18 Replies Latest reply on Jan 27, 2009 4:32 PM by director.lionel

    Is my audio doomed?

    director.lionel Level 1
      We shot the footage for my feature-length film with the Sony F-900, using Sony HDCAM tapes. My DP was a first timer. He thinks he may have recorded the sound at 20 bit depth, since he guesses that this is the camera's default (The sound recordist was relying on the DP to make the setting, so he doesn't know either.)

      Not being certain which would be the right setting, I captured the audio at 24-bit depth. However, the captured audio seems to have static and distortion. Could the discrepancy (or inaccuracy) in bit-depth be the problem?

      If so, is there anyway to fix it without having to recapture all the audio? I started to do a lot of editing with the audio already. My hearing is poor, so I didn't notice the problem until too late.

      Any thoughts?
        • 1. Re: Is my audio doomed?
          There is a possibility soundbooth can do something for you? I'm not very adept with soundbooth, try some of those gurus from the soundbooth forums, otherwise call up a professional audio house or reshoot!
          • 2. Re: Is my audio doomed?
            the_wine_snob Level 9
            lionel,

            I would say that your "static" is more likely caused by the Audio being recorded at too high a level (overmodulated) and is the result of clipping, rather than sample-rate and bit-depth.

            If you have Audition, or Soundbooth, the first thing that I would do is open the Audio files there and study the Waveforms closely. This will also tell you exactly what sample-rate and bit-depth was actually used. It seems that there is still some question on what setting was used in the camera. If you do not have either handy, try the freeware, Audacity. You'll have far less processing options in it, but it should still show the Waveforms. Look closely at the peaks. Also watch the meters, and be aware of any spikes going above 0db (into the red).

            If you DO have clipping, Audio material has been lost and spurious signals likely introduced. You *might* be able to re-process your Audio to minimize the distortion, but will likely not be able to fully reclaim it. If you do have clipping, then I would do exactly as JousmaJett suggests and post to the appropriate audio program forum. As you will now know exactly what the specs of your Audio file are, be sure to tell the audio guys what you have. Also give them info that you observe, when playing the file. There are a lot of tricks to improve the Audio, and they can probably get you started. Whether it will save you having to reshoot will have to be determined. Maybe, but maybe not. You will likely only be able to start with a preset, and the rest will be by trial and error.

            I will refrain from giving a lecture on the importance of a "sound guy," as you do not need to hear that now. You have some Audio to save, if at all possible. Hope you can save it, without the reshoot.

            Good luck,

            Hunt
            • 3. Re: Is my audio doomed?
              Jim_Simon Level 8
              >I will refrain from giving a lecture on the importance of a "sound guy," as you do not need to hear that now.

              Well...sometime before the next shoot might be good.
              • 4. Re: Is my audio doomed?
                the_wine_snob Level 9
                Jim,

                That is for others to address. Thanks for taking up the standard.

                Hunt
                • 5. Re: Is my audio doomed?
                  director.lionel Level 1
                  Jousma: Actually, I do have soundbooth and tried using it. Problem is with my hearing, I'm not accurately interpreting the results. People are telling me there's all kinds of distortion in the audio after I do clean up work. Yeah, I may have to try someone in audio.

                  Bill: When I look at my clips in soundbooth, I don't see a lot of clipping, but what I do see is a lot of orange "snow" in the background, showing the static noise. How do you use soundbooth to see what the originally recorded bit depth was? I know that I captured with ppro in 24 bit from what I can see in "properties" in ppro. I just don't know what we did when we shot it. I do suppose I could take a tape to a post house and have them figure out what bit depth it was, if all else fails.

                  I did have a sound guy on my shoot. If you mean, a sound guy for editing, no I haven't had one.

                  Either way, I don't think I need to reshoot anything. I let one guy at a post house take some footage from a couple of my takes to make a reel for one of my actresses. According to her, there was no problem with the sound. That's why I suspect something happened during the capture off the tapes into my system.
                  • 6. Re: Is my audio doomed?
                    Jim_Simon Level 8
                    >I did have a sound guy on my shoot. If you mean, a sound guy for editing

                    No. What we meant was that the sound guy on the shoot is the one responsible for the quality of the audio. He should not have left anything up to the DP, whose primary responsibility is the image. If the audio guy couldn't hear the problem live, then one of three things is to blame. Either he doesn't have the right equipment (headphones) for the job, he's just not good enough for the job, or as you found there's nothing actually wrong with the original audio.

                    (On a side note, I recall working with one sound recordist who I swear could hear a spider walking across a carpet in the other room.)
                    • 7. Re: Is my audio doomed?
                      the_wine_snob Level 9
                      lionel,

                      I do not have/use Soundbooth, so this might differ with Audition. There, the properties are displayed along the bottom right of the edit screen. It *ought* to be similar in SB. If not, look in Window (top of the Menubar) and see if there is a "Properties" Panel.

                      Even with poor hearing, a good pair of noise-canceling headphones will go a very long way to helping you edit the Audio. Unless you have a well-setup editing booth, using monitors, in lieu of headphones, will be difficult.

                      Good luck,

                      Hunt
                      • 8. Re: Is my audio doomed?
                        director.lionel Level 1
                        hey guys, do you know of a post studio in L.A. that would let me bring in a few of my tapes to figure out the recorded bit-depth and actual sound quality for a reasonable rate?

                        (Bill: I don't think soundbooth has a properties panel.)
                        • 9. Re: Is my audio doomed?
                          the_wine_snob Level 9
                          lionel,

                          Thanks for the update on SB. I had the beta, but never used it, because of Audition doing all that I needed.

                          Now, I do not know of an Audio post-house in LA.

                          However, if you have a sample of your Audio file, attach it in an e-mail to me - look at my profile. Make sure that you put Adobe Premiere in the Subject Line Header, so that MailWasher does not flag it for deletion. I'll be happy to look at it, and make suggestions on it. Remember, my perspecitve is from the NLE end of things. I had two blocks of Audio in film school, but that was many decades ago. Still, I handle all of my Audio work in an Adobe program. I'll run this attachment through Audition, and comment on anything that I can find. Plus, if I find anything that Audition can handle, I'll send back an edited version for you to test with your production team.

                          Hunt
                          • 10. Re: Is my audio doomed?
                            director.lionel Level 1
                            Thanks, Bill. I'll try to send you a couple audio clips to see what you think after I set it up.
                            • 11. Re: Is my audio doomed?
                              the_wine_snob Level 9
                              lionel,

                              I will be looking. Just make sure to put Adobe Premiere in the Subject, so I do not miss it.

                              Hunt
                              • 12. Re: Is my audio doomed?
                                Level 1
                                Does the audio sound OK when played back on the camera using headphones? (and if you can't hear it to tell the difference then you need to find someone who can. That might be a problem throughout the process of editing-hearing, I mean). If it sounds fine while being played back on the camera it should be fine. You are just having a problem downloading and need to find the proper settings.

                                Jim's point about a experienced, reputable, capable sound guy (and DP for that matter)is relevant here again (especially if YOU can't hear). You should not have recorded one minute of footage for this without having recorded and played back video on a good monitor and audio through great headphones. Experienced, reputable, capable people do not let this happen. If they were free-then you got your moneys worth. Soory to kick you when you are down but....
                                • 13. Re: Is my audio doomed?
                                  director.lionel Level 1
                                  hi Robert. I need to find someone who can help me listen to my HDCAM tapes to hear the actual quality. I no longer have the camera or capture deck. Please let me know if you know of a facility in L.A., who would let me do that. I'm willing to pay a reasonable rate.
                                  • 14. Re: Is my audio doomed?
                                    Level 1
                                    I imagine there are many thousands of production houses in the LA area. Using a phone book, or other such business directory, call as many as you need to to find one that will help you. You might also consider equipment rental houses which there are probably hundreds of. They may let you use a camera to listen to your audio?

                                    Are you REALLY producing a feature film?
                                    • 15. Re: Is my audio doomed?
                                      director.lionel Level 1
                                      Robert: Yes, I am producing a feature film, but I'm just a small, indie producer with an even smaller budget. It seems you haven't communicated with many who are like myself.
                                      • 16. Re: Is my audio doomed?
                                        Level 1
                                        No, I think he's just a little bit surprised that you don't already have
                                        connections with others in the industry since I know for a fact you
                                        can't swing a cat without smacking one kind of production house or
                                        another in LA.

                                        But, like he says, drop in a couple local places. Should not be too hard
                                        to find someone who would help.
                                        • 17. Re: Is my audio doomed?
                                          Level 1
                                          You are correct lionel. I have not communicated with many who are like yourself.
                                          • 18. Re: Is my audio doomed?
                                            director.lionel Level 1
                                            hi raymond: I've made and been making the calls. But it's always better to get a referral from someone who has personal experience with another. You don't know whom you can trust or what the quality is. And it was very eye opening to talk to many post places who didn't have the service I needed. I finally found someone who let me check my tapes, and there is a bit-depth discrepancy, which is where my problem is. I'll need to re-capture the audio.