eden-emu/opus
20
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

SILK fixes following last codec WG meeting

Browse source 
decoder:
- fixed incorrect scaling of filter states for the smallest quantization
  step sizes
- NLSF2A now limits the prediction gain of LPC filters

encoder:
- increased damping of LTP coefficients in LTP analysis
- increased white noise fraction in noise shaping LPC analysis
- introduced maximum total prediction gain.  Used by Burg's method to
  exit early if prediction gain is exceeded.  This improves packet
  loss robustness and numerical robustness in Burg's method
- Prefiltered signal is now in int32 Q10 domain, from int16 Q0
- Increased max number of iterations in CBR gain control loop from 5 to 6
- Removed useless code from LTP scaling control
- Optimization: smarter LPC loop unrolling
- Switched default win32 compile mode to be floating-point

resampler:
- made resampler have constant delay of 0.75 ms; removed delay
  compensation from silk code.
- removed obsolete table entries (~850 Bytes)
- increased downsampling filter order from 16 to 18/24/36 (depending on
  frequency ratio)
- reoptimized filter coefficients
This commit is contained in:
Koen Vos 2011-12-13 14:47:31 -05:00 • committed by Jean-Marc Valin
parent 6619a73637
commit bf75c8ec4d
71 changed files with 961 additions and 1005 deletions
Download patch file Download diff file Expand all files Collapse all files

32
silk/SigProc_FIX.h
View file

@ -52,19 +52,20 @@ extern "C"
* Initialize/reset the resampler state for a given pair of input/output sampling rates
*/
opus_int silk_resampler_init(
silk_resampler_state_struct *S, /* I/O Resampler state */
opus_int32 Fs_Hz_in, /* I Input sampling rate (Hz) */
opus_int32 Fs_Hz_out /* I Output sampling rate (Hz) */
silk_resampler_state_struct *S, /* I/O Resampler state */
opus_int32 Fs_Hz_in, /* I Input sampling rate (Hz) */
opus_int32 Fs_Hz_out, /* I Output sampling rate (Hz) */
opus_int forEnc /* I If 1: encoder; if 0: decoder */
);
/*!
* Resampler: convert from one sampling rate to another
*/
opus_int silk_resampler(
silk_resampler_state_struct *S, /* I/O Resampler state */
opus_int16 out[], /* O Output signal */
const opus_int16 in[], /* I Input signal */
opus_int32 inLen /* I Number of input samples */
silk_resampler_state_struct *S, /* I/O Resampler state */
opus_int16 out[], /* O Output signal */
const opus_int16 in[], /* I Input signal */
opus_int32 inLen /* I Number of input samples */
);
/*!
@ -127,15 +128,14 @@ void silk_bwexpander_32(
/* Compute inverse of LPC prediction gain, and */
/* test if LPC coefficients are stable (all poles within unit circle) */
opus_int silk_LPC_inverse_pred_gain( /* O Returns 1 if unstable, otherwise 0 */
opus_int32 *invGain_Q30, /* O Inverse prediction gain, Q30 energy domain */
opus_int32 silk_LPC_inverse_pred_gain( /* O Returns inverse prediction gain in energy domain, Q30 */
const opus_int16 *A_Q12, /* I Prediction coefficients, Q12 [order] */
const opus_int order /* I Prediction order */
);
opus_int silk_LPC_inverse_pred_gain_Q24( /* O Returns 1 if unstable, otherwise 0 */
opus_int32 *invGain_Q30, /* O Inverse prediction gain, Q30 energy domain */
const opus_int32 *A_Q24, /* I Prediction coefficients, Q24 [order] */
/* For input in Q24 domain */
opus_int32 silk_LPC_inverse_pred_gain_Q24( /* O Returns inverse prediction gain in energy domain, Q30 */
const opus_int32 *A_Q24, /* I Prediction coefficients [order] */
const opus_int order /* I Prediction order */
);
@ -313,9 +313,9 @@ void silk_burg_modified(
opus_int *res_nrg_Q, /* O Residual energy Q value */
opus_int32 A_Q16[], /* O Prediction coefficients (length order) */
const opus_int16 x[], /* I Input signal, length: nb_subfr * ( D + subfr_length ) */
const opus_int32 minInvGain_Q30, /* I Inverse of max prediction gain */
const opus_int subfr_length, /* I Input signal subframe length (incl. D preceeding samples) */
const opus_int nb_subfr, /* I Number of subframes stacked in x */
const opus_int32 WhiteNoiseFrac_Q32, /* I Fraction added to zero-lag autocorrelation */
const opus_int D /* I Order */
);
@ -388,9 +388,9 @@ static inline opus_int32 silk_ROR32( opus_int32 a32, opus_int rot )
#endif
/* Useful Macros that can be adjusted to other platforms */
#define silk_memcpy(a, b, c) memcpy((a), (b), (c)) /* Dest, Src, ByteCount */
#define silk_memset(a, b, c) memset((a), (b), (c)) /* Dest, value, ByteCount */
#define silk_memmove(a, b, c) memmove((a), (b), (c)) /* Dest, Src, ByteCount */
#define silk_memcpy(dest, src, size) memcpy((dest), (src), (size))
#define silk_memset(dest, src, size) memset((dest), (src), (size))
#define silk_memmove(dest, src, size) memmove((dest), (src), (size))
/* Fixed point macros */