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diff --git a/media/libopus/silk/gain_quant.c b/media/libopus/silk/gain_quant.c
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+/***********************************************************************
+Copyright (c) 2006-2011, Skype Limited. All rights reserved.
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+- Redistributions of source code must retain the above copyright notice,
+this list of conditions and the following disclaimer.
+- Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in the
+documentation and/or other materials provided with the distribution.
+- Neither the name of Internet Society, IETF or IETF Trust, nor the
+names of specific contributors, may be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+***********************************************************************/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "main.h"
+
+#define OFFSET ( ( MIN_QGAIN_DB * 128 ) / 6 + 16 * 128 )
+#define SCALE_Q16 ( ( 65536 * ( N_LEVELS_QGAIN - 1 ) ) / ( ( ( MAX_QGAIN_DB - MIN_QGAIN_DB ) * 128 ) / 6 ) )
+#define INV_SCALE_Q16 ( ( 65536 * ( ( ( MAX_QGAIN_DB - MIN_QGAIN_DB ) * 128 ) / 6 ) ) / ( N_LEVELS_QGAIN - 1 ) )
+
+/* Gain scalar quantization with hysteresis, uniform on log scale */
+void silk_gains_quant(
+ opus_int8 ind[ MAX_NB_SUBFR ], /* O gain indices */
+ opus_int32 gain_Q16[ MAX_NB_SUBFR ], /* I/O gains (quantized out) */
+ opus_int8 *prev_ind, /* I/O last index in previous frame */
+ const opus_int conditional, /* I first gain is delta coded if 1 */
+ const opus_int nb_subfr /* I number of subframes */
+)
+{
+ opus_int k, double_step_size_threshold;
+
+ for( k = 0; k < nb_subfr; k++ ) {
+ /* Convert to log scale, scale, floor() */
+ ind[ k ] = silk_SMULWB( SCALE_Q16, silk_lin2log( gain_Q16[ k ] ) - OFFSET );
+
+ /* Round towards previous quantized gain (hysteresis) */
+ if( ind[ k ] < *prev_ind ) {
+ ind[ k ]++;
+ }
+ ind[ k ] = silk_LIMIT_int( ind[ k ], 0, N_LEVELS_QGAIN - 1 );
+
+ /* Compute delta indices and limit */
+ if( k == 0 && conditional == 0 ) {
+ /* Full index */
+ ind[ k ] = silk_LIMIT_int( ind[ k ], *prev_ind + MIN_DELTA_GAIN_QUANT, N_LEVELS_QGAIN - 1 );
+ *prev_ind = ind[ k ];
+ } else {
+ /* Delta index */
+ ind[ k ] = ind[ k ] - *prev_ind;
+
+ /* Double the quantization step size for large gain increases, so that the max gain level can be reached */
+ double_step_size_threshold = 2 * MAX_DELTA_GAIN_QUANT - N_LEVELS_QGAIN + *prev_ind;
+ if( ind[ k ] > double_step_size_threshold ) {
+ ind[ k ] = double_step_size_threshold + silk_RSHIFT( ind[ k ] - double_step_size_threshold + 1, 1 );
+ }
+
+ ind[ k ] = silk_LIMIT_int( ind[ k ], MIN_DELTA_GAIN_QUANT, MAX_DELTA_GAIN_QUANT );
+
+ /* Accumulate deltas */
+ if( ind[ k ] > double_step_size_threshold ) {
+ *prev_ind += silk_LSHIFT( ind[ k ], 1 ) - double_step_size_threshold;
+ } else {
+ *prev_ind += ind[ k ];
+ }
+
+ /* Shift to make non-negative */
+ ind[ k ] -= MIN_DELTA_GAIN_QUANT;
+ }
+
+ /* Scale and convert to linear scale */
+ gain_Q16[ k ] = silk_log2lin( silk_min_32( silk_SMULWB( INV_SCALE_Q16, *prev_ind ) + OFFSET, 3967 ) ); /* 3967 = 31 in Q7 */
+ }
+}
+
+/* Gains scalar dequantization, uniform on log scale */
+void silk_gains_dequant(
+ opus_int32 gain_Q16[ MAX_NB_SUBFR ], /* O quantized gains */
+ const opus_int8 ind[ MAX_NB_SUBFR ], /* I gain indices */
+ opus_int8 *prev_ind, /* I/O last index in previous frame */
+ const opus_int conditional, /* I first gain is delta coded if 1 */
+ const opus_int nb_subfr /* I number of subframes */
+)
+{
+ opus_int k, ind_tmp, double_step_size_threshold;
+
+ for( k = 0; k < nb_subfr; k++ ) {
+ if( k == 0 && conditional == 0 ) {
+ /* Gain index is not allowed to go down more than 16 steps (~21.8 dB) */
+ *prev_ind = silk_max_int( ind[ k ], *prev_ind - 16 );
+ } else {
+ /* Delta index */
+ ind_tmp = ind[ k ] + MIN_DELTA_GAIN_QUANT;
+
+ /* Accumulate deltas */
+ double_step_size_threshold = 2 * MAX_DELTA_GAIN_QUANT - N_LEVELS_QGAIN + *prev_ind;
+ if( ind_tmp > double_step_size_threshold ) {
+ *prev_ind += silk_LSHIFT( ind_tmp, 1 ) - double_step_size_threshold;
+ } else {
+ *prev_ind += ind_tmp;
+ }
+ }
+ *prev_ind = silk_LIMIT_int( *prev_ind, 0, N_LEVELS_QGAIN - 1 );
+
+ /* Scale and convert to linear scale */
+ gain_Q16[ k ] = silk_log2lin( silk_min_32( silk_SMULWB( INV_SCALE_Q16, *prev_ind ) + OFFSET, 3967 ) ); /* 3967 = 31 in Q7 */
+ }
+}
+
+/* Compute unique identifier of gain indices vector */
+opus_int32 silk_gains_ID( /* O returns unique identifier of gains */
+ const opus_int8 ind[ MAX_NB_SUBFR ], /* I gain indices */
+ const opus_int nb_subfr /* I number of subframes */
+)
+{
+ opus_int k;
+ opus_int32 gainsID;
+
+ gainsID = 0;
+ for( k = 0; k < nb_subfr; k++ ) {
+ gainsID = silk_ADD_LSHIFT32( ind[ k ], gainsID, 8 );
+ }
+
+ return gainsID;
+}