1 /*********************************************************************** 2 Copyright (c) 2006-2011, Skype Limited. All rights reserved. 3 Redistribution and use in source and binary forms, with or without 4 modification, are permitted provided that the following conditions 5 are met: 6 - Redistributions of source code must retain the above copyright notice, 7 this list of conditions and the following disclaimer. 8 - Redistributions in binary form must reproduce the above copyright 9 notice, this list of conditions and the following disclaimer in the 10 documentation and/or other materials provided with the distribution. 11 - Neither the name of Internet Society, IETF or IETF Trust, nor the 12 names of specific contributors, may be used to endorse or promote 13 products derived from this software without specific prior written 14 permission. 15 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 16 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 19 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25 POSSIBILITY OF SUCH DAMAGE. 26 ***********************************************************************/ 27 28 #ifdef HAVE_CONFIG_H 29 #include "config.h" 30 #endif 31 #ifdef FIXED_POINT 32 #include "main_FIX.h" 33 #define silk_encoder_state_Fxx silk_encoder_state_FIX 34 #else 35 #include "main_FLP.h" 36 #define silk_encoder_state_Fxx silk_encoder_state_FLP 37 #endif 38 #include "stack_alloc.h" 39 #include "tuning_parameters.h" 40 #include "pitch_est_defines.h" 41 42 static opus_int silk_setup_resamplers( 43 silk_encoder_state_Fxx *psEnc, /* I/O */ 44 opus_int fs_kHz /* I */ 45 ); 46 47 static opus_int silk_setup_fs( 48 silk_encoder_state_Fxx *psEnc, /* I/O */ 49 opus_int fs_kHz, /* I */ 50 opus_int PacketSize_ms /* I */ 51 ); 52 53 static opus_int silk_setup_complexity( 54 silk_encoder_state *psEncC, /* I/O */ 55 opus_int Complexity /* I */ 56 ); 57 58 static OPUS_INLINE opus_int silk_setup_LBRR( 59 silk_encoder_state *psEncC, /* I/O */ 60 const opus_int32 TargetRate_bps /* I */ 61 ); 62 63 64 /* Control encoder */ 65 opus_int silk_control_encoder( 66 silk_encoder_state_Fxx *psEnc, /* I/O Pointer to Silk encoder state */ 67 silk_EncControlStruct *encControl, /* I Control structure */ 68 const opus_int32 TargetRate_bps, /* I Target max bitrate (bps) */ 69 const opus_int allow_bw_switch, /* I Flag to allow switching audio bandwidth */ 70 const opus_int channelNb, /* I Channel number */ 71 const opus_int force_fs_kHz 72 ) 73 { 74 opus_int fs_kHz, ret = 0; 75 76 psEnc->sCmn.useDTX = encControl->useDTX; 77 psEnc->sCmn.useCBR = encControl->useCBR; 78 psEnc->sCmn.API_fs_Hz = encControl->API_sampleRate; 79 psEnc->sCmn.maxInternal_fs_Hz = encControl->maxInternalSampleRate; 80 psEnc->sCmn.minInternal_fs_Hz = encControl->minInternalSampleRate; 81 psEnc->sCmn.desiredInternal_fs_Hz = encControl->desiredInternalSampleRate; 82 psEnc->sCmn.useInBandFEC = encControl->useInBandFEC; 83 psEnc->sCmn.nChannelsAPI = encControl->nChannelsAPI; 84 psEnc->sCmn.nChannelsInternal = encControl->nChannelsInternal; 85 psEnc->sCmn.allow_bandwidth_switch = allow_bw_switch; 86 psEnc->sCmn.channelNb = channelNb; 87 88 if( psEnc->sCmn.controlled_since_last_payload != 0 && psEnc->sCmn.prefillFlag == 0 ) { 89 if( psEnc->sCmn.API_fs_Hz != psEnc->sCmn.prev_API_fs_Hz && psEnc->sCmn.fs_kHz > 0 ) { 90 /* Change in API sampling rate in the middle of encoding a packet */ 91 ret += silk_setup_resamplers( psEnc, psEnc->sCmn.fs_kHz ); 92 } 93 return ret; 94 } 95 96 /* Beyond this point we know that there are no previously coded frames in the payload buffer */ 97 98 /********************************************/ 99 /* Determine internal sampling rate */ 100 /********************************************/ 101 fs_kHz = silk_control_audio_bandwidth( &psEnc->sCmn, encControl ); 102 if( force_fs_kHz ) { 103 fs_kHz = force_fs_kHz; 104 } 105 /********************************************/ 106 /* Prepare resampler and buffered data */ 107 /********************************************/ 108 ret += silk_setup_resamplers( psEnc, fs_kHz ); 109 110 /********************************************/ 111 /* Set internal sampling frequency */ 112 /********************************************/ 113 ret += silk_setup_fs( psEnc, fs_kHz, encControl->payloadSize_ms ); 114 115 /********************************************/ 116 /* Set encoding complexity */ 117 /********************************************/ 118 ret += silk_setup_complexity( &psEnc->sCmn, encControl->complexity ); 119 120 /********************************************/ 121 /* Set packet loss rate measured by farend */ 122 /********************************************/ 123 psEnc->sCmn.PacketLoss_perc = encControl->packetLossPercentage; 124 125 /********************************************/ 126 /* Set LBRR usage */ 127 /********************************************/ 128 ret += silk_setup_LBRR( &psEnc->sCmn, TargetRate_bps ); 129 130 psEnc->sCmn.controlled_since_last_payload = 1; 131 132 return ret; 133 } 134 135 static opus_int silk_setup_resamplers( 136 silk_encoder_state_Fxx *psEnc, /* I/O */ 137 opus_int fs_kHz /* I */ 138 ) 139 { 140 opus_int ret = SILK_NO_ERROR; 141 SAVE_STACK; 142 143 if( psEnc->sCmn.fs_kHz != fs_kHz || psEnc->sCmn.prev_API_fs_Hz != psEnc->sCmn.API_fs_Hz ) 144 { 145 if( psEnc->sCmn.fs_kHz == 0 ) { 146 /* Initialize the resampler for enc_API.c preparing resampling from API_fs_Hz to fs_kHz */ 147 ret += silk_resampler_init( &psEnc->sCmn.resampler_state, psEnc->sCmn.API_fs_Hz, fs_kHz * 1000, 1 ); 148 } else { 149 VARDECL( opus_int16, x_buf_API_fs_Hz ); 150 VARDECL( silk_resampler_state_struct, temp_resampler_state ); 151 #ifdef FIXED_POINT 152 opus_int16 *x_bufFIX = psEnc->x_buf; 153 #else 154 VARDECL( opus_int16, x_bufFIX ); 155 opus_int32 new_buf_samples; 156 #endif 157 opus_int32 api_buf_samples; 158 opus_int32 old_buf_samples; 159 opus_int32 buf_length_ms; 160 161 buf_length_ms = silk_LSHIFT( psEnc->sCmn.nb_subfr * 5, 1 ) + LA_SHAPE_MS; 162 old_buf_samples = buf_length_ms * psEnc->sCmn.fs_kHz; 163 164 #ifndef FIXED_POINT 165 new_buf_samples = buf_length_ms * fs_kHz; 166 ALLOC( x_bufFIX, silk_max( old_buf_samples, new_buf_samples ), 167 opus_int16 ); 168 silk_float2short_array( x_bufFIX, psEnc->x_buf, old_buf_samples ); 169 #endif 170 171 /* Initialize resampler for temporary resampling of x_buf data to API_fs_Hz */ 172 ALLOC( temp_resampler_state, 1, silk_resampler_state_struct ); 173 ret += silk_resampler_init( temp_resampler_state, silk_SMULBB( psEnc->sCmn.fs_kHz, 1000 ), psEnc->sCmn.API_fs_Hz, 0 ); 174 175 /* Calculate number of samples to temporarily upsample */ 176 api_buf_samples = buf_length_ms * silk_DIV32_16( psEnc->sCmn.API_fs_Hz, 1000 ); 177 178 /* Temporary resampling of x_buf data to API_fs_Hz */ 179 ALLOC( x_buf_API_fs_Hz, api_buf_samples, opus_int16 ); 180 ret += silk_resampler( temp_resampler_state, x_buf_API_fs_Hz, x_bufFIX, old_buf_samples ); 181 182 /* Initialize the resampler for enc_API.c preparing resampling from API_fs_Hz to fs_kHz */ 183 ret += silk_resampler_init( &psEnc->sCmn.resampler_state, psEnc->sCmn.API_fs_Hz, silk_SMULBB( fs_kHz, 1000 ), 1 ); 184 185 /* Correct resampler state by resampling buffered data from API_fs_Hz to fs_kHz */ 186 ret += silk_resampler( &psEnc->sCmn.resampler_state, x_bufFIX, x_buf_API_fs_Hz, api_buf_samples ); 187 188 #ifndef FIXED_POINT 189 silk_short2float_array( psEnc->x_buf, x_bufFIX, new_buf_samples); 190 #endif 191 } 192 } 193 194 psEnc->sCmn.prev_API_fs_Hz = psEnc->sCmn.API_fs_Hz; 195 196 RESTORE_STACK; 197 return ret; 198 } 199 200 static opus_int silk_setup_fs( 201 silk_encoder_state_Fxx *psEnc, /* I/O */ 202 opus_int fs_kHz, /* I */ 203 opus_int PacketSize_ms /* I */ 204 ) 205 { 206 opus_int ret = SILK_NO_ERROR; 207 208 /* Set packet size */ 209 if( PacketSize_ms != psEnc->sCmn.PacketSize_ms ) { 210 if( ( PacketSize_ms != 10 ) && 211 ( PacketSize_ms != 20 ) && 212 ( PacketSize_ms != 40 ) && 213 ( PacketSize_ms != 60 ) ) { 214 ret = SILK_ENC_PACKET_SIZE_NOT_SUPPORTED; 215 } 216 if( PacketSize_ms <= 10 ) { 217 psEnc->sCmn.nFramesPerPacket = 1; 218 psEnc->sCmn.nb_subfr = PacketSize_ms == 10 ? 2 : 1; 219 psEnc->sCmn.frame_length = silk_SMULBB( PacketSize_ms, fs_kHz ); 220 psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS_2_SF, fs_kHz ); 221 if( psEnc->sCmn.fs_kHz == 8 ) { 222 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_NB_iCDF; 223 } else { 224 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_iCDF; 225 } 226 } else { 227 psEnc->sCmn.nFramesPerPacket = silk_DIV32_16( PacketSize_ms, MAX_FRAME_LENGTH_MS ); 228 psEnc->sCmn.nb_subfr = MAX_NB_SUBFR; 229 psEnc->sCmn.frame_length = silk_SMULBB( 20, fs_kHz ); 230 psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS, fs_kHz ); 231 if( psEnc->sCmn.fs_kHz == 8 ) { 232 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_NB_iCDF; 233 } else { 234 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_iCDF; 235 } 236 } 237 psEnc->sCmn.PacketSize_ms = PacketSize_ms; 238 psEnc->sCmn.TargetRate_bps = 0; /* trigger new SNR computation */ 239 } 240 241 /* Set internal sampling frequency */ 242 silk_assert( fs_kHz == 8 || fs_kHz == 12 || fs_kHz == 16 ); 243 silk_assert( psEnc->sCmn.nb_subfr == 2 || psEnc->sCmn.nb_subfr == 4 ); 244 if( psEnc->sCmn.fs_kHz != fs_kHz ) { 245 /* reset part of the state */ 246 silk_memset( &psEnc->sShape, 0, sizeof( psEnc->sShape ) ); 247 silk_memset( &psEnc->sPrefilt, 0, sizeof( psEnc->sPrefilt ) ); 248 silk_memset( &psEnc->sCmn.sNSQ, 0, sizeof( psEnc->sCmn.sNSQ ) ); 249 silk_memset( psEnc->sCmn.prev_NLSFq_Q15, 0, sizeof( psEnc->sCmn.prev_NLSFq_Q15 ) ); 250 silk_memset( &psEnc->sCmn.sLP.In_LP_State, 0, sizeof( psEnc->sCmn.sLP.In_LP_State ) ); 251 psEnc->sCmn.inputBufIx = 0; 252 psEnc->sCmn.nFramesEncoded = 0; 253 psEnc->sCmn.TargetRate_bps = 0; /* trigger new SNR computation */ 254 255 /* Initialize non-zero parameters */ 256 psEnc->sCmn.prevLag = 100; 257 psEnc->sCmn.first_frame_after_reset = 1; 258 psEnc->sPrefilt.lagPrev = 100; 259 psEnc->sShape.LastGainIndex = 10; 260 psEnc->sCmn.sNSQ.lagPrev = 100; 261 psEnc->sCmn.sNSQ.prev_gain_Q16 = 65536; 262 psEnc->sCmn.prevSignalType = TYPE_NO_VOICE_ACTIVITY; 263 264 psEnc->sCmn.fs_kHz = fs_kHz; 265 if( psEnc->sCmn.fs_kHz == 8 ) { 266 if( psEnc->sCmn.nb_subfr == MAX_NB_SUBFR ) { 267 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_NB_iCDF; 268 } else { 269 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_NB_iCDF; 270 } 271 } else { 272 if( psEnc->sCmn.nb_subfr == MAX_NB_SUBFR ) { 273 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_iCDF; 274 } else { 275 psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_iCDF; 276 } 277 } 278 if( psEnc->sCmn.fs_kHz == 8 || psEnc->sCmn.fs_kHz == 12 ) { 279 psEnc->sCmn.predictLPCOrder = MIN_LPC_ORDER; 280 psEnc->sCmn.psNLSF_CB = &silk_NLSF_CB_NB_MB; 281 } else { 282 psEnc->sCmn.predictLPCOrder = MAX_LPC_ORDER; 283 psEnc->sCmn.psNLSF_CB = &silk_NLSF_CB_WB; 284 } 285 psEnc->sCmn.subfr_length = SUB_FRAME_LENGTH_MS * fs_kHz; 286 psEnc->sCmn.frame_length = silk_SMULBB( psEnc->sCmn.subfr_length, psEnc->sCmn.nb_subfr ); 287 psEnc->sCmn.ltp_mem_length = silk_SMULBB( LTP_MEM_LENGTH_MS, fs_kHz ); 288 psEnc->sCmn.la_pitch = silk_SMULBB( LA_PITCH_MS, fs_kHz ); 289 psEnc->sCmn.max_pitch_lag = silk_SMULBB( 18, fs_kHz ); 290 if( psEnc->sCmn.nb_subfr == MAX_NB_SUBFR ) { 291 psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS, fs_kHz ); 292 } else { 293 psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS_2_SF, fs_kHz ); 294 } 295 if( psEnc->sCmn.fs_kHz == 16 ) { 296 psEnc->sCmn.mu_LTP_Q9 = SILK_FIX_CONST( MU_LTP_QUANT_WB, 9 ); 297 psEnc->sCmn.pitch_lag_low_bits_iCDF = silk_uniform8_iCDF; 298 } else if( psEnc->sCmn.fs_kHz == 12 ) { 299 psEnc->sCmn.mu_LTP_Q9 = SILK_FIX_CONST( MU_LTP_QUANT_MB, 9 ); 300 psEnc->sCmn.pitch_lag_low_bits_iCDF = silk_uniform6_iCDF; 301 } else { 302 psEnc->sCmn.mu_LTP_Q9 = SILK_FIX_CONST( MU_LTP_QUANT_NB, 9 ); 303 psEnc->sCmn.pitch_lag_low_bits_iCDF = silk_uniform4_iCDF; 304 } 305 } 306 307 /* Check that settings are valid */ 308 silk_assert( ( psEnc->sCmn.subfr_length * psEnc->sCmn.nb_subfr ) == psEnc->sCmn.frame_length ); 309 310 return ret; 311 } 312 313 static opus_int silk_setup_complexity( 314 silk_encoder_state *psEncC, /* I/O */ 315 opus_int Complexity /* I */ 316 ) 317 { 318 opus_int ret = 0; 319 320 /* Set encoding complexity */ 321 silk_assert( Complexity >= 0 && Complexity <= 10 ); 322 if( Complexity < 2 ) { 323 psEncC->pitchEstimationComplexity = SILK_PE_MIN_COMPLEX; 324 psEncC->pitchEstimationThreshold_Q16 = SILK_FIX_CONST( 0.8, 16 ); 325 psEncC->pitchEstimationLPCOrder = 6; 326 psEncC->shapingLPCOrder = 8; 327 psEncC->la_shape = 3 * psEncC->fs_kHz; 328 psEncC->nStatesDelayedDecision = 1; 329 psEncC->useInterpolatedNLSFs = 0; 330 psEncC->LTPQuantLowComplexity = 1; 331 psEncC->NLSF_MSVQ_Survivors = 2; 332 psEncC->warping_Q16 = 0; 333 } else if( Complexity < 4 ) { 334 psEncC->pitchEstimationComplexity = SILK_PE_MID_COMPLEX; 335 psEncC->pitchEstimationThreshold_Q16 = SILK_FIX_CONST( 0.76, 16 ); 336 psEncC->pitchEstimationLPCOrder = 8; 337 psEncC->shapingLPCOrder = 10; 338 psEncC->la_shape = 5 * psEncC->fs_kHz; 339 psEncC->nStatesDelayedDecision = 1; 340 psEncC->useInterpolatedNLSFs = 0; 341 psEncC->LTPQuantLowComplexity = 0; 342 psEncC->NLSF_MSVQ_Survivors = 4; 343 psEncC->warping_Q16 = 0; 344 } else if( Complexity < 6 ) { 345 psEncC->pitchEstimationComplexity = SILK_PE_MID_COMPLEX; 346 psEncC->pitchEstimationThreshold_Q16 = SILK_FIX_CONST( 0.74, 16 ); 347 psEncC->pitchEstimationLPCOrder = 10; 348 psEncC->shapingLPCOrder = 12; 349 psEncC->la_shape = 5 * psEncC->fs_kHz; 350 psEncC->nStatesDelayedDecision = 2; 351 psEncC->useInterpolatedNLSFs = 1; 352 psEncC->LTPQuantLowComplexity = 0; 353 psEncC->NLSF_MSVQ_Survivors = 8; 354 psEncC->warping_Q16 = psEncC->fs_kHz * SILK_FIX_CONST( WARPING_MULTIPLIER, 16 ); 355 } else if( Complexity < 8 ) { 356 psEncC->pitchEstimationComplexity = SILK_PE_MID_COMPLEX; 357 psEncC->pitchEstimationThreshold_Q16 = SILK_FIX_CONST( 0.72, 16 ); 358 psEncC->pitchEstimationLPCOrder = 12; 359 psEncC->shapingLPCOrder = 14; 360 psEncC->la_shape = 5 * psEncC->fs_kHz; 361 psEncC->nStatesDelayedDecision = 3; 362 psEncC->useInterpolatedNLSFs = 1; 363 psEncC->LTPQuantLowComplexity = 0; 364 psEncC->NLSF_MSVQ_Survivors = 16; 365 psEncC->warping_Q16 = psEncC->fs_kHz * SILK_FIX_CONST( WARPING_MULTIPLIER, 16 ); 366 } else { 367 psEncC->pitchEstimationComplexity = SILK_PE_MAX_COMPLEX; 368 psEncC->pitchEstimationThreshold_Q16 = SILK_FIX_CONST( 0.7, 16 ); 369 psEncC->pitchEstimationLPCOrder = 16; 370 psEncC->shapingLPCOrder = 16; 371 psEncC->la_shape = 5 * psEncC->fs_kHz; 372 psEncC->nStatesDelayedDecision = MAX_DEL_DEC_STATES; 373 psEncC->useInterpolatedNLSFs = 1; 374 psEncC->LTPQuantLowComplexity = 0; 375 psEncC->NLSF_MSVQ_Survivors = 32; 376 psEncC->warping_Q16 = psEncC->fs_kHz * SILK_FIX_CONST( WARPING_MULTIPLIER, 16 ); 377 } 378 379 /* Do not allow higher pitch estimation LPC order than predict LPC order */ 380 psEncC->pitchEstimationLPCOrder = silk_min_int( psEncC->pitchEstimationLPCOrder, psEncC->predictLPCOrder ); 381 psEncC->shapeWinLength = SUB_FRAME_LENGTH_MS * psEncC->fs_kHz + 2 * psEncC->la_shape; 382 psEncC->Complexity = Complexity; 383 384 silk_assert( psEncC->pitchEstimationLPCOrder <= MAX_FIND_PITCH_LPC_ORDER ); 385 silk_assert( psEncC->shapingLPCOrder <= MAX_SHAPE_LPC_ORDER ); 386 silk_assert( psEncC->nStatesDelayedDecision <= MAX_DEL_DEC_STATES ); 387 silk_assert( psEncC->warping_Q16 <= 32767 ); 388 silk_assert( psEncC->la_shape <= LA_SHAPE_MAX ); 389 silk_assert( psEncC->shapeWinLength <= SHAPE_LPC_WIN_MAX ); 390 silk_assert( psEncC->NLSF_MSVQ_Survivors <= NLSF_VQ_MAX_SURVIVORS ); 391 392 return ret; 393 } 394 395 static OPUS_INLINE opus_int silk_setup_LBRR( 396 silk_encoder_state *psEncC, /* I/O */ 397 const opus_int32 TargetRate_bps /* I */ 398 ) 399 { 400 opus_int ret = SILK_NO_ERROR; 401 opus_int32 LBRR_rate_thres_bps; 402 403 psEncC->LBRR_enabled = 0; 404 if( psEncC->useInBandFEC && psEncC->PacketLoss_perc > 0 ) { 405 if( psEncC->fs_kHz == 8 ) { 406 LBRR_rate_thres_bps = LBRR_NB_MIN_RATE_BPS; 407 } else if( psEncC->fs_kHz == 12 ) { 408 LBRR_rate_thres_bps = LBRR_MB_MIN_RATE_BPS; 409 } else { 410 LBRR_rate_thres_bps = LBRR_WB_MIN_RATE_BPS; 411 } 412 LBRR_rate_thres_bps = silk_SMULWB( silk_MUL( LBRR_rate_thres_bps, 125 - silk_min( psEncC->PacketLoss_perc, 25 ) ), SILK_FIX_CONST( 0.01, 16 ) ); 413 414 if( TargetRate_bps > LBRR_rate_thres_bps ) { 415 /* Set gain increase for coding LBRR excitation */ 416 psEncC->LBRR_enabled = 1; 417 psEncC->LBRR_GainIncreases = silk_max_int( 7 - silk_SMULWB( (opus_int32)psEncC->PacketLoss_perc, SILK_FIX_CONST( 0.4, 16 ) ), 2 ); 418 } 419 } 420 421 return ret; 422 } 423
