Juddery Sound on VideoStudio 10

juniet · Post by **juniet** » Tue Jul 29, 2008 12:31 am

Your assistance is required once again please.
I am using VS10, since I've imported an audio track from a CD into my project, the video track in the clip is juddery. Its fine if I just play the clip but when I play back the project it is juddery (sometimes both sound and picture).
Theres also a point where I slowed a clip down slightly, but then the following clip starts juddering also. It plays fine when playing it as a clip on its own, but if I select project and play back the same point it judders.

p.s: I haven't quite finished the project so I havent burnt it on DVD as yet, but I've ran out of ideas in why its doing it.

Can anyone help?

If it helps my Project Properties are:

PAL (25 fps)
MPEG files
24 bits, 720 x 576, 25 fps
Upper Field First
(DVD-PAL), 4:3
Video data rate: Variable (Max. 9496 kbps)
Audio data rate: 256 kbps
Dolby Digital Audio, 48 KHz, 2/0(L,R)

Post by **Ken Berry** » Tue Jul 29, 2008 1:20 am

Can you right click on the audio file within Video Studio, please, and copy its properties here please. If it is mp3, then Video Studio doesn't like certain mp3 codecs. The easiest solution is to use a third party audio program and convert the audio track to standard .wav format and use that instead.

The reason associated video is becoming juddery is possibly because Video Studio is struggling with the audio format and is diverting resources to that, leaving less for a smooth playback of the video stream... Just a thought!

Then again, the Project Properties suggest that the video may have come from either a hard disk or mini DVD disk camera. Can you confirm that, please. As to that, I would simply note that though it is a variable bit rate, the maximum level plus the existing Dolby audio puts it pretty close to the upper limit allowable for a DVD (which is 10,000 kbps in all). Adding the extra audio could push it over the limit at times and VS may not like that. While I would be looking at my mp3/wav suggestion first, if that does not work, then I would be lowering the VBR max rate to 8000 kbps. In any case, you need to be aware that many stand-alone players -- which is where your eventual DVD be played -- have difficulty with any disc which uses a bitrate much over 8000 kbps.

sjj1805 · Post by **sjj1805** » Tue Jul 29, 2008 1:22 am

You Video Data Rate is on the high side, try reducing it to 8000 kbps or lower. How long does the video last for - as a rough guide
1 hour - 8000 kbps
90 mins - 4000 kbps
2 hours 2500 kbps

Next - export the audio as a WAV file and then replace the existing audio with the new one just created. see if this helps.

juniet · Post by **juniet** » Tue Jul 29, 2008 8:49 pm

Ken
I think you are right, The files name ends with .mpg instead of my usual avi.
Here is the info when I right click on the audio track:

Video type: MPEG-2 Video, Upper Field First
Total Frames: 42,204 frames
Attributes: 24bits, 720 x 576, 4:3
Frame Rate: 25,000 frames/sec
Data Rate: Variable bit rate [max. 9496 kbps]

Audio type: Dolby Digital Audio
Total Samples: 81,031,680 Samples
Attributes: 48000 HZ
Layer: None
Bit rate: 256 kbp

Boy! am I in trouble now.

I used my sister in-laws DVD camcorder to film her wedding as I thought the quality would be a bit better than my old DV camera. Using a stand alone DVD recorder I transferred it over to DVD-R, so I could upload it to my PC.
Somewhere along the line it got converted to mpg instead of my usual AVI.
Can you recommend anything I could use to convert it to AVI? Whats a third party audio program??
I haven't got her camera anymore as she has taken it on her honeymoon.

Help

(I still don't understand why it would play perfectly in Clip Mode and not in Project Mode though).

Black Lab · Post by **Black Lab** » Tue Jul 29, 2008 9:16 pm

Since it is already in a DVD-compliant format you do not want to convert to avi, as you will lose quality.

A good, and free, third party audio editor is Audacity.

Post by **Ken Berry** » Tue Jul 29, 2008 10:02 pm

Just to add to that: the international standard for DVD requires that the only video format which can be burned to a DVD is mpeg-2 (and mpeg-1). So even if you had DV/AVI, such as you get from your own camera, that has to be converted at some stage to DVD-compatible mpeg-2. Now with your sister's mini DVD camera, that already films in DVD format, which means DVD-compatible mpeg-2, as Black Lab has said. Converting to AVI means that you are going from a compressed mpeg-2 format to a less compressed AVI format, and VS has to in effect invent the extra data out of thin air. That means loss of quality. Then to burn the final DVD, it has to be compressed back to mpeg-2, which means data is thrown away -- more loss of quality. You don't want that.

So the format is fine. So first try converting that CD audio to .wav if it is mp3. Apart from Audacity, if you have the Nero suite, it contains a good audio editor called WaveEditor which is the one I always use. It is easy, like Audacity.

But as you will have seen, Steve also thinks like me and we feel it could also be the bitrate used which is causing the problem. So once you finish your editing, you choose Share > Create Video File > Custom. In the dialogue box which appears, in the box down at the bottom, you will see that the properties are the same as the Project Properties (or they should be). Click on the Options button on that box and then select the Compression tab on the new box. Then change the 'Video Data Rate' in about centre of screen from 9496 (or whatever it says) down to 8000. Also make sure on the General tab that the Frame Type is set to Upper Field First. Click OK then give the new file a name, and click OK again. Conversion will begin and the new file will be created. Test it to make sure it plays OK.

Note also that after you produce your new mpeg-2, you go to File > New Project. Don't worry about giving your new project a name. The objective is just to clear the timeline of your current project.

Once that is done, you select Share > Create Disc > DVD. The burning module will open. Use the Add Media button at the top to insert your new mpeg-2 in the burning timeline. Then go to the middle of the three icons in the bottom left of the burning screen. There is a little box beside the words 'Do not convert compliant mpeg files'. Make sure that box is ticked (it usually is by default). That way, your already compliant mpeg file will not be re-encoded. Then build your menus and burn.

sjj1805 · Post by **sjj1805** » Wed Jul 30, 2008 1:33 am

juniet wrote:.......
I used my sister in-laws DVD camcorder to film her wedding as I thought the quality would be a bit better than my old DV camera. ......

No... it is the other way round your "old" DV Camcorder is better quality than a DVD camcorder. A DV camcorder will record onto tape in a format called DV (hence the name of the camcorder) This stands for Digital Video and is a format developed by Microsoft and uses 13 Gigabytes of hard drive space per hour. It is perhaps the best format that exists for recording and editing "standard definition" home video. High definition is a different matter and there are various competing formats but we will keep this reply simple.

DVD Camcorders record on small DVD discs (hence the name of the camcorder) - these discs cannot hold as much information as a tape and so they are recorded in an MPEG2 format. Typically 1 hour of best quality MPEG2 uses 4 Gigabytes of hard drive space per hour.

Think of it another way.
DV is to Video what a BMP is to a still image, large file size but very high quality that does not lose its quality when you edit the image.
MPEG is to video what a JPG is to a still image. Smaller file size - initially the quality will look as good as the BMP file but as soon as you start to edit it, then the picture loses quality. Try and open a JPG file in an image editor and then save it (use a copy - don't want you destroying the original) - compare the file size before and after saving. Now repeat that process several times.

What happens to the file size.
What happens to the quality of the picture.

Repeat the experiment with a BMP image.

juniet · Post by **juniet** » Thu Jul 31, 2008 9:03 pm

Gents,
Thanks for all your advice and support on this issue.
Good news, the panic is over.

Would you believe I took a chance and burnt my very juddery wedding project onto DVD and it is perfect. (My sister in-law will be proud of it).
Not sure what was causing the judder on both sound and picture in Project Mode but it was fine once burnt onto DVD.

One to remember i guess.
FYI
I used Lower Feild First.

Thanks again for all your advice.

Black Lab · Post by **Black Lab** » Thu Jul 31, 2008 9:09 pm

As you have found out, the preview window is not always representative of the way the final project will look. Could be because your pc is low resourced, you had things running in the background (i.e. automatic updates), etc.