22 Replies Latest reply on May 9, 2009 12:48 PM by Techshoot

    2 channel audio import problem

    Techshoot

      Hi - I've got some footage recorded with audio on both channels, on a Sony Z1.  When I import into a Matrox sequence in prem, an extra audio track appears beneath the standard one on audio1 track as expected,  but there is no audio on it - it is all on audio track 1.

       

      Not sure what I'm doing wrong - i've set audio up on cam to record audio on ch1 & ch2 seperatly from both XLR sources and that is borne out when listening to playback from the cam, as you can hear the seperate audio through headphones.

      I've tried several different settings in capture but always the same result.  During capture thru prem, the audio monitor appears showing both channels but only one appears active during capture.  I realsie this is likely to be a cam setting issue, but could do with some guidance.

       

      System is prem CS4 / matrox rtx.2 / Vista 32/ 4gb ram / 2x xeon quad core / capture from Sony GDV300 deck/

       

      Source is shot on DVCAM tape / SD / 48k audio.  prem sequence is matrox SD/PAL widescreen.

       

      Many thanks

        • 1. Re: 2 channel audio import problem
          Harm Millaard Level 7

          Make sure that in your sequence settings you have source stereo tracks set, as they are by default. The behavour you mention could very well be caused by setting the tracks in your sequence as mono.

          • 2. Re: 2 channel audio import problem
            Techshoot Level 1

            OK, I'll check that - but I would have thought that even if they were set to mono, there would be mono audio on each audio track.

             

            Thanks

            • 3. Re: 2 channel audio import problem
              Harm Millaard Level 7

              When you record with both channels (left and right) enabled, it is as if you are using a single stereo mic, at least for the data recording. They can be completely different mics, recording different sounds, but they are treated as a stereo signal. When you transfer the data during capturing, which is nothing less than a digital transfer of data, nothing changes. The computer sees it as a single stereo track, even though the left and right channel may be completely different. It makes no difference for the computer. If you need to separate the two channels, first copy the audio track to a new track, use fill left on one track and fill right on the other track. That effectively separates the two channels into separate tracks.

              • 4. Re: 2 channel audio import problem
                Techshoot Level 1

                Hi, that is very interesting - didn't realise that, but then Ive never needed to seperate the audio before.  I will try this out tomorrow, thanks for the advice.

                • 5. Re: 2 channel audio import problem
                  the_wine_snob Level 9

                  Per Harm's suggestion, look at your Audio Tracks (the Header to the left of the Timeline). Do you see one "speaker" icon in the empty Track, or two? In the "new" Track, do you see one speaker, or two?

                   

                  Now, for your Track with the Audio, Open up Audio Mixer Panel and take a look at it, while you play. Do you see only one VU meter, or two?

                   

                  If your Sequence is set up with only mono Audio Tracks, PrPro will "create" appropriate Audio Tracks to match your source material, and these will usually be "below" any existing Audio Tracks. Do not know if that last statement holds true with CS4 and Track Targeting - might create elsewhere in the hierarchy.

                   

                  Good luck,

                   

                  Hunt

                  • 6. Re: 2 channel audio import problem
                    Jim_Simon Level 8

                    The computer sees it as a single stereo track, even though the left and right channel may be completely different.

                     

                    Well, to be more accurate, Premiere treats them as a single stereo track.  Avid does properly see the file as having two separate audio channels requiring two audio tracks in the sequence, either of which can be routed to any output speaker, or even both.  (This would make another nice upgrade to Premiere Pro, I think.)

                    • 7. Re: 2 channel audio import problem
                      Techshoot Level 1

                      Hi,  the header for audio track 1 - where the audio is residing - shows one speaker icon;  audio track 2 - the 'silent' track - also shows only one speaker icon.

                       

                      The mixer window shows only one VU meter.  ( the audio monitor window that opens during capture shows 2 but one is silent with no activity)

                       

                      Ive tried toggling on and off etc but no difference.

                      • 8. Re: 2 channel audio import problem
                        Jim_Simon Level 8
                        the audio monitor window that opens during capture

                         

                        This suggests you're capturing with a Matrox preset.  Try not doing that, using a normal DV preset.

                        • 9. Re: 2 channel audio import problem
                          Techshoot Level 1

                          Hi, I've had a look at trying this - but I don't see an option to fill left or right - I do remember that option on my old prem 6.5 tho.

                           

                          When I look at options / actions for the clip - under audio options, there are 4/5 commands and include one called 'source channel mapping'  which sounds promising - but they are greyed out!  (exc 'audio gain')

                           

                          Any suggestions?

                           

                          Many thanks

                          • 10. Re: 2 channel audio import problem
                            Techshoot Level 1

                            OK will try as soon as  I can.

                             

                            Many thanks

                            • 11. Re: 2 channel audio import problem
                              Techshoot Level 1

                              Sorry Jim, forgot to ask - do you mean try capturing to a DV preset project?  Or did you mean set my capture settings to DV, not Matrox?

                               

                              Thanks

                              • 12. Re: 2 channel audio import problem
                                Jim_Simon Level 8

                                Both.

                                 

                                Also, in Premiere Pro the Fill commands are now effects, not Menu options.  They're in the Audio Effects folders.

                                • 13. Re: 2 channel audio import problem
                                  Techshoot Level 1

                                  Hi Jim, OK thanks thats a big help - I'll check it as soon as poss.

                                   

                                  Do you know why the 'source channel mapping' option is greyed out and, more importantly - what does it do?

                                   

                                  Thanks

                                   

                                  Frank

                                  • 14. Re: 2 channel audio import problem
                                    the_wine_snob Level 9

                                    This indicates that the source file is mono.

                                     

                                    Hunt

                                    • 15. Re: 2 channel audio import problem
                                      Techshoot Level 1

                                      Hi Hunt

                                       

                                      'This indicates that the source file is mono.' 

                                       

                                      The audio track clearly shows it to be stereo and also, if I open the track in the source window I can see that is stereo by the different waveform patterns so its definately a stereo track.

                                       

                                      Any other reasons why 'source channel mapping ' is greyed out?

                                       

                                      All responses welcome.

                                       

                                      Many thanks

                                      • 16. Re: 2 channel audio import problem
                                        Harm Millaard Level 7

                                        I don't know why it is greyed out because I do not know how your project is setup in detail. It is not greyed out here, but I have a master 5.1 track. Maybe that could account for the reason. However that is only for playback on the computer. Channel mapping is intended to map the audio to a specific speaker if you so desire. See the help file for more info. I don't see the relevancy to your problem of this channel mapping.

                                         

                                        Is your import problem, using non-Matrox material and a non-Matrox but standard Adobe preset fixed by using any of the suggestions above or not?

                                         

                                        If not, please supply details on your sequence settings, capture method and attach a screenshot of your timeline.

                                        • 17. Re: 2 channel audio import problem
                                          Stan Jones Adobe Community Professional & MVP

                                          I have CS3, but I assume this is the same in CS4.   Another reason channel mapping may be greyed out is that it can only be used before a clip is used in a timeline.  Once used, you can no longer use channel mapping.

                                          • 18. Re: 2 channel audio import problem
                                            the_wine_snob Level 9

                                            What the single "speaker" indicates is that PrPro "thinks" that it is mono, regardless of what the original source material indicates. Why? I do not know, but that might be part of the problem.

                                             

                                            Good luck,

                                             

                                            Hunt

                                            • 19. Re: 2 channel audio import problem
                                              the_wine_snob Level 9

                                              In the Audio Effects, there are Mono, Stereo and 5.1 Effects. Fill-Left and Fill-Right should be in the Mono sub-folder, unless CS4 moved things.

                                               

                                              Good luck,

                                               

                                              Hunt

                                              • 20. Re: 2 channel audio import problem
                                                Techshoot Level 1

                                                Hi Hunt / Harm,

                                                 

                                                thanks for that - I can't test now until Monday, but very useful advice - I get the mapping function now I think, and  will go to audio effects and try the fill options.  I'm confident that will seperate the L & R channels for me.  I just need to work on setting variances to get the second audio track active.

                                                 

                                                Can I just explain how I am recording audio on the Z1 - I have a mic input on ch1 and another on ch2;  In the menu, I have these channels seperated and I can monitor the seperate inputs thru headphones.    When this footage is captured, 2 VU meters appear, but only one active and when the clip is placed on the timeline, an extra audio track appears below audio track1 - albeit silent.

                                                 

                                                In the camera menu, if I switch ch1 and ch2 inputs to both go to ch1 - instead of seperating them - this footage when captured, only has the normal, single audio track.

                                                This is what makes me think it is a setting issue also and something in prem.

                                                 

                                                Thanks for your input - appreciated.

                                                • 21. Re: 2 channel audio import problem
                                                  Harm Millaard Level 7

                                                  In the camera menu you need to set to XLR CH SEL to CH 1, not to CH1, CH2, because that setting effectively makes the first XLR mic behave as a stereo mic, by copying the track to both channels. This is clearly displayed in the menu when you set up the camera. If you have done this correctly, then your capture/sequence settings may be wrong. Can you post a screenshot of your sequence settings?

                                                  • 22. Re: 2 channel audio import problem
                                                    Techshoot Level 1

                                                    Hello Harm,  yes that is how Ive set it up - XLR CH sel is set to CH1.

                                                     

                                                    I will send a screenshot of settings on Monday when I am back at work.

                                                     

                                                    Many thanks