Severe skipping with certain volume normalizer?

[wildbilldubs]

Hello all...

I'm using dbPowerAMP Music Converter (unsure of the exact version, but I will check later) and it is simply an excellent little program. It does exactly what I need and want...so I registered the MP3 encoder and power pack. I am a very happy customer...but I think I've run into a problem.

I've started to explore some of the more detailed options available in the program...such as the volume normalizer in the PowerPack DSP. It is here that I ran into a problem. I found that when using one of the normalizer methods (again, I'll have to check to see which one as I am away from that computer now) that there were severe audio skips, dropouts or major "jumps" occuring in almost every file that I encoded. (Some files were fine.)

I figured at first that A) my portable music player was being asked to do something beyond its abilities or B) that Windows Media 9 encoding was causing the problem. So I switched to a low-bitrate MP3 conversion and found the problem was still around with files converted and then played on either the computer or the music player.

What I'd like to know is where I'm going wrong. I don't think I have an underpowered computer--the machine in question has dual SATA hard disks, 1GB of RAM and a 3.4GHz Pentium 4 processor. Windows 2000 Professional SP4 is the operating system. Can anyone help me or explain what's going on?

[Spoon]

If you could report which exact Volume normalize was selected, the settings, what the length of an audio file that had skipping and the time locations of the skipping.

There is a similar bug that is being investigated.

[wildbilldubs]

Here's what I can report. This was tried with both 64Kbit Windows Media and 80 or 64 Kbit LAME MP3 compression.

I turned on the PowerPack DSP and selected "volume normalize". The method of normalization used the "Adaptive" type with all default settings and a 6000mSec window size. (It should be noted that the simple normalization type worked fine for me...) The defaults on my system appear to be Desired Volume: 100% of maximum or -0.0 dB, Max Multiply x28, Window Size 6000mSec and Multiply Signal is greyed out but set to x 1.500.

No other filters or DSP goodies were used.

Song length didn't seem to matter. I had long (4 minute+) songs that played fine, 2 minute ones that didn't and ones that were the other way around.

Character of the problem was the strange part--sometimes the affected songs just skipped for a moment. Other times the song would "jump" quite far. There were also songs that played fine until what should have been the end was reached. Then a portion of the song would repeat itself. This is what made me think at first that my portable MP3/WMA player was being asked to do something beyond what it could comprehend...but then I played the files on a desktop computer and had the same problem.

[wildbilldubs]

Maybe the best way to isolate this problem would be to make some samples?

It didn't take very long, so here they are. The first is the sample indicating the problem. The second is a "good" version with no power pack DSP effects applied. Both are 56Kbit MP3 files and are about 1.83 MB in size.

You will hear the flaws through the first 45 or so seconds of the first file.

Both were encoded on a 3.4 GHz P4 running Windows 2000 Professional SP4.

http://greyghost.dyndns.org/dbpa-sample1.mp3
http://greyghost.dyndns.org/dbpa-sample2.mp3

Hopefully these might help.

Wild Bill

[Spoon]

Thanks, have the files - will look when the moment allows.

[Devon]

Yeah just kidding...wrong program.

[TheSmacK420]

Yeah, I have the same problem with skipping and jumps in the mp3s when using adaptive normalization. It makes me sad.......

[neilthecellist]

me third.

[wildbilldubs]

Okay, it's looking like it's been a while since anything has happened on this...

Now I don't mean to sound rude, but what's up? Has there been any progress on this issue? A quick check of the support forum (and this thread) didn't show anything interesting having happened.

Maybe a little later I will pull down the latest revision of dbPowerAMP and try again to see what happens.

Wild Bill

[Spoon]

It was fixed in this thread:

http://forum.dbpoweramp.com/showthread.php?t=6878&highlight=adaptive

It will be in the next beta of dMC (start to change something and keep going...R11.1 is going to be a much bigger update than initially thought: freedb proto6, mp3 encoding conditioning, redesigned dmc config).