Tremor

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

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 maybe 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 or just download

• 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!