*
* 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 <stdint.h>
+
/**
(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 */
projects / ffmpeg / blobdiff