dcadsp.c
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1 /*
2  * Copyright (c) 2004 Gildas Bazin
3  * Copyright (c) 2010 Mans Rullgard <mans@mansr.com>
4  *
5  * This file is part of Libav.
6  *
7  * Libav is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * Libav is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "config.h"
23 #include "libavutil/intreadwrite.h"
24 #include "dcadsp.h"
25 
26 static void dca_lfe_fir_c(float *out, const float *in, const float *coefs,
27  int decifactor, float scale)
28 {
29  float *out2 = out + decifactor;
30  const float *cf0 = coefs;
31  const float *cf1 = coefs + 256;
32  int j, k;
33 
34  /* One decimated sample generates 2*decifactor interpolated ones */
35  for (k = 0; k < decifactor; k++) {
36  float v0 = 0.0;
37  float v1 = 0.0;
38  for (j = 0; j < 256 / decifactor; j++) {
39  float s = in[-j];
40  v0 += s * *cf0++;
41  v1 += s * *--cf1;
42  }
43  *out++ = v0 * scale;
44  *out2++ = v1 * scale;
45  }
46 }
47 
48 static void dca_qmf_32_subbands(float samples_in[32][8], int sb_act,
49  SynthFilterContext *synth, FFTContext *imdct,
50  float synth_buf_ptr[512],
51  int *synth_buf_offset, float synth_buf2[32],
52  const float window[512], float *samples_out,
53  float raXin[32], float scale)
54 {
55  int i;
56  int subindex;
57 
58  for (i = sb_act; i < 32; i++)
59  raXin[i] = 0.0;
60 
61  /* Reconstructed channel sample index */
62  for (subindex = 0; subindex < 8; subindex++) {
63  /* Load in one sample from each subband and clear inactive subbands */
64  for (i = 0; i < sb_act; i++) {
65  unsigned sign = (i - 1) & 2;
66  uint32_t v = AV_RN32A(&samples_in[i][subindex]) ^ sign << 30;
67  AV_WN32A(&raXin[i], v);
68  }
69 
70  synth->synth_filter_float(imdct, synth_buf_ptr, synth_buf_offset,
71  synth_buf2, window, samples_out, raXin, scale);
72  samples_out += 32;
73  }
74 }
75 
77 {
81 }