11 Replies Latest reply on Jan 6, 2013 2:42 PM by mjdanek13

    Audio just cuts off suddenly


      I was working on a particular project last week and all was fine. I worked on others in the meantime and now this morning when I opened the project the main soundtrack (Audio 3) has half disappeared - please see attached.




      This is not the first time this has happened. OK, with a bit of work I can replace it but if this is a known phenonmena then for the future I'd like to avoid doing whatever it is I'm doing wrong.


      I have the very latest version of PrePro, all files are on an external Caldigit AV Drive with masses of free space and I'm using either an up-to-date iMac or this year's MacBook Pro depending on availability.


      Thanks in advance for any guidance etc.

        • 1. Re: Audio just cuts off suddenly
          the_wine_snob Level 9

          What is the format/CODEC of the Audio file that is now truncated?


          Audio file truncation is most often seen when, upon Import, the Conforming is not allowed to complete. However, if this file was NOT truncated, after the initial Import, and Conforming, I cannot think of anything that would cause it to truncate later.


          When played in the Source Monitor (which is directly from the HDD, unlike when you play it from the Timeline), does the full Duration play there?


          If you choose Render Replace, does that change the file on the Timeline?


          If you use the Match Frame function, does that change the file on the Timeline?


          Good luck, and hope that others have expereince with this behavior.



          • 2. Re: Audio just cuts off suddenly
            briantho Level 1

            The clip (which is both audio and video) is:


            File Path: /Volumes/CalDigit2/AvenueQ/AveQfootage/AvQTM300NewCAM_MEM/AVCHD/BDMV/STREAM/00000.MTS

            Type: MPEG Movie

            File Size: 4.0 GB

            Image Size: 1920 x 1080

            Frame Rate: 25.00

            Source Audio Format: 48000 Hz - compressed - Stereo

            Project Audio Format: 48000 Hz - 32 bit floating point - Stereo

            Total Duration: 01:00:20:04

            Average Data Rate: 1.1 MB / second

            Pixel Aspect Ratio: 1.0



            As I mentioned, the clip was fine last week during the many hours I was editing it, first using multicam and later when adding chapter points etc. Conforming, as I understand it, would have been done at the beginning, yes?


            Maybe there a file which contains 'conforming' information which perhaps I could delete so that Premiere is forced to Conform again or doesn't it work like that?


            The problem shows up in exactly the same way whether the clip is Imported or Opened in the Source Monitor. The video clip is about an hour but the audio part simply stops at around 28 minutes.


            I did a Render and Replace for that part of the clip (I chopped it down to a minute before the point when the audio just stops and a minute after) but the ouput of the process has exactly the same problem.


            Match Frame doesn't appear to have any effect. The clip plays in the Source Monitor in exactly the same way with the audio cutting out in the same place.


            I have trashed the preferences (in Finder I went down the path: me, Documents, Adobe, Premiere Pro and under that I moved the entire directory "5.5" to trash).


            I went back into Premiere, Premiere Pro, Preferences, Media, pressed the Clean button, OK. I exited Premiere Pro and rebooted the machine, I created a new project and using the Media Browser I Imported the file, right click, New Sequence from Clip, but the audio stops in exactly the same place.


            In desperation I started up Final Cut Pro and did a Log and Transfer and once that had finished the full created clip is just fine with audio all the way through. So it has to be some other pointer in Premiere that I need to delete/reset (or whatever) which has become screwed up for this particular clip. I have three other clips (from three other camcorders used at the same show) and they are just fine. Please, any more ideas? Anything else I could try?

            • 3. Re: Audio just cuts off suddenly
              the_wine_snob Level 9

              Thanks for the details, and results of the tests. Those data will help others.


              The clip plays in the Source Monitor in exactly the same way with the audio cutting out in the same place.

              OK, next test. Go to that original file on the HDD, and play it in a compatible software player. Do you then get the full Duration?


              Good luck,



              • 4. Re: Audio just cuts off suddenly
                briantho Level 1

                Well I'll certainly try that but in view of the fact that FCP was independently able to injest the clip and both the video and the entire audio came out perfectly for the complete duration of the clip I've got a feeling that there's no problem with what's on the HDD but rather with some pointer (or whatever) within Premiere that needs resetting, deleting or something similar. This happened on another project some weeks ago so I'm really interested in what can be done. Any ideas?

                • 5. Re: Audio just cuts off suddenly
                  Harm Millaard Level 7

                  Clean your media cache, open the project and let the indexing, conforming and creating peak files complete before starting editing again.

                  • 6. Re: Audio just cuts off suddenly
                    briantho Level 1

                    Thanks for that but unfortunately that gives exactly the same result - see penultimate paragraph in my second post. I have a project with only that clip in it cut down to a minute before and a minute after the audio cut off point. Apart from what you suggest and trashing the preferences (I assume I'm trashing the right files, also detailed in the same post above) is there something else I can trash/delete to get it to think we're starting from scratch? I know the clip is OK thanks to the FCP test.

                    • 7. Re: Audio just cuts off suddenly
                      the_wine_snob Level 9

                      So, you have played that file from the HDD in FCP, and everything is fine?


                      I would have used a software player to test, rather than an NLE, but if FCP plays the file from the HDD, then something is truncating it in PrPro, and that file is in perfect condition.


                      I cannot think of what would cause the truncation, but would definitely try Harm's suggestion, in case PrPro has locked onto a truncated CFA (the Conformed Audio file, that PrPro uses on the Timeline).


                      Good luck,



                      • 8. Re: Audio just cuts off suddenly
                        briantho Level 1

                        Yes, as I mentioned, FCP read the entire contents of the problem clip, converted and expanded it massively ('Log and Transfer' process) into a separate file so that editing and viewing can take place with any viewer or editor.


                        You mention CFA files. I didn't know about them, thanks. I see there are quite a few under 'Adobe Premiere Pro Preview Files' for the original project name. (In the meantime I've done a Save As - old habit so as to reduce the risk of other undesirable things happening. There are no .cfa nor .pek files under the project name I am actually working with). Obviously I don't know but if I were to delete some or all of these files (and the .pek files?) might the clips 'Conform' themselves again and then, hopefully, the empty part of the audio (which I have proved to actually be there) will reappear? Is there is a way of knowing which of these files relates to which clips on the HDD?


                        Thanks for all your suggestions!

                        • 9. Re: Audio just cuts off suddenly
                          the_wine_snob Level 9

                          Yes, the CFA files are created by PrPro, when the Audio is Imported. They are the Conformed Audio files, and are then in 32-bit floating point, for editing. The PEK files, also created then, are the Waveform Display files. In your screen-cap, the PEK shows truncation, right where you say the Audio drops out. That was one reason, that I was thinking that Conforming might have been interrupted.


                          This ARTICLE goes into a few more details on Conforming.


                          Good luck,



                          • 10. Re: Audio just cuts off suddenly
                            briantho Level 1

                            Thanks for the info. I was really hoping for one of those "delete such-and-such" type of responses but once this project's out the door I'll do some experimentation. If I am to keep running into the same problem again and again then I'll need some practical experience as well as the articles you mentioned.

                            • 11. Re: Audio just cuts off suddenly

                              I have the problem of disappearing audio at about 30 seconds on every .mts file that goes that long.  This files play perfectly in Microsoft Media Player.  Thinking that my habit of loading my projects may not give enough time to "conform" I just loaded a problem clip of 70 seconds, waiting over 70 seconds before I opened the file in the preview window of Elements 10.  As usual, the video faded at 30 seconds.  The only way I've been able to solve this problem is to buy a $40 video converter and convert my files longer than 30 seconds to .vob.  Then they will run OK on Elements 11.  I have to tell you that I've been editing video for probably 10 years and have bought about every editing software on the market, and they all have problems.  Not this one, but some problem.   Any further thoughts on the fading audio?  thanks,