10 Replies Latest reply on Feb 7, 2009 7:07 AM by scott mackenzie

    Anybody know about VBR and CBR?

    scott mackenzie

      I'm using PPro CS3 at the moment since I can't get CS4 to work very well on my computer.

      On exporting.

      I would like to export- adobe media encoder -to Flash video and to quicktime.

      I'm sure I used to be able to set VBR 2 pass etc etc with different mbps.

      Have I lost these? Can you point me in the right direction?

      I only seem to have CBR settings?

      I am using CS3 v 3.0 (I don't want to install update to 3.2 as when I did this all audio sync went out by about twelve frames- the ability to batch capture vanished too)


      scott mackenzie
        • 1. Re: Anybody know about VBR and CBR?
          Colin Brougham Level 6
          If you're talking about Flash Video (specifically, On2 VP6), then there is no 2-pass VBR option in CS3. This was added in AME CS4, however. Unfortunately, Flash encoding got *worse* in CS4, in my opinion. I use Sorenson Squeeze for Flash 5, with On2 VP6, and get far better results.

          Re: Quicktime: you may have 2-pass options, but it will probably depend on what codec you use.
          • 2. Re: Anybody know about VBR and CBR?
            scott mackenzie Level 1
            Thanks Colin,

            I will try those settings for flash you suggest.

            • 3. Re: Anybody know about VBR and CBR?
              Level 1
              It got worse in CS4 you say? Huh. I thought they were using the On2
              Basic encoder in Premiere. I bought the Pro version cause I wanted the
              better VBR 2 Pass options, and was kinda annoyed to discover that the
              On2Pro could not be accessed from within Premiere. Have to encode a
              lossless file and then feed it to On2. The odd thing is that the On2
              encoder IS avail directly as an export option out of AE.
              • 4. Re: Anybody know about VBR and CBR?
                Colin Brougham Level 6

                In CS3, you do have access to On2 VP6 through the "Flash Video" option. You can pick from that or the vastly-inferior Sorenson Spark (Flash 6) codec. However, there are no 2-pass options--only 1-pass CBR or 1-pass VBR. Though not great, I was often able to get very good/excellent results using the CS3 media encoder when going to VP6; it rivaled what I was getting with Squeeze for Flash (separate standalone application, with the VP6 codec).

                Then CS4 came out, with the new AME, and they added 2-pass VBR to the Flash options. Excellent, I thought--I won't use Squeeze as much anymore (especially since we all lost the ability to use DebugMode Frameserver to feed our third-party encoding applications). About the same time, Sorenson released a point-update to Squeeze. In my (albeit limited) testing of CS4, I've been pretty displeased with VP6 output, regardless of CBR or VBR, 1-pass or 2-pass, and it appears to me that Squeeze has gotten much better with VP6 for some reason or another. I have to believe that it has less to do with the codec or encoding options and a great deal to do with Adobe's abysmal deinterlacing scheme--Squeeze's method is far superior. As such, Squeeze has once again become very important to my export workflow.

                Another thing: I'm not sure that there is such a thing as a "Basic" or "Pro" version of the On2 VP6 codec. It is what it is. I think, instead, that it is up to the software author (ie. Sorenson, Adobe, or On2 themselves with their Flix software) to take advantage of the various options and parameters that can be set with the codec. I use x264, the open source H.264 encoder, frequently, and some of the various encoding GUIs (x264 itself is strictly a command line application) give access to more or less of the myriad parameters that can be tweaked for the codec. The codec itself contains all possible options defined by the standard--the same should apply to VP6.
                • 5. Re: Anybody know about VBR and CBR?
                  Level 1
                  On2's offers their flash VP6 codec (as well as other flash formats)
                  encoder under their Flix product banner, so yes you are correct in your
                  statement. The basic version seems to have exactly the same interface as
                  the Adobe Flash On2 VP6. The Pro version offers a good deal more bells
                  and whistles.

                  So you feel Sorenson has really got it together with squeeze this time?
                  I used to use them years ago, then they seemed to fall behind and I went
                  with the On2 Flix product.

                  I've been dithering on the CS4 upgrade going back and forth between
                  sinking the money into another Adobe suite, or just going over to Final
                  Cut for about the same price. I lean towards Adobe mostly because they
                  now seem to have dynamic link working from Premiere to AE and back,
                  whereas before it was just one way AE to PR.
                  • 6. Re: Anybody know about VBR and CBR?
                    Colin Brougham Level 6
                    Ah, I see--didn't realize you were talking about Flix and not about the codec itself. I haven't played with Flix in awhile, but just now I looked at the features and screenshots of the program--the Pro variation is, more or less, on par with Squeeze for Flash 5. It appeared that all the same features were available with each program--neither had something the other didn't.

                    I went back and forth for awhile before I settled on Squeeze--which I sort of have a love/hate relationship with. I had a lot of prior experience using squeeze for MPG compression and the like, so I was familiar with the program. However, I always felt that it was kind of clunky, and that you were paying more money for glitz, and because Squeeze ultimately supports more codecs than Flix ever will. I liked that Flix came from the people that developed VP6, and I just felt I'd be getting more out of that particular codec with Flix than Squeeze. In the end, I settled on Squeeze, and I'm fairly happy I did.

                    Because of its architecture, Squeeze is going to provide for much greater latitude when it comes to other encoding options, and provides an upgrade path if you want to go from the Flash flavor of the program to the full-blown version. With Flix, you're stuck with their codecs. If all you ever want is Flash output, then you're probably fine with either--but I think Squeeze offers some other features (pretty good filtering, batch capability and so on). The last build of Squeeze for Flash (for Windows, it's seems much faster and more stable to me than did the first 5.0 version. For instance, there was this really annoying bug where if you input a file with a 29.97 framerate and set the options to "Same As Source", it would round down to 29fps instead of rounding up to 30fps. The result was a one-frame stutter every second--very annoying. The program no longer does this, thankfully. I've found the output quality of the video to be particularly good--it took some tweaking but I'm able to get really good looking video at around 600kbps, 480x360. Here's an example.
                    • 7. Re: Anybody know about VBR and CBR?
                      Level 1
                      Yes, I agree, thats very good quality. The flash products have really
                      been improving by leaps and bounds. I would almost say there is no
                      reason to put up a web video in any other format unless you wanted the
                      user to be able to easily D/L it as well.
                      • 8. Re: Anybody know about VBR and CBR?
                        scott mackenzie Level 1
                        Hi Colin,

                        The quality of your video is very good.

                        Just to check, what were the settings you used?

                        PPro CS4 / sorenson squeeze / vbr 2 pass etc

                        many thanks

                        • 9. Re: Anybody know about VBR and CBR?
                          Colin Brougham Level 6

                          That particular video was encoded using VP6 2-pass VBR, 650kbps, 480x352, from Sorenson Squeeze for Flash v5.0.4.10. I use the VP6-E profile--the VP6-S profile is more if you're exporting HD-sized videos, but since this is originated from SD there's no need to incur extra decoding cycle. I turn on auto keyframes, and generally leave it around the Squeeze default; you may need to edit this setting depending on the footage you're encoding. Leave compression speed set to "best"--this is a counter-intuitive setting that actually should be labeled "compression quality" or have options ranging from "slow" to "faster". "Best" means the encoding runs slower, but results in a higher quality output. Strange, but true.

                          I crank the minimum quality slider up to about 70-75; this keeps the compressor from getting a little too overzealous. I find that it prevents some blockiness when transitioning from one scene to the next--and in my experience, the added file weight is pretty minimal for the quality gained. If you have fairly static footage with few transitions, you can gain better compression ratios by leaving the minimum quality slider set to a lower threshold. It's these settings that let VBR do its thing.

                          I never, or at least I haven't yet, enabled the "drop frames" setting. Unless you're trying to compress and distribute HD-sized videos, I think the prevalence and speed of high-bandwidth Internet connections negates this. On the other hand, if you need to stay within a certain bitrate threshold, like for some sort of hardware playout device, you'll probably have to experiment with this in order to produce files that meet the requirements of the hardware. For general web distribution, I've never found the need for this.

                          For sharpness and noise pre-processing, you'll again have to experiment. There's no magic number for these: it's going to depend on your footage and your tastes. They will both slow down encoding, and can have either a positive or negative effect on your video. I will sometimes use noise pre-processing if I'm encoding from DV or the like, to try to eliminate some of the noise and grain. This makes for a more efficient encode, because the compressor isn't trying to preserve details you don't want to see. These two settings sort of need to work in concert with each other, because one is going to blur the footage to remove noise, and the other is going to sharpen it and bring it back to a certain extent. I suggest experimenting with a short section of video, going with the extremes and then a couple settings in the middle--you'll quickly see the difference. I probably had sharpness set to 5-7, and noise pre-processing set to about 1-2, for this particular video. I think the result is quite clean.

                          Finally, I leave the minimum/maximum VBR and undershoot settings where they are--haven't needed to tweak these yet. These get pretty technical, and are again really the crux of VBR 2-pass encoding. They are what allow the compressor to "bit budget" an allocated bitrate for a given passage of video, and make sure that the final output stays as close as possible to that allocated bitrate. So far, the defaults have done the trick for me.

                          One note that I should probably explain, and that's to do with frame size. You might notice above that my output dimensions are 480x352, and not 480x360, as you might expect for a 4:3 video. This is because On2 VP6 (and many other codecs, like H.264) operate optimally in what is called mod16. What this means is that a mod16 codec will first break an input stream into 16x16 blocks, then 8x8 blocks, and then other sizes like 8x4 and 4x4. If you use a dimension that is evenly divisible by 16 (like 352 pixels high) you maximize the efficiency of the codec. I suggest doing this by cropping, and then scaling--not by scaling alone. I typically leave the "Maintain Aspect Ratio" radio button selected in the options, set one dimension (height or width, whichever), and then experiment with the crop filters until you get the other dimension evenly divisible by 16. Once you find the magic number, save the crop filter as a preset and save yourself some headache later! The crop filter will have to change depending on your export size--sometimes you'll crop vertically, and sometimes you'll crop horizontally. And it will also change if you're exporting to a 16x9 file. Sadly, that math stuff we all got into video to avoid will rear its ugly head yet again ;)

                          Good luck, and let me know if you need any other assistance. The biggest thing to remember is that there is NO magic formula to encoding, regardless of the source footage, the destination, or the codec used. Experimentation is really the only way.
                          • 10. Re: Anybody know about VBR and CBR?
                            scott mackenzie Level 1
                            Hi Colin,

                            Thanks for your reply!!

                            I am new to encoding for the web and really need to get my head round this. I love the quality of your video.

                            Here is an example of one of mine.


                            I recorded it on a sony v1e 25fps progressive and exported to quicktime 1280x720 at 10mbps etc.

                            I still think it doesn't look as good as yours!!

                            I will keep trying.