[FFmpeg-cvslog] r19571 - in trunk/libavcodec: Makefile lsp.c lsp.h qcelp_lsp.c qcelpdec.c
superdump
subversion
Mon Aug 3 10:37:02 CEST 2009
Author: superdump
Date: Mon Aug 3 10:37:02 2009
New Revision: 19571
Log:
Expose QCELP's floating-point LSP-to-LPC function
qcelp_lsp exported a single function, ff_acelp_lspd2lpc, which was not
specific to qcelp. It can be kept with its fixed-point version
ff_acelp_lsp2lpc in lpc.c.
Patch by Colin McQuillan ( m.niloc googlemail com )
Deleted:
trunk/libavcodec/qcelp_lsp.c
Modified:
trunk/libavcodec/Makefile
trunk/libavcodec/lsp.c
trunk/libavcodec/lsp.h
trunk/libavcodec/qcelpdec.c
Modified: trunk/libavcodec/Makefile
==============================================================================
--- trunk/libavcodec/Makefile Mon Aug 3 10:31:20 2009 (r19570)
+++ trunk/libavcodec/Makefile Mon Aug 3 10:37:02 2009 (r19571)
@@ -177,7 +177,7 @@ OBJS-$(CONFIG_PNG_ENCODER) +
OBJS-$(CONFIG_PPM_DECODER) += pnmenc.o pnm.o
OBJS-$(CONFIG_PPM_ENCODER) += pnmenc.o
OBJS-$(CONFIG_PTX_DECODER) += ptx.o
-OBJS-$(CONFIG_QCELP_DECODER) += qcelpdec.o qcelp_lsp.o celp_math.o celp_filters.o acelp_vectors.o
+OBJS-$(CONFIG_QCELP_DECODER) += qcelpdec.o lsp.o celp_math.o celp_filters.o acelp_vectors.o
OBJS-$(CONFIG_QDM2_DECODER) += qdm2.o mpegaudiodec.o mpegaudiodecheader.o mpegaudio.o mpegaudiodata.o
OBJS-$(CONFIG_QDRAW_DECODER) += qdrw.o
OBJS-$(CONFIG_QPEG_DECODER) += qpeg.o
Modified: trunk/libavcodec/lsp.c
==============================================================================
--- trunk/libavcodec/lsp.c Mon Aug 3 10:31:20 2009 (r19570)
+++ trunk/libavcodec/lsp.c Mon Aug 3 10:37:02 2009 (r19571)
@@ -1,6 +1,7 @@
/*
* LSP routines for ACELP-based codecs
*
+ * Copyright (c) 2007 Reynaldo H. Verdejo Pinochet (QCELP decoder)
* Copyright (c) 2008 Vladimir Voroshilov
*
* This file is part of FFmpeg.
@@ -118,3 +119,48 @@ void ff_acelp_lp_decode(int16_t* lp_1st,
/* LSP values for second subframe (3.2.5 of G.729)*/
ff_acelp_lsp2lpc(lp_2nd, lsp_2nd, lp_order >> 1);
}
+
+/**
+ * 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
+ */
+static void lsp2polyf(const double *lsp, double *f, int lp_half_order)
+{
+ int i, j;
+
+ f[0] = 1.0;
+ f[1] = -2 * lsp[0];
+ lsp -= 2;
+ for(i=2; i<=lp_half_order; i++)
+ {
+ double val = -2 * lsp[2*i];
+ f[i] = val * f[i-1] + 2*f[i-2];
+ for(j=i-1; j>1; j--)
+ f[j] += f[j-1] * val + f[j-2];
+ f[1] += val;
+ }
+}
+
+void ff_acelp_lspd2lpc(const double *lsp, float *lpc)
+{
+ double pa[6], qa[6];
+ int i;
+
+ lsp2polyf(lsp, pa, 5);
+ lsp2polyf(lsp + 1, qa, 5);
+
+ for (i=4; i>=0; i--)
+ {
+ double paf = pa[i+1] + pa[i];
+ double qaf = qa[i+1] - qa[i];
+
+ lpc[i ] = 0.5*(paf+qaf);
+ lpc[9-i] = 0.5*(paf-qaf);
+ }
+}
Modified: trunk/libavcodec/lsp.h
==============================================================================
--- trunk/libavcodec/lsp.h Mon Aug 3 10:31:20 2009 (r19570)
+++ trunk/libavcodec/lsp.h Mon Aug 3 10:37:02 2009 (r19571)
@@ -67,4 +67,14 @@ void ff_acelp_lsp2lpc(int16_t* lp, const
*/
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);
+/**
+ * Reconstructs LPC coefficients from the line spectral pair frequencies.
+ *
+ * @param lsp line spectral pairs in cosine domain
+ * @param lpc linear predictive coding coefficients
+ *
+ * TIA/EIA/IS-733 2.4.3.3.5
+ */
+void ff_acelp_lspd2lpc(const double *lsp, float *lpc);
+
#endif /* AVCODEC_LSP_H */
Modified: trunk/libavcodec/qcelpdec.c
==============================================================================
--- trunk/libavcodec/qcelpdec.c Mon Aug 3 10:31:20 2009 (r19570)
+++ trunk/libavcodec/qcelpdec.c Mon Aug 3 10:37:02 2009 (r19571)
@@ -38,6 +38,7 @@
#include "celp_math.h"
#include "celp_filters.h"
#include "acelp_vectors.h"
+#include "lsp.h"
#undef NDEBUG
#include <assert.h>
@@ -76,13 +77,6 @@ typedef struct
} QCELPContext;
/**
- * Reconstructs LPC coefficients from the line spectral pair frequencies.
- *
- * TIA/EIA/IS-733 2.4.3.3.5
- */
-void ff_acelp_lspd2lpc(const double *lsp, float *lpc);
-
-/**
* Initialize the speech codec according to the specification.
*
* TIA/EIA/IS-733 2.4.9
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