Audio drops out in exported hi-def video

[peggig]

I recently upgraded my OS to Win7-64 in the hopes of being able to edit high definition videos with PRE7. Up until today, I've been very happy. It no longer hangs or crashes like it did frequently under 32-bit Vista. Sometimes, after doing a lot of edits in a project, it flakes out but I found that, if I delete the log file for the project and reboot, I'm able to continue editing.

I always create a number of small projects, export the video using MPEG2 1030i, with the quality set to 5 (highest quality), and then import those files into a master project. Since upgrading the OS, I've exported about a half dozen short videos that all worked fine but, In the last one I exported, the audio in the exported file drops out after less than a minute. (It plays fine in PRE7; it's only in the exported file that the audio drops out.)

I've had this same issue in the past, before I upgraded my OS, and it was one of the reasons I gave up on high definition editing. When this first happened a couple of years ago, I called Adobe tech support and they had no idea what to do about it. They finally said to uninstall the software, scrub the registry, create a new administrator account, and reinstall the software using the new account. Over the past year and a half, I've done that many times whenever I run into this issue, and sometimes it has worked. The last couple of times, it didn't, so I ended up having to export the videos as AVI instead. At that time, I gave up on trying to edit in high definition.

After having upgraded my OS, I was delighted to finally be able to edit in high definition. It's very frustrating to run up against this same insurmountable issue again. Has anybody else ever encountered this? Is there any way to fix it or work around it other than exporting to AVI? I'm totally bummed out at the prospect of having to go back to standard definition again.

[RJ Johnston]

One thing I would want to know is if it's the audio decoder that is causing the problem, not the audio encoder during rendering to a file or disc.

You don't say what the source audio is, but I will guess that it is MPEG audio. Anyway, we need to convert that to an audio format that we know Premiere Elements likes. There's a command in Premiere Elements that makes that easy.

1. Save your project under a different name.
2. Select all the audio clips in your project.
3. From the menu select Clip > Audio Options > Render and Replace
All the audio on the timeline will be replaced with new audio clips in a format that Premiere Elements likes.
4. Share (export) to a file format that's given problems in the past.

If this procedure cures the problem, then it was the decoding of the mpeg audio format (or whatever format is used for the audio in your source files) that was causing problems during the rendering phase.

[peggig]

Thank you, RJ. I just tried your suggestion. Unfortunately, it didn't work. The newly exported video still drops out the audio at about the same point, approximately 18 seconds into the video.

This is so strange because I have several small projects, each 2-4 minutes in length, and yesterday I made some final adjustments to a few of them and then opened up each project in turn and exported them. (I had already exported three on previous days, using the same export presets.) The first two yesterday worked fine, as had the previous ones. I did everything exactly the same way but, on the third one I exported, the audio dropped out.

This has been my experience in the past, also. After a fresh install of PRE, it will work for a while then, for no reason, the audio starts dropping out every time I export any project as MPEG2. It isn't like it sometimes happens and sometimes doesn't. Once it happens, it happens consistently on every project I export from then on.

I assume it's a problem with the MPEG2 codec, but this is a clean machine that was just flattened and rebuilt as a 64-bit machine. The only software installed on it is MS Office, Canon ZoomBrowser & FileViewer, Adobe PhotoShop CS2, HDVSplit, and PRE7. The only software I've actually used on it (other than Internet Explorer) is PRE7. It's pretty much a dedicated video editing machine. So there couldn't be some other MPEG2 codec on it that isn't compatible with PRE7, unless it's the codec that comes with HDVSplit but everybody seems to use that.

Is there anything else you can recommend, short of exporting to AVI instead of MPEG? I really would like to do this project as a high definition video and it just seems there's got to be a way to do that.

[Steve Grisetti]

Peg, a common cause of this is a failure by the program to fully conform the audio for the clip.

When you first add a clip to your project, the program conforms it to the project's specs. This can take anywhere from a few seconds for a short clip to several minutes for a longer one. You can watch the progress in the lower right of the Premiere Elements interface.

If you interrupt this process and start editing a clip before it's done, you can get only part of the clip's audio.

Try clearing the clip from the project and then re-importing. Watch and wait until the program has fully conformed the audio before you do anything else with it.

[RJ Johnston]

After you did a "Render and Replace," there should have been audio drop out after playing back the timeline 18 seconds. Right? Was that the case?

[peggig]

Try clearing the clip from the project and then re-importing. Watch and wait until the program has fully conformed the audio before you do anything else with it.

Steve, the only audio in the project is the audio track from the video, imported from the camera. Clearing and re-importing it would mean scrapping the entire project and starting over again. I've done lots of editing in the project (color adjustments, splices, transitions, etc.), so it would be a lot of work to redo it all. But I'll try that if nothing else works.

My experience in the past, however, has been that once this happens, it happens consistently on every MPEG I export from then on, regardless of the project. That's why I think it must be a codec problem. Also, if I export it as an AVI file, the audio is fine. (At least, that's been my experience in the past; I haven't tried it with this particular project, as I'd really like to be able to do this in high definition.)

I always wait until the clips are finished conforming before I start editing them, but I do frequently continue importing clips while previous clips are still conforming. Could that be an issue? That never occurred to me.

After you did a "Render and Replace," there should have been audio drop out after playing back the timeline 18 seconds. Right? Was that the case?

RJ, there has never been an audio dropout in the timeline (either before or after I did the Render and Replace). It always plays fine in the timeline. It's only in the exported .m2t file that the audio drops out. That's why it's so frustrating. It seems like everything is fine while I'm editing but, when it's all done, the result is unusable.

[peggig]

Does anybody have any ideas on how I might be able to replace the MPEG2 codec used by PRE7?

[RJ Johnston]

You can't replace the encoders that Premiere Elements uses for MPEG2.

You really shouldn't be having the problem you are having. I don't have any problems with audio dropping out and my computer is borderline capable of processing high definition.

When you add the exported file back to your project and add it to the timeline, does the audio waveform show anything missing?

What playback software are you listening to when the audio drops out.

Please post your computer specifications by following this procedure:

Start > Run
Then type DXDiag and press enter.
After the DirectX Diagnositic window opens, click the "Save All Information" button and enter a name for the text file.
Open the text file with notepad or wordpad and copy and paste the information from these sections into your next post:

1. System Information
2. Display Devices
3. Sound Devices

Thanks.

[peggig]

When you add the exported file back to your project and add it to the timeline, does the audio waveform show anything missing?

Thank you, RJ! I can't believe I never thought of doing that myself. It turns out the audio drops out for one long segment, and there is no waveform on the timeline in the imported mpeg during that segment. I wish I had thought of doing that myself. I just assumed I was running into the same issue I'd run into so many times in the past before upgrading my system.

Thank you a million times! I'm so relieved and happy (in spite of feeling like an idiot for not having thought to verify it myself by importing it into a new project).

I love this forum. You guys are great.

[peggig]

I have another question. While checking out the Advanced settings on the MPEG2 1440x1080i preset, on the Audio tab, I noticed that the default bit rate is set to 192 kbps. But, when you click the dropdown, it says "228 or higher provides good quality for stereo." The available options are:

• 128
• 160
• 192
• 224
• 256
• 320
• 384
• 448

Would I get better audio quality by selecting a higher bitrate? Are there any tradeoffs? Do you have any ideas on why the default is set to 192, when they recommend 228 or higher for stereo?

Thanks again!

[RJ Johnston]

I usually use 384 for Dolby Stereo, unless I'm running out of room on a DVD disc, in which case I just keep it at 192.

I'm not sure why you are so happy about the results of the waveform. Are you sure that Premiere Elements had enough time to ccreate the waveform peak file and update your display after adding the video file back to your project? If your video is long, the waveform is updated in segments on the timeline if you just added the file to your project. Premiere Elements shows the status in the lower right of the screen as the waveform is being created after you add a file to your project.

If the waveform peak file has been fully created and you still see missing sections of the waveform on the timeline, then that means there was a problem during the encoding (sharing) phase. I still don't know much about you computer specs. That might hold a clue.

[peggig]

I'm not sure why you are so happy about the results of the waveform.

RJ, I'm happy because it was user error, rather than a problem in the software or the system. User error is easy to fix, once it's identified, which you helped me do. Somehow, the audio level had dropped on that one clip, which I replaced, and now everything is working fine. I am hugely relieved.

After upgrading to Win7-64, I was pleased that I was no longer getting crashes and hangs when editing in hi-def, and was able to export to MPEG without encountering the same issues I had repeatedly encountered on 32-bit Vista. Then, when it seemed like one of the issues that had plagued me previously was occurring on the new configuration, I plummeted (prematurely) into the depths of despair.

I'm both embarrassed that I foolishly jumped to the assumption that it was the same issue, without taking steps to verify it, and at the same time delighted that the issue is not with PRE7 or my system configuration.

Thank you!

[RJ Johnston]

Thanks for clearing that up. It's good to know you have resolved this issue. That calls for a celebration of some kind.

[Chuck Engels]

Let's have an eParty !!!

[peggig]

You guys are great!