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Support and General Use => Audio Playback, Database and Playlists => Topic started by: ilikedirt on June 18, 2008, 09:58:57 PM

Title: Musepack playback glitch (Gigabeat F)
Post by: ilikedirt on June 18, 2008, 09:58:57 PM
Hi,

I stumbled accross a glitch with a certain Musepack file. A loud "blip" sound appers on certain times in this file when played back with Rockbox (latest build r17732 as well as older build from 2008-05-19). The same file plays back in foobar2000 just fine. I dont know if more files are affected. If someone is interested I could send the file for examination.
Title: Re: Musepack playback glitch (Gigabeat F)
Post by: saratoga on June 19, 2008, 12:16:31 AM
Theres been a lot of changes to MPC in the last two months.  Trying a build from mid or early April would be interesting.
Title: Re: Musepack playback glitch (Gigabeat F)
Post by: ilikedirt on June 19, 2008, 07:55:26 AM
Is there a place where I can find builds older than one month? Or can someone upload one for me? That would be somewhat easier for me than setting up the build enviroment myself - appart from me not beeing familiar with using it.
Title: Re: Musepack playback glitch (Gigabeat F)
Post by: GodEater on June 19, 2008, 09:49:03 AM
Is there a place where I can find builds older than one month?

Nope - 1 month is all we keep.

Quote
Or can someone upload one for me? That would be somewhat easier for me than setting up the build environment myself - apart from me not being familiar with using it.

Possibly someone can - but it might be worth the trouble of learning how to do the building - it's not as tough and scary as it looks!
Title: Re: Musepack playback glitch (Gigabeat F)
Post by: ilikedirt on June 20, 2008, 12:08:39 PM
I build r16903 from April 1st. The glitches on my file are already there.
Title: Re: Musepack playback glitch (Gigabeat F)
Post by: Buschel on June 21, 2008, 05:00:58 AM
Hi,

is there any possibility get this file for further debugging? I have an idea about this issue...

Buschel
Title: Re: Musepack playback glitch (Gigabeat F)
Post by: ilikedirt on June 21, 2008, 07:13:38 AM
Hi Buschel,

of course. How would you like me to send you the file, email? You could PM me your adress.
Title: Re: Musepack playback glitch (Gigabeat F)
Post by: Buschel on June 28, 2008, 09:02:42 AM
hi,

should be solved with r17829. the (already present) hack never seemed to work correctly due to the wrong default scalefactor.
musepack uses differential scf-coding in time domain. if you decode from the beginning everything is fine. if you seek with in a file, the decoder may not know the reference-scf after seek -- in the file i've tested this happened with highest subband. in this case the decoder uses a much too high scf what results in burst noise. solution (or better hack) is to use the lowest scf (equals fading out of the subband) until there was a reference scf decoded (1st non-differential coded scf).

please report, if the problem is solved now.

thanks,
buschel

EDIT: The bug is reported as fixed with r17829.