Make lsp2polyf() function non-static for upcoming usage in SIPR

[ffmpeg] / libavcodec / lsp.h

diff --git a/libavcodec/lsp.h b/libavcodec/lsp.h
index ea5c5b95cb2a217d71298f29d09c2a5ef67a7031..c3aee7b7dca012df30589a77e8e86b8228214cb9 100644 (file)
--- a/libavcodec/lsp.h
+++ b/libavcodec/lsp.h
@@ -20,8 +20,11 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#ifndef FFMPEG_ACELP_LPC_H
-#define FFMPEG_ACELP_LPC_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
 */
@@ -32,24 +35,40 @@
  * \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_acelp_reorder_lsf(int16_t* lsfq, int lsfq_min_distance, int lsqf_min, int lsfq_max);
+void ff_set_min_dist_lsf(float *lsf, double min_spacing, int 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)
+ * \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);
+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 lp [out] 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);
+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)
@@ -57,7 +76,44 @@ void ff_acelp_lsp2lpc(int16_t* lp, const int16_t* lsp);
  * \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)
+ * \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
+
+/**
+ * Reconstructs 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);
+
+/**
+ * Computes 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 f [out] 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_ACELP_LPC_H
+#endif /* AVCODEC_LSP_H */