Audio Skips in MSP8

[jangardiner]

I'm still struggling to get MSP8 back to where I was with MSP7, and I don't want to go back because of the great new features in MSP8. Now I'm getting intermittent audio skips. This is primarily when I preview a decent size (at least a30 seconds) of video.

NTSC drop frame (29.97 fps)
Microsoft AVI files
24 bits, 720 x 480, 4:3, 29.97 fps
Lower Field First
DV Video Encoder -- type 1
DV Audio -- NTSC, 48.000 kHz, 16 Bit, Stereo

The audio I'm using is a .WAV, and I've tried PCM and Microsoft ADPCM at 44,100 kHz When I select a smaller portion to preview that includes the location of the skip, it plays fine, so that would seem to not be a problem with the .wav file.

I've just played around with the playback options, and I seem to be able to make it worse but not better. Currently, I have audio cache disabled, multi-threading enabled and preview quality Auto.

Ideas much appreciated.

[jangardiner]

Still doing trouble-shooting on this. It seems to happen when I am looking at the timeline and previewing in a small window, not full screen. I have tracked it down to correspond to when the timeline view is refreshed while playing.

Granted, this is less annoying than thinking it will also cause problems in full screen, but is this due to my preview settings or is it a known problem with MSP8?

Thanks again.

[Devil]

This could simply be a lack of horsepower (CPU type, speed, RAM, FSB etc.) or even due to HDD fragmentation. "Instant" preview takes short cuts to work and sometimes unexpected things can happen, especially if you use lots of effects. If you do the quality preview, where it actually renders to a temp file, you probably wouldn't have this problem. Does it mainly happen when you have a red line?

[jangardiner]

Here are some more answers:

1. No red line anywhere on this one. At this point, just trying to get a simple video to work correctly. I just have video, stills and an occasional narrative audio clip plus a .wav file of music running throughout. I haven't gotten to the point of fine tuning with effects.

2. Decently powered machine, I think. Dell XPS Pentium 4 2.8 GHz with 1GB RAM.

3. On my main drive, I have 92 GB free and it's barely fragmented at all. I run defrag weekly and I just checked it this morning. On my second drive also used with Ulead, I have 138 GB free. Just to be sure, I'll defrag both again and recheck.

All for now. Thanks.

[Terry Stetler]

DV uses 48khz audio and you state you're using a 41khz source, so the best move is to convert your audio sources 48 khz before including them in a DV project.

This way MSPro doesn't have to try and do the upconversion during the preview. Depending on the total system load at the time and how much RAM is installed this could easily cause audio dropouts.

[Devil]

Well spotted, Terry! I should have seen that!

[averse thule]

I am having a similar problem using MSP6. The funny thing is it worked fine for 3 or 4 versions of the video segment I made and then suddenly I am having this problem.

I am using raw clips at 30fps, 640x512, pcm 44.1kz (16bit stereo). (Fraps Codec)

I have tried making the movie in DV-1 at 44k audio, 48k audio, and even converted the raw footage using MSP's "smart link and convert" feature before making the movie....all to no avail.

There is a mp3 music file that is at 44k audio, which is where I hear the skips, but I am not sure how to convert that to 48k.

I did notice that if I tinkered with the project settings and change the audio I would get "unable to load the audio codec" error often. I tried changing the audio output(?) to mp3 to match. Is the error due to DV-1 not compatible with mp3?

Anyway, I finally just reverted back to making the project in Cinepak Codec by Radius and it creates a video just fine. Hopefully I can take that created video and load it in Windows Movie Maker to convert it again to a filesize that works for me.

[Devil]

No, it is due to some implementations of mp3 not being correctly formatted. You see, mp3 is NOT an audio format, at all. It is an audio layer of MPEG-1 video file. Stripping off the video and just using the audio layer as a standalone is not part of the MPEG standards and different users do it in different ways, some of them stripping away essential information needed to use it, in order to reduce the file sizes to a minimum. MP3 players have no problem with this, because they are designed to accept almost anything and to replace missing info. You cannot do this in an editing environment. At the best, you will get some form of distortion, snap, crackle and pop. At the worst, you will get silence. The workaround is to do what the players do: try and replace the missing info. The easiest way of doing this is to convert the mp3 file to a wav file in an audio editor (I recommend the open-source, free, Audacity but there are many suitable ones) and insert the wav file in your project. Ideally, the sampling frequency of your wav file should be the same as that of your project.

[averse thule]

Doh!

Well I used cooledit2k to change the mp3 to 48k sampling rate and then to a wav file. I dont get as bad of chopping but it is still noticable enough to be detrimental to the finished product.

Thanks for the tips, they have helped. I gotta say I love this program so far! I got it a few years ago but didnt have a pc strong enough to really put it to use and now that I have a little better system I am really enjoying learning the new hobby! MSP is really remarkable and I probably havent touched the surface of what I can do with it yet!

[averse thule]

heh, So I was working on the 2nd segment to my video as another file. I was ready to combine them and I couldnt copy and paste all the 2nd file info from the timeline into the first file (error message) and instead had to drag the grouped timeline of the 2nd file out several minutes. Then I was able to copy the first file timeline info and past it into the start of the 2nd file. I encoded the combined clips to DV-1 and it works fine now.