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whtknt1066
whtknt1066
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why is the audio outrunning the video?

Aug 16, 2012 4:08 PM

Tags: #help #video #audio #10 #problems #elements_10

First off, I'd like to say thanks to the gentlemen who helped with my last question; you guys lead me to the information that allowed me to figure out what was wrong and how to fix it.  I now have a new problem that's making me tear my hair out, and I'm hoping you guys can help me with this one as well. 

 

Background:

I'm attempting to make a video resume to supplement my paper resume in order to get a job with a technology educator called Techshop.  I have an old video production degree, but I'm new to digital editing.  For equipment I have a reasonably powerful computer (it exceeded the specs), a Panasonic HC-V10 camera (it records in ACVHD lite 720 60p, I think), Premier Elements 10, and a file viewer and converter called Wondershare Video Converter Platinum. 

 

My troubles all started when I, in my beginner's ignorance, didn't use Premier to capture the video clips off my camera directly, but instead took the SD card out and transfered the files onto my computer's hard drive directly.  I no longer have the video on the SD card, all I have is the files.  There is too much video to re-shoot; I need to use this footage. 

 

I set up my project as ACVHD lite 720 60p and, again not understanding what I was doing, washed all the raw footage through the video converter.  This was to get the resolution of the video up to 1280X720 from 960X540 and to label the video instead of just having numerical codes (pre-sorting).  I was changing the resolution because I couldn't find a Premiere preset for that resolution.  I converted the audio at 48 MhZ (after initially converting at a sample rate of 44.1, which seemed to cause a problem-though in hindsight, it may not have), which is the same as my project preset.

 

After converting the footage, it appeared to play perfectly in Wondershare.  I looked at the footage with MediaInfo, and it appeared to match my video presets exactly.  I used Get Media to pull the files into Premiere, and that's when it hit the fan.  The audio was outracing the video!  At the start of the clip it appeared to be in synch.  A few seconds in, and there was 'something funny going on'.  A minute in and it was badly out of synch, and a few minutes into a clip (several takes in one clip) it was so badly out of synch I couldn't even match the sections up.  The audio ended before the video in every clip I imported.  I'm not sure, but I think it's losing about 2 seconds a minute.  I also tried a test export, and the problem was exactly the same.

 

Now here's the interesting wrinkle.  When I look at the Properties of the clips in Wondershare and MediaInfo, they both tell me the frame rate is 29.97 fps and the audio is sampled at 48MhZ.  However, when I look at the Properties of the same clip in Premiere, it says the audio sample rate was 48MhZ, but the frame rate is 29.00!  If I'm calculating this correctly (though I'm not certain I am), I think losing .97 frames per second accounts for the audio/video missmatch-the video is playing slightly slower than the audio.

 

As an afterthought, when I Get Media the files into my Premiere project, I get a tiny message at the bottom of the screen that says Premiere is Conforming each video with a progress bar, leading me to believe that the project presets do NOT match the source video; only problem is, Wondershare and MediaInfo say it does!

 

Question:

What is happening?  How come Premiere is saying that these files have a framerate of 29.00 fps when everything else says they're 29.97?  Did I convert it oddly?  I checked, and I set the frame rate on Wondershare to 29.97 (which is what it and MediaInfo both say the video is playing at).  I even re-converted some of the video from the raw source with Wondershare at at 29.00 setting, and it STILL has the missmatch problem.  Did Premiere interpret it strangely?  If so, any idea why?  It doesn't appear to need to Render-there's no red bar above my project or anything.

 

Also, is there a way I can tell Premiere to play the video back with the same audio rate, but at 29.97 fps instead of the 29.00 fps it says it's using?  Or stipulate that the video files be played at the correct rate, or something?  Or really, any other ideas on how to address this issue?  Uncoupling the video and audio and then time-stretching seems very imprecise and cumbersome, so I'd rather not try it.  I'd like to simply adjust Premiere to use the video correctly, since my video is already labeled and correctly sized (and some of it is cropped and color corrected too). 

 

Edit: I just loaded in the unconverted footage for kicks, and the audio problem doesn't seem to be occuring.  Simple fix, right?  Well...I'd like to still figure out what's going on for future projects.  I also would like to still use the converted and labeled video since I took SO LONG pre-sorting it!  Lastly, I had at one point attempted to load all the unconverted footage into Premiere and just re-label there, but Premiere spat up a message that it was "running low on system resources" and soon locked up/stopped responding.  My computer doesn't seem to be able to handle 135 video clips in one project, and thus my need to pre-sort.  Just wondering, but is it the preview images that are the problem?  If I chop up the footage into multiple folders, will that help?

 

I have already read the articles by Bill Hunt and others about "File format as a wrapper" and "What's in a Codec" and such-VERY informative!-so no need to point me to one of them unless I've clearly forgotten something. 

 

Gentlemen, I thank you in advance for your advice and assistance, and I am very appreciative that you make your experience available to new users such as myself.  Thanks again!

1261 Views   10 Replies   Latest reply: Bill Hunt, Nov 15, 2012 6:49 AM
 
Replies
  • Steve Grisetti
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    1. Steve Grisetti,
    Aug 16, 2012 7:46 PM   in reply to whtknt1066
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    You should be able to use video from that camcorder directly in a project set up for AVCHD Lite (1280x720p) -- assuming you shot it in 1280x720. Trying to convert it is just going to take you farther from a solution. No reason to make it more complicated than it is.

     

    It doesn't matter if you used Premiere Elements to download the video from your camcorder or if you just used Windows Explorer or Mac Finder to do it. The results will be the same.

     

    You'll know you've got the right project settings if you see NO red lines above your clips when you add them to your timeline. Is that the case in your project?

     

    If your project is set up correctly and you're still seeing your audio leading your video or vice versa, it could be that your computer isn't quite up to snuff. Can you tell us your processor and its speed, how much RAM you have and if you are using more than one drive to edit your video on?

     
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  • whtknt1066
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    2. whtknt1066,
    Aug 16, 2012 9:58 PM   in reply to Steve Grisetti
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    Thanks Steve.  After taking a breather and coming back to my project it seems that the video converter, or how Premiere is reacting to the converter's files are the issue at hand.  I loaded some raw footage into Premiere and had no issues with it, even though I recorded at some funky in-between resolution (920X540p).  I then re-converted some raw footage I KNEW was good, both with my presets and then specifying 29.97 fps.  Both Mediainfo and Wondershare again insisted that the video was at 29.97, while Premiere listed the fps as 29.00 in the Properties.  This being the case I don't think it's a hardware issue (though I'll still post specs if ppl think I need to).  Any idea what's going on?  Is it possibly an odd CODEC issue?  And I'm still wondering if there's a way to force Premiere to play back the video at 29.97 fps.  At this point it'd simply be about 1-1/2 hours more convenient, but I'd like to understand for future reference.  I know that using converted video is just adding another layer of issues and lost resolution, but...I guess I just want to figure this out for the future.  Oh, and if I DID end up converting my MP4 files in the future, what's the best file format to convert them into for Premiere to use?  And no, there were no red bars above my clips at any point.  Thanks for the reply Steve, I appreciate it.

     
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  • Steve Grisetti
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    3. Steve Grisetti,
    Aug 17, 2012 4:57 AM   in reply to whtknt1066
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    Again, you should not convert your video. You are nearly always better shooting your video in a format the program will read, as I discussed above, and then editing it in that format. Every time you convert video -- unless you really know what you're doing -- you're taking a risk that you're moving farther from rather than closer to a format Premiere Elements wants.

     

    As for the frame rate, Premiere Elements 29 fps IS 29.97 fps. It's merely abbreviated.

     

    These low-end HD camcorders that are hitting the market often play by a slightly different set of rules. Perhaps the best advice is to start a new project, place a sample video on your timeline and, when Premiere Elements offers to change the project settings for you, select that option. You can later go to Edit/Project Settings later to see which project settings the program selected.

     

    I would not recommend shooting in 920x540. It's too high-def to fit a standard DV project and too low-def to fit an HD project. Shoot in 1280x720 and select either the AVCHD Lite option or the Flip Camcorder HD project setting (You may need to experiment) -- or let the program decide for you.

     

    It may not be an exact fit. But, if you find project settings that do NOT show red lines above your clips when you place your clips on the timeline, please report back so we'll know for future reference.

     

    All we can do is offer our best recommendation. You are going to have to experiment in this case to find a solution for your particular situation.

     
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  • whtknt1066
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    4. whtknt1066,
    Aug 17, 2012 8:06 AM   in reply to Steve Grisetti
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    Hi Steve, and thanks again for continuing the discussion.  I agree that it's best to shoot in the format of the project I'll be working in, and set up my project in the format that I'm resording in.  Yeah, pretty much that old GIGO saying; Garbage In, Garbage Out.  I've started shooting my video in AVCHD Lite 1280x720 now that I've learned enough about Premiere and resolutions to understand the differences. 

     

    However...that doesn't solve my current problem.  I have an entire project's worth of video that I shot at 960x540 (sorry, I'd typed it wrong earlier) that I HAVE to use.  I don't have the time or resources to go back and reshoot.  I think I've discovered that I can use the raw 960x540 footage even though the project is set up for 1280x720; it didn't ask me to change the settings when I did this, and I'm hoping that it doesn't do something sneaky like give me a tiny output video or somesuch.  When I use the raw footage, the audio SEEMS to be ok, so at this point I'm going to try it.  This is not the fix I was looking for (I'm repeating a LOT of work here), but perhaps it's the best.

     

    Your statement above, "As for the frame rate, Premiere Elements 29 fps IS 29.97 fps. It's merely abbreviated" Doesn't seem to be correct, and I'd love to know if playback framerate can be specified or forced.  Understand, I'm not trying to argue or one-up, I'm just trying to understand.  The reason I'm saying this is that when I import the raw files as taken from my camera, right-click on the clip and then choose Properties, it tells me that the framerate is 29.97 and the audio seems stable and correct.  When I convert the files and try to import them the audio is ok OUTSIDE Premiere and both Wondershare converter and MediaInfo report that the framerate is 29.97.  When I import that converted clip (identical to the raw clip, just resized and color corrected) is when things go wrong, the audio progressively gets out-of-synch with the video, and the right-click/Properties reports the video as being 29.00 frames per second.  So it seems that Premiere literally means that it thinks it should play back the video at 29.00 fps, not 29.97 fps, and that this wierd interpretation on Premiere's part is what's messing up my audio. 

     

    I'd really like to know what's going on so I can avoid future problems and perhaps rescue all the work I've already done.  I need to either force Premiere to interpret or accept the video as 29.97 fps, or alter the properties of the footage to have it play back at 29.97, or something to that effect.  If you or anyone has any ideas as to what's wrong or, more specifically, how to fix it (or force a fix) I'd really like to know.  Thank you!

     
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  • Steve Grisetti
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    5. Steve Grisetti,
    Aug 17, 2012 8:59 AM   in reply to whtknt1066
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    >"As for the frame rate, Premiere Elements 29 fps IS 29.97 fps. It's merely abbreviated" Doesn't seem to be correct.

     

    It is correct. Adobe did not invent a new frame rate.

     
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  • Keledole
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    6. Keledole,
    Aug 18, 2012 3:50 AM   in reply to whtknt1066
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    I don't know why the audio sync problem is happening but I can offer a workaround that has helped me salvage files that were not able to be reshot.  The common denominator for the audio sync problems I have encountered in (some, not all) clips were 60fps.  It has been a while since I had to do this so please bear with me as I am doing this from memory.  Also, this is based on PE10 but will probably work with older versions but I don't own any.

     

    1.  Right click the clip in your timeline and select "Unlink Audio and Video"

     

    2.  Click any other place on your timeline to de-select the problematic clip and then click on the AUDIO portion to only select it.  To confirm that you did it correctly only the audio portion of the clip will be highlighted.

     

    3.  Right click on the highlighted auido clip and select "Time Stretch...".  A small box will pop up with 4 adjustments - Speed, Duration, Reverse Speed and Maintain Audio Pitch.  Here is where the trial and error begins.

     

    4.  If I recall, I used a few different methods to determine how much to stretch the audio to get things right.

     

                              a) You could determine how much time there is between the audio finishing and the video finishing by subtracting the values in the timeline counter.  Remember the last two numbers are frames and not fractions of a second.  Now add that value to the "Duration" value in the second line down in the open box.  It should get you pretty close to back to normal sync. If not good enough you can tweak the duration to get it right.  Next, check the box to "Maintain Audio Pitch" or you will sound funny.  If the pitch sounds funny you could add the "PitchShifter" effect from the audio effects toolbox though I have not had to this.

     

                             b)  You could click into the speed % box and enter an amount up to two decimal places in value.  Based on the fact that mediainfo says the clip is 29.00 fps (for whatever reason) I would try (29.00/29.97=.9676 X 100 =) 96.76% and see what happens.  Check the ' Maintain the Audio Pitch" box as above.  If this works then it may serve as a confirmation that Elements is indeed incorrectly interpreting the clips properties.

     

                             c)  Run and Gun.  Just start changing duration values or Speed percentages until you get it right.  Ya know, caveman style.

     

    Another way that is possible I'm guessing is to click and drag the audio into sync.  Do steps 1 and 2 above.  Expand the timeline to show the waveform better.  Hover your cursor over the right side of the audio clip until the backwards "C" shows up.  Click and drag the clip to the right using the waveform as a visual reference.  I have not done it this way but in theory it should work.

     

    When you get everything the way you want it you can trim off the audio portion that overruns the video to make them the same physical size.  Then hold the shift key down while selecting both the audio and video portions of the clip.  Be sure they are both highlighted.  Right click on the clips and select "Link Audio and Video" to relink the clips. 

     

    Hope this helps you.  It is not ideal by any standard but what workaround ever is.  Good luck.

     
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  • surbanna
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    7. surbanna,
    Nov 14, 2012 9:48 PM   in reply to whtknt1066
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    I am having the same EXACT issue when I use Wondershare to convert .MOV files to .MP4. My converted footage from Wondershare is 29.97 fps, but Premiere (I use Premiere Pro CS5.5) is showing it as 29.00 fps. If I import the raw .MOV footage, Premiere shows is as 29.97 fps. So you are correct in that it is adjusting the frame rate. My footage, as well, starts out in sync, then slowly the video starts to lag behind the audio. It also doesn't match up with my externally recorded audio. I could attempt to make manual speed/duration adjustments to match it up, but that somewhat defeats the purpose of me using Wondershare to convert the footage (which was about making my the videos easier to edit since .MOV files don't playback smoothly).

     

    The same happens with my 24 fps converted footage. Premiere is showing it as 23.00 fps, but instead of it being out of sync, the footage becomes gradually choppy. No matter how I alter the setting in Wondershare or in Premiere, it doesn't read the video as the correct frame rate.

     

    Have you figured out a solution to this issue? There seems to be something that occurs during the import into Premiere and not so much the conversion in Wondershare.

     
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  • surbanna
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    8. surbanna,
    Nov 15, 2012 5:49 AM   in reply to whtknt1066
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    whtknt1066 -- I figured out how to "force" the frame rate. After importing your clips, if you right-click and select "Modify" and then "Interpret Footage" you can manually adjust the frame rate. This helped my issue with the choppy and lagging video. HOWEVER, when you do this it either lengthens or shortens the entire track, so it also adjusts the audio track, and the tracks are still out of sync. At this point, you will need to do what was suggested in #6. I found that with changing 23fps to 24fps, I had to adjust the audio track speed to 96%. Despite that issue, I was able to now sync the video with my external audio without any issue or adjustments.

     

    Long story short, you can fix the frame rate, but you will have to manually adjust or sync the audio. And you will have to review/edit footage all in the timeline instead of using the Source Monitor.

     
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  • whtknt1066
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    9. whtknt1066,
    Nov 15, 2012 6:01 AM   in reply to surbanna
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    Sadly, no, I never did. I wish I had because Wondershare seems to be a very useful program. I particularly liked it for the ability to preview and choose good takes and change the filenames on those takes-it was a great pre-sorter as well as file converter. I eventually just bit the bullet and imported all my original video into the Premier project. I believe there's just some odd incompatibility between the two programs, either just a wierd codec thing or an intentional error to make you use Wondershare's video editor (which could be a $40 fix for you).

         Since your audio and video are already unlinked (you mentions that they're separate files, right?), why don't you try the time stretch trick the gentleman above suggested and play the video back at 96.97% speed as you resynch the audio?  it's a kludgy fix for something that ought to be easy, but it's the best I have. Good luck!

     
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  • Bill Hunt
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    10. Bill Hunt,
    Nov 15, 2012 6:49 AM   in reply to surbanna
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    What is the CODEC used in the MOV files?

     

    Why are you converting the MOV files to MP4 with Wondershare?

     

    When played in QT Player, do your MOV exhibit OOS (Out Of Sync), or only after you have run the file through Wondershare?

     

    Good luck,

     

    Hunt

     
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