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-rw-r--r--lib/rbcodec/codecs/libwmavoice/acelp_filters.c145
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;
+}
+