diff options
Diffstat (limited to 'third_party/libwebrtc/modules/audio_coding/codecs/ilbc/decode.c')
| -rw-r--r-- | third_party/libwebrtc/modules/audio_coding/codecs/ilbc/decode.c | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/decode.c b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/decode.c new file mode 100644 index 0000000000..d7621d5b65 --- /dev/null +++ b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/decode.c @@ -0,0 +1,261 @@ +/* + * Copyright (c) 2012 The WebRTC project authors. All Rights Reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +/****************************************************************** + + iLBC Speech Coder ANSI-C Source Code + + WebRtcIlbcfix_Decode.c + +******************************************************************/ + +#include "modules/audio_coding/codecs/ilbc/decode.h" + +#include "modules/audio_coding/codecs/ilbc/constants.h" +#include "modules/audio_coding/codecs/ilbc/decode_residual.h" +#include "modules/audio_coding/codecs/ilbc/decoder_interpolate_lsf.h" +#include "modules/audio_coding/codecs/ilbc/defines.h" +#include "modules/audio_coding/codecs/ilbc/do_plc.h" +#include "modules/audio_coding/codecs/ilbc/enhancer_interface.h" +#include "modules/audio_coding/codecs/ilbc/hp_output.h" +#include "modules/audio_coding/codecs/ilbc/index_conv_dec.h" +#include "modules/audio_coding/codecs/ilbc/init_decode.h" +#include "modules/audio_coding/codecs/ilbc/lsf_check.h" +#include "modules/audio_coding/codecs/ilbc/simple_lsf_dequant.h" +#include "modules/audio_coding/codecs/ilbc/unpack_bits.h" +#include "modules/audio_coding/codecs/ilbc/xcorr_coef.h" +#include "rtc_base/system/arch.h" + +#ifndef WEBRTC_ARCH_BIG_ENDIAN +#include "modules/audio_coding/codecs/ilbc/swap_bytes.h" +#endif + +/*----------------------------------------------------------------* + * main decoder function + *---------------------------------------------------------------*/ + +int WebRtcIlbcfix_DecodeImpl( + int16_t *decblock, /* (o) decoded signal block */ + const uint16_t *bytes, /* (i) encoded signal bits */ + IlbcDecoder *iLBCdec_inst, /* (i/o) the decoder state + structure */ + int16_t mode /* (i) 0: bad packet, PLC, + 1: normal */ + ) { + const int old_mode = iLBCdec_inst->mode; + const int old_use_enhancer = iLBCdec_inst->use_enhancer; + + size_t i; + int16_t order_plus_one; + + int16_t last_bit; + int16_t *data; + /* Stack based */ + int16_t decresidual[BLOCKL_MAX]; + int16_t PLCresidual[BLOCKL_MAX + LPC_FILTERORDER]; + int16_t syntdenum[NSUB_MAX*(LPC_FILTERORDER+1)]; + int16_t PLClpc[LPC_FILTERORDER + 1]; +#ifndef WEBRTC_ARCH_BIG_ENDIAN + uint16_t swapped[NO_OF_WORDS_30MS]; +#endif + iLBC_bits *iLBCbits_inst = (iLBC_bits*)PLCresidual; + + /* Reuse some buffers that are non overlapping in order to save stack memory */ + data = &PLCresidual[LPC_FILTERORDER]; + + if (mode) { /* the data are good */ + + /* decode data */ + + /* Unpacketize bits into parameters */ + +#ifndef WEBRTC_ARCH_BIG_ENDIAN + WebRtcIlbcfix_SwapBytes(bytes, iLBCdec_inst->no_of_words, swapped); + last_bit = WebRtcIlbcfix_UnpackBits(swapped, iLBCbits_inst, iLBCdec_inst->mode); +#else + last_bit = WebRtcIlbcfix_UnpackBits(bytes, iLBCbits_inst, iLBCdec_inst->mode); +#endif + + /* Check for bit errors */ + if (iLBCbits_inst->startIdx<1) + mode = 0; + if ((iLBCdec_inst->mode==20) && (iLBCbits_inst->startIdx>3)) + mode = 0; + if ((iLBCdec_inst->mode==30) && (iLBCbits_inst->startIdx>5)) + mode = 0; + if (last_bit==1) + mode = 0; + + if (mode) { /* No bit errors was detected, continue decoding */ + /* Stack based */ + int16_t lsfdeq[LPC_FILTERORDER*LPC_N_MAX]; + int16_t weightdenum[(LPC_FILTERORDER + 1)*NSUB_MAX]; + + /* adjust index */ + WebRtcIlbcfix_IndexConvDec(iLBCbits_inst->cb_index); + + /* decode the lsf */ + WebRtcIlbcfix_SimpleLsfDeQ(lsfdeq, (int16_t*)(iLBCbits_inst->lsf), iLBCdec_inst->lpc_n); + WebRtcIlbcfix_LsfCheck(lsfdeq, LPC_FILTERORDER, iLBCdec_inst->lpc_n); + WebRtcIlbcfix_DecoderInterpolateLsp(syntdenum, weightdenum, + lsfdeq, LPC_FILTERORDER, iLBCdec_inst); + + /* Decode the residual using the cb and gain indexes */ + if (!WebRtcIlbcfix_DecodeResidual(iLBCdec_inst, iLBCbits_inst, + decresidual, syntdenum)) + goto error; + + /* preparing the plc for a future loss! */ + WebRtcIlbcfix_DoThePlc( + PLCresidual, PLClpc, 0, decresidual, + syntdenum + (LPC_FILTERORDER + 1) * (iLBCdec_inst->nsub - 1), + iLBCdec_inst->last_lag, iLBCdec_inst); + + /* Use the output from doThePLC */ + WEBRTC_SPL_MEMCPY_W16(decresidual, PLCresidual, iLBCdec_inst->blockl); + } + + } + + if (mode == 0) { + /* the data is bad (either a PLC call + * was made or a bit error was detected) + */ + + /* packet loss conceal */ + + WebRtcIlbcfix_DoThePlc(PLCresidual, PLClpc, 1, decresidual, syntdenum, + iLBCdec_inst->last_lag, iLBCdec_inst); + + WEBRTC_SPL_MEMCPY_W16(decresidual, PLCresidual, iLBCdec_inst->blockl); + + order_plus_one = LPC_FILTERORDER + 1; + + for (i = 0; i < iLBCdec_inst->nsub; i++) { + WEBRTC_SPL_MEMCPY_W16(syntdenum+(i*order_plus_one), + PLClpc, order_plus_one); + } + } + + if ((*iLBCdec_inst).use_enhancer == 1) { /* Enhancer activated */ + + /* Update the filter and filter coefficients if there was a packet loss */ + if (iLBCdec_inst->prev_enh_pl==2) { + for (i=0;i<iLBCdec_inst->nsub;i++) { + WEBRTC_SPL_MEMCPY_W16(&(iLBCdec_inst->old_syntdenum[i*(LPC_FILTERORDER+1)]), + syntdenum, (LPC_FILTERORDER+1)); + } + } + + /* post filtering */ + (*iLBCdec_inst).last_lag = + WebRtcIlbcfix_EnhancerInterface(data, decresidual, iLBCdec_inst); + + /* synthesis filtering */ + + /* Set up the filter state */ + WEBRTC_SPL_MEMCPY_W16(&data[-LPC_FILTERORDER], iLBCdec_inst->syntMem, LPC_FILTERORDER); + + if (iLBCdec_inst->mode==20) { + /* Enhancer has 40 samples delay */ + i=0; + WebRtcSpl_FilterARFastQ12( + data, data, + iLBCdec_inst->old_syntdenum + (i+iLBCdec_inst->nsub-1)*(LPC_FILTERORDER+1), + LPC_FILTERORDER+1, SUBL); + + for (i=1; i < iLBCdec_inst->nsub; i++) { + WebRtcSpl_FilterARFastQ12( + data+i*SUBL, data+i*SUBL, + syntdenum+(i-1)*(LPC_FILTERORDER+1), + LPC_FILTERORDER+1, SUBL); + } + + } else if (iLBCdec_inst->mode==30) { + /* Enhancer has 80 samples delay */ + for (i=0; i < 2; i++) { + WebRtcSpl_FilterARFastQ12( + data+i*SUBL, data+i*SUBL, + iLBCdec_inst->old_syntdenum + (i+4)*(LPC_FILTERORDER+1), + LPC_FILTERORDER+1, SUBL); + } + for (i=2; i < iLBCdec_inst->nsub; i++) { + WebRtcSpl_FilterARFastQ12( + data+i*SUBL, data+i*SUBL, + syntdenum+(i-2)*(LPC_FILTERORDER+1), + LPC_FILTERORDER+1, SUBL); + } + } + + /* Save the filter state */ + WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->syntMem, &data[iLBCdec_inst->blockl-LPC_FILTERORDER], LPC_FILTERORDER); + + } else { /* Enhancer not activated */ + size_t lag; + + /* Find last lag (since the enhancer is not called to give this info) */ + lag = 20; + if (iLBCdec_inst->mode==20) { + lag = WebRtcIlbcfix_XcorrCoef( + &decresidual[iLBCdec_inst->blockl-60], + &decresidual[iLBCdec_inst->blockl-60-lag], + 60, + 80, lag, -1); + } else { + lag = WebRtcIlbcfix_XcorrCoef( + &decresidual[iLBCdec_inst->blockl-ENH_BLOCKL], + &decresidual[iLBCdec_inst->blockl-ENH_BLOCKL-lag], + ENH_BLOCKL, + 100, lag, -1); + } + + /* Store lag (it is needed if next packet is lost) */ + (*iLBCdec_inst).last_lag = lag; + + /* copy data and run synthesis filter */ + WEBRTC_SPL_MEMCPY_W16(data, decresidual, iLBCdec_inst->blockl); + + /* Set up the filter state */ + WEBRTC_SPL_MEMCPY_W16(&data[-LPC_FILTERORDER], iLBCdec_inst->syntMem, LPC_FILTERORDER); + + for (i=0; i < iLBCdec_inst->nsub; i++) { + WebRtcSpl_FilterARFastQ12( + data+i*SUBL, data+i*SUBL, + syntdenum + i*(LPC_FILTERORDER+1), + LPC_FILTERORDER+1, SUBL); + } + + /* Save the filter state */ + WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->syntMem, &data[iLBCdec_inst->blockl-LPC_FILTERORDER], LPC_FILTERORDER); + } + + WEBRTC_SPL_MEMCPY_W16(decblock,data,iLBCdec_inst->blockl); + + /* High pass filter the signal (with upscaling a factor 2 and saturation) */ + WebRtcIlbcfix_HpOutput(decblock, (int16_t*)WebRtcIlbcfix_kHpOutCoefs, + iLBCdec_inst->hpimemy, iLBCdec_inst->hpimemx, + iLBCdec_inst->blockl); + + WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->old_syntdenum, + syntdenum, iLBCdec_inst->nsub*(LPC_FILTERORDER+1)); + + iLBCdec_inst->prev_enh_pl=0; + + if (mode==0) { /* PLC was used */ + iLBCdec_inst->prev_enh_pl=1; + } + + return 0; // Success. + +error: + // The decoder got sick from eating that data. Reset it and return. + WebRtcIlbcfix_InitDecode(iLBCdec_inst, old_mode, old_use_enhancer); + return -1; // Error +} |