Tremor: Difference between revisions

Revision as of 20:28, 15 March 2010

Tremor is a fixed-point version of the Ogg Vorbis decoder for those platforms that can't do floating point math.

Platforms

ARM/Coldfire/MIPS CPUs

You will probably want to use the Tremor main branch. You can check it out here:

svn co http://svn.xiph.org/trunk/Tremor/

It contains some optimizations for ARM and the overall lowest computational complexity. It should run on most devices with a few hundred KB of codec RAM.

Texas Instruments TMS320C55x DSP Family

Download the generic lowmem source using Subversion. This is probably the version you want to start working with for a DSP, but may be slower on normal CPUs.

svn co http://svn.xiph.org/branches/lowmem-branch/Tremor/

There is also a no-byte branch for platforms whose smallest data unit is larger than 8 bits.

Required / Suggested Changes to the code as downloaded:

Roland Wintersteller's various fixes

See the mailing list entry

Johannes Sandvall's performance improvements

See the mailing list entry

alloca removal

The TI compiler does not support this.

misc compiler warning fixes
hooks to TI DSPLIB functions cfft3216_NOSCALE and cbrev32

These are part of the TI DSPLIB which can be downloaded from the TI website.

64-bit math functions
converting all ints assumed to be 32 bits to ogg_int32_t

Links

Tremor Mailing List - lots of info here, but have to wade through a lot!

@@ Line 25: / Line 25: @@
 See the [http://lists.xiph.org/pipermail/tremor/2004-October/001114.html mailing list entry]
 * Johannes Sandvall's performance improvements
-See the [http://lists.xiph.org/pipermail/tremor/2004-March/000957.html mailing list entry] or just [http://www.sandvall.nu/patch download]
+See the [http://lists.xiph.org/pipermail/tremor/2004-March/000957.html mailing list entry]
 * alloca removal
 The TI compiler does not support this.