10 Replies Latest reply on Aug 15, 2008 9:52 AM by (nexus)

    FLV quality discrepancies

      In the standalone Adobe Flash Video Encoder, the following settings produce a crisp, clear flv:

      - On2VP6 encoder
      - Max data rate: 400 kilobits per second
      - 10 fps
      - Keyframe placement: automatic

      Those same settings--used in Premiere CS3's "Adobe Media Encoder"--produce a very blurry flv.

      This causes us an additional step in the workflow: we have to encode the file as an HD mpeg, and then we dump that file into the standalone Adobe Flash Video Encoder. The result is good, but time's a'wastin'.

      Any insight?

        • 1. Re: FLV quality discrepancies
          Level 1
          Assuming you're coming from HDV source (hence the HD MPEG).

          1) You're using 10 fps? That's not too austere for your needs?

          2) The included Media Encoder does, ironically, have some issues. Start by using one of the presets and see if that creates a better quality.
          • 2. Re: FLV quality discrepancies
            Level 1
            Check out http://www.firstchristianonline.com/currentseries.html or http://www.firstchristianonline.com/video1.html - We prefer to cut the frame rate down to reduce file size. It doesn't seem like the most popular method, but you end up with crisp image quality and quick downloads.

            Is there some sort of patch or something that makes Premiere's method of flv encoding match that of Flash Video Encoder? With Premiere and Flash Video Encoder both belonging to the same CS3 bundle, I don't understand why identical settings yield different results.
            • 3. Re: FLV quality discrepancies
              Andy Urtu Level 1
              I think it might have to do with "down sizing" your video.
              Premiere Pro does not do a great job with taking HD material and scaling it down to Standard Def.

              What are your original files and what size are you outputting the FLV?

              There is a very long thread about this HDV --> SD DVD Workflow?
              • 4. Re: FLV quality discrepancies
                Dan Isaacs Level 2
                Funny you should mention it... I was thinking along the same lines. I have a theory:

                1.) In Adobe Media Encoder, when FLV is selected, the "deinterlace" checkbox is checked by default. This will slash the vertical resolution in half prior to scaling, which usually does not yield the nicest results.

                2.) In the standalone FLV encoder, deinterlace is off by default. In this case, interlacing is "ignored" and the image is simply scaled down. The will generally provide nicer resutls for vertical size reductions that are less than half of the original resolution (such as the examples posted).

                You may want to try ensuring that the deinterlace box is not checked in Adobe Media Encoder. If my theory is correct you should be able to achieve results similar to that of the standalone encoder.

                That being said, you should check out HDV --> SD DVD thread as Andy suggested and have a look at my basic workflow example:


                If you are able to get this going I can easily create a custom AviSynth script for your FLV output that should get much nicer results than you are currently getting. (Sharper, less jaggies, no lossy intermediary compression stage...)

                The only downside is that you'll still need an "extra step", but it will obviate the need for creating an HDV mpeg intermediary file.

                Instead, you would create a lossless AVI file at the same resolution and framerate as the final FLV. You would use the standalone FLV encoder to convert this AVI to your final product.

                Also: Have you thought about using 15 fps instead of 10? It seems to me like a better option but that is just my opinion.

                If you use my suggested method you could also achieve a very nice conversion to 12 fps. This would be accomplished by converting your interlaced 30i source to 60p and then selecting every 5th frame.
                • 5. Re: FLV quality discrepancies
                  Level 1
                  Thanks for your quick posts, guys.

                  Andy, the material is shot in 1080i and captured as an mpeg. (Sometimes, live, we scale it to 720p and capture the material using the Motu V3HD, which uses the DVCProHD codec. But that's not really an issue here because whichever route we take, we get the same blurry result with Premiere's onboard flv encoder.) The final flv is 440 pixels wide and 248 pixels tall.

                  Dan, good idea about interlacing/deinterlacing. I too thought that may be the culprit, but it comes out blurry both ways. I'm really interested in the workflow you suggest. Am I right in assuming that (A) the end result will look better and (B) it will take less time to render a downsized avi file than it takes to encode a 1080i mpeg?

                  Heading over to the HDV --> SD DVD thread...

                  Thanks again.
                  • 6. Re: FLV quality discrepancies
                    Level 1
                    unintentional emoticon there... intended that to be part B of the sentence.
                    • 7. Re: FLV quality discrepancies
                      Dan Isaacs Level 2
                      > it will take less time to render a downsized avi file than it takes to encode a 1080i mpeg

                      Probably. It will also probably take less time to write this AVI than to write your MPEG2 file (well, there are lot of options that could alter the equation on both sides, honestly, but...)
                      • 8. Re: FLV quality discrepancies
                        Level 1

                        The frameserver software is sharp stuff--a great timesaver.

                        We use a Motu V3HD firewire interface to capture HD video into Premiere. The video is captured as an mxf file. The following would seem like a nice workflow for us: 1) place the mxf file in the Premiere timeline, 2) export via frameserver, 3) encode as flv using Adobe Flash Video Encoder. The problem is that Adobe Flash Video Encoder displays this message where the video should be: "The file has no readable video track." So we'll probably need the additional step which requires AviSynth. Is there an AviSynth code that can make this mxf file readable to Adobe Flash Video Encoder? Or do you see an even better option?

                        And yes, we're definitely interested in your methods of enhancing the image quality.

                        Thanks again,
                        • 9. Re: FLV quality discrepancies
                          Dan Isaacs Level 2
                          > Adobe Flash Video Encoder displays this message where the video should be: "The file has no readable video track."

                          Did you try setting DebugMode to RGB24... RGB32?

                          > Is there an AviSynth code that can make this mxf file readable

                          Not that I know of -- directly anyway. However, if you frameserve the .mxf file(s) from PPro, AviSynth will read it fine.

                          Assuming you are outputting 1080i via DebugMode (as YUY2), try this in an AviSynth script using notepad, save as "fs_to_flv.avs" (requires AviSynth 2.5.7 and the SmoothDeinterlacer, ColorMatrix and GrapeSmoother .dlls in your AviSynth plugins folder):

                          ColorMatrix(mode="Rec.709->Rec.601", clamp=false)

                          SmoothDeinterlace(tff=true, doublerate=true, lacethresh=24, edgethresh=40, blend=false)

                          # converts 60i -> 15 fps. Use SelectEvery(5,0) for 12 fps


                          This will create 440x248 @ 14.985 fps output from your HDV 1080/60i source <- (that's what it is, right?)

                          Open the "fs_to_flv.avs" file in VirtualDub, save it as a lossless .AVI and bring it into the standalone Flash encoder.

                          Does it work?
                          • 10. Re: FLV quality discrepancies
                            I have a flash player and I playing my FLV files off my browser I'm using dreamweaver... I don't understand why my video show horizontal line across the video epically when to camera zooms in or out or the person in front of the camera moves...

                            My website is http://www.untv1.com

                            Can you please help me figure this one out...