Audio skips on frame transitions

[Jake]

Hi

I've just had a go at creating my first movie with MM2. I was a bit
disappointed that the audio seemed to skip very noticeably on transitions
between frames.

Referring to PapaJohn's Web site I found a link to the following KB article:
http://support.microsoft.com/default.aspx?scid=kb;en-us;812610 (Audio File
Sound Skips During Image Transitions) which says that low quality MP3s will
tend to cause this. However, I used a low quality MP3 on the first half of
the video and that rendered perfectly. I used a high quality WMA file on
the second half of the video and that's where the problems occurred!

I would like to rule out computer performance issues as I've just got a new
PC with a P4 2.8 HT processor, 512MB RAM and all the other whistles and
bells that you'd expect with a new PC.

I will have a go at re-rendering the project to see if I get the same
results, but in the mean time if anybody else has experienced this and can
suggest if I may be doing something wrong then I'd be happy to hear from
you.

Thanks

Jake

 

[Jake]

Hi

I've just had a go at creating my first movie with MM2. I was a bit
disappointed that the audio seemed to skip very noticeably on transitions
between frames.

Referring to PapaJohn's Web site I found a link to the following KB article:
http://support.microsoft.com/default.aspx?scid=kb;en-us;812610 (Audio File
Sound Skips During Image Transitions) which says that low quality MP3s will
tend to cause this. However, I used a low quality MP3 on the first half of
the video and that rendered perfectly. I used a high quality WMA file on
the second half of the video and that's where the problems occurred!

I would like to rule out computer performance issues as I've just got a new
PC with a P4 2.8 HT processor, 512MB RAM and all the other whistles and
bells that you'd expect with a new PC.

I will have a go at re-rendering the project to see if I get the same
results, but in the mean time if anybody else has experienced this and can
suggest if I may be doing something wrong then I'd be happy to hear from
you.

Thanks

Jake

Just re-rendered it and the audio drops out in EXACTLY the same places.

I forgot to mention that I'm rendering it to DV AVI format (PAL).

Jake

 

[MAC]

-----Original Message-----
following KB
article: low quality MP3s
will on the first half
of I've just got a
new


Just re-rendered it and the audio drops out in EXACTLY the same places.

I forgot to mention that I'm rendering it to DV AVI format (PAL).

Jake


.

My projects do exactly the same thing. I have been
wondering how to fix this. I thought it might have been a
resource issue. However I upgraded from 256 to 512 ram
and it didn't seem to matter. Next I was going to get a
separate hard drive to see if running the system,
moviemaker, and writing a DV-AVI file was too taxing on
one hard drive. But I haven't had a chance to test that
yet. The most interesting part of it is when you preview
the project, it doesn't do this - it runs fine. It only
happens when the file is rendered. This seems strange
since it should be able to just take longer or command
more resources during the rendering process than during
the preview. Hopefully someone can answer this question
and provide a solution.

MAC

 

[Jake]

My projects do exactly the same thing. I have been
wondering how to fix this. I thought it might have been a
resource issue. However I upgraded from 256 to 512 ram
and it didn't seem to matter. Next I was going to get a
separate hard drive to see if running the system,
moviemaker, and writing a DV-AVI file was too taxing on
one hard drive. But I haven't had a chance to test that
yet. The most interesting part of it is when you preview
the project, it doesn't do this - it runs fine. It only
happens when the file is rendered. This seems strange
since it should be able to just take longer or command
more resources during the rendering process than during
the preview. Hopefully someone can answer this question
and provide a solution.

MAC

I would like to reinforce the point about the lack of audio skipping in the
preview. I also forgot to mention this, but I think it's important to note.
I can watch the entire preview at about 15fps and it never misses a beat.

If it was CPU, memory or hard disk performance related then I would expect
to see problems at random times, but since the problem occurred at exactly
the same points then I can only imagine that it's a bug.

In a way I'm glad it's not just me that has this problem, although it still
doesn't solve it!

Jake

 

[Michel]

This is a well known often reported bug in MM2.

 

[Jake]

This is a well known often reported bug in MM2.

I see, thanks. Kind of helps - at least I know it's not just me!

Time to learn how to use Premier, maybe ;-)

Jake

 

[Val Kulkov]

Yes, I came across this bug, too. These audio hiccups are incredibly
annoying. Having invested quite a few hours in getting my movie under
control so that it finally runs well and feels well, it was so frustrating
to find out that no, you have no control over these hiccups and basically
all you can do is give up. There is no way as far as I can tell to import
your MM2 movie project into Premiere or anything else. You have to start
from scratch.

Effectively, this bug renders MM2 useless as home video making software,
IMO.

There is one thing that just came to my mind. In my case, the audio skips
appeared at the end of the movie, too. The first 10 min or so ran smoothly.
Maybe, I could split my movie into 10-min chunks and render them one by one,
and then somehow glue them together afterwards. Just a thought...

Val

 

[Jake]

Yes, I came across this bug, too. These audio hiccups are incredibly
annoying. Having invested quite a few hours in getting my movie under
control so that it finally runs well and feels well, it was so frustrating
to find out that no, you have no control over these hiccups and basically
all you can do is give up. There is no way as far as I can tell to import
your MM2 movie project into Premiere or anything else. You have to start
from scratch.

Effectively, this bug renders MM2 useless as home video making software,
IMO.

There is one thing that just came to my mind. In my case, the audio skips
appeared at the end of the movie, too. The first 10 min or so ran smoothly.
Maybe, I could split my movie into 10-min chunks and render them one by one,
and then somehow glue them together afterwards. Just a thought...

Val

I don't think that splitting it into ten minute chunks will help. I've had
the problem half way through 5 and 7 minute chunks.

I've narrowed it down to this:

The problem doesn't occur with MP3 audio files. It occurs with WMA files
which I created by saving an audio track from CD via Media Player.

When rendering the final cut, the problems occur where there is a
significant frame transition, i.e. 100% of the pixels change - a cut between
scenes. Too much data for MM2's rendering engine to handle? I noticed this
because one of the 'effects' I've tried is cutting a clip in two places but
allowing them to run together as if they're one, applying a change in speed
between them (normal -> slow down -> speed up) to give an apparent change in
speed within the same clip (good for comedy effect, BTW, if used well). The
audio didn't skip between them even though they behave as separate clips
within MM2.

Having said that, one thing I haven't tested is the clip transition. I
usually use the simple cross fade transition and the problem always happens
then, but I haven't checked to see if I get the problem when using a
straight cut. I will try this out tonight.

Jake

 

[Jake]

In my case, the problem occured with 192kbps MP3 files. When I converted
them into WAV files, the problem became slightly less pronounced however the
quality was still far from being adequate. Indeed, it does look like the
problems occur where there is a significant frame transition.

It looks like MM2 rendering engine chokes up on the audio when processing
transitions. It certainly should not be that way. MM2 should take as much
time as needed to render transitions properly. Instead, it acts as if it
was required to produce a real-time output. I believe Microsoft may have
brainlessly used the rendering code from MS Media Encoder... In any way, it
is a gaping hole in MM2 and until it's fixed, I think MM2 is as good as the
house I haven't yet built.

- Val

I've now had the same problem with mp3 files, but not as pronounced as wma
files.

I think it's time for me to learn how to use Premier!

Jake