jpeg2000: split off inverse MCT decoding as Jpeg2000DSP

This makes the addition of arch optimized functions easier.

Reviewed-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: James Almer <jamrial@gmail.com>

1 files changed, 98 insertions, 0 deletions

diff --git a/libavcodec/jpeg2000dsp.c b/libavcodec/jpeg2000dsp.c
new file mode 100644
index 0000000000..a7c7f53b7a
--- /dev/null
+++ b/libavcodec/jpeg2000dsp.c
@@ -0,0 +1,98 @@
+/*
+ * JPEG 2000 DSP functions
+ * Copyright (c) 2007 Kamil Nowosad
+ * Copyright (c) 2013 Nicolas Bertrand <nicoinattendu@gmail.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 "config.h"
+#include "libavutil/attributes.h"
+#include "jpeg2000dsp.h"
+
+/* Inverse ICT parameters in float and integer.
+ * int value = (float value) * (1<<16) */
+static const float f_ict_params[4] = {
+    1.402f,
+    0.34413f,
+    0.71414f,
+    1.772f
+};
+
+static const int i_ict_params[4] = {
+     91881,
+     22553,
+     46802,
+    116130
+};
+
+static void ict_float(void *_src0, void *_src1, void *_src2, int csize)
+{
+    float *src0 = _src0, *src1 = _src1, *src2 = _src2;
+    float i0f, i1f, i2f;
+    int i;
+
+    for (i = 0; i < csize; i++) {
+        i0f = *src0 + (f_ict_params[0] * *src2);
+        i1f = *src0 - (f_ict_params[1] * *src1)
+                    - (f_ict_params[2] * *src2);
+        i2f = *src0 + (f_ict_params[3] * *src1);
+        *src0++ = i0f;
+        *src1++ = i1f;
+        *src2++ = i2f;
+    }
+}
+
+static void ict_int(void *_src0, void *_src1, void *_src2, int csize)
+{
+    int32_t *src0 = _src0, *src1 = _src1, *src2 = _src2;
+    int32_t i0, i1, i2;
+    int i;
+
+    for (i = 0; i < csize; i++) {
+        i0 = *src0 + (((i_ict_params[0] * *src2) + (1 << 15)) >> 16);
+        i1 = *src0 - (((i_ict_params[1] * *src1) + (1 << 15)) >> 16)
+                   - (((i_ict_params[2] * *src2) + (1 << 15)) >> 16);
+        i2 = *src0 + (((i_ict_params[3] * *src1) + (1 << 15)) >> 16);
+        *src0++ = i0;
+        *src1++ = i1;
+        *src2++ = i2;
+    }
+}
+
+static void rct_int(void *_src0, void *_src1, void *_src2, int csize)
+{
+    int32_t *src0 = _src0, *src1 = _src1, *src2 = _src2;
+    int32_t i0, i1, i2;
+    int i;
+
+    for (i = 0; i < csize; i++) {
+        i1 = *src0 - (*src2 + *src1 >> 2);
+        i0 = i1 + *src2;
+        i2 = i1 + *src1;
+        *src0++ = i0;
+        *src1++ = i1;
+        *src2++ = i2;
+    }
+}
+
+av_cold void ff_jpeg2000dsp_init(Jpeg2000DSPContext *c)
+{
+    c->mct_decode[FF_DWT97]     = ict_float;
+    c->mct_decode[FF_DWT53]     = rct_int;
+    c->mct_decode[FF_DWT97_INT] = ict_int;
+}