12 Replies Latest reply on Jan 25, 2010 11:59 AM by Dag Norum

    Adobe Premiere Pro audio distortion

    str4ngS Level 1

      Hi,

       

      I have Adobe Premiere CS2 and some audio distortion problems. I captured a footage from my Sony DV Digital-8 camcorder. It's a standard DV footage with 16-bit PCM audio. When audio is nearly-peaking (not peaking), it gets distorted in Premiere, but doesn't in other applications (VirtualDub, Media Player Classic, Windows Media Player, mplayer). I'm sure this is because an internal conversion (called conforming) from 16-bit PCM to 32-bit floating point PCM. Project Setting of the Audio Track is 48000Hz 32bit floating point - Stereo for a DV project, despites DV standard supports 16 or 12 bit Audio tracks. In user manual they write the following:

       

      "For maximum editing performance and audio quality, Adobe Premiere Pro processes each audio channel, including audio channels in video clips, as 32-bit floating-point data at the project’s sample rate. To do this it must conform certain types of audio to match the 32-bit format and the project sample rate."

       

      Well, if I'm a professional video editor, I can (and have the right to) decide whether which sample rate and bit-depth are the best for me, but they don't let me set audio other than the default, there is no option like bit-depth available not even when creating a NEW project. No problem if Adobe's genius developers thought 32-bit mixing provides much more quality, but if they forget to implement 16-bit to 32-bit internal conversion correctly, please let me decide to use at least a fallback method.

       

      Thanks for your help
      stringZ

        • 1. Re: Adobe Premiere Pro audio distortion
          Harm Millaard Level 7
          I'm sure this is because an internal conversion (called conforming) from 16-bit PCM to 32-bit floating point PCM.

           

          I disagree. I'm sure this is because the mic was too hot. Either reshoot or accept that the audio levels were too high. Avoid that in the future.

          • 2. Re: Adobe Premiere Pro audio distortion
            Jeff Bellune Adobe Community Professional

            No problem if Adobe's genius developers thought 32-bit mixing provides much more quality, but if they forget to implement 16-bit to 32-bit internal conversion correctly, please let me decide to use at least a fallback method.

            Welcome to the forum.  May I suggest, that as the new guy here, you show up with a better attitude than that?

             

            Do you have a specific question?  If so, you need to do a better job of forming that question.  Your post comes off as more of a rant.

             

            -Jeff

            • 3. Re: Adobe Premiere Pro audio distortion
              str4ngS Level 1

              Thank you for your answers.

              I disagree. I'm sure this is because the mic was too hot. Either reshoot or accept that the audio levels were too high. Avoid that in the future.

               

              Then I'm curious why the distortion is not present in any other applications other than Adobe Premiere Pro. You can disagree, yes, and I'm so glad about that you don't have to waste your time posting here getting disagreements as answer. I'm sure the the mic was too hot, but not too hot to cause serious distortion. Afterwards I exported the audio from the footage to WAV using mplayer's PCM output. This is basically a stream copy. Then I re-imported the separate audio track into Premiere and voila, no distortion. This proves that Premiere is the bad guy.

               

               

              Welcome to the forum.  May I suggest, that as the new guy here, you show up with a better attitude than that?

              Do you have a specific question?  If so, you need to do a better job of forming that question.  Your post comes off as more of a rant.

               

              I'm sorry, no offense, I appreciate your suggestion. If you think I did a bad job forming my question, then it was just as bad as Premiere's DV audio handling in this case. By the way, yes, I have a question: How can I fix this? No I won't re-shoot the scene, because I know I don't need to. If other applications read the audio track correctly, without distortion, then I don't need to. I paid good money for Adobe Premiere and I'm disgusted with this case, REALLY. What attitude should I have? I paid hundreds of dollars for a software which seems to be failing at a BASIC THING. As a community professional you could understand.

              • 4. Re: Adobe Premiere Pro audio distortion
                Jeff Bellune Adobe Community Professional

                Since this is version 4 of Premiere Pro, and since Premiere did DV for 2 versions before Premiere Pro was written, it's reasonable to assume that Adobe's developers know how to handle 16-bit, 12-bit and 32-bit float audio when they write the app.

                 

                For you to show up here claiming incompetence on their part is arrogant on your part.  You asked what attitude you should have?  One with less condescension and a more open mind.

                 

                It's more likely that your source audio or your workflow is the root of the problem.  But maybe not.  My mind is open to the possibility that, in this case, it might be a Premiere problem.

                 

                -Jeff

                • 5. Re: Adobe Premiere Pro audio distortion
                  the_wine_snob Level 9

                  I use PrPro 2.0, and have never encountered this behavior. Now, I am very careful with my Levels, but never have any distortion, if I have done things correctly. I agree with Harm, your signal is too high at the time of recording.

                   

                  Good luck,

                   

                  Hunt

                  • 6. Re: Adobe Premiere Pro audio distortion
                    str4ngS Level 1
                    Since this is version 4 of Premiere Pro, and since Premiere did DV for 2 versions before Premiere Pro was written, it's reasonable to assume that Adobe's developers know how to handle 16-bit, 12-bit and 32-bit float audio when they write the app.

                     

                    I agree, it's reasonable to assume and I want to believe in most cases it works correctly, but in my case it doesn't. I've attached a sample, test-avi.zip (it's a compressed ZIP archive containing a file test.avi). This is a DV-type 2 (PCM AUDIO) blank video with nearly-peaking audio track, that plays correctly (without noticable distortion) with Windows Media Player, Media Player Classic, VirtualDub, MPlayer, but causes a heavy distortion in Premiere Pro. If you're open minded, I like that, so try it for yourself. Import it to Premiere Pro then double-click on it to take it in the Source Window. Start playing it. You'll hear the first distortion in the right channel at 00:00:00:21. I'm sure you have one of the media players mentioned above, if not, get mplayer from http://smplayer.sourceforge.net/ or http://www.mplayerhq.hu/design7/dload.html then play the sample with it, there will be no distortion. You can try it out using Media Player Classic or anything else than Premiere. I'm pretty sure you won't experience serious distortions.

                     

                    I know this sample is an extreme one, and I agree with people who say I should pay more attention to my peak levels or say I should never produce peak levels that this clip has. This was made to show you (reproduce) the problem.

                    • 7. Re: Adobe Premiere Pro audio distortion
                      Harm Millaard Level 7

                      Just looking at the waveform confirmed my initial reaction: Way, way oversteered. Everything is clipped and your best approach is to reshoot. That some players can handle this seriously mistreated audio may be caused by audio limiters. They should, otherwise you would blow up your speakers.

                      • 8. Re: Adobe Premiere Pro audio distortion
                        str4ngS Level 1
                        Just looking at the waveform confirmed my initial reaction: Way, way
                        oversteered. Everything is clipped and your best approach is to
                        reshoot. That some players can handle this seriously mistreated audio
                        may be caused by audio limiters. They should, otherwise you would blow
                        up your speakers.

                         

                        Well, you can say that and if this sample was a music maximized with compressors, it would distort too. Sony Digital-8 camcorder has an internal limiter, so only soft-peaking can occur, but no serious distortion. Media Players (eg. mplayer) don't have limiters unless you specify an external limiter filter. I've already told this isn't the clip you want me to re-shoot. This is a sample I created to show you the problem. I sent this to one of my friends who has Ulead MediaStudio Pro 7.0. It doesn't distort there either. Have you tried loading it to an audio editor like Audacity or Adobe Audition? You can see no hard-peaking or distortion if you zoom in the waveform.

                         

                        no_distortion_here.png

                        Waveform at 00:00:00:21. No distortion, only high levels can be seen on this waveform.

                         

                        right_peaking_here.png

                        Waveform after 00:00:00:21. Soft peaking in right (bottom) channel.

                         

                        I'd appreciate if someone took this seriously instead of repeating "reshoot it" and "high levels".

                        • 9. Re: Adobe Premiere Pro audio distortion
                          Jeff Bellune Adobe Community Professional

                          The left channel is clean, but the right channel is completely clipped starting at that timecode.  I examined it in Audition, Soundbooth and Premiere.  Something else is wonky with it as well, because GSpot doesn't list any audio data for the clip at all, other than it exists.  GSpot always properly identifies my DV audio.  SonicFire Pro won't import the audio from the clip, yet it imports all of my DV audio.  Premiere doesn't recognize its audio properties, yet Premiere correctly identifies all of my DV audio.  In short, your source audio is the problem.

                           

                          WMP, MPC-HC and Adobe Bridge all play the clip without distortion.  I don't know why.  But if Audition 3 shows clipped audio, and the distortion starts when the clipping starts, then you can bet the audio is clipped at the source.

                           

                          Is this a DV .avi captured right off the camera?  Which camera?  Which software was used to capture?

                           

                          -Jeff

                          • 10. Re: Adobe Premiere Pro audio distortion
                            str4ngS Level 1

                            Jeff, thanks for trying it out.

                            WMP, MPC-HC and Adobe Bridge all play the clip without distortion.  I don't know why.

                            I know why, because Premiere can't handle it correctly and according to you Audition can't either - they may use the same source filters or decoders.

                             

                            Is this a DV .avi captured right off the camera?  Which camera?  Which software was used to capture?

                            Yes, this was captured right off the camera using Windows Movie Maker. My camcorder is a Sony DCR-TRV355E. I asked my friend to re-encode it using Ulead VE 7.0, he sent it back to me, guess what? The distortion is gone (in Premiere) even with PCM audio. So may WMM generate nonstandard DV AVI files? Still shame on Premiere in comparison with cheap or free Media Players.

                             

                            Btw, what DV type do your videos have? DV-Type 1 (DV AUDIO) or Type 2 (PCM AUDIO)?

                            • 11. Re: Adobe Premiere Pro audio distortion
                              Jeff Bellune Adobe Community Professional

                              WMM creates a type-1 DV .avi file.  Pr only works with type-2 DV .avi files.  Ulead (and Sony!) both work best with type-1 DV .avi files.  It's time to compare apples to apples.

                               

                              Capture the clip with Pr.  What happens?

                               

                              -Jeff

                              • 12. Re: Adobe Premiere Pro audio distortion
                                Dag Norum Level 2

                                A couple of side comments,

                                 

                                I know why, because Premiere can't handle it correctly and according to you Audition can't either


                                In my opinion, to handle audio correctly is NOT to do any modifications when it comes to level or bandwidth, like soft-clipping (aka level adjustments at small parts of the audio), frequency filtering like high pass or low pass (sort of also done when soft-clipping).

                                 

                                Up-sampling on the other hand, done correctly though, is quite another thing, and usually quite acceptable. Won't gain anything except for no further losses when audio worked on, and, will for sure not lose anything except for some time waiting for the conforming.

                                 

                                Now, that an up-sampling algorithm will/can do strange things when input level is to high, is quite normal and how I would prefer it to be. It then gives me a warning that something is wrong with my original audio and I can correct/adjust it in a program suited for such (like Audition).

                                 

                                If any auto-correction should be done in Premiere, I would for sure want to be warned about that and have the possibility to turn it off.

                                 

                                PS! I do also understand that some want the "life light" when it comes to "hot" audio.

                                 

                                Dag

                                 

                                PPS! I'm not defending Premiere's way of up-sampling, it's just that there are more views than one on what's correct.