                  • 6. Re: Bitrate won't change - Elements 8
                    Steve Grisetti Adobe Community Professional

                    Well, any attempt to produce a small file for the web is going to a fight between compression and quality. Something has got to compromise, of course.

                     

                    You'll likely find the best settings for an H.264/MP4 to share online under Share/To a Portable Device, in my opinion. These settings (the iPhone, for instance) are meant to be a balance of quality and file size.

                     

                    But, as I say, you can't have it all. In order to produce a file small and compressed enough to stream over the internet, you're going to have to compromise quality.

                    • 7. Re: Bitrate won't change - Elements 8
                      A.T. Romano Level 7

                      Steve

                       

                      I have been trying to simulate your issue. The work is still in progress. Here is where I am now.

                       

                      I downloaded a sample video from the Nikon D90. From what I have read and see, the video codec = MotionJPEG and has a .AVI wrapper (1280 x 720 16:9 at 24 frames per second). The audio is reported as PCM (mono). The file that I downloaded has a file size of 34.5 MB, a duration of 12:00 (seconds/ frames), and an average bitrate of about 2.9 MB/sec (megabytes per second). I brought that into Premiere Elements 8.0.1 with the project preset = NTSC HDV HDV 720p30.

                       

                      Starting out with information that file size is influenced, among other things, by:

                      compressor

                      frame size

                      frame rate

                       

                      Here is the first puzzlement for me. Is your Nikon D90 set for NTSC or PAL (the literature says either). This deals with frame rate of your export.

                       

                      Let us cut to Share/Personal Computer/MPEG and the settings that you are using:

                       

                      Under MPEG, the preset of H.264 1440 x 1080i30.

                      Under Advance Button, you say that you set for PAL; change the frame size from 1440 x 1080 to 1280 x 720; set the target bitrate for 1.5 Mbps and the average bitrate for 10 Mbps. Keep in mind that the bitrate units under Advance are Mbps = megabits per second and not the MBps (MB/second) = megabytes per second that you see in Premiere Elements properties. That was digressing. When you set as you did, did you notice that you were stuck with a frame rate of 50 frames per second, that is, frame rate = 50 with no option to change it.

                      When I exported my 34.5 MB 12:00 MotionJPEG.AVI through this route, I got a .m2t file with a size of 16.1 MB, frame rate = 50 frames per second. In Premiere Elements properties, the average bitrate for this .m2t was 1.3 MBps (megabytes per second). Now the duration was posted as 11:49.

                       

                      With the same as above except, under the Advance Button,

                      Set for NTSC instead of PAL and set the frame rate for 24 frames per second.

                      When this was done, my exported 34.5 MB 12:00 MotionJPEG.AVI resulted in a 16.1 MB .m2t file with Premiere Elements Properties showing 24 frames per second, average bitrate = 1.3 MBps, and but duration of 11:29.

                       

                      Bottom line: I have not confirmed your increase in file size (MotionJPEG.AVI Timeline to H.264.m2t export) and question the frame rate of the file route that you say that you used.

                       

                      See what you make of all that and think about alternative strategy.

                       

                      To be continued if necessary.

                       

                      ATR

                      • 8. Re: Bitrate won't change - Elements 8
                        EskimoSteve Level 1

                        Hi ATR,

                         

                        Import appears to be the same, except D90 is set to PAL and import setting in Elements are PAL-HDV-HDV 720p 25.

                         

                        File size for import looks right.

                         

                        The settings you've given for export look correct - frame rate is stuck at 50fps as you mentioned.

                         

                        The advanced panel estimate for my 1:46 video is 45megabytes (which I'd expect, based on my friends experience). The actual saved file output is 144megabytes.

                         

                        I've just tried the following:

                         

                        * importing a single d90 mpeg file - 28.8megabytes, duration of 12s

                        * using the same outputs - resulting file is estimated at 4 megabytes, but results in a file of 16 megabytes (similar to your results)

                         

                        For the length of time of the clips, the output file is consistent (roughly 1/2 of the original). However the estimate in Elements is 1/4 of the resulting size.

                         

                        Perhaps the estimate in Elements is widely incorrect. I may need to look at alternative methods (settings or software) to get the results that I'm after.

                         

                        I also forgot to mention that I bought the target bitrate down to 0.4 and there was no difference in file size. The change in bitrate appeared to have no effect,although I though it should give a smaller file size.

                         

                        thanks,

                         

                        Steve.