/*
- * Atrac common functions
- * Copyright (c) 2006-2008 Maxim Poliakovski
+ * common functions for the ATRAC family of decoders
+ *
+ * Copyright (c) 2006-2013 Maxim Poliakovski
* Copyright (c) 2006-2008 Benjamin Larsson
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <math.h>
#include <stddef.h>
#include <stdio.h>
+#include <string.h>
#include "avcodec.h"
-#include "dsputil.h"
#include "atrac.h"
-float sf_table[64];
-float qmf_window[48];
+float ff_atrac_sf_table[64];
+static float qmf_window[48];
static const float qmf_48tap_half[24] = {
-0.00001461907, -0.00009205479,-0.000056157569,0.00030117269,
-0.043596379, -0.099384367, 0.13207909, 0.46424159
};
-/**
- * Generate common tables
- */
-
-void atrac_generate_tables(void)
+av_cold void ff_atrac_generate_tables(void)
{
int i;
float s;
/* Generate scale factors */
- if (!sf_table[63])
+ if (!ff_atrac_sf_table[63])
for (i=0 ; i<64 ; i++)
- sf_table[i] = pow(2.0, (i - 15) / 3.0);
+ ff_atrac_sf_table[i] = pow(2.0, (i - 15) / 3.0);
/* Generate the QMF window. */
if (!qmf_window[47])
}
}
+av_cold void ff_atrac_init_gain_compensation(AtracGCContext *gctx, int id2exp_offset,
+ int loc_scale)
+{
+ int i;
-/**
- * Quadrature mirror synthesis filter.
- *
- * @param inlo lower part of spectrum
- * @param inhi higher part of spectrum
- * @param nIn size of spectrum buffer
- * @param pOut out buffer
- * @param delayBuf delayBuf buffer
- * @param temp temp buffer
- */
+ gctx->loc_scale = loc_scale;
+ gctx->loc_size = 1 << loc_scale;
+ gctx->id2exp_offset = id2exp_offset;
+ /* Generate gain level table. */
+ for (i = 0; i < 16; i++)
+ gctx->gain_tab1[i] = powf(2.0, id2exp_offset - i);
-void atrac_iqmf (float *inlo, float *inhi, unsigned int nIn, float *pOut, float *delayBuf, float *temp)
+ /* Generate gain interpolation table. */
+ for (i = -15; i < 16; i++)
+ gctx->gain_tab2[i + 15] = powf(2.0, -1.0f / gctx->loc_size * i);
+}
+
+void ff_atrac_gain_compensation(AtracGCContext *gctx, float *in, float *prev,
+ AtracGainInfo *gc_now, AtracGainInfo *gc_next,
+ int num_samples, float *out)
+{
+ float lev, gc_scale, gain_inc;
+ int i, pos, lastpos;
+
+ gc_scale = gc_next->num_points ? gctx->gain_tab1[gc_next->lev_code[0]]
+ : 1.0f;
+
+ if (!gc_now->num_points) {
+ for (pos = 0; pos < num_samples; pos++)
+ out[pos] = in[pos] * gc_scale + prev[pos];
+ } else {
+ pos = 0;
+
+ for (i = 0; i < gc_now->num_points; i++) {
+ lastpos = gc_now->loc_code[i] << gctx->loc_scale;
+
+ lev = gctx->gain_tab1[gc_now->lev_code[i]];
+ gain_inc = gctx->gain_tab2[(i + 1 < gc_now->num_points ? gc_now->lev_code[i + 1]
+ : gctx->id2exp_offset) -
+ gc_now->lev_code[i] + 15];
+
+ /* apply constant gain level and overlap */
+ for (; pos < lastpos; pos++)
+ out[pos] = (in[pos] * gc_scale + prev[pos]) * lev;
+
+ /* interpolate between two different gain levels */
+ for (; pos < lastpos + gctx->loc_size; pos++) {
+ out[pos] = (in[pos] * gc_scale + prev[pos]) * lev;
+ lev *= gain_inc;
+ }
+ }
+
+ for (; pos < num_samples; pos++)
+ out[pos] = in[pos] * gc_scale + prev[pos];
+ }
+
+ /* copy the overlapping part into the delay buffer */
+ memcpy(prev, &in[num_samples], num_samples * sizeof(float));
+}
+
+void ff_atrac_iqmf (float *inlo, float *inhi, unsigned int nIn, float *pOut, float *delayBuf, float *temp)
{
int i, j;
float *p1, *p3;
/* Update the delay buffer. */
memcpy(delayBuf, temp + nIn*2, 46*sizeof(float));
}
-