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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
commit43a97878ce14b72f0981164f87f2e35e14151312 (patch)
tree620249daf56c0258faa40cbdcf9cfba06de2a846 /media/ffvpx/libavcodec/dct.c
parentInitial commit. (diff)
downloadfirefox-43a97878ce14b72f0981164f87f2e35e14151312.tar.xz
firefox-43a97878ce14b72f0981164f87f2e35e14151312.zip
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--media/ffvpx/libavcodec/dct.c228
1 files changed, 228 insertions, 0 deletions
diff --git a/media/ffvpx/libavcodec/dct.c b/media/ffvpx/libavcodec/dct.c
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+/*
+ * (I)DCT Transforms
+ * Copyright (c) 2009 Peter Ross <pross@xvid.org>
+ * Copyright (c) 2010 Alex Converse <alex.converse@gmail.com>
+ * Copyright (c) 2010 Vitor Sessak
+ *
+ * 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 St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * (Inverse) Discrete Cosine Transforms. These are also known as the
+ * type II and type III DCTs respectively.
+ */
+
+#include <math.h>
+#include <string.h>
+
+#include "libavutil/error.h"
+#include "libavutil/mathematics.h"
+#include "libavutil/mem.h"
+#include "dct.h"
+#include "dct32.h"
+
+/* sin((M_PI * x / (2 * n)) */
+#define SIN(s, n, x) (s->costab[(n) - (x)])
+
+/* cos((M_PI * x / (2 * n)) */
+#define COS(s, n, x) (s->costab[x])
+
+static void dst_calc_I_c(DCTContext *ctx, FFTSample *data)
+{
+ int n = 1 << ctx->nbits;
+ int i;
+
+ data[0] = 0;
+ for (i = 1; i < n / 2; i++) {
+ float tmp1 = data[i ];
+ float tmp2 = data[n - i];
+ float s = SIN(ctx, n, 2 * i);
+
+ s *= tmp1 + tmp2;
+ tmp1 = (tmp1 - tmp2) * 0.5f;
+ data[i] = s + tmp1;
+ data[n - i] = s - tmp1;
+ }
+
+ data[n / 2] *= 2;
+ ctx->rdft.rdft_calc(&ctx->rdft, data);
+
+ data[0] *= 0.5f;
+
+ for (i = 1; i < n - 2; i += 2) {
+ data[i + 1] += data[i - 1];
+ data[i] = -data[i + 2];
+ }
+
+ data[n - 1] = 0;
+}
+
+static void dct_calc_I_c(DCTContext *ctx, FFTSample *data)
+{
+ int n = 1 << ctx->nbits;
+ int i;
+ float next = -0.5f * (data[0] - data[n]);
+
+ for (i = 0; i < n / 2; i++) {
+ float tmp1 = data[i];
+ float tmp2 = data[n - i];
+ float s = SIN(ctx, n, 2 * i);
+ float c = COS(ctx, n, 2 * i);
+
+ c *= tmp1 - tmp2;
+ s *= tmp1 - tmp2;
+
+ next += c;
+
+ tmp1 = (tmp1 + tmp2) * 0.5f;
+ data[i] = tmp1 - s;
+ data[n - i] = tmp1 + s;
+ }
+
+ ctx->rdft.rdft_calc(&ctx->rdft, data);
+ data[n] = data[1];
+ data[1] = next;
+
+ for (i = 3; i <= n; i += 2)
+ data[i] = data[i - 2] - data[i];
+}
+
+static void dct_calc_III_c(DCTContext *ctx, FFTSample *data)
+{
+ int n = 1 << ctx->nbits;
+ int i;
+
+ float next = data[n - 1];
+ float inv_n = 1.0f / n;
+
+ for (i = n - 2; i >= 2; i -= 2) {
+ float val1 = data[i];
+ float val2 = data[i - 1] - data[i + 1];
+ float c = COS(ctx, n, i);
+ float s = SIN(ctx, n, i);
+
+ data[i] = c * val1 + s * val2;
+ data[i + 1] = s * val1 - c * val2;
+ }
+
+ data[1] = 2 * next;
+
+ ctx->rdft.rdft_calc(&ctx->rdft, data);
+
+ for (i = 0; i < n / 2; i++) {
+ float tmp1 = data[i] * inv_n;
+ float tmp2 = data[n - i - 1] * inv_n;
+ float csc = ctx->csc2[i] * (tmp1 - tmp2);
+
+ tmp1 += tmp2;
+ data[i] = tmp1 + csc;
+ data[n - i - 1] = tmp1 - csc;
+ }
+}
+
+static void dct_calc_II_c(DCTContext *ctx, FFTSample *data)
+{
+ int n = 1 << ctx->nbits;
+ int i;
+ float next;
+
+ for (i = 0; i < n / 2; i++) {
+ float tmp1 = data[i];
+ float tmp2 = data[n - i - 1];
+ float s = SIN(ctx, n, 2 * i + 1);
+
+ s *= tmp1 - tmp2;
+ tmp1 = (tmp1 + tmp2) * 0.5f;
+
+ data[i] = tmp1 + s;
+ data[n-i-1] = tmp1 - s;
+ }
+
+ ctx->rdft.rdft_calc(&ctx->rdft, data);
+
+ next = data[1] * 0.5;
+ data[1] *= -1;
+
+ for (i = n - 2; i >= 0; i -= 2) {
+ float inr = data[i ];
+ float ini = data[i + 1];
+ float c = COS(ctx, n, i);
+ float s = SIN(ctx, n, i);
+
+ data[i] = c * inr + s * ini;
+ data[i + 1] = next;
+
+ next += s * inr - c * ini;
+ }
+}
+
+static void dct32_func(DCTContext *ctx, FFTSample *data)
+{
+ ctx->dct32(data, data);
+}
+
+av_cold int ff_dct_init(DCTContext *s, int nbits, enum DCTTransformType inverse)
+{
+ int n = 1 << nbits;
+ int i;
+ int ret;
+
+ memset(s, 0, sizeof(*s));
+
+ s->nbits = nbits;
+ s->inverse = inverse;
+
+ if (inverse == DCT_II && nbits == 5) {
+ s->dct_calc = dct32_func;
+ } else {
+ ff_init_ff_cos_tabs(nbits + 2);
+
+ s->costab = ff_cos_tabs[nbits + 2];
+ s->csc2 = av_malloc_array(n / 2, sizeof(FFTSample));
+ if (!s->csc2)
+ return AVERROR(ENOMEM);
+
+ if ((ret = ff_rdft_init(&s->rdft, nbits, inverse == DCT_III)) < 0) {
+ av_freep(&s->csc2);
+ return ret;
+ }
+
+ for (i = 0; i < n / 2; i++)
+ s->csc2[i] = 0.5 / sin((M_PI / (2 * n) * (2 * i + 1)));
+
+ switch (inverse) {
+ case DCT_I : s->dct_calc = dct_calc_I_c; break;
+ case DCT_II : s->dct_calc = dct_calc_II_c; break;
+ case DCT_III: s->dct_calc = dct_calc_III_c; break;
+ case DST_I : s->dct_calc = dst_calc_I_c; break;
+ }
+ }
+
+ s->dct32 = ff_dct32_float;
+#if ARCH_X86
+ ff_dct_init_x86(s);
+#endif
+
+ return 0;
+}
+
+av_cold void ff_dct_end(DCTContext *s)
+{
+ ff_rdft_end(&s->rdft);
+ av_freep(&s->csc2);
+}