Background
==========

- Priority scale: High, Medium and Low

- Complexity scale: C1, C2, C4 and C8.  The complexity scale is exponential,
  with complexity 1 being the lowest complexity.  Complexity is a function
  of both task 'complexity' and task 'scope'.

  The general rule of thumb is that a complexity 1 task should take 1-2 weeks
  for a person very familiar with oFono codebase.  Higher complexity tasks
  require more time and have higher uncertainty.

  Higher complexity tasks should be refined into several lower complexity tasks
  once the task is better understood.

Encoder optimizations
=====================

- Currently, only the decoder is optimized to take advantage of advanced
  processor instruction sets. In use cases like HFP 1.6, optimizing the
  encoder will bring a significant latency, power and performance advantage.
  For example, the MMX encoder is 3 to 6 time faster than the SIMD encoder.

  Priority: High
  Complexity: C8

- Use a log2 table for byte integer scale factors calculation (sum log2
  results for high and low bytes) fill bitpool by 16 bits instead of one
  at a time in bits allocation/bitpool generation port to the dsp

  Priority: Medium
  Complexity: C2

- The neon optimization code is split in two parts. Sample reordering and
  blocks encoding. There is a neon optimization for encoding SBC. But mSBC
  is not supported by this optimizer because the reordering has been
  specifically for mSBC.

  Priority: Low
  Complexity: C2

Decoder optimizations
=====================

- The decoder is optimized to take advantage of advanced processor
  instruction sets. Currently implemented are MMX, arm neon, arm v6
  and iwmmxt. SSE3 is available since almost 10 years now, on a large
  range of Intel processors. It should be interesting to implement it
  and to compare with MMX implementation on Intel processors.

  Priority: Medium
  Complexity: C4