cannam@154: /*********************************************************************** cannam@154: Copyright (c) 2006-2011, Skype Limited. All rights reserved. cannam@154: Redistribution and use in source and binary forms, with or without cannam@154: modification, are permitted provided that the following conditions cannam@154: are met: cannam@154: - Redistributions of source code must retain the above copyright notice, cannam@154: this list of conditions and the following disclaimer. cannam@154: - Redistributions in binary form must reproduce the above copyright cannam@154: notice, this list of conditions and the following disclaimer in the cannam@154: documentation and/or other materials provided with the distribution. cannam@154: - Neither the name of Internet Society, IETF or IETF Trust, nor the cannam@154: names of specific contributors, may be used to endorse or promote cannam@154: products derived from this software without specific prior written cannam@154: permission. cannam@154: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" cannam@154: AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE cannam@154: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE cannam@154: ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE cannam@154: LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR cannam@154: CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF cannam@154: SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS cannam@154: INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN cannam@154: CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) cannam@154: ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE cannam@154: POSSIBILITY OF SUCH DAMAGE. cannam@154: ***********************************************************************/ cannam@154: cannam@154: #ifdef HAVE_CONFIG_H cannam@154: #include "config.h" cannam@154: #endif cannam@154: cannam@154: #include "main.h" cannam@154: cannam@154: #define OFFSET ( ( MIN_QGAIN_DB * 128 ) / 6 + 16 * 128 ) cannam@154: #define SCALE_Q16 ( ( 65536 * ( N_LEVELS_QGAIN - 1 ) ) / ( ( ( MAX_QGAIN_DB - MIN_QGAIN_DB ) * 128 ) / 6 ) ) cannam@154: #define INV_SCALE_Q16 ( ( 65536 * ( ( ( MAX_QGAIN_DB - MIN_QGAIN_DB ) * 128 ) / 6 ) ) / ( N_LEVELS_QGAIN - 1 ) ) cannam@154: cannam@154: /* Gain scalar quantization with hysteresis, uniform on log scale */ cannam@154: void silk_gains_quant( cannam@154: opus_int8 ind[ MAX_NB_SUBFR ], /* O gain indices */ cannam@154: opus_int32 gain_Q16[ MAX_NB_SUBFR ], /* I/O gains (quantized out) */ cannam@154: opus_int8 *prev_ind, /* I/O last index in previous frame */ cannam@154: const opus_int conditional, /* I first gain is delta coded if 1 */ cannam@154: const opus_int nb_subfr /* I number of subframes */ cannam@154: ) cannam@154: { cannam@154: opus_int k, double_step_size_threshold; cannam@154: cannam@154: for( k = 0; k < nb_subfr; k++ ) { cannam@154: /* Convert to log scale, scale, floor() */ cannam@154: ind[ k ] = silk_SMULWB( SCALE_Q16, silk_lin2log( gain_Q16[ k ] ) - OFFSET ); cannam@154: cannam@154: /* Round towards previous quantized gain (hysteresis) */ cannam@154: if( ind[ k ] < *prev_ind ) { cannam@154: ind[ k ]++; cannam@154: } cannam@154: ind[ k ] = silk_LIMIT_int( ind[ k ], 0, N_LEVELS_QGAIN - 1 ); cannam@154: cannam@154: /* Compute delta indices and limit */ cannam@154: if( k == 0 && conditional == 0 ) { cannam@154: /* Full index */ cannam@154: ind[ k ] = silk_LIMIT_int( ind[ k ], *prev_ind + MIN_DELTA_GAIN_QUANT, N_LEVELS_QGAIN - 1 ); cannam@154: *prev_ind = ind[ k ]; cannam@154: } else { cannam@154: /* Delta index */ cannam@154: ind[ k ] = ind[ k ] - *prev_ind; cannam@154: cannam@154: /* Double the quantization step size for large gain increases, so that the max gain level can be reached */ cannam@154: double_step_size_threshold = 2 * MAX_DELTA_GAIN_QUANT - N_LEVELS_QGAIN + *prev_ind; cannam@154: if( ind[ k ] > double_step_size_threshold ) { cannam@154: ind[ k ] = double_step_size_threshold + silk_RSHIFT( ind[ k ] - double_step_size_threshold + 1, 1 ); cannam@154: } cannam@154: cannam@154: ind[ k ] = silk_LIMIT_int( ind[ k ], MIN_DELTA_GAIN_QUANT, MAX_DELTA_GAIN_QUANT ); cannam@154: cannam@154: /* Accumulate deltas */ cannam@154: if( ind[ k ] > double_step_size_threshold ) { cannam@154: *prev_ind += silk_LSHIFT( ind[ k ], 1 ) - double_step_size_threshold; cannam@154: *prev_ind = silk_min_int( *prev_ind, N_LEVELS_QGAIN - 1 ); cannam@154: } else { cannam@154: *prev_ind += ind[ k ]; cannam@154: } cannam@154: cannam@154: /* Shift to make non-negative */ cannam@154: ind[ k ] -= MIN_DELTA_GAIN_QUANT; cannam@154: } cannam@154: cannam@154: /* Scale and convert to linear scale */ cannam@154: gain_Q16[ k ] = silk_log2lin( silk_min_32( silk_SMULWB( INV_SCALE_Q16, *prev_ind ) + OFFSET, 3967 ) ); /* 3967 = 31 in Q7 */ cannam@154: } cannam@154: } cannam@154: cannam@154: /* Gains scalar dequantization, uniform on log scale */ cannam@154: void silk_gains_dequant( cannam@154: opus_int32 gain_Q16[ MAX_NB_SUBFR ], /* O quantized gains */ cannam@154: const opus_int8 ind[ MAX_NB_SUBFR ], /* I gain indices */ cannam@154: opus_int8 *prev_ind, /* I/O last index in previous frame */ cannam@154: const opus_int conditional, /* I first gain is delta coded if 1 */ cannam@154: const opus_int nb_subfr /* I number of subframes */ cannam@154: ) cannam@154: { cannam@154: opus_int k, ind_tmp, double_step_size_threshold; cannam@154: cannam@154: for( k = 0; k < nb_subfr; k++ ) { cannam@154: if( k == 0 && conditional == 0 ) { cannam@154: /* Gain index is not allowed to go down more than 16 steps (~21.8 dB) */ cannam@154: *prev_ind = silk_max_int( ind[ k ], *prev_ind - 16 ); cannam@154: } else { cannam@154: /* Delta index */ cannam@154: ind_tmp = ind[ k ] + MIN_DELTA_GAIN_QUANT; cannam@154: cannam@154: /* Accumulate deltas */ cannam@154: double_step_size_threshold = 2 * MAX_DELTA_GAIN_QUANT - N_LEVELS_QGAIN + *prev_ind; cannam@154: if( ind_tmp > double_step_size_threshold ) { cannam@154: *prev_ind += silk_LSHIFT( ind_tmp, 1 ) - double_step_size_threshold; cannam@154: } else { cannam@154: *prev_ind += ind_tmp; cannam@154: } cannam@154: } cannam@154: *prev_ind = silk_LIMIT_int( *prev_ind, 0, N_LEVELS_QGAIN - 1 ); cannam@154: cannam@154: /* Scale and convert to linear scale */ cannam@154: gain_Q16[ k ] = silk_log2lin( silk_min_32( silk_SMULWB( INV_SCALE_Q16, *prev_ind ) + OFFSET, 3967 ) ); /* 3967 = 31 in Q7 */ cannam@154: } cannam@154: } cannam@154: cannam@154: /* Compute unique identifier of gain indices vector */ cannam@154: opus_int32 silk_gains_ID( /* O returns unique identifier of gains */ cannam@154: const opus_int8 ind[ MAX_NB_SUBFR ], /* I gain indices */ cannam@154: const opus_int nb_subfr /* I number of subframes */ cannam@154: ) cannam@154: { cannam@154: opus_int k; cannam@154: opus_int32 gainsID; cannam@154: cannam@154: gainsID = 0; cannam@154: for( k = 0; k < nb_subfr; k++ ) { cannam@154: gainsID = silk_ADD_LSHIFT32( ind[ k ], gainsID, 8 ); cannam@154: } cannam@154: cannam@154: return gainsID; cannam@154: }