• Status Closed
  • Percent Complete
  • Task Type Bugs
  • Category Codecs
  • Assigned To No-one
  • Operating System SW-codec
  • Severity Low
  • Priority Very Low
  • Reported Version Daily build (which?)
  • Due in Version Undecided
  • Due Date Undecided
  • Votes
  • Private
Attached to Project: Rockbox
Opened by tyama - 2008-11-08
Last edited by BigBambi - 2009-12-17

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

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.

Closed by  BigBambi
2009-12-17 22:13
Reason for closing:  Fixed
Additional comments about closing:   Warning: Undefined array key "typography" in /home/rockbox/flyspray/plugins/dokuwiki/inc/parserutils.php on line 371 Warning: Undefined array key "camelcase" in /home/rockbox/flyspray/plugins/dokuwiki/inc/parserutils.php on line 407

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.

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

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.

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.


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