avcodec/lpc: Split inline functions into a header of their own

And move compute_ref_coefs() to its only user: lpc.c
There is no overlap between the users of compute_lpc_coefs()
and lpc proper.

Reviewed-by: Lynne <dev@lynne.ee>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/aac_defines.h

@@ -73,7 +73,7 @@ typedef int                 AAC_SIGNE;
 #define AAC_HALF_SUM(x, y)  (((x) >> 1) + ((y) >> 1))
 
 #ifdef LPC_USE_FIXED
-#error aac_defines.h must be included before lpc.h for fixed point decoder
+#error aac_defines.h must be included before lpc_functions.h for fixed point decoder
 #endif
 
 #define LPC_USE_FIXED 1

libavcodec/aacdec.c

@@ -40,7 +40,6 @@
 #include "avcodec.h"
 #include "codec_internal.h"
 #include "get_bits.h"
-#include "lpc.h"
 #include "kbdwin.h"
 #include "sinewin.h"
 

libavcodec/aacdec_fixed.c

@@ -75,7 +75,6 @@
 #include "aacdectab.h"
 #include "adts_header.h"
 #include "cbrt_data.h"
-#include "lpc.h"
 #include "sbr.h"
 #include "aacsbr.h"
 #include "mpeg4audio.h"

libavcodec/aacdec_template.c

@@ -93,6 +93,7 @@
 #include "libavutil/thread.h"
 #include "decode.h"
 #include "internal.h"
+#include "lpc_functions.h"
 
 static int output_configure(AACDecContext *ac,
                             uint8_t layout_map[MAX_ELEM_ID*4][3], int tags,

libavcodec/aacenc_tns.c

@@ -30,6 +30,7 @@
 #include "aacenc_tns.h"
 #include "aactab.h"
 #include "aacenc_utils.h"
+#include "lpc_functions.h"
 
 /* Could be set to 3 to save an additional bit at the cost of little quality */
 #define TNS_Q_BITS 4

libavcodec/cngenc.c

@@ -21,6 +21,7 @@
 
 #include <math.h>
 
+#include "libavutil/avassert.h"
 #include "libavutil/common.h"
 #include "avcodec.h"
 #include "codec_internal.h"

libavcodec/lpc.c

@@ -25,8 +25,39 @@
 
 #define LPC_USE_DOUBLE
 #include "lpc.h"
+#include "lpc_functions.h"
 #include "libavutil/avassert.h"
 
+/**
+ * Schur recursion.
+ * Produces reflection coefficients from autocorrelation data.
+ */
+static inline void compute_ref_coefs(const LPC_TYPE *autoc, int max_order,
+                                     LPC_TYPE *ref, LPC_TYPE *error)
+{
+    LPC_TYPE err;
+    LPC_TYPE gen0[MAX_LPC_ORDER], gen1[MAX_LPC_ORDER];
+
+    for (int i = 0; i < max_order; i++)
+        gen0[i] = gen1[i] = autoc[i + 1];
+
+    err    = autoc[0];
+    ref[0] = -gen1[0] / ((LPC_USE_FIXED || err) ? err : 1);
+    err   +=  gen1[0] * ref[0];
+    if (error)
+        error[0] = err;
+    for (int i = 1; i < max_order; i++) {
+        for (int j = 0; j < max_order - i; j++) {
+            gen1[j] = gen1[j + 1] + ref[i - 1] * gen0[j];
+            gen0[j] = gen1[j + 1] * ref[i - 1] + gen0[j];
+        }
+        ref[i] = -gen1[0] / ((LPC_USE_FIXED || err) ? err : 1);
+        err   +=  gen1[0] * ref[i];
+        if (error)
+            error[i] = err;
+    }
+}
+
 
 /**
  * Apply Welch window function to audio block

libavcodec/lpc.h

@@ -24,7 +24,6 @@
 
 #include <stdint.h>
 #include <stddef.h>
-#include "libavutil/avassert.h"
 #include "libavutil/lls.h"
 
 #define ORDER_METHOD_EST     0
@@ -116,109 +115,4 @@ void ff_lpc_init_x86(LPCContext *s);
  */
 void ff_lpc_end(LPCContext *s);
 
-#ifndef LPC_USE_FIXED
-#define LPC_USE_FIXED 0
-#endif
-
-#if LPC_USE_FIXED
-typedef int LPC_TYPE;
-typedef unsigned LPC_TYPE_U;
-#else
-#ifndef LPC_SRA_R
-#define LPC_SRA_R(x, y) (x)
-#define LPC_MUL26(x, y) ((x) * (y))
-#define LPC_FIXR(x)     ((float)(x))
-#endif
-
-#ifdef LPC_USE_DOUBLE
-typedef double LPC_TYPE;
-typedef double LPC_TYPE_U;
-#else
-typedef float LPC_TYPE;
-typedef float LPC_TYPE_U;
-#endif
-#endif // USE_FIXED
-
-/**
- * Schur recursion.
- * Produces reflection coefficients from autocorrelation data.
- */
-static inline void compute_ref_coefs(const LPC_TYPE *autoc, int max_order,
-                                     LPC_TYPE *ref, LPC_TYPE *error)
-{
-    int i, j;
-    LPC_TYPE err;
-    LPC_TYPE gen0[MAX_LPC_ORDER], gen1[MAX_LPC_ORDER];
-
-    for (i = 0; i < max_order; i++)
-        gen0[i] = gen1[i] = autoc[i + 1];
-
-    err    = autoc[0];
-    ref[0] = -gen1[0] / ((LPC_USE_FIXED || err) ? err : 1);
-    err   +=  gen1[0] * ref[0];
-    if (error)
-        error[0] = err;
-    for (i = 1; i < max_order; i++) {
-        for (j = 0; j < max_order - i; j++) {
-            gen1[j] = gen1[j + 1] + ref[i - 1] * gen0[j];
-            gen0[j] = gen1[j + 1] * ref[i - 1] + gen0[j];
-        }
-        ref[i] = -gen1[0] / ((LPC_USE_FIXED || err) ? err : 1);
-        err   +=  gen1[0] * ref[i];
-        if (error)
-            error[i] = err;
-    }
-}
-
-/**
- * Levinson-Durbin recursion.
- * Produce LPC coefficients from autocorrelation data.
- */
-static inline int compute_lpc_coefs(const LPC_TYPE *autoc, int max_order,
-                                    LPC_TYPE *lpc, int lpc_stride, int fail,
-                                    int normalize)
-{
-    int i, j;
-    LPC_TYPE err = 0;
-    LPC_TYPE *lpc_last = lpc;
-
-    av_assert2(normalize || !fail);
-
-    if (normalize)
-        err = *autoc++;
-
-    if (fail && (autoc[max_order - 1] == 0 || err <= 0))
-        return -1;
-
-    for(i=0; i<max_order; i++) {
-        LPC_TYPE r = LPC_SRA_R(-autoc[i], 5);
-
-        if (normalize) {
-            for(j=0; j<i; j++)
-                r -= lpc_last[j] * autoc[i-j-1];
-
-            if (err)
-                r /= err;
-            err *= LPC_FIXR(1.0) - (r * r);
-        }
-
-        lpc[i] = r;
-
-        for(j=0; j < (i+1)>>1; j++) {
-            LPC_TYPE f = lpc_last[    j];
-            LPC_TYPE b = lpc_last[i-1-j];
-            lpc[    j] = f + (LPC_TYPE_U)LPC_MUL26(r, b);
-            lpc[i-1-j] = b + (LPC_TYPE_U)LPC_MUL26(r, f);
-        }
-
-        if (fail && err < 0)
-            return -1;
-
-        lpc_last = lpc;
-        lpc += lpc_stride;
-    }
-
-    return 0;
-}
-
 #endif /* AVCODEC_LPC_H */

libavcodec/lpc_functions.h

@@ -0,0 +1,100 @@
+/*
+ * LPC utility functions
+ * Copyright (c) 2006  Justin Ruggles <justin.ruggles@gmail.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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,
+ * 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
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_LPC_FUNCTIONS_H
+#define AVCODEC_LPC_FUNCTIONS_H
+
+#include "libavutil/avassert.h"
+
+#ifndef LPC_USE_FIXED
+#define LPC_USE_FIXED 0
+#endif
+
+#if LPC_USE_FIXED
+typedef int LPC_TYPE;
+typedef unsigned LPC_TYPE_U;
+#else
+#ifndef LPC_SRA_R
+#define LPC_SRA_R(x, y) (x)
+#define LPC_MUL26(x, y) ((x) * (y))
+#define LPC_FIXR(x)     ((float)(x))
+#endif
+
+#ifdef LPC_USE_DOUBLE
+typedef double LPC_TYPE;
+typedef double LPC_TYPE_U;
+#else
+typedef float LPC_TYPE;
+typedef float LPC_TYPE_U;
+#endif
+#endif // USE_FIXED
+
+/**
+ * Levinson-Durbin recursion.
+ * Produce LPC coefficients from autocorrelation data.
+ */
+static inline int compute_lpc_coefs(const LPC_TYPE *autoc, int max_order,
+                                    LPC_TYPE *lpc, int lpc_stride, int fail,
+                                    int normalize)
+{
+    LPC_TYPE err = 0;
+    LPC_TYPE *lpc_last = lpc;
+
+    av_assert2(normalize || !fail);
+
+    if (normalize)
+        err = *autoc++;
+
+    if (fail && (autoc[max_order - 1] == 0 || err <= 0))
+        return -1;
+
+    for(int i = 0; i < max_order; i++) {
+        LPC_TYPE r = LPC_SRA_R(-autoc[i], 5);
+
+        if (normalize) {
+            for(int j = 0; j < i; j++)
+                r -= lpc_last[j] * autoc[i-j-1];
+
+            if (err)
+                r /= err;
+            err *= LPC_FIXR(1.0) - (r * r);
+        }
+
+        lpc[i] = r;
+
+        for(int j = 0; j < (i + 1) >> 1; j++) {
+            LPC_TYPE f = lpc_last[    j];
+            LPC_TYPE b = lpc_last[i-1-j];
+            lpc[    j] = f + (LPC_TYPE_U)LPC_MUL26(r, b);
+            lpc[i-1-j] = b + (LPC_TYPE_U)LPC_MUL26(r, f);
+        }
+
+        if (fail && err < 0)
+            return -1;
+
+        lpc_last = lpc;
+        lpc += lpc_stride;
+    }
+
+    return 0;
+}
+
+#endif /* AVCODEC_LPC_FUNCTIONS_H */

libavcodec/ra288.c

@@ -30,7 +30,7 @@
 #include "codec_internal.h"
 #include "decode.h"
 #include "get_bits.h"
-#include "lpc.h"
+#include "lpc_functions.h"
 #include "ra288.h"
 
 #define MAX_BACKWARD_FILTER_ORDER  36