diff options
Diffstat (limited to 'lib/rbcodec/codecs/libwmavoice/acelp_filters.c')
-rw-r--r-- | lib/rbcodec/codecs/libwmavoice/acelp_filters.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/lib/rbcodec/codecs/libwmavoice/acelp_filters.c b/lib/rbcodec/codecs/libwmavoice/acelp_filters.c new file mode 100644 index 0000000000..c48c0e72ce --- /dev/null +++ b/lib/rbcodec/codecs/libwmavoice/acelp_filters.c @@ -0,0 +1,145 @@ +/* + * various filters for ACELP-based codecs + * + * Copyright (c) 2008 Vladimir Voroshilov + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <inttypes.h> + +#include "avcodec.h" +#include "acelp_filters.h" + +const int16_t ff_acelp_interp_filter[61] = { /* (0.15) */ + 29443, 28346, 25207, 20449, 14701, 8693, + 3143, -1352, -4402, -5865, -5850, -4673, + -2783, -672, 1211, 2536, 3130, 2991, + 2259, 1170, 0, -1001, -1652, -1868, + -1666, -1147, -464, 218, 756, 1060, + 1099, 904, 550, 135, -245, -514, + -634, -602, -451, -231, 0, 191, + 308, 340, 296, 198, 78, -36, + -120, -163, -165, -132, -79, -19, + 34, 73, 91, 89, 70, 38, + 0, +}; + +void ff_acelp_interpolate(int16_t* out, const int16_t* in, + const int16_t* filter_coeffs, int precision, + int frac_pos, int filter_length, int length) +{ + int n, i; + + //assert(frac_pos >= 0 && frac_pos < precision); + + for (n = 0; n < length; n++) { + int idx = 0; + int v = 0x4000; + + for (i = 0; i < filter_length;) { + + /* The reference G.729 and AMR fixed point code performs clipping after + each of the two following accumulations. + Since clipping affects only the synthetic OVERFLOW test without + causing an int type overflow, it was moved outside the loop. */ + + /* R(x):=ac_v[-k+x] + v += R(n-i)*ff_acelp_interp_filter(t+6i) + v += R(n+i+1)*ff_acelp_interp_filter(6-t+6i) */ + + v += in[n + i] * filter_coeffs[idx + frac_pos]; + idx += precision; + i++; + v += in[n - i] * filter_coeffs[idx - frac_pos]; + } + if (av_clip_int16(v >> 15) != (v >> 15)) + av_log(NULL, AV_LOG_WARNING, "overflow that would need cliping in ff_acelp_interpolate()\n"); + out[n] = v >> 15; + } +} + +void ff_acelp_interpolatef(float *out, const float *in, + const float *filter_coeffs, int precision, + int frac_pos, int filter_length, int length) +{ + int n, i; + + for (n = 0; n < length; n++) { + int idx = 0; + float v = 0; + + for (i = 0; i < filter_length;) { + v += in[n + i] * filter_coeffs[idx + frac_pos]; + idx += precision; + i++; + v += in[n - i] * filter_coeffs[idx - frac_pos]; + } + out[n] = v; + } +} + + +void ff_acelp_high_pass_filter(int16_t* out, int hpf_f[2], + const int16_t* in, int length) +{ + int i; + int tmp; + + for (i = 0; i < length; i++) { + tmp = (hpf_f[0]* 15836LL) >> 13; + tmp += (hpf_f[1]* -7667LL) >> 13; + tmp += 7699 * (in[i] - 2*in[i-1] + in[i-2]); + + /* With "+0x800" rounding, clipping is needed + for ALGTHM and SPEECH tests. */ + out[i] = av_clip_int16((tmp + 0x800) >> 12); + + hpf_f[1] = hpf_f[0]; + hpf_f[0] = tmp; + } +} + +void ff_acelp_apply_order_2_transfer_function(float *out, const float *in, + const float zero_coeffs[2], + const float pole_coeffs[2], + float gain, float mem[2], int n) +{ + int i; + float tmp; + + for (i = 0; i < n; i++) { + tmp = gain * in[i] - pole_coeffs[0] * mem[0] - pole_coeffs[1] * mem[1]; + out[i] = tmp + zero_coeffs[0] * mem[0] + zero_coeffs[1] * mem[1]; + + mem[1] = mem[0]; + mem[0] = tmp; + } +} + +void ff_tilt_compensation(float *mem, float tilt, float *samples, int size) +{ + float new_tilt_mem = samples[size - 1]; + int i; + + for (i = size - 1; i > 0; i--) + samples[i] -= tilt * samples[i - 1]; + + samples[0] -= tilt * *mem; + *mem = new_tilt_mem; +} + |