MSP 8 Audio Track Issues

[krwzmann]

Hi all. Just upgraded from Media Studio Pro 7 to 8 today. While doing some video editing I noticed something strange w/ my audio tracks. At the end of one of my video clips, I wanted to cue up to the end of a song. In MSP 7 I would find the point in the song where there's a loud crash and then match that up with a certain point in my video. The problem with MSP 8 i'm finding though is that the point on the song I find changes all the time. One time i'll check and it will be at for example 3 mins and 10 secs. Then when I check again without making any other changes, that same audio point is now found at 3 mins and 20 secs. Perhaps there's some new functionality in MSP8 that i need to learn or is this just a bug?

[Devil]

Ah-hah!

10-1 says that your song is inserted with a different sampling rate than your project. E.g., you introduce a 44 kHz song into a DV project at 48 kHz or similar.

Winning bets via PayPal

[Downstairs Video]

Hi Devil,

I'm confused, (that's easy for me) If you can import different video formats and MP3's etc, why do you get a shift in the audio? Shouldn't it still be were you put it?
Coud yopu please explain?

[Devil]

Audio is not the same as video. It is not in 25-30 frames per sec, but a whole audio file is like a single frame of indeterminate length of n samples. If you don't adjust n correctly before introducing it on the timeline, then, depending on the file header information, it will assume the n samples are at the default sampling rate. This is also why, if you open a new audio track to put in an audio file starting, say, after 5 minutes into the video, it is good practice to put a silence clip between 0 and the start, as a place holder. As for MP3s, it is possible to introduce them only if their attributes match the project; sometimes they won't play at all. I always recommend converting MP3s to wav files before putting the latter on the timeline..

[krwzmann]

Thanks for the info! I would have never known. I ended up just finishing the project in MSP7 last night but i'll keep your info in mind going forward. Is there a particular KHZ to use if i'm looking to do just stereo quality videos (not dolby digital etc)? I'll have to make sure my mp3 conversion program encodes the song into mp3 at the same khz as was my video is at so I guess i'd have to go ahead and settle on a khz value.

Also though, the song that was shifting was an .mp3 file and Devil you mention that it can only be introduced if it matches the project? If I was able to put it into the project and timeline, does that mean it matches the project and that the khz should match? I'll have to double check later today to see if the khz are indeed off or not.

I also completed a project last night in MSP8 where I dubbed in audio speech recorded from my portable digital recording device onto the video from my camcorder. For the most part the dubbing went by ok. There was one instance where I lowered the levels of one audio track to the lowest (mute) yet the audio still played from that track and the volume was as if the track wasent even adjusted. After a save and restart of the computer it looks like the audio track reset itself back to the original volume and when i adjusted it again, it worked.

But thanks for the info Devil! I'll keep that info in mind!

[heinz-oz]

Please excuse my ignorance, why would you want to convert an existing sound file to MP3 prior to putting it into your project? The audio part of a video clip is very small and compressing the audio does not, IMHO, give you a great deal of additional disk space for the video content.

[Terry Stetler]

The audio portion of, for example, a DV clip is uncompressed just as in a WAV file. This can indeed take up a lot of space.

The problem is, as noted by Devil, that if you're adding compressed audio to such a project (lets keep it DV for consistancy) it can mess up the synch.

Mixing audio goes much smoother when everything is in the same format.

[krwzmann]

The reason I have mp3 audio is because for my projects, the background music I insert for some scenes are in the .mp3 format. I also include microphone audio (bride and groom vows) that I have recorded through a portable recording device which I then dub in in .mp3 format to the matching video.

Just finished another part of my project last night and the audio dubbing worked out fine this time!

[Downstairs Video]

Devil,

That was the best explanation I have had regarding audio issues.
Finally it makes sense - even to me!

[NickJushchyshyn]

Thanks for the info! I would have never known. I ended up just finishing the project in MSP7 last night but i'll keep your info in mind going forward.

Mmmmm.
Technicalities aside, if this "worked" fine in MSP 7, but MSP8 doesn't behave in the same, logical, predictable way as 7 .... wouldn't this be something that should be reported and considered for some future service pack?

[Terry Stetler]

If I had a dollar for every post on DMN where MP3 audio caused synch problems in MSP7 it would pay for this years deer hunt, so don't presume "worked fine in xxxx" is a consistant behavior.

[krwzmann]

I was wondering then, to make things a little more reliable... would converting the already .mp3 to a .wav file be best so that everything could synch up or is it too late if the file is already a .mp3?

[Terry Stetler]

I convert MP3, WMA etc. to *.wav for use on the timeline all the time. There are countless tools online for doing such things, but MSPro's audio editor can handle several of the more popular formats.

[Devil]

I was wondering then, to make things a little more reliable... would converting the already .mp3 to a .wav file be best so that everything could synch up or is it too late if the file is already a .mp3?

See the 4th post in this thread.