From 504eee37debbf7ce6ec3b79ae8825727258c3fd7 Mon Sep 17 00:00:00 2001 From: Vitor Sessak Date: Tue, 27 Oct 2009 23:53:18 +0000 Subject: Commit some functions that are used by both SIPR and AMR. Based on AMR SoC code by Robert Swain and Colin McQuillan. Originally committed as revision 20392 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/lsp.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'libavcodec/lsp.h') diff --git a/libavcodec/lsp.h b/libavcodec/lsp.h index 0fa585016a..9aee5fad7d 100644 --- a/libavcodec/lsp.h +++ b/libavcodec/lsp.h @@ -39,6 +39,19 @@ */ 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, float min_spacing, int order); + /** * \brief Convert LSF to LSP * \param lsp [out] LSP coefficients (-0x8000 <= (0.15) < 0x8000) -- cgit v1.2.3