Timothy B. Terriberry authored 14 years ago and Jean-Marc Valin committed 14 years ago

This unifies the byte buffer, encoder, and decoder into a single
 struct.
The common encoder and decoder functions (such as ec_tell()) can
 operate on either one, simplifying code which uses both.
The precision argument to ec_tell() has been removed.
It now comes in two precisions:
  ec_tell() gives 1 bit precision in two operations, and
  ec_tell_frac() gives 1/8th bit precision in... somewhat more.
ec_{enc|dec}_bit_prob() were removed (they are no longer needed).
Some of the byte buffer access functions were made static and
 removed from the cross-module API.
All of the code in rangeenc.c and rangedec.c was merged into
 entenc.c and entdec.c, respectively, as we are no longer
 considering alternative backends.
rangeenc.c and rangede.c have been removed entirely.

This passes make check, after disabling the modes that we removed
 support for in cf5d3a8c.

by POSIX. The other _t types that are not part of the API are still there
for now. Also, got rid of all that was left of the 64-bit types.

Timothy B. Terriberry authored 15 years ago and Jean-Marc Valin committed 15 years ago

Adds specialized O(N*log(K)) versions of cwrsi() and O(N) versions of icwrs()
 for N={3,4,5}, which allows them to operate all the way up to the theoretical
 pulse limit without serious performance degredation.
Also substantially reduces the computation time and stack usage of
 get_required_bits().
On x86-64, this gives a 2% speed-up for 256 sample frames, and almost a 16%
 speed-up for 64 sample frames.

problems when building shared libraries only.

Timothy B. Terriberry authored 16 years ago and Jean-Marc Valin committed 16 years ago

It is no slower with a large number of pulses, and as much as 30% faster with
 a large number of dimensions.

Timothy B. Terriberry authored 16 years ago and Jean-Marc Valin committed 16 years ago

This lets us encode and decode directly from the pulse vector without an
 intermediate transformation.
This makes old streams undecodable.
Additionally, ncwrs_u32() has been sped up for large N by using the sliding
 recurrence from Mohorko et al.
ncwrs_u64 could be sped up in a similar manner, but would require a larger
 table of multiplicative inverses (or several 32x32->64 bit multiplies).
Note that U(N,M) is now everywhere 1/2 the value it used to be.

need to iterate at least once.

Timothy B. Terriberry authored 16 years ago and Jean-Marc Valin committed 16 years ago

This eliminates an extra O(nm) lookups on decode, and reduces the rate control
 from O(nm^2) to O(nm), in addition to eliminating O(m) lookups on both encode
 and decode.
Although the interface is slightly more complex, the internal code is also
 simpler.