diff options
Diffstat (limited to 'third_party/g7221/decode/coef2sam.c')
| -rw-r--r-- | third_party/g7221/decode/coef2sam.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/third_party/g7221/decode/coef2sam.c b/third_party/g7221/decode/coef2sam.c new file mode 100644 index 00000000..18a88acd --- /dev/null +++ b/third_party/g7221/decode/coef2sam.c @@ -0,0 +1,180 @@ +/***************************************************************************** +** +** ITU-T G.722.1 (2005-05) - Fixed point implementation for main body and Annex C +** > Software Release 2.1 (2008-06) +** (Simple repackaging; no change from 2005-05 Release 2.0 code) +** +** © 2004 Polycom, Inc. +** +** All rights reserved. +** +*****************************************************************************/ + +/***************************************************************************** +* Filename: rmlt_coefs_to_samples.c +* +* Purpose: Convert Reversed MLT (Modulated Lapped Transform) +* Coefficients to Samples +* +* The "Reversed MLT" is an overlapped block transform which uses +* even symmetry * on the left, odd symmetry on the right and a +* Type IV DCT as the block transform. * It is thus similar to a +* MLT which uses odd symmetry on the left, even symmetry * on the +* right and a Type IV DST as the block transform. In fact, it is +* equivalent * to reversing the order of the samples, performing +* an MLT and then negating all * the even-numbered coefficients. +* +*****************************************************************************/ + +/*************************************************************************** + Include files +***************************************************************************/ +#include "defs.h" +#include "tables.h" +#include "count.h" + +/*************************************************************************** + Function: rmlt_coefs_to_samples + + Syntax: void rmlt_coefs_to_samples(Word16 *coefs, + Word16 *old_samples, + Word16 *out_samples, + Word16 dct_length, + Word16 mag_shift) + + inputs: Word16 *coefs + Word16 *old_samples + Word16 dct_length + Word16 mag_shift + + + outputs: Word16 *out_samples + + Description: Converts the mlt_coefs to samples + + Design Notes: + + WMOPS: 7kHz | 24kbit | 32kbit + -------|--------------|---------------- + AVG | 1.91 | 1.91 + -------|--------------|---------------- + MAX | 1.91 | 1.91 + -------|--------------|---------------- + + 14kHz | 24kbit | 32kbit | 48kbit + -------|--------------|----------------|---------------- + AVG | 3.97 | 3.97 | 3.97 + -------|--------------|----------------|---------------- + MAX | 3.97 | 3.97 | 3.97 + -------|--------------|----------------|---------------- + +***************************************************************************/ + +void rmlt_coefs_to_samples(Word16 *coefs, + Word16 *old_samples, + Word16 *out_samples, + Word16 dct_length, + Word16 mag_shift) +{ + + + Word16 index, vals_left; + Word16 new_samples[MAX_DCT_LENGTH]; + Word16 *new_ptr, *old_ptr; + Word16 *win_new, *win_old; + Word16 *out_ptr; + Word16 half_dct_size; + Word32 sum; + + + + half_dct_size = shr(dct_length,1); + + /* Perform a Type IV (inverse) DCT on the coefficients */ + dct_type_iv_s(coefs, new_samples, dct_length); + + test(); + if (mag_shift > 0) + { + for(index=0;index<dct_length;index++) + { + new_samples[index] = shr(new_samples[index],mag_shift); + move16(); + } + } + else + { + test(); + if (mag_shift < 0) + { + mag_shift = negate(mag_shift); + for(index=0;index<dct_length;index++) + { + new_samples[index] = shl(new_samples[index],mag_shift); + move16(); + } + } + + } + + /* Get the first half of the windowed samples */ + + out_ptr = out_samples; + move16(); + test(); + if (dct_length==DCT_LENGTH) + { + win_new = rmlt_to_samples_window; + move16(); + win_old = rmlt_to_samples_window + dct_length; + move16(); + } + else + { + win_new = max_rmlt_to_samples_window; + move16(); + win_old = max_rmlt_to_samples_window + dct_length; + move16(); + } + old_ptr = old_samples; + move16(); + new_ptr = new_samples + half_dct_size; + move16(); + + for (vals_left = half_dct_size; vals_left > 0; vals_left--) + { + sum = 0L; + move32(); + sum = L_mac(sum,*win_new++, *--new_ptr); + sum = L_mac(sum,*--win_old, *old_ptr++); + *out_ptr++ = round(L_shl(sum,2)); + move16(); + + } + + /* Get the second half of the windowed samples */ + + for (vals_left = half_dct_size; vals_left > 0; vals_left--) + { + sum = 0L; + move32(); + sum = L_mac(sum,*win_new++, *new_ptr++); + sum = L_mac(sum,negate(*--win_old), *--old_ptr); + *out_ptr++ = round(L_shl(sum,2)); + move16(); + } + + /* Save the second half of the new samples for */ + /* next time, when they will be the old samples. */ + + /* pointer arithmetic */ + new_ptr = new_samples + half_dct_size; + move16(); + old_ptr = old_samples; + move16(); + for (vals_left = half_dct_size; vals_left > 0; vals_left--) + { + *old_ptr++ = *new_ptr++; + move16(); + } +} |