Rockbox Technical Forums

Rockbox General => Rockbox General Discussion => Topic started by: shoe on October 27, 2007, 09:14:20 PM

Title: WMA sound issues on Gigabeat
Post by: shoe on October 27, 2007, 09:14:20 PM
Hi I've been using a 4g ipod, but due to hardware issues caused by dropping it too many times,  I just got a GigabeatF.   I have tons of wma files and they all play fine on the ipod, but on the Gigabeat, certain albums are full of terrible popping and static (r15335).  These same files play fine with foobar2000, the ipod, and the Gigabeat simulator!  Mp3s play fine by the way.  

Does anyone else have this problem with the Gigabeat?  Maybe I just got a bad one hardware-wise, or maybe wma firmware is still not to the same state for this player as the ipod?  Any ideas, suggestions?  Thanks.
Title: Re: WMA sound issues on Gigabeat
Post by: Chronon on October 27, 2007, 10:26:02 PM
I don't listen to many WMA files (on my F40), but the only ones I have tried have all played back properly.  
Title: Re: WMA sound issues on Gigabeat
Post by: shoe on October 27, 2007, 10:55:04 PM
I could email you a sample problem wma file, if you would be willing to check it on your player.  You can PM me your email.
Title: Re: WMA sound issues on Gigabeat
Post by: saratoga on October 28, 2007, 02:46:35 AM
If they play differently on the Gigabeat, something is wrong with the gigabeat.  No point in sending the files to someone else.
Title: Re: WMA sound issues on Gigabeat
Post by: Mad Cow on October 28, 2007, 11:18:08 AM
Mine does that too with some WMAs. I have 1 that works fine, but a whole album of ones that pop alot.
Title: Re: WMA sound issues on Gigabeat
Post by: shoe on October 28, 2007, 12:08:00 PM
If they play differently on the Gigabeat, something is wrong with the gigabeat.  No point in sending the files to someone else.
You mean wrong with this particular one, or with the gigabeat in general?  What kind of problem could it be, do you think?  Otherwise it seems to work perfectly, and I dont have any problems at all with mp3s.  Doesnt really make sense to me...
Title: Re: WMA sound issues on Gigabeat
Post by: misterpink on October 28, 2007, 01:05:56 PM
I don't have many wmas but I have noticed this on some too. I'm sure it didn't do this a while ago so I'll try installing some old builds to pin point the change that caused it. Of course it could just be that I didn't play any files that did it before. I wonder if its a certain wma version that causes it?
Title: Re: WMA sound issues on Gigabeat
Post by: saratoga on October 28, 2007, 01:50:40 PM
If they play differently on the Gigabeat, something is wrong with the gigabeat.  No point in sending the files to someone else.
You mean wrong with this particular one, or with the gigabeat in general?  What kind of problem could it be, do you think?  Otherwise it seems to work perfectly, and I dont have any problems at all with mp3s.  Doesnt really make sense to me...

Well, the decoder is the same on both the Gigabeat and Ipod (they're both ARM CPUs), so if one works and the other doesn't I'd assume something is wrong with the Gigabeat.  Could be a bad install of rockbox.

How many files don't decode right?  And do they always have exactly the same problem in the same part of the track?
Title: Re: WMA sound issues on Gigabeat
Post by: saratoga on October 28, 2007, 02:07:01 PM
Mine does that too with some WMAs. I have 1 that works fine, but a whole album of ones that pop alot.

What player?  And how do they sound in a PC app like foobar?
Title: Re: WMA sound issues on Gigabeat
Post by: shoe on October 28, 2007, 02:09:27 PM
How many files don't decode right?  And do they always have exactly the same problem in the same part of the track?
It seems to vary by entire album.  I will do some investigation after the kids go to bed tonight, as to how many, and if the sounds are always in the same spots.  

Could it be that the ipod as well as my computer sound card do some kind of hardware filtering that is not done in the gigabeat hardware?  That could explain why the ipod/gigabeat simulator wouldnt show problems in the wma files.
Title: Re: WMA sound issues on Gigabeat
Post by: Llorean on October 28, 2007, 02:36:31 PM
Why don't you tell us what settings are different from default, or post a paste of your config file's contents?
Title: Re: WMA sound issues on Gigabeat
Post by: Mad Cow on October 28, 2007, 02:52:30 PM
I'll reset my settings and put on the latest SVN build and try again.

EDIT: Found the problem, turning dithering on makes it crackle and pop.
Title: Re: WMA sound issues on Gigabeat
Post by: shoe on October 28, 2007, 08:17:02 PM
EDIT: Found the problem, turning dithering on makes it crackle and pop.
You're right!  I didnt realize I had dithering turned on, and that explains the differences.  Thanks a lot, and sorry for not being more diligent, and double checking the settings to begin with.  Now I am completely happy with my new Gigabeat.   :)
Title: Re: WMA sound issues on Gigabeat
Post by: saratoga on October 28, 2007, 11:17:09 PM
Dithering will not introduce pops like that.

It sounds like you have clipping, which will often happen with lossy encoded files if they are very loud.  Have you tried replaygain scanning your files or lowering the preamp in audio settings?  
Title: Re: WMA sound issues on Gigabeat
Post by: shoe on October 29, 2007, 01:25:16 AM
I always get popping when dithering is turned on (all other settings default).  Only on certain albums though (purchased in wma format, I don't know the encoding settings).  I tried enabling replaygain, (all tracks, prevent clipping, pre-amp at -12).  Still loud popping, and it goes away with dithering turned off.  It's not a problem for me though, I could never hear any difference from dithering anyway (on tracks that don't pop that is).
Title: Re: WMA sound issues on Gigabeat
Post by: preglow on October 29, 2007, 06:57:40 AM
Do these same files sound crap with dithering enabled on the Ipod too? If so, I'd love to have one of these files so I can debug the problem.
Title: Re: WMA sound issues on Gigabeat
Post by: shoe on October 29, 2007, 12:50:00 PM
Do these same files sound crap with dithering enabled on the Ipod too? If so, I'd love to have one of these files so I can debug the problem.
I believe they sound bad if I enable dithering on the Ipod too.  I will check when I get home.  Here is a sample file (rename to wma file extension):
errorWmaFile (7.72 MB) (http://www.hotshare.net/file/14277-80479437f1.html)
Title: Re: WMA sound issues on Gigabeat
Post by: saratoga on October 29, 2007, 02:11:55 PM
Do these same files sound crap with dithering enabled on the Ipod too? If so, I'd love to have one of these files so I can debug the problem.
I believe they sound bad if I enable dithering on the Ipod too.  I will check when I get home.  Here is a sample file (rename to wma file extension):
errorWmaFile (7.72 MB) (http://www.hotshare.net/file/14277-80479437f1.html)

Theres no replaygain on that file.  Did you actually scan it with foobar to add the replaygain tag?

Anyway, that file is peak normalized to 1.0, so yes, I would expect it to clip if you don't have replaygain info.  
Title: Re: WMA sound issues on Gigabeat
Post by: shoe on October 29, 2007, 04:30:28 PM
No I didn't scan it with foobar to add replaygain tags.  I never used replaygain before, I don't know anything about it.  I gather the replaygain setting in RockBox only works if you have added the tag to the files previously with another program?  I can read up on it to find out what it is all about.  I'm not as worried about it anymore, since it sounds fine with dithering turned off.
Title: Re: WMA sound issues on Gigabeat
Post by: preglow on October 29, 2007, 05:44:53 PM
Confirmed dithering makes it sounds bad, I'll see if I can fix it.
Title: Re: WMA sound issues on Gigabeat
Post by: saratoga on October 29, 2007, 05:48:55 PM
Odd.  I tested on a loud track and couldn't reproduce it with WMA.  Any idea whats special about this file?
Title: Re: WMA sound issues on Gigabeat
Post by: preglow on October 29, 2007, 07:24:11 PM
The bug is in the clipper part of the dither function, it has bugs that only occur at the high output bit depths that wma uses. Any positive clip in WMA should trigger the bug. I will commit a fix shortly, let me know it works.
Title: Re: WMA sound issues on Gigabeat
Post by: shoe on October 29, 2007, 09:01:35 PM
I tested it on two albums that previously had the problem, now they sound fine either way (dither on or off).  

The response time for squashing bugs by the Rockbox development team is incredible, most of the bugs I've reported have been fixed within hours.  Big thanks to you guys!