todo

一个开源的sip源代码

For 1.2beta2:
*Use full complex values for fft results?
*get rid of crap that shouldn't be exposed in speex.h
*Reduce wideband RAM requirements
*Make foreground filter 16 bits in AEC.
*Enable resampler in build
*Add dumping of data for debug purposes.
*remove wideband pseudo-stack
*pitch prediction saturation to prevent NaN-based DoS attacks.
*Fix jitter buffer

speex_decoder_ctl() call to detect silence
Complete resampler API (error codes)
Fix resampler corner case
Use lower sinc oversampling when down-sampling
**Fix register issue on Blackfin
Merge TriMedia stuff
Make it possible to decode a "raw" packet with SpeexBits
Control delay in new AEC API.

Later:
Do VAD properly
Warning/error handling
--enable-{aec,preprocessor,jitter,resampler}


Optimisations
- Add restrict in a few places?
- enable 4x4 version of pitch_xcorr()?

Would be nice:
Implement wideband split as IIR instead of QMF.

Allocator override (speex_lib_ctl?)
Better error handling
Fixed-point:
  - Wideband
  - Jitter buffer
Denoiser:
  - Better noise adaptation
AGC:
  - Use median filtering instead of "non-linear mean"?

Features
-Improve error handling (with perror-like call?)

Standards
-Complete Speex RTP profile
-MIME type registration

ideas:
Peelable stream (double codebook, higher bands, stereo)
LPC from spectral domain