Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 120 insertions, 0 deletions

diff --git a/media/ffvpx/libavcodec/rdft.c b/media/ffvpx/libavcodec/rdft.c
new file mode 100644
index 0000000000..ac6f5d6781
--- /dev/null
+++ b/media/ffvpx/libavcodec/rdft.c
@@ -0,0 +1,120 @@
+/*
+ * (I)RDFT transforms
+ * Copyright (c) 2009 Alex Converse <alex dot converse at gmail dot com>
+ *
+ * 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 <stdlib.h>
+#include <math.h>
+#include "libavutil/error.h"
+#include "libavutil/mathematics.h"
+#include "rdft.h"
+
+/**
+ * @file
+ * (Inverse) Real Discrete Fourier Transforms.
+ */
+
+/** Map one real FFT into two parallel real even and odd FFTs. Then interleave
+ * the two real FFTs into one complex FFT. Unmangle the results.
+ * ref: http://www.engineeringproductivitytools.com/stuff/T0001/PT10.HTM
+ */
+static void rdft_calc_c(RDFTContext *s, FFTSample *data)
+{
+    int i, i1, i2;
+    FFTComplex ev, od, odsum;
+    const int n = 1 << s->nbits;
+    const float k1 = 0.5;
+    const float k2 = 0.5 - s->inverse;
+    const FFTSample *tcos = s->tcos;
+    const FFTSample *tsin = s->tsin;
+
+    if (!s->inverse) {
+        s->fft.fft_permute(&s->fft, (FFTComplex*)data);
+        s->fft.fft_calc(&s->fft, (FFTComplex*)data);
+    }
+    /* i=0 is a special case because of packing, the DC term is real, so we
+       are going to throw the N/2 term (also real) in with it. */
+    ev.re = data[0];
+    data[0] = ev.re+data[1];
+    data[1] = ev.re-data[1];
+
+#define RDFT_UNMANGLE(sign0, sign1)                                         \
+    for (i = 1; i < (n>>2); i++) {                                          \
+        i1 = 2*i;                                                           \
+        i2 = n-i1;                                                          \
+        /* Separate even and odd FFTs */                                    \
+        ev.re =  k1*(data[i1  ]+data[i2  ]);                                \
+        od.im =  k2*(data[i2  ]-data[i1  ]);                                \
+        ev.im =  k1*(data[i1+1]-data[i2+1]);                                \
+        od.re =  k2*(data[i1+1]+data[i2+1]);                                \
+        /* Apply twiddle factors to the odd FFT and add to the even FFT */  \
+        odsum.re = od.re*tcos[i] sign0 od.im*tsin[i];                       \
+        odsum.im = od.im*tcos[i] sign1 od.re*tsin[i];                       \
+        data[i1  ] =  ev.re + odsum.re;                                     \
+        data[i1+1] =  ev.im + odsum.im;                                     \
+        data[i2  ] =  ev.re - odsum.re;                                     \
+        data[i2+1] =  odsum.im - ev.im;                                     \
+    }
+
+    if (s->negative_sin) {
+        RDFT_UNMANGLE(+,-)
+    } else {
+        RDFT_UNMANGLE(-,+)
+    }
+
+    data[2*i+1]=s->sign_convention*data[2*i+1];
+    if (s->inverse) {
+        data[0] *= k1;
+        data[1] *= k1;
+        s->fft.fft_permute(&s->fft, (FFTComplex*)data);
+        s->fft.fft_calc(&s->fft, (FFTComplex*)data);
+    }
+}
+
+av_cold int ff_rdft_init(RDFTContext *s, int nbits, enum RDFTransformType trans)
+{
+    int n = 1 << nbits;
+    int ret;
+
+    s->nbits           = nbits;
+    s->inverse         = trans == IDFT_C2R || trans == DFT_C2R;
+    s->sign_convention = trans == IDFT_R2C || trans == DFT_C2R ? 1 : -1;
+    s->negative_sin    = trans == DFT_C2R || trans == DFT_R2C;
+
+    if (nbits < 4 || nbits > 16)
+        return AVERROR(EINVAL);
+
+    if ((ret = ff_fft_init(&s->fft, nbits-1, trans == IDFT_C2R || trans == IDFT_R2C)) < 0)
+        return ret;
+
+    ff_init_ff_cos_tabs(nbits);
+    s->tcos = ff_cos_tabs[nbits];
+    s->tsin = ff_cos_tabs[nbits] + (n >> 2);
+    s->rdft_calc   = rdft_calc_c;
+
+#if ARCH_ARM
+    ff_rdft_init_arm(s);
+#endif
+
+    return 0;
+}
+
+av_cold void ff_rdft_end(RDFTContext *s)
+{
+    ff_fft_end(&s->fft);
+}