• Status Closed
  • Percent Complete
  • Task Type Patches
  • Category Codecs
  • Assigned To No-one
  • Operating System PortalPlayer-based
  • Severity Low
  • Priority Very Low
  • Reported Version
  • Due in Version Undecided
  • Due Date Undecided
  • Votes
  • Private
Attached to Project: Rockbox
Opened by tmal - 2007-02-18

FS#6670 - Small dct32 routine for the MPA codec

The dct32 routine in libmad/synth.c is pretty big and it causes lots of cache misses. I have written a smaller one in ARM assembler. It isn't as optimal in terms of number of arithmetic operations, but it's much more cache friendly because of smaller code size. It helps a lot on Iriver iFP where SRAM is really slow. I would like someone with other ARM targets to check if it helps on them as well.

The routine is currently compiled to SRAM, but I suppose it's worth trying to move it to IRAM.

Closed by  tmal
2007-02-27 23:53
Reason for closing:  Duplicate
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

Moved to  FS#6705 

What are we looking for? I've tested this on a 5.5G 30GB Video iPod

tmal commented on 2007-02-24 20:17

As tested by Preglow on Feb 18th (see irc logs), it doesn't improve performance on Ipod (I'm not sure which model). We were looking for smaller boost ratio (info→debug→view audio thread).

Okay what about  FS#6357  does that help or is it an outdated patch?


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