From f40bfc9267b13b54e6379dfe7539447662879d24 Mon Sep 17 00:00:00 2001 From: Sean Bartell Date: Sat, 25 Jun 2011 21:32:25 -0400 Subject: Add codecs to librbcodec. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Change-Id: Id7f4717d51ed02d67cb9f9cb3c0ada4a81843f97 Reviewed-on: http://gerrit.rockbox.org/137 Reviewed-by: Nils Wallménius Tested-by: Nils Wallménius --- lib/rbcodec/codecs/libwmavoice/lsp.h | 120 +++++++++++++++++++++++++++++++++++ 1 file changed, 120 insertions(+) create mode 100644 lib/rbcodec/codecs/libwmavoice/lsp.h (limited to 'lib/rbcodec/codecs/libwmavoice/lsp.h') diff --git a/lib/rbcodec/codecs/libwmavoice/lsp.h b/lib/rbcodec/codecs/libwmavoice/lsp.h new file mode 100644 index 0000000000..5ee5c277bc --- /dev/null +++ b/lib/rbcodec/codecs/libwmavoice/lsp.h @@ -0,0 +1,120 @@ +/* + * LSP computing for ACELP-based codecs + * + * Copyright (c) 2008 Vladimir Voroshilov + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef AVCODEC_LSP_H +#define AVCODEC_LSP_H + +#include + +/** + (I.F) means fixed-point value with F fractional and I integer bits +*/ + +/** + * \brief ensure a minimum distance between LSFs + * \param[in,out] lsfq LSF to check and adjust + * \param lsfq_min_distance minimum distance between LSFs + * \param lsfq_min minimum allowed LSF value + * \param lsfq_max maximum allowed LSF value + * \param lp_order LP filter order + */ +void ff_acelp_reorder_lsf(int16_t* lsfq, int lsfq_min_distance, int lsfq_min, int lsfq_max, int lp_order); + +/** + * Adjust the quantized LSFs so they are increasing and not too close. + * + * This step is not mentioned in the AMR spec but is in the reference C decoder. + * Omitting this step creates audible distortion on the sinusoidal sweep + * test vectors in 3GPP TS 26.074. + * + * @param[in,out] lsf LSFs in Hertz + * @param min_spacing minimum distance between two consecutive lsf values + * @param size size of the lsf vector + */ +void ff_set_min_dist_lsf(float *lsf, double min_spacing, int size); + +/** + * \brief Convert LSF to LSP + * \param[out] lsp LSP coefficients (-0x8000 <= (0.15) < 0x8000) + * \param lsf normalized LSF coefficients (0 <= (2.13) < 0x2000 * PI) + * \param lp_order LP filter order + * + * \remark It is safe to pass the same array into the lsf and lsp parameters. + */ +void ff_acelp_lsf2lsp(int16_t *lsp, const int16_t *lsf, int lp_order); + +/** + * \brief LSP to LP conversion (3.2.6 of G.729) + * \param[out] lp decoded LP coefficients (-0x8000 <= (3.12) < 0x8000) + * \param lsp LSP coefficients (-0x8000 <= (0.15) < 0x8000) + * \param lp_half_order LP filter order, divided by 2 + */ +void ff_acelp_lsp2lpc(int16_t* lp, const int16_t* lsp, int lp_half_order); + +/** + * \brief Interpolate LSP for the first subframe and convert LSP -> LP for both subframes (3.2.5 and 3.2.6 of G.729) + * \param[out] lp_1st decoded LP coefficients for first subframe (-0x8000 <= (3.12) < 0x8000) + * \param[out] lp_2nd decoded LP coefficients for second subframe (-0x8000 <= (3.12) < 0x8000) + * \param lsp_2nd LSP coefficients of the second subframe (-0x8000 <= (0.15) < 0x8000) + * \param lsp_prev LSP coefficients from the second subframe of the previous frame (-0x8000 <= (0.15) < 0x8000) + * \param lp_order LP filter order + */ +void ff_acelp_lp_decode(int16_t* lp_1st, int16_t* lp_2nd, const int16_t* lsp_2nd, const int16_t* lsp_prev, int lp_order); + + +#define MAX_LP_HALF_ORDER 8 +#define MAX_LP_ORDER (2*MAX_LP_HALF_ORDER) + +/** + * Reconstruct LPC coefficients from the line spectral pair frequencies. + * + * @param lsp line spectral pairs in cosine domain + * @param lpc linear predictive coding coefficients + * @param lp_half_order half the number of the amount of LPCs to be + * reconstructed, need to be smaller or equal to MAX_LP_HALF_ORDER + * + * @note buffers should have a minimux size of 2*lp_half_order elements. + * + * TIA/EIA/IS-733 2.4.3.3.5 + */ +void ff_acelp_lspd2lpc(const double *lsp, float *lpc, int lp_half_order); + +/** + * Sort values in ascending order. + * + * @note O(n) if data already sorted, O(n^2) - otherwise + */ +void ff_sort_nearly_sorted_floats(float *vals, int len); + +/** + * Compute the Pa / (1 + z(-1)) or Qa / (1 - z(-1)) coefficients + * needed for LSP to LPC conversion. + * We only need to calculate the 6 first elements of the polynomial. + * + * @param lsp line spectral pairs in cosine domain + * @param[out] f polynomial input/output as a vector + * + * TIA/EIA/IS-733 2.4.3.3.5-1/2 + */ +void ff_lsp2polyf(const double *lsp, double *f, int lp_half_order); + +#endif /* AVCODEC_LSP_H */ -- cgit v1.2.3