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Diffstat (limited to '')
-rw-r--r-- | third_party/libwebrtc/modules/audio_coding/codecs/ilbc/lpc_encode.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/lpc_encode.c b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/lpc_encode.c new file mode 100644 index 0000000000..89f6d29724 --- /dev/null +++ b/third_party/libwebrtc/modules/audio_coding/codecs/ilbc/lpc_encode.c @@ -0,0 +1,62 @@ +/* + * Copyright (c) 2011 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_LpcEncode.c + +******************************************************************/ + +#include "modules/audio_coding/codecs/ilbc/lpc_encode.h" + +#include "modules/audio_coding/codecs/ilbc/constants.h" +#include "modules/audio_coding/codecs/ilbc/defines.h" +#include "modules/audio_coding/codecs/ilbc/lsf_check.h" +#include "modules/audio_coding/codecs/ilbc/simple_interpolate_lsf.h" +#include "modules/audio_coding/codecs/ilbc/simple_lpc_analysis.h" +#include "modules/audio_coding/codecs/ilbc/simple_lsf_quant.h" + +/*----------------------------------------------------------------* + * lpc encoder + *---------------------------------------------------------------*/ + +void WebRtcIlbcfix_LpcEncode( + int16_t *syntdenum, /* (i/o) synthesis filter coefficients + before/after encoding */ + int16_t *weightdenum, /* (i/o) weighting denumerator coefficients + before/after encoding */ + int16_t *lsf_index, /* (o) lsf quantization index */ + int16_t *data, /* (i) Speech to do LPC analysis on */ + IlbcEncoder *iLBCenc_inst + /* (i/o) the encoder state structure */ + ) { + /* Stack based */ + int16_t lsf[LPC_FILTERORDER * LPC_N_MAX]; + int16_t lsfdeq[LPC_FILTERORDER * LPC_N_MAX]; + + /* Calculate LSF's from the input speech */ + WebRtcIlbcfix_SimpleLpcAnalysis(lsf, data, iLBCenc_inst); + + /* Quantize the LSF's */ + WebRtcIlbcfix_SimpleLsfQ(lsfdeq, lsf_index, lsf, iLBCenc_inst->lpc_n); + + /* Stableize the LSF's if needed */ + WebRtcIlbcfix_LsfCheck(lsfdeq, LPC_FILTERORDER, iLBCenc_inst->lpc_n); + + /* Calculate the synthesis and weighting filter coefficients from + the optimal LSF and the dequantized LSF */ + WebRtcIlbcfix_SimpleInterpolateLsf(syntdenum, weightdenum, + lsf, lsfdeq, iLBCenc_inst->lsfold, + iLBCenc_inst->lsfdeqold, LPC_FILTERORDER, iLBCenc_inst); + + return; +} |