X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Flsp.h;h=4b955678eecd081526baa31b16741dbcf6a197ec;hb=9a07c1332cfe092b57b5758f22b686ca58806c60;hp=6222edb5fe2879c3022f5b56a5c8912c293fa7a2;hpb=3ddf7fe945c9942ee7290b4055778932ad5216ea;p=ffmpeg diff --git a/libavcodec/lsp.h b/libavcodec/lsp.h index 6222edb5fe2..4b955678eec 100644 --- a/libavcodec/lsp.h +++ b/libavcodec/lsp.h @@ -3,61 +3,128 @@ * * Copyright (c) 2008 Vladimir Voroshilov * - * This file is part of FFmpeg. + * This file is part of Libav. * - * FFmpeg is free software; you can redistribute it and/or + * Libav 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, + * Libav 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 + * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ -#ifndef FFMPEG_LSP_H -#define FFMPEG_LSP_H +#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 lsfq [in/out] 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 + * @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); + +/** + * Floating point version of ff_acelp_lsf2lsp() + */ +void ff_acelp_lsf2lspd(double *lsp, const float *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); + +/** + * LSP to LP conversion (5.2.4 of AMR-WB) */ -void ff_acelp_reorder_lsf(int16_t* lsfq, int lsfq_min_distance, int lsqf_min, int lsfq_max); +void ff_amrwb_lsp2lpc(const double *lsp, float *lp, int lp_order); /** - * \brief Convert LSF to LSP - * \param lsp [out] LSP coefficients (-0x8000 <= (0.15) < 0x8000) - * \param lsf normalized LSF coefficients (0 <= (2.13) < 0x2000 * PI) + * @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 10 +#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. * - * \remark It is safe to pass the same array into the lsf and lsp parameters. + * TIA/EIA/IS-733 2.4.3.3.5 */ -void ff_acelp_lsf2lsp(int16_t *lsp, const int16_t *lsf); +void ff_acelp_lspd2lpc(const double *lsp, float *lpc, int lp_half_order); /** - * \brief LSP to LP conversion (3.2.6 of G.729) - * \param lp [out] decoded LP coefficients (-0x8000 <= (3.12) < 0x8000) - * \param lsp LSP coefficients (-0x8000 <= (0.15) < 0x8000) + * Sort values in ascending order. + * + * @note O(n) if data already sorted, O(n^2) - otherwise */ -void ff_acelp_lsp2lpc(int16_t* lp, const int16_t* lsp); +void ff_sort_nearly_sorted_floats(float *vals, int len); /** - * \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 lp_1st [out] decoded LP coefficients for first subframe (-0x8000 <= (3.12) < 0x8000) - * \param lp_2nd [out] 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) + * 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_acelp_lp_decode(int16_t* lp_1st, int16_t* lp_2nd, const int16_t* lsp_2nd, const int16_t* lsp_prev); +void ff_lsp2polyf(const double *lsp, double *f, int lp_half_order); -#endif /* FFMPEG_LSP_H */ +#endif /* AVCODEC_LSP_H */