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Diffstat (limited to 'lib/rbcodec/codecs/libopus/celt/mdct.h')
-rw-r--r-- | lib/rbcodec/codecs/libopus/celt/mdct.h | 70 |
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diff --git a/lib/rbcodec/codecs/libopus/celt/mdct.h b/lib/rbcodec/codecs/libopus/celt/mdct.h new file mode 100644 index 0000000000..d72182138a --- /dev/null +++ b/lib/rbcodec/codecs/libopus/celt/mdct.h | |||
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1 | /* Copyright (c) 2007-2008 CSIRO | ||
2 | Copyright (c) 2007-2008 Xiph.Org Foundation | ||
3 | Written by Jean-Marc Valin */ | ||
4 | /* | ||
5 | Redistribution and use in source and binary forms, with or without | ||
6 | modification, are permitted provided that the following conditions | ||
7 | are met: | ||
8 | |||
9 | - Redistributions of source code must retain the above copyright | ||
10 | notice, this list of conditions and the following disclaimer. | ||
11 | |||
12 | - Redistributions in binary form must reproduce the above copyright | ||
13 | notice, this list of conditions and the following disclaimer in the | ||
14 | documentation and/or other materials provided with the distribution. | ||
15 | |||
16 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | ||
17 | ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | ||
18 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | ||
19 | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER | ||
20 | OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | ||
21 | EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | ||
22 | PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR | ||
23 | PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF | ||
24 | LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING | ||
25 | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS | ||
26 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | ||
27 | */ | ||
28 | |||
29 | /* This is a simple MDCT implementation that uses a N/4 complex FFT | ||
30 | to do most of the work. It should be relatively straightforward to | ||
31 | plug in pretty much and FFT here. | ||
32 | |||
33 | This replaces the Vorbis FFT (and uses the exact same API), which | ||
34 | was a bit too messy and that was ending up duplicating code | ||
35 | (might as well use the same FFT everywhere). | ||
36 | |||
37 | The algorithm is similar to (and inspired from) Fabrice Bellard's | ||
38 | MDCT implementation in FFMPEG, but has differences in signs, ordering | ||
39 | and scaling in many places. | ||
40 | */ | ||
41 | |||
42 | #ifndef MDCT_H | ||
43 | #define MDCT_H | ||
44 | |||
45 | #include "opus_defines.h" | ||
46 | #include "kiss_fft.h" | ||
47 | #include "arch.h" | ||
48 | |||
49 | typedef struct { | ||
50 | int n; | ||
51 | int maxshift; | ||
52 | const kiss_fft_state *kfft[4]; | ||
53 | const kiss_twiddle_scalar * OPUS_RESTRICT trig; | ||
54 | } mdct_lookup; | ||
55 | |||
56 | int clt_mdct_init(mdct_lookup *l,int N, int maxshift); | ||
57 | void clt_mdct_clear(mdct_lookup *l); | ||
58 | |||
59 | /** Compute a forward MDCT and scale by 4/N, trashes the input array */ | ||
60 | void clt_mdct_forward(const mdct_lookup *l, kiss_fft_scalar *in, | ||
61 | kiss_fft_scalar * OPUS_RESTRICT out, | ||
62 | const opus_val16 *window, int overlap, int shift, int stride); | ||
63 | |||
64 | /** Compute a backward MDCT (no scaling) and performs weighted overlap-add | ||
65 | (scales implicitly by 1/2) */ | ||
66 | void clt_mdct_backward(const mdct_lookup *l, kiss_fft_scalar *in, | ||
67 | kiss_fft_scalar * OPUS_RESTRICT out, | ||
68 | const opus_val16 * OPUS_RESTRICT window, int overlap, int shift, int stride); | ||
69 | |||
70 | #endif | ||