FS#9536 - wma.codec does not decode low bitrate files correctly

Attached to Project: Rockbox
Opened by tyama (tyama) - Saturday, 08 November 2008, 08:18 GMT
Last edited by Alex Parker (BigBambi) - Thursday, 17 December 2009, 22:13 GMT
Task Type Bugs
Category Codecs
Status Closed
Assigned To No-one
Operating System SW-codec
Severity Low
Priority Normal
Reported Version Daily build (which?)
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 0
Private No


I tried to listen to music whose bitrate is 32kbps.
Then I hear too many noises.

So I have encoded a music file to wma with some bitrates.
When I encoded with 48kbps, it played fine.
32kbps bad.

I upload the sample, so could you fix it?
#The song is Arthur/HappyBirthDay(, which is in public domain.

#According to the svn log, wma.codec was not correctly initialize huffman decoder, but I suspect it is initialized correctly now.
This task depends upon

Closed by  Alex Parker (BigBambi)
Thursday, 17 December 2009, 22:13 GMT
Reason for closing:  Fixed
Additional comments about closing:  The one remaining glitch in ..48.wma is also present when played with mplayer, except it skips the affected part rather than playing static. Either way, it is an error in the file.
Comment by Jonas Häggqvist (rasher) - Thursday, 11 December 2008, 18:37 GMT
  • Field changed: Status (Unconfirmed → New)
  • Field changed: Operating System (All players → SW-codec)
happybirth_32_32.wma has severe artifacts with r19376
happybirth_32_48.wma has a single noise about halfway through

Both play fine with mplayer/ffmpeg
Comment by Tom Ross (midgey34) - Friday, 19 December 2008, 21:33 GMT
Looks like there's a problem with the noise coding on low bitrate files. Try the patch I've attached; it makes 32kpbs sound much better. The glitch is still present in the 48 kbps file (all of a sudden there is a massive spike in volume - clipping). I'm not sure what's causing the 48 kbps issue.
Comment by MichaelGiacomelli (saratoga) - Saturday, 20 December 2008, 02:42 GMT
This appears mostly fixed as of r19494, however there is a minor glitch due to a parse error which the parser insists is due to a broken packet. Do you have any other tracks with distortion in them? They'd be interesting to look at.