[FFmpeg-devel] [PATCH 14/17] avcodec/dsd_tablegen: Merge header into dsd.c

Andreas Rheinhardt andreas.rheinhardt at outlook.com
Tue Jun 15 01:41:30 EEST 2021


Since b492fbcc6e87094804fdf71308dc500976c6b165, the DSD tables are
always initialized at runtime, so merge the dsd_tablegen.h header
into dsd.c.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
---
 libavcodec/dsd.c          | 44 ++++++++++++++++++++++-
 libavcodec/dsd_tablegen.h | 75 ---------------------------------------
 2 files changed, 43 insertions(+), 76 deletions(-)
 delete mode 100644 libavcodec/dsd_tablegen.h

diff --git a/libavcodec/dsd.c b/libavcodec/dsd.c
index 95aab61ea4..c18e20436a 100644
--- a/libavcodec/dsd.c
+++ b/libavcodec/dsd.c
@@ -25,9 +25,51 @@
 #include "libavcodec/internal.h"
 #include "libavcodec/mathops.h"
 #include "avcodec.h"
-#include "dsd_tablegen.h"
 #include "dsd.h"
 
+#define CTABLES ((HTAPS + 7) / 8) /** number of "8 MACs" lookup tables */
+
+/*
+ * Properties of this 96-tap lowpass filter when applied on a signal
+ * with sampling rate of 44100*64 Hz:
+ *
+ * () has a delay of 17 microseconds.
+ *
+ * () flat response up to 48 kHz
+ *
+ * () if you downsample afterwards by a factor of 8, the
+ *    spectrum below 70 kHz is practically alias-free.
+ *
+ * () stopband rejection is about 160 dB
+ *
+ * The coefficient tables ("ctables") take only 6 Kibi Bytes and
+ * should fit into a modern processor's fast cache.
+ */
+
+/**
+ * The 2nd half (48 coeffs) of a 96-tap symmetric lowpass filter
+ */
+static const double htaps[HTAPS] = {
+     0.09950731974056658,    0.09562845727714668,    0.08819647126516944,
+     0.07782552527068175,    0.06534876523171299,    0.05172629311427257,
+     0.0379429484910187,     0.02490921351762261,    0.0133774746265897,
+     0.003883043418804416,  -0.003284703416210726,  -0.008080250212687497,
+    -0.01067241812471033,   -0.01139427235000863,   -0.0106813877974587,
+    -0.009007905078766049,  -0.006828859761015335,  -0.004535184322001496,
+    -0.002425035959059578,  -0.0006922187080790708,  0.0005700762133516592,
+     0.001353838005269448,   0.001713709169690937,   0.001742046839472948,
+     0.001545601648013235,   0.001226696225277855,   0.0008704322683580222,
+     0.0005381636200535649,  0.000266446345425276,   7.002968738383528e-05,
+    -5.279407053811266e-05, -0.0001140625650874684, -0.0001304796361231895,
+    -0.0001189970287491285, -9.396247155265073e-05, -6.577634378272832e-05,
+    -4.07492895872535e-05,  -2.17407957554587e-05,  -9.163058931391722e-06,
+    -2.017460145032201e-06,  1.249721855219005e-06,  2.166655190537392e-06,
+     1.930520892991082e-06,  1.319400334374195e-06,  7.410039764949091e-07,
+     3.423230509967409e-07,  1.244182214744588e-07,  3.130441005359396e-08
+};
+
+static float ctables[CTABLES][256];
+
 static av_cold void dsd_ctables_tableinit(void)
 {
     int t, e, m, sign;
diff --git a/libavcodec/dsd_tablegen.h b/libavcodec/dsd_tablegen.h
deleted file mode 100644
index e5da86a1dc..0000000000
--- a/libavcodec/dsd_tablegen.h
+++ /dev/null
@@ -1,75 +0,0 @@
-/*
- * Header file for hardcoded DSD tables
- * based on BSD licensed dsd2pcm by Sebastian Gesemann
- * Copyright (c) 2009, 2011 Sebastian Gesemann. All rights reserved.
- *
- * 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_DSD_TABLEGEN_H
-#define AVCODEC_DSD_TABLEGEN_H
-
-#include <stdint.h>
-#include "libavutil/attributes.h"
-#include "dsd.h"
-
-#define HTAPS   48                /** number of FIR constants */
-#define CTABLES ((HTAPS + 7) / 8) /** number of "8 MACs" lookup tables */
-
-#include "libavutil/common.h"
-
-/*
- * Properties of this 96-tap lowpass filter when applied on a signal
- * with sampling rate of 44100*64 Hz:
- *
- * () has a delay of 17 microseconds.
- *
- * () flat response up to 48 kHz
- *
- * () if you downsample afterwards by a factor of 8, the
- *    spectrum below 70 kHz is practically alias-free.
- *
- * () stopband rejection is about 160 dB
- *
- * The coefficient tables ("ctables") take only 6 Kibi Bytes and
- * should fit into a modern processor's fast cache.
- */
-
-/**
- * The 2nd half (48 coeffs) of a 96-tap symmetric lowpass filter
- */
-static const double htaps[HTAPS] = {
-     0.09950731974056658,    0.09562845727714668,    0.08819647126516944,
-     0.07782552527068175,    0.06534876523171299,    0.05172629311427257,
-     0.0379429484910187,     0.02490921351762261,    0.0133774746265897,
-     0.003883043418804416,  -0.003284703416210726,  -0.008080250212687497,
-    -0.01067241812471033,   -0.01139427235000863,   -0.0106813877974587,
-    -0.009007905078766049,  -0.006828859761015335,  -0.004535184322001496,
-    -0.002425035959059578,  -0.0006922187080790708,  0.0005700762133516592,
-     0.001353838005269448,   0.001713709169690937,   0.001742046839472948,
-     0.001545601648013235,   0.001226696225277855,   0.0008704322683580222,
-     0.0005381636200535649,  0.000266446345425276,   7.002968738383528e-05,
-    -5.279407053811266e-05, -0.0001140625650874684, -0.0001304796361231895,
-    -0.0001189970287491285, -9.396247155265073e-05, -6.577634378272832e-05,
-    -4.07492895872535e-05,  -2.17407957554587e-05,  -9.163058931391722e-06,
-    -2.017460145032201e-06,  1.249721855219005e-06,  2.166655190537392e-06,
-     1.930520892991082e-06,  1.319400334374195e-06,  7.410039764949091e-07,
-     3.423230509967409e-07,  1.244182214744588e-07,  3.130441005359396e-08
-};
-
-static float ctables[CTABLES][256];
-#endif /* AVCODEC_DSD_TABLEGEN_H */
-- 
2.27.0



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